The Role of Cesium Cation in Controlling Interphasial Chemistry on Graphite Anode in Propylene Carbonate-Rich Electrolytes

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• 作者：Hongfa Xiang ; Donghai Mei ; Pengfei Yan ; Priyanka Bhattacharya ; Sarah D. Burton ; Arthur von Wald Cresce ; Ruiguo Cao ; Mark H. Engelhard ; Mark E. Bowden ; Zihua Zhu ; Bryant J. Polzin ; Chong-Min Wang ; Kang Xu ; Ji-Guang Zhang ; Wu Xu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：September 23, 2015
• 年：2015
• 卷：7
• 期：37
• 页码：20687-20695
• 全文大小：577K
• ISSN：1944-8252

文摘

Despite the potential advantages it brings, such as wider liquid range and lower cost, propylene carbonate (PC) is seldom used in lithium-ion batteries because of its sustained cointercalation into the graphene structure and the eventual graphite exfoliation. Here, we report that cesium cation (Cs⁺) directs the formation of solid electrolyte interphase on graphite anode in PC-rich electrolytes through its preferential solvation by ethylene carbonate (EC) and the subsequent higher reduction potential of the complex cation. Effective suppression of PC-decomposition and graphite-exfoliation is achieved by adjusting the EC/PC ratio in electrolytes to allow a reductive decomposition of Cs⁺-(EC)_m (1 鈮?m 鈮?2) complex preceding that of Li⁺-(PC)_n (3 鈮?n 鈮?5). Such Cs⁺-directed interphase is stable, ultrathin, and compact, leading to significant improvement in battery performances. In a broader context, the accurate tailoring of interphasial chemistry by introducing a new solvation center represents a fundamental breakthrough in manipulating interfacial reactions that once were elusive to control.