Zou Lianfeng, Gao Peiyuan, Jia Haiping, Cao Xia, Wu Haiping, Wang Hui, Zhao Wengao, Matthews Bethany E, Xu Zhijie, Li Xiaolin, Zhang Ji-Guang, Xu Wu, Wang Chongmin
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, Washington 99354, United States.
Advanced Computing, Mathematics, and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States.
ACS Appl Mater Interfaces. 2022 Jan 26;14(3):4111-4118. doi: 10.1021/acsami.1c20789. Epub 2022 Jan 11.
Solid-electrolyte interphases is essential for stable cycling of rechargeable batteries. The traditional approach for interphase design follows the decomposition of additives prior to the host electrolyte, which, as governed by the thermodynamic rule, however, inherently limits the viable additives. Here we report an alternative approach of using a nonsacrificial additive. This is exemplified by the localized high-concentration electrolytes, where the fluoroethylene carbonate (FEC) plays a nonsacrificial role for modifying the chemistry, structure, and formation mechanism of the cathode-electrolyte interphase (CEI) layers toward enhanced cycling stