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Rational Electrolyte Design to Form Inorganic–Polymeric Interphase on Silicon-Based Anodes

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journal contribution
posted on 2021-04-15, 21:14 authored by Shaoxiong Yang, Yuping Zhang, Zhongliang Li, Norio Takenaka, Yan Liu, Hanqin Zou, Wenting Chen, Mingcong Du, Xu-Jia Hong, Rui Shang, Eiichi Nakamura, Yue-Peng Cai, Ya-Qian Lan, Qifeng Zheng, Yuki Yamada, Atsuo Yamada
Silicon-based materials have been regarded as the most promising anodes for high-energy batteries, when combined with high- voltage/capacity nickel-rich layered cathodes. However, challenges arise from unstable electrode/electrolyte interphases on the anode and cathode as well as from safety hazards associated with highly flammable commercial electrolytes. Herein, we rationally design a nonflammable cyclic phosphate-based electrolyte to tune the electrode/electrolyte interphase components by controlling the reduction of a cyclic phosphate and Li salt. This strategy enables the electrolyte to form a highly elastic, robust inorganic–polymeric interphase on microsized silicon-based anodes that can accommodate the immense volume changes. Furthermore, by generating a stable polymeric interphase on the surface of the cathode as well, a SiO|LiNi0.6Mn0.2Co0.2O2 cell demonstrated an extremely high energy density of ∼590 Wh·kg–1 with 71.4% capacity retained over 300 cycles and high Coulombic efficiency of 99.9%. This interfacial regulation strategy is of vital importance for designing new electrolytes for high-energy-density batteries.