1 Introduction

1.1  Background

The current global interest in renewable energy sources is primarily driven by the necessity to reduce reliance on fossil fuels and mitigate environmental degradation caused by conventional energy generation technologies. In a report published in June 2023 [1] by the International Energy Agency (IEA), it was projected that solar photovoltaic and wind energies would account for unprecedented major annual growth in additional renewable energy capacity. In 2023, the largest growth globally was projected to occur from 107 GW to over 440 GW, with solar PV accounting for a 66% share. This development is expected to grow further in the year 2024. This trend has become a global movement with far-reaching benefits. These benefits range from preserving the natural ecosystem to mitigating health risks and ensuring energy independence.The abundance of these renewable energy sources ensures sustainability for generations and fosters a global responsibility to reduce the effects of climate change. This has the potential to foster innovation and grow economies. The incorporation of renewable sources, such as geothermal, wind, and solar, into current energy systems becomes paramount in the global quest for more sustainable energy for years to come. This necessarily requires the need to efficiently utilize energy and reduce losses as much as possible, as practiced in conventional energy generation systems [2]. This paper reviewed the strategic function of battery storage systems in the integration of renewable energy into current energy systems.

From time to time, the industry evolves with newer battery technology, and each time, they are commercially promoted as better technologies than the existing ones. Notwithstanding the higher investment costs, field reports on the deployment of newer technologies do reveal salient challenges that may not have been envisaged. Challenges such as the additional cost of providing a suitable environment for deployment, professional services, and monitoring are typical, especially in developing nations. This usually causes users to fall back on the good old, trusted technology. The launch of the NASA Vanguard 1 satellite on March 17, 1958, with the deployment of solar cells for power generation, and the harvested energy stored in batteries [3], marking a significant leap in the deployment of lead-acid batteries for energy storage. Over time, new technologies like NiCad, alkaline, and the recent lithium batteries were developed, but lead-acid batteries continue to be relevant in many applications despite the advantages offered by newer technologies. In fact, the lead-acid industry too has evolved over the century with improvements in technology. This study could elucidate the reasons for the sustained relevance of lead-acid technology in today’s energy storage applications. The study could also reveal some lessons new technology could adopt from the lead-acidindustry to enhance competitiveness and a larger market share.

1.2 Novelty and key contribution

Renewable integration is a major challenge in developing countries like Nigeria, where inadequate power generation is compounded with instability in the grid, making the integration of renewables very challenging. Most governments resort to off-grid applications which will necessarily require energy storage solutions. Depreciating currencies and rising inflationary trends increase sharply the cost of imported items. Design engineers are therefore faced with the options of designing battery storage technology either based on performance or cost. Performance favors newer technologies, while cost favors older technologies. This study aims to strike a balance between performance and cost in the design decisions on battery energy storage systems for practitioners in developing nations which rely on importation of electrochemical storage technologies. Striking a balance between commercial promotion and the reality of deploying batteries for renewable energy storage will allow professionals and users to make informed decisions on the choice of battery. This study discusses economic viability, in addition to technology, as a means of evaluation for design engineers, when taking decisions on the suitability of battery technology in the context of the application. Such decisions are able to balance both technical and financial goals within prevailing circumstances. This study has not been reported elsewhere in the literature. Hence, the motivation is routed on the imperative of this discussion and its timeliness.

1.3 Scope

This study limits its scope to developing economies that rely heavily on off-grid renewable energy systems to improve access to electricity. Batteries considered are the lead-acid and the lithium technologies. These technologies are matured and have been successful ones in the industry for many years. The study does not cover battery technologies for mobile devices, automotive and electric vehicle applications.

1.4 Article transition

The review highlighted the crucial role of energy storage solutions, especially in off-grid renewable energy systems, emphasizing the importance of battery technologies for grid stability and balancing supply and demand. It thoroughly compared lead-acid and lithium batteries, discussing their characteristics, safety, advantages, and key factors: cycle life, power density, energy density, efficiency, and cost considerations. The paper acknowledged the enduring relevance of lead-acid batteries for reliability and cost-effectiveness, while also recognizing the unique advantages of lithium batteries. Both technologies are poised for advancements, focusing on sustainability, safety, and performance, with project-specific decisions prioritizing the option with the lowest total cost of ownership. The work was arranged in the following manner: Introduction of the topic containing background study, motivation, novelty and scope and methodology adopted in the work formed the first section of this review. Section 2 discusses renewable energy and its challenges in integrating it into the mainstream grid. Section 3 discusses overview of lead acid batteries and lithium-ion batteries technologies. In Sect. 4, battery storage principles and practice were discussed. Section 5 discusses critical findings of the review work, while Sect. 4.8.4 discusses the conclusion.

1.5 Methodology

The review type adopted in this study was mixed studies review which combined both literature review and mixed studies [4]. Relevant articles were downloaded from Scopus database and google scholar database. A total of 200 peer-reviewed articles were downloaded. Thereafter, 70 were discarded and 130 were used for the study. Among the articles used were book chapters, conference proceedings, as well as research articles.

2 Renewable energy integration challenges

2.1 Variability and intermittency of renewable sources

While renewable energy sources offer a clean and sustainable solution to the global energy crisis, their inherent variability and intermittency pose challenges to their harvesting and utilization. They are prone to variability in energy production due to the time of day, weather conditions [5], and the effects of climate change. For example, a solar power plant produces energy that is closely correlated with the presence of sunshine during the day. Variations in the sun’s position, cloud cover, and seasonal weather cause fluctuations in solar energy output. The same variations in output are also true for wind turbines concerning the availability of wind resources.

To ensure steady and reliable energy supply to load centers, grid operators must manage the challenges posed by fluctuation and intermittency. Mismatches between energy supply and demand may result in abrupt declines or spikes in the output, which might potentially cause blackouts or grid instability. When renewables are integrated into the grid, variability and intermittency create instability, making energy storage a desired solution [6]. In the case of off-grid systems, energy storage systems are deployed to store excess energy when production is at its peak for use when generation is low or not available [7]. They mitigate the erratic nature of renewable energy generation, thereby enabling the efficient and effective utilization of energy produced at peak periods or seasons.

