Highly stable lithium anode enabled by self-assembled monolayer of dihexadecanoalkyl phosphate
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Li has been considered as the ultimate anode material for high energy density secondary Li batteries. However, its practical application has been limited due to its low Coulombic efficiency (CE) and the formation of lithium dendrites. Recently, we have developed a microspherical Li-carbon nanotube (Li-CNT) composite material passivated with octadecylphosphonic acid (OPA) self-assembled monolayer (SAM) exhibiting suppressed lithium dendrite formation and improved environmental/electrochemical stability. In this work, we demonstrated the significantly enhanced passivation effects of a SAM using dihexadecanoalkyl phosphate (DHP), a molecule that is comprised of double hydrophobic alkyl chains and forms a denser SAM on surfaces with large curvature. As a result, the DHP SAM delivers superior environmental and electrochemical stability to the OPA passivated Li-CNT material. In specific, the DHP passivated Li-CNT composite (DHP-Li-CNT) delivers a high CE of 99.25% under a 33.3% depth of discharge (DOD) at 1 C, when it is paired with a LiFePO4 cathode. The evolution of the SAM during cycling and the effects of DOD and current density on the CE of the DHP-Li-CNT anode have also been investigated. The improved SAM passivation constitutes an important step in achieving the goal of practically applicable Li anodes.
KeywordsLi metal anode Li-CNT self-assembled monolayer depth of discharge Coulombic efficiency
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This work was financially supported by the National Natural Science Foundation of China (Nos. 21625304 and 21733012), the “Strategic Priority Research Program” of Chinese Academy of Sciences (No. XDA09010600), and the Ministry of Science and Technology (No. 2016YFA0200703).
- Ma, L. B.; Chen, R. P.; Hu, Y.; Zhang, W. J.; Zhu, G. Y.; Zhao, P. Y.; Chen, T.; Wang, C. X.; Yan, W.; Wang, Y. R. et al. Nanoporous and lyophilic battery separator from regenerated eggshell membrane with effective suppression of dendritic lithium growth. Energy Storage Mater.2018, 14, 258–266.CrossRefGoogle Scholar
- Ma, L. B.; Zhu, G. Y.; Zhang, W. J.; Zhao, P. Y.; Hu, Y.; Wang, Y. R.; Wang, L.; Chen, R. P.; Chen, T.; Tie, Z. X. et al. Three-dimensional spongy framework as superlyophilic, strongly absorbing, and electro-catalytic polysulfide reservoir layer for high-rate and long-cycling lithium-sulfur batteries. Nano Res.2018, 11, 6436–6446.CrossRefGoogle Scholar
- Erickson, E. M.; Markevich, E.; Salitra, G.; Sharon, D.; Hirshberg, D.; de la Llave, E.; Shterenberg, I.; Rosenman, A.; Frimer, A.; Aurbach, D. Review-development of advanced rechargeable batteries: A continuous challenge in the choice of suitable electrolyte solutions. J. Electrochem. Soc.2015, 162, A2424–A2438.CrossRefGoogle Scholar
- Chen, T.; Kong, W. H.; Zhang, Z. W.; Wang, L.; Hu, Y.; Zhu, G. Y.; Chen, R. P.; Ma, L. B.; Yan, W.; Wang, Y. R. et al. Ionic liquid-immobilized polymer gel electrolyte with self-healing capability, high ionic conductivity and heat resistance for dendrite-free lithium metal batteries. Nano Energy2018, 54, 17–25.CrossRefGoogle Scholar
- Contour, J.; Salesse, A.; Froment, M.; Garreau, M.; Thevenin, J.; Warin, D. Analysis by electron-microscopy and XPS of lithium surfaces polarized in anhydrous organic electrolytes. J. Microsc. Spect. Electron.1979, 4, 483–491.Google Scholar