In-situ preparation of mesoporous carbon contained graphite-zinc quantum dots for enhancing the electrochemical performance of LiFePO4
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Conductive porous carbons generally are used as the additives to contact with active materials to generate conductive network for electrodes of commercial lithium ion batteries (LIBs). As a cathode material, LiFePO4 (LFP) has been widely used for LIBs. However, it needs higher quantity of conductive carbons to enhance its electrochemical performances due to the low ion diffusion coefficient and low electronic conductivity. In this work, we synthesize the mesoporous carbon contained graphite-zinc quantum dots (MC-GZQDs) via the carbonization of zeolitic imidazolate frameworks-8 (ZIF-8) under anaerobic condition. X-ray diffraction (XRD) test proves that the MC-GZQDs sample is a kind of graphite-type carbon. The N2 adsorption and desorption analysis reveals the hierarchical pore structure and typical ordered mesoporous characteristic. High-resolution transmission electron microscopy (HRTEM) indicates that the sample possesses QDs and it has heterogeneous core (metal Zn)-shell (graphite) structure. As an additive, MC-GZQDs can improve both electronic conductivity and ion diffusion coefficient of LFP due to its high conductivity and porous structure. LFP mixing with MC-GZQDs delivers a high rate performance of 154.6 mAh g−1 at a current rate of 0.5 C and a capacity retention ratio of approximate 99.9% after 60 cycles at 10.0 C.
KeywordsLiFePO4 Zeolitic imidazolate frameworks-8 Mesoporous carbon Graphite-zinc quantum dots
This work is supported by the Scientific and Technological Development Project of the Beijing Education Committee (No. KZ201710005009), the State Grid Technology Project (No. DG71-17-031), and the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions (CIT&TCD 201504019).
- 18.Salunkhe RR, Young C, Tang J, Takei T, Ide Y, Kobayashia N, Yamauchi Y (2016) Chem Commun 52:476Google Scholar
- 20.Xu XL, Wang H, Liu JB, Yan H (2017) J Mater Sci Mater Electron 28:1Google Scholar
- 27.Sun YH, He GP, Ma GZ (2016) Practical manual of physical chemistry. Chemical Industry Press, BeijingGoogle Scholar
- 38.Zhang LJ, Su ZX, Jiang FL, Yang LL, Qian JJ, Zhou YF, Li W, Hong M (2014) Nano 6:6590Google Scholar