2.2 Renewable energy systems and energy storage

Transmission conductors, in conventional energy generation, form the backbone of efficient energy delivery to load centers [8]. Similarly, batteries play a pivotal role in storing electricity for renewables, allowing for efficient storage and retrieval. Advanced battery technologies, like lithium-ion, are increasingly utilized for surplus energy storage and released when renewable sources are not actively generating electricity [9]. Batteries provide rapid response times and high discharge rates, addressing the variability of renewable energy production.Energy storage systems should also be economically viable to promote adoption, especially for commercial purposes. The increasing deployment of large-scale battery storage projects worldwide underscores the importance of energy storage in renewable energy systems. Additionally, they facilitate the integration of a larger proportion of renewable energy into existing power generation infrastructure, reducing reliance on fossil fuels and decreasing greenhouse gas emissions [10].

It is indisputable that energy storage is crucial for reducing the unpredictability and intermittent nature of renewable sources. Energy storage technologies not only solve the problem of intermittency but also support the deployment of renewable energy at scale, in line with global efforts aimed at carbon footprint reduction and combating climate change [11]. As theworld moves closer to a low-carbon energy future, energy independence and improved grid dependability, the global transition to a resilient and sustainable energy landscape can be facilitated, in part, by the integration of storage solutions into renewable energy systems.

3 Overview of battery technologies

Chemistry and electricity combine through electrochemical processes to produce precise products [12]. Secondary cells or batteries store and release an electrical energy through reversible electrochemical processes. Chemical energy is first converted into electrical energy, and alternately, electrical energy is converted to chemical energy. This process involves the movement of charged particles (ions) between two electrodes through an electrolyte [13]. Oxidation occurs at the anode, the electrode where, during discharge, electrons are released to the external circuit. In the reverse reaction, reduction occurs at the cathode, the electrode where, during discharge, electrons are accepted from the external circuit. The electrolyte completes the electrical circuit, allowing ions to flow between the anode and cathode.

3.1 Lead-acid battery chemistry

Lead-acid batteries are one of the oldest and most widely used rechargeable battery technologies [14]. They are renowned for their high reliability and cost-effectiveness. The chemistry of lead-acid batteries involves reversible electrochemical reactions that occur within cells. During discharge, chemical energy converts to electrical energy, and during charging, the reverse occurs. This chemistry involves reversible reactions between lead oxide (PbO2), lead (Pb), and sulfuric acid (H2SO4) in an aqueous electrolyte [15,16,17,18,19], illustrated in Fig. 1.

Fig. 1
figure 1

Lead-acid battery chemistry [19]

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The cathode, positive plate, is made of lead oxide while the anode, negative plate, is made of sponge lead material. Chemical reactions take place at the two electrodes during discharge and charge cycles as shown in Eqs. 1–6.:

  1. (a)

    Discharge reactionat the (lead oxide) Cathode.

Lead oxide(PbO2), goes through reduction reaction:

$$PbO_{2} + 4{\text{~}}H^{ + } + SO_{4} ^{{2 - }} + 2{\text{e}}^{ - } \to PbSO_{4} + 2H_{2} O$$
(1)
  1. (b)

    Discharge reaction at the (lead) Anode.

Lead (Pb), goes through oxidation reaction:

$${\text{Pb + SO}}_{{\text{4}}} ^{{{\text{2 - }}}} \to {\text{ Pb}}SO_{4} + \,2e^{ - }$$
(2)
  1. (c)

    Overall cell discharge reaction:

The overall discharge reaction combines these two half-reactions:

$${\text{PbO}}_{{\text{2}}} {\text{ + Pb + 2H}}_{{\text{2}}} {\text{SO}}_{{\text{4}}} {\text{ }}\, \to \,{\text{2PbSO}}_{{\text{4}}} {\text{ + 2H}}_{{\text{2}}} {\text{O}}$$
(3)

Chemical energy stored in the reactants is converted to electrical energy.

  1. (d)

    Charging reaction (reverse of discharge):

The charging process is characterized by an external voltage applied to the battery, causing reverse reactions to occur:

$${\text{PbSO}}_{{\text{4}}} {\text{ + 2H}}_{{\text{2}}} {\text{O}} \to {\text{PbO}}_{{\text{2}}} {\text{ + pb + 2H}}_{{\text{2}}} {\text{SO}}_{{\text{4}}} {\text{ }}$$
(4)

Electrical energy is used to drive the chemical reactions where electrical energy is converted to chemical energy stored in the battery.

  1. (e)

    Electrolyte (sulfuric acid):

The sulfuric acid (H2SO4) in the electrolyte serves multiple purposes. It provides the medium for ions to flow between the two plates during discharging and charging. Additionally, it plays a key function in lead sulfate (PbSO4) formation on both plates.

  1. (f)

    Lead sulfate formation:

Lead sulfate (PbSO4) forms on both plates during discharging, subsequently breaking down during charging. The formation and dissolution of lead sulfate are crucial for the reversible nature of the lead-acid battery.

Lead sulfate is dissolved during the process of charging:

$${\text{2PbSO}}_{{\text{4}}} {\text{ + 2H}}_{{\text{2}}} {\text{O}} \to {\text{ PbO}}_{{\text{2}}} {\text{ + pb + 2H}}_{{\text{2}}} {\text{SO}}_{{\text{4}}}$$
(5)

And the formation of lead sulfate during discharge:

$${\text{PbO}}_{{\text{2}}} {\text{ + Pb + 2H}}_{{\text{2}}} {\text{SO}}_{{\text{4}}} {\text{ ? 2PbSO}}_{{\text{4}}} {\text{ + 2H}}_{{\text{2}}} {\text{O}}$$
(6)

Lead acid batteries have a long-standing track record amongst the oldest and well established technologies for storing energy. Theyhave been a staple in renewable energy storage applications for decades, providing a high round-trip efficient and cost-effective solution for capturing and storing electricity generated from intermittent renewable sources. This comparative review explores recent research papers on three lead-acid battery technologies: Flooded Lead-Acid (FLA), Valve Regulated Lead Acid (VRLA), and Lead-Carbon. The analysis will delve into the key characteristics, advancements, and challenges associated with each type.

3.1.1 Flooded lead-acid batteries

FLA batteries, the traditional workhorses of the energy storage industry, have been extensively researched for their performance in renewable energy applications. The liquid electrolyte is enclosed in a vented casing that allows for escape of gases during charging, and addition of distilled water after charging. Figure 2 shows a typical flooded lead acid battery.

Fig. 2
figure 2

Flooded lead acid battery [19]

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In the study by Wagner [20], flooded lead-acid batteries were found to have an extensive track record, having been utilized in various applications for decades. The manufacturing process was explored, which involves immersing lead plates in an electrolyte solution, typically sulfuric acid. This simple yet robust construction contributes to their widespread use in applications like renewable energy storage, uninterruptible power supplies (UPS), and backup power systems. In another paper by Wang et al. [21], advancements in flooded lead-acid battery technology were explored, focusing on improvements in plate design and separator materials. The research demonstrated better cycle life and charge retention, making FLA batteries more suitable for demanding renewable energy storage applications. The study also addressed environmental concerns, proposing recycling methods to reduce the environmental impact of lead-acid batteries.

Lu et al. [22] explored the importance of understanding and managing the electrolyte stratification phenomenon in flooded lead-acid batteries. The paper highlighted how stratification, caused by different charge and discharge rates, can impact the battery’s efficiency and cycle life. Strategies for mitigating stratification, such as optimized charging profiles, were discussed. In a study by Crown Battery [23], the life expectancy of FLA batteries was affected by factors such as depth of discharge, temperature, and maintenance practices, while FLA batteries generally had a moderate cycle life. The paper further advised how longevity can be extended through proper care, regular maintenance, and controlled operating conditions. Cycling characteristics of FLA batteries make them suitable for applications requiring occasional deep discharges, such as in off-grid solar installations.

Equalization, a controlled overcharge process, is essential for FLA batteries to address cell imbalances and sulfation. Gallardo-Lozano et al. [24] posited that equalization benefits include improving charge distribution among cells, minimizing stratification, and mitigating the risk of premature failure. This process contributes to enhanced performance and increased overall battery life. Sulfation, the buildup of hard lead sulfate crystals on battery plates, is a common issue in FLA batteries. Manwell et al. [25] investigated this phenomenon and observed that it occurs when batteries are consistently undercharged or subjected to prolonged periods of inactivity. Sulfation negatively impacts battery performance by reducing capacity and increasing internal resistance. It suggested regular maintenance, proper charging practices, and periodic equalization could help mitigate sulfation issues.

Several failure modes can affect flooded lead-acid batteries. Leung et al. [26] and Yang et al. [27] in separate technical publications listed plate corrosion, electrolyte stratification, and shedding of active material as common issues leading to reduced performance and premature failure. The research established that overcharging, excessive cycling, and exposure to high temperatures can exacerbate these failure modes. Recovery methods for FLA batteries aimed to address performance degradation and extend their service life. Banguero et al. [28] and Roy et al. [29] in their study revealed that equalization (controlled overcharging) is a primary method to desulfate (dissolving hard lead sulfate crystals) in order to restore capacity. Additionally, desulfation devices and additives were employed to break down the sulfate crystals and rejuvenate the battery. Regular maintenance, monitoring electrolyte levels, and temperature control are integral aspects of successful recovery methods.

3.1.2 Valve regulated lead acid (VRLA) batteries

VRLA batteries are designed as sealed maintenance free, with immobilized electrolyte (Fig. 3). They come in two variants, Absorbent Glass Mat (AGM) and Gel batteries. They have gained popularity due to their maintenance-free design and suitability for various renewable energy storage applications.

Fig. 3
figure 3

VRLA batteries [30]

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Rand et al. [31] agree that VRLA batteries have gained widespread acceptance since their introduction, finding applications in diverse fields such as renewable energy systems, uninterruptible power supplies (UPS), and telecommunications. In another study, Weighall [32] also noted that the manufacturing process involves sealing the battery, limiting the release of gases, and incorporating a pressure-relief valve to regulate internal pressure. A comparative analysis by Chen et al. [33] evaluated the performance of AGM and Gel batteries in terms of cycle life, charge retention, and efficiency. The publication identified AGM batteries as more suitable for high-rate applications, such as photovoltaic systems with intermittent high-power demands. Furthermore, a study by Gupta et al. [34] delved into the advancements in VRLA battery technology to address limitations such as acid stratification and thermal management. The paper explored the use of advanced materials for separators and the impact on improving charge-discharge performance. The findings showcased the prospects of VRLA batteries to contribute significantly to the reliability and efficiency of renewable energy systems.

Chang et al. [35] believed that the “maintenance-free” feature claimed for VRLA batteries can be a misrepresentation of the actual design. This claim has led many users to neglect VRLA batteries leading to initial internal problems and eventual battery failure. VRLA batteries still require maintenance activities like the provision of a temperature-controlled environment at not more than 25 °C, keeping charging voltage within specifications, and providing a battery monitoring system. The life expectancy of VRLA batteries is affected by factors like operating conditions, charging practices, and ambient temperature, as noted by Hatanaka et al. [36]. These batteries exhibit favorable cycling characteristics, making them suitable for applications requiring frequent charge-discharge cycles. Svoboda et al. [37] advised that proper charging practices and temperature control contribute to optimizing their life expectancy. In research by May et al. [38], VRLA batteries demonstrated sensitivity to ambient temperature, with performance being affected by extremes in heat or cold. Fairweather et al. [39] also contributed to the discussion noting high temperatures can accelerate chemical reactions, leading to increased water loss and accelerated aging, while low temperatures can result in reduced capacity and slower chemical reactions. Proper temperature management is crucial to ensuring optimal VRLA battery performance.

Sulfation, the formation of lead sulfate on battery plates, remains a concern for VRLA batteries according to Crown Battery [40]. Although the sealed design minimizes electrolyte evaporation, sulfation can still occur, impacting capacity and performance. Yahmadi et al. [41] posited that regular maintenance and appropriate charging practices are essential to mitigate sulfation-related issues. In a study carried out by Wagner [42], common failure modes in VRLA batteries include plate corrosion, electrolyte stratification, and thermal runaway. While the sealed design minimizes the risk of acid leakage, internal failures can still occur, leading to diminished performance and premature failure. Jung et al. [43] explored how overcharging, excessive cycling, and manufacturing defects contribute to failure modes in VRLA batteries. Nakamura et al. [44] in a study noted that recovery methods for VRLA batteries primarily focus on preventive measures, as the sealed design limits the accessibility for traditional maintenance practices while Crown Battery’s recommendations [40] such as ensuring proper charging practices, regular capacity testing, and monitoring internal resistance are integral to extending the life of VRLA batteries. Desulfation devices and controlled charging can also be employed to address sulfation-related issues.

3.1.3 Lead-carbon batteries

Lead-carbon batteries, a hybrid of VRLA chemistry and carbon additives at the electrodes, have become an impressivelead acid technology for storage of renewable energy. Figure 4 shows a typical battery design.

Fig. 4
figure 4

Lead carbon battery [45]

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Zhang et al. [46], in a more elaborate review, explored the unique features of lead-carbon batteries, including improved cycle life and charge-discharge efficiency. The paper discussed the role of carbon additives in mitigating sulfation, a common issue in lead-acid batteries, and enhancing overall performance. Moreover, research by Yanamandra et al. [47] investigated the impact of carbon nanostructure additions to the negative plate. The study revealed that incorporating nanostructured carbon materials improved cycle life and enhances retention capacity. These findings contributed to the ongoing optimization of lead-carbon battery technology for renewable energy applications. Huang et al. [48], in a study, noted that lead-carbon batteries have gained attention for their potential in renewable energy integration and grid-scale applications. Calábek et al. [49] reviews showed that the manufacturing process involves incorporating additives of carbon to the negative electrode, providing benefits such as improved charge acceptance and reduced sulfation.

The life expectancy of lead-carbon batteries is influenced by factors like charge-discharge cycles, depth of discharge, and operational conditions, as observed by Yogeswari et al. [50]. These batteries exhibit favorable cycling characteristics, showing potential for applications requiring frequent charge-discharge cycles. The addition of carbon enhances their performance, contributing to longer life expectancy. Lu et al. [51], in a study, noted that lead-carbon batteries demonstrated resilience to ambient temperature variations, making them suitable for a range of climates. The combination of lead-acid and carbon technologies mitigates some of the temperature sensitivity observed in traditional lead-acid batteries. This characteristic enhances their performance in diverse environmental conditions. Bao et al. [52] were able to identify why sulfation remains a concern for lead-carbon batteries, albeit to a lesser extent compared to traditional lead-acid batteries. Moseley et al. [53], in a review, discussed extensively how the presence of carbon additives helps to mitigate sulfation issues by providing a conductive framework that facilitates charge acceptance, reducing the risk of lead sulfate accumulation on the battery plates.

Ball et al. [54] and Li et al. [55], in their studies, noted that common failure modes in lead-carbon batteries include electrolyte stratification, electrode corrosion, and thermal runaway, while carbon additives contribute to improved performance. Challenges related to the interface between the carbon and lead components may still lead to failure modes if not properly addressed. According to Pavlov &Nikolov [56], recovery methods for lead-carbon batteries focus on optimizing charge-discharge cycles, preventing sulfation, and ensuring proper maintenance practices. Controlled charging, regular capacity testing, and monitoring internal resistance are vital aspects of recovery methods. In research by Sadhasivam et al. [57], carbon-enhanced electrodes contribute to effective recovery by facilitating improved charge acceptance.

3.1.4 Comparative analysis

When comparing the aforementioned lead-acid battery technologies, several key factors come to light. Firstly, flooded lead-acid batteries have demonstrated their reliability and effectiveness over decades. Their simple design, cost-effectiveness, and well-established maintenance practices contribute to their continued relevance in various applications. However, challenges such as electrolyte stratification and environmental concerns continue to drive research for improvements. Understanding their cycling characteristics, equalization benefits, sulfation issues, and recovery methods is essential for optimizing performance and maximizing the life expectancy of FLA batteries.

VRLAbattery technology is established as a reliable and convenient energy storage solution in various applications. Their sealed design, maintenance-free operation, and favorable cycling characteristics make them well-suited for scenarios where traditional flooded lead-acid batteries may be less practical. Advances in separator materials and charging profiles contribute to their suitability for diverse renewable energy storage scenarios. However, considerations for ambient temperature effects, sulfation issues, and potential failure modes necessitate careful management and monitoring to ensure optimal performance and longevity. Nevertheless, the trade-off between cycle life and high-rate performance remains a consideration in the selection process.

Lead-carbon batteries, a relatively newer entrant, represent a significant advancement in lead-acid battery technology, offering improved cycling characteristics and a reduced risk of sulfation. This represents improved lead acid characteristics with respect to enhanced efficiency and extended cycle life. The incorporation of carbon additives, especially nanostructured materials, demonstrates a pathway to further optimizing their performance. The hybrid nature of lead-carbon batteries positioned them as a potential bridge between traditional lead-acid and advanced lithium-ion technologies. While challenges related to failure modes persist, current efforts in research and development seek to optimize the performance and longevity of lead-carbon batteries.

3.2 Lithium batteries

3.2.1 Lithium batterychemistry

Lithium-ion (Li-ion) batteries have become ubiquitous in various applications requiring energy storage like mobile devices, electric vehicles and renewable energy systems. Basically, the chemistry of lithium-ion batteries relies on the movement of lithium ions, during charge and discharge cycles, between the positive electrode and the negative electrode [58,59,60,61,62,63,64], as shown in Fig. 5.

Fig. 5
figure 5

Lithium ion battery chemistry [64]

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This process is facilitated by the use of different materials for the electrodes and an electrolyte solution containing lithium salts. Detailed below is the lithium battery chemistry based on key components.

  1. A.

    Cathode (positive electrode):

    • The lithium-ion cathode is usually made of lithium metal oxide material, typically oxides of Lithium Cobalt (LiCoO2), Lithium Manganese (LiMn2O4), Lithium Nickel Manganese Cobalt (LiNiMnCoO2 or NMC), and Lithium Iron Phosphate (LiFePO4). The discharge process starts with the movement of lithium ions from the cathode towards the anode via the electrolyte and separator material.

  1. B.

    Anode (negative electrode):

    • Lithium-ion anode is typically composed of graphite material, although silicon and other materials are also being researched for their potential to enhance energy density. The discharge process is characterized by movement of lithium ions from the anode to the cathode through the electrolyte. The anode goes through a process known as intercalation, where lithium ions are implanted into the anode material crystal lattice structure.

  1. C.

    Electrolyte:

    • Electrolytes in lithium-ion are made from salts of lithiumdissolved in a solvent. Salts such as Lithium hexafluorophosphate (LiPF6), Lithium tetrafluoroborate (LiBF4), andlithium perchlorate (LiClO4) are common electrolyte materials. The solvent is usually a combination of diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylene carbonate (EC). The electrolyte serves as a means for the movement of lithium ions between the electrodes. The choice of electrolyte affects the temperature stability, performance and battery safety.

  1. D.

    Separator:

    • In Lithium-ion battery, the separator is a membrane designed to be thin and porous. It physically separates the anode from the cathode. It is positioned toallow the flow of lithium ions whilst preventing direct contact and short circuits between the two electrodes.Due to the excellent performance of polypropylene and polyethylene, they are commonly used as separator materials.

  1. E.

    Lithium-ion battery working principle:

    • During discharge, when the battery is providing electrical power, lithium ions move through the electrolyte from the anode to the cathode. Simultaneously, electrons flow through the circuit connected externally, creating an electric current. Lithium ions at the cathode are intercalated into the crystal lattice of the cathode material.

Anode (discharge):

$$ {\text{LiC}}_{{\text{6}}} \to {\text{Li}}^{{\text{ + }}} {\text{ + e}}^{{\text{ - }}} {\text{ + C}}_{{\text{6}}} $$
(7)

Cathode (discharge):

$$ {\text{LiCoO}}_{{\text{2}}} {\text{ + Li}}^{{\text{ + }}} {\text{ + e}}^{{\text{ - }}} \to {\text{Li}}_{{\text{2}}} {\text{CoO}}_{{\text{2}}} $$
(8)

During charging, in a reversed process, lithium ions migrate from the cathode back to the anode, just as electrons flow back into the anode.

Anode (charge):

$$ {\text{Li}}^{{\text{ + }}} {\text{ + e}}^{{\text{ - }}} + {\text{C}}_{6} \to {\text{LiC}}_{{\text{6}}} $$
(9)

Cathode (charge):

$$ {\text{Li}}_{{\text{2}}} {\text{CoO}}_{{\text{2}}} \to {\text{LiCoO}}_{{\text{2}}} {\text{ + Li}}^{{\text{ + }}} {\text{ + e}}^{{\text{ - }}} $$
(10)

Lithium-ion has emerged as a dominant technology in renewable energy storage, offering improved efficiency, long cycle life, and high energy density. Within this realm, two prominent types are Lithium Nickel Manganese Cobalt Oxide (NMC), and Lithium Iron Phosphate (LFP). This comparative review aims to explore recent research papers on LFP and NMC battery technologies, focusing on key characteristics, advancements, and associated challenges.

3.2.2 Lithium iron phosphate (LFP) batteries

LFP are typically assembled in packs containing, battery rack, batteries and battery management system (BMS) as shown in Fig. 6 [64].

Fig. 6
figure 6

50kWh LFP battery bank [64]

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In a study, Li & Ma [65], advanced that LFP batteries have established a robust track record, especially in renewable energy storage and electric vehicles (EVs). Liu et al. [66], was able to break down the manufacturing process of LFP which includes combining lithium iron phosphate cathodes with graphite anodes, and an electrolyte, forming a stable and high-performance lithium-ion battery. Dunn et al. [67], in a study, recorded LFP batteries to be exhibiting an impressive life expectancy, often surpassing 2000 cycles. Their inherent stability and resistance to thermal runaway contribute to prolonged cycle life. In an experimental study by Krieger et al. [68]. , , LFP batteries demonstrated excellent cycling characteristics, making them suitable for applications requiring frequent charge-discharge cycles, such as grid storage and electric vehicles. Ma et al. [69] explored the temperature characteristics of LFP batteries and results showed a robust performance across a wide range of ambient temperatures. The thermal stability of LFP chemistry contributes to their suitability in various climates. Their ability to maintain high performance even in extreme temperatures makes them attractive for diverse applications globally.

Etacheri et al. [70] noted that sulfation is generally minimal in LFP batteries due to their stable cathode chemistry. The absence of traditional lead-acid battery sulfation issues contributes to the long-term reliability of LFP batteries. Their inherent resistance to sulfation enhances their suitability for applications where intermittent use is common. Kaliaperumal et al. [71], in a review, deduced that common failure modes in LFP batteries are primarily related to overcharging, which can lead to thermal runaway and reduced capacity. However, LFP batteries are inherently safer than some other lithium-ion chemistries, and rigorous battery management systems (BMS) are implemented to prevent these failure modes. A review by Hendricks et al. [72] concluded that the use of Failure Modes, Mechanisms, and Effects Analysis (FMMEA) to improve test and design in LFP batteries can help realize higher system safety and reliability. Various studies show that recovery methods for LFP batteries focus on preventing overcharging, optimizing BMS settings, and ensuring balanced cell performance. While LFP batteries are known for their stability, preventive measures are crucial to extending their already impressive cycle life. Okay et al. [73], in a study, noted that advanced BMS technology contributes to effective recovery by maintaining optimal operating conditions.

LFP batteries have garnered attention for their exceptional safety and thermal stability. A study by Aravindan et al. [74] emphasized how the intrinsic safety of LFP cathodes is attributed to the robustness of the Fe–O bond. The paper discussed how the unique crystal structure of LFP contributes to its lower susceptibility to thermal runaway reactions, making it a safer option for renewable energy storage applications. Research by Li et al. [75] delved into the optimization of LFP battery performance by exploring the effect of particle size on cycling stability. Further revelations showed that smaller particle sizes contributed to improved lithium-ion diffusion kinetics and enhanced cycle life. The findings suggested strategies for tailoring LFP electrode materials to achieve superior electrochemical performance. Zhang et al. [76] explored the specific application of LFP batteries in renewable energy systems, particularly in conjunction with solar photovoltaic installations. The paper discussed the compatibility of LFP batteries with intermittent energy sources, emphasizing their ability to provide a stable and reliable storage solution. The research further highlighted the significance of LFP batteries in supporting the integration of renewable energy into the power grid.

3.2.3 Lithium nickel manganese cobalt oxide (NMC) batteries

NMC batteries also come in packs of battery rack, batteries and battery management system (BMS) as shown in Fig. 7 [77].

Fig. 7
figure 7

NMC battery bank [77]

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According to Liu et al. [78], NMC batteries have demonstrated a strong track record, particularly in electric vehicles and portable electronics. In a study by Lu et al. [79], the manufacturing process involved combining lithium, nickel, manganese, and cobalt oxides to create cathodes with varying compositions. This flexibility allows tailoring NMC batteries to specific application requirements. Research by Sahana&Gopalan [80] suggested that NMC batteries exhibit competitive life expectancy, with advancements in electrode design contributing to prolonged cycle life. The ability to modify the nickel, manganese, and cobalt ratios allows optimizing the trade-offs between energy density and cycle life. NMC batteries show promising cycling characteristics, suitable for both consumer electronics and electric vehicle applications. NMC batteries demonstrates moderate sensitivity to ambient temperatures, with performance influenced by both high and low-temperature extremes. A detailed description of this behavior can be found in a recent study by Li et al. [81]. Advances in thermal management systems contribute to mitigating temperature-related challenges. NMC batteries remain a preferred choice for applications with controlled operating conditions. Cheng et al. [82] were able to successfully establish that sulfation, while generally less pronounced in NMC batteries compared to lead-acid chemistries, can still occur and impact performance. The design of NMC batteries with appropriate voltage ranges and advanced battery management systems helps minimize sulfation risks. Regular maintenance practices and controlled charging contribute to mitigating sulfation-related issues.

In a study by Zheng et al. [83], common failure modes in NMC batteries include thermal runaway, electrode degradation, and capacity fade overcharging, while high operating temperatures can contribute to these failure modes. Ongoing research focuses on improving electrode design, electrolyte formulations, and safety features to address potential failure modes and enhance overall battery reliability [84,85,86,87]. Recovery methods for NMC batteries emphasize preventive measures, such as optimizing charging protocols and implementing advanced battery management systems, as detailed by Lei et al. [88] in a study. Innovations in materials science and cell design contribute to mitigating common failure modes. A recent study by Lipu et al. [89] concluded that controlled charging and discharging, along with proper thermal management, play pivotal roles in the recovery and long-term performance of NMC batteries. NMC batteries, known for their high energy density, have been a focal point of research aiming to enhance their performance further. A comprehensive review by Manthiram et al. [90] outlined the evolution of NMC cathodes, exploring various nickel, manganese, and cobalt compositions. The paper discusses the challenge of balancing between structural stability and energy density, providing insights into the challenges associated with optimizing NMC chemistry.

Xu et al. [91] investigated the fast charging capabilities of NMC batteries, an essential aspect for renewable energy systems requiring rapid energy storage replenishment. The study explores the influence of charging rates on the electrochemical characterization of NMC electrodes, offering valuable insights into the design considerations for achieving high-power performance without compromising cycle life. Given the potential for thermal issues in high-energy-density systems, studies such as that carried out by Wang et al. [92] focused on thermal management strategies for NMC batteries. The paper explores the effectiveness of different cooling methods in mitigating temperature-related degradation mechanisms. Understanding and controlling thermal effects are essential for ensuring safety and durability of NMC batteries in renewable energy applications.

3.2.4 Comparative analysis

  1. A.

    Safety and stability:

    • LFP batteries, with their iron phosphate cathodes, are recognized for their inherent safety and thermal stability. The robust Fe–O bond structure contributes to a lower risk of thermal runaway reactions. On the other hand, NMC batteries, while offering higher energy density, may pose challenges related to thermal management due to the presence of nickel, which can contribute to increased reactivity.

  1. B.

    Cycle life and performance:

    • LFP batteries benefit from smaller particle sizes, enhancing lithium-ion diffusion kinetics and extending cycle life. In NMC batteries, the challenge lies in balancing energy density with structural stability, and research is focused on optimizing cathode compositions to achieve superior electrochemical performance.

  1. C.

    Applications in renewable energy systems:

    • LFP batteries are well-suited for renewable energy systems, particularly in solar installations, due to their stability and reliability. The ability of LFP batteries to integrate seamlessly with intermittent energy sources aligns with the requirements of renewable energy applications. NMC batteries, with their high energy density, are also applicable in renewable energy systems, providing ample storage capacity for fluctuating energy generation.

  1. D,

    Cost considerations:

    • NMC batteries may have higher initial cost relative to LFP batteries, primarily due to the use of materials like cobalt. However, ongoing advancements are reducing the cost gap. NMC batteries are commonly found in applications where a balance between cost and energy density is crucial, electric vehicles and certain grid storage projects are typical examples.

3.3 Comparative analysis in performance metrics betweenlead acid batteries and Lithium batteries

3.3.1 Energy density

Lead acid batteries normally have energy density that is lower relative totheir lithium counterpart.The limited energy densitycan be a constraint in applications where space and weight considerations are critical [93].Lithium batteries exhibit significantly higher energy density, offering a superior capacity to store energy per unit weight and volume. This characteristic makes lithium batteries more suitable for applications demanding high energy density [94], such as renewable storage and electric vehicles.

3.3.2 Power density

Lead acid batteries typically have lower power density than lithium batteries [95]. This implies that lead acid batteries may have limitations in delivering high power outputs in applications requiring rapid charge and discharge cycles.Lithium batteries excel in power density, enabling them to provide high power outputs efficiently. This feature is advantageous in applications like power tools and electric vehicles, where quick bursts of energy are essential [96].

3.3.3 Cycle life

Cycle life in lead acid is generally lower compared to lithium batteries [97]. This naturally limits the number of charge and discharge cycles that lead acid batteries can undergo, making them less suitable for applications requiring long-term, repetitive use.Lithium batteries demonstrate a longer cycle life, making them more durable and reliable over an extended period. This characteristic is crucial in applications where batteries are subjected to frequent charge and discharge cycles, such as renewable energy storage.

3.3.4 Efficiency

Lead acid batteries may have lower efficiency compared to lithium batteries [98], especially in terms of charge and discharge efficiency. This could result in energy losses during the charging and discharging processes.Lithium batteries are known for their higher charge and discharge efficiency, minimizing energy losses during power transfers. This efficiency is advantageous in various applications, contributing to overall system performance.

3.3.5 Cost considerations

Lead acid batteries are generally more cost-effective upfront compared to lithium batteries. The lower initial cost makes lead acid batteries a preferred choice in applications where cost is a primary concern [99].Lithium batteries have a higher investment cost relative to lead acid batteries.Nonetheless, advancements in technology and increased production volumes are gradually reducing the cost gap, making lithium batteries more economically viable over the long term [100].

3.3.6 Environmental impact

Lead acid batteries can have a higher environmental impact due to the use of lead, a toxic heavy metal. Proper recycling and disposal practices are essential to mitigate environmental risks associated with lead acid batteries [101].Lithium batteries, while generally considered to be friendlierto the environment than lead acid batteries, pose challenges in terms of resource extraction and disposal. Improved recycling methods and sustainable sourcing practices are crucial to minimize the environmental footprint of lithium batteries [102].

3.3.7 Application/Suitability

Lead acid batteries are suitable for storage solutions where cost is a primary consideration, and lower energy and power densities are acceptable. Common applications include uninterruptible power supplies (UPS), backup power systems, and stationary energy storage for renewable sources [103].Lithium batteries find widespread use in applications demanding high energy and power densities, such as grid-scale renewable energy storage, electric vehicles and portable electronics. Their superior performance features make them suitable for demanding and flexible applications [104].

3.4 Total cost of ownership

Energy storage systems are playing pivotal roles in renewable energy in ensuring the reliability and stability of power supply from intermittent sources. Assessing the total cost of ownership (TCO) of batteries in these applications is crucial for evaluating their economic feasibility over the entire lifecycle. TCO encompasses various factors beyond initial costs, including maintenance, replacement, and operational expenses.

  1. A.

    Initial investment:

    • The upfront cost of batteries constitutes a significant portion of the TCO. Different battery chemistries have varying initial costs based on factors like energy density and technology maturity.

  1. B.

    Operational and maintenance costs:

    • Operational expenses include the costs associated with maintaining and operating the energy storage system. This involves monitoring, cooling systems, and periodic maintenance to ensure optimal performance. VRLA, lead carbon batteries [105] and Lithium-ion batteries generally have lower maintenance costs compared to FLA batteries due to their sealed design and extended cycle life [106].

  1. C.

    Round-trip energy efficiency:

    • Energy efficiency, expressed as the proportion of output energy to input energy, influences the TCO. Batteries with higher round-trip efficiency minimise energy losses during charge and discharge cycles, leading to lower operational costs over time. Lithium-ion batteries often exhibit higher round-trip efficiency compared to lead acid batteries, contributing to their economic advantage [107].

  1. D.

    Cycle life and degradation:

    • The number of charge and discharge cycles a battery is able to undergo before significant degradation is a critical factor. Batteries with longer cycle life often have a lower TCO as they require less frequent replacements. Lithium-ion batteries, particularly certain chemistries like Lithium Iron Phosphate (LFP), commonly offer much better cycle life relative to lead acid batteries [108].

  1. E,

    Charging and discharging characteristics:

    • The efficiency and performance of energy storage system are influenced by the charging and discharging characteristics. Rapid charge and discharge capabilities, especially in lithium-ion batteries, can enhance the overall system efficiency, contributing to a lower TCO [109].

  1. F.

    End-of-life and recycling:

    • Recycling of batteries and proper disposal after End of Life (EOL) is a significant aspect of TCO. Lithium-ion batteries may pose challenges in terms of recycling due to complex chemistries, while lead acid batteries have established recycling processes with high recovery rates [110].

  1. G.

    Economic viability over time:

    • Evaluating batteries for their economic viability involves considering a number of factors like cost per kilowatt-hour ($/kWh) stored, the cost per cycle, and the total capacity over the system’s life. Advances in battery technology, economies of scale, and research and development efforts contribute to the continuous improvement of TCO for various battery chemistries [111].

4 Battery storage: the offing

4.1 Future trends and innovations

Future trends in lead acid industry include improvements in advanced technologies, such as enhanced FLA and VRLA batteries [112].Innovations will focus on optimizing existing lead-acid chemistries to improve performance, cycle life, and efficiency. Future trends for lithium batteries involve continuous innovations to enhance energy density, safety, and cost-effectiveness. Lithium-air andlithium-sulfur batteries are emerging as potential breakthrough technologies, offering higher energy densities and addressing environmental concerns [113].

4.2 Emerging battery technologies

Emerging technologies for lead acid batteries include advanced lead-carbon, which aim to improve upon charge acceptance and cycle life while reducing environmental impact [114]. Lithium-silicon and lithium-solid-state batteries are emerging as breakthrough technologies for lithium batteries, promising higher energy density, faster charging, and improved safety features [115].

4.3 Research and development directions

Research in lead acid technologycenters on advanced materials, like carbon additives and modified lead alloys, to enhance performance and reduce environmental impact [116]. Research in lithium batteries is directed towards developing new cathode and anode materials, exploring solid-state electrolytes, and optimizing cell designs for improved safety and performance [117].

4.4 Market trends

Lead acid batteries continue to dominate markets for specific applications like automotive starting, backup power and stationary energy storage due to their cost-effectiveness [118]. Lithium batteries are experiencing significant market growth, driven by the increasing demand for grid-scale energy storage, electric vehicles and portable electronics.

4.5 Industry outlook

The lead acid battery industry is evolving to meet modern energy storage needs, with a focus on improving performance, recycling processes, and exploring new applications. The lithium battery industry is dynamic, with a strong emphasis on scaling production, reducing costs, and addressing concerns related to resource availability and environmental impact [119].

5 Review outcomes

5.1 Chemistry and characteristics

Two battery chemistries commonly employed in renewable energy applications were identified. Lead acid batteries are based on acid electrochemistry with Deep Cycle FLA, VRLA and Lead-Carbon types being favorites for renewable energy storage applications. Overall, deep cycle FLA batteries, VRLA batteries (AGM and Gel), and lead carbon batteries each have unique characteristics and advantages, making them suitable for various applications drawing strength from features like cycling, operational efficiency and maintenance requirements. The choice of battery type is influenced by specific requirements of the solution and the available budget.On the other hand, lithium batteries, based on alkaline electrochemistry haveLFP and NMC as the widely applied technologies for renewable energy storage [120]. Both LFP and NMC batteries offer unique advantages in tackling specific challenges in the context of renewable energy storage. LFP batteries stand out for their safety and stability, making them well-suited for applications where these attributes are critical. NMC batteries, with their high energy density, offer greater storage capacity but necessitate careful thermal management to address potential challenges.

5.2 The future oflead acid and lithium batteries

Going by the increase in demand for storage solutions for renewable energies, both lead acid and lithium technologies, just like photovoltaic and hydrogen storage technologies [121, 122], are undergoing significant advancements in research and development to address key challenges and improve overall performance. A cursory look into the lead acid industry reveals innovative formulations and manufacturing techniques are at the forefront of developments. Researchers are exploring the integration of carbon additives, particularly in lead-carbon batteries, to enhance charge acceptance, reduce sulfation, and improve efficiency. Advanced plate designs and construction methods are also being investigated to boost energy density and overall efficiency. The incorporation of smart battery management systems (BMS) is another noteworthy trend, offering improved monitoring, optimized charging algorithms, and preventive maintenance to increaseservice life. Moreover, a strong emphasis on recycling technologies aims to address environmental concerns and promote sustainable practices in the industry.

Lithium batteries are witnessing a dynamic landscape of innovations. The evolution towards high-nickel cathodes, exemplified by NMC 811, represents a major trend aiming to improve energy density while simultaneously reducing costs. Solid-state lithium batteries were developed as groundbreaking innovation, promising higher energy density, extended cycle life and improved safety, overexisting lithium-ion batteries. Silicon anodes, with their higher capacity compared to traditional graphite anodes, contribute to increased energy density in lithium batteries. Furthermore, the integration of advanced electrolytes and the rise of artificial intelligence (AI)-enabled battery management systems highlight the commitment to optimizingperformance, safety, and efficiency in lithium battery technologies. Sustainability is also a key focus, with ongoing efforts directed towards efficient methods for recycling lithium-ion batteries and minimizing environmental impact.

While lead acid batteries are exploring advancements in carbon additives, smart BMS, and recycling technologies, lithium batteries are witnessing a paradigm shift with innovations in high-nickel cathodes, solid-state technology, silicon anodes, and AI-enabled management systems. Both technologies are evolving to meet the diverse and expanding needs of applications, including renewable energy storage, mobile devices, and electric vehicles.

5.3 The resilience and relevance of lead acid batteries in modern times

Lead acid batteries continue to demonstrate resilience and relevance in modern times despite being a first generation battery technology. While lithium-ion batteries have captured significant attention, lead acid batteries maintain a strong foothold in various applications due to their unique set of advantages, making them competitive in today’s diverse energy storage landscape. The technology has stood the test of time and continues to compete in modern times. Its proven track record, cost-effectiveness, recyclability, robustness, and suitability for specific applications contribute to its ongoing relevance. As technology evolves, lead acid batteries find their niche, complementing other energy storage solutions and demonstrating that, in the diverse landscape of modern energy storage, there is room for both traditional and cutting-edge technologies.

5.4 Application and suitability

The choice between lead acid batteries and lithium batteries is influenced by the actualrequirements of the application. Lead acid batteries may be more appropriate in cost-sensitive applications with lower energy and power density needs, while lithium batteries offer superior performance in applications requiring higher efficiency, longer cycle life, and increased energy and power densities. These technologies represent two distinct approaches to energy storage, with theirdistinctivebenefits and drawbacks. While lead acid batteries continue to be relevant in specific applications due to their cost-effectiveness per kWh, lithium batteries are driving innovation and dominating markets with their superior energy density and versatility.Beyond technical aspects, the financial feasibility of an energy storage solution plays a pivotal role. Factors such as government incentives, tax credits, and ongoing advancements in manufacturing that reduce costs can significantly impact the financial feasibility of adopting specific technologies. Understanding the economic landscape and available financial support is crucial in determining the TCO.

5.5 Total cost of ownership

Recognizing the important role total cost of ownership (TCO) playsin renewable energy storage applications is vital for making informed decisions regarding battery technology selection and system design [123]. While both battery technologies have reciprocal advantages over each other, the choice of the most economically viable solution depends on specific project requirements, including energy storage capacity, operational conditions, initial investment, operational and maintenance costs, round-trip efficiency, cycle life, end-of-life, recycling, and economic viability over time. In the quest to achieve efficiency and sustainability inlithium ion battery energy storage [124], a comprehensive TCO analysis that encompasses both technical and financial considerations is essential. Technologies like lithium-ion batteries, with their evolving chemistries and favorable performance metrics, often present attractive TCO propositions. However, the suitability of an energy storage solution depends on particular applications, operational specifications, and the prevailing economic context. A careful assessment that balances technical and financial feasibility is integral to making informed decisions in the dynamic landscape of energy storage solutions.

6 Conclusion

This review underscored the enduring relevance of lead-acid battery technologies in achieving a harmonious balance between reliability, cost-effectiveness, and environmental sustainability, particularly in medium to large-scale storage applications within the evolving renewable energy landscape. Future research directions are poised to enhance these technologies, focusing on optimization, innovative materials, and targeted solutions to meet the growing storage demands of renewable energy applications.On the other hand, the more recent lithium battery technologies emerge as unique solutions, addressing challenges related to greater storage capacity, high energy density, stability, and safety. The increased emphasis on battery monitoring and meticulous thermal management reflects the evolving landscape. The future trajectory of battery technology appears promising, with advancements expected in both lead-acid and lithium-based systems, maintaining a focus on sustainability, safety, and performance. Ongoing investigations will further explore applications like grid-scale energy storage, propelling the continuous evolution of lithium battery technologies.Both lead-acid and lithium-based systems are well-positioned in their respective niche areas, signaling their sustained relevance. The future trajectory of battery technology appears promising with advancements expected in both lead-acid and lithium-based systems, with an unwavering focus on sustainability, safety, and performance. Project-specific battery choices will hinge on a thorough assessment of technical feasibility, followed by a comprehensive financial analysis considering all cost elements. The ultimate recommendation for battery technology adoption will prioritize the option with the lowest total cost of ownership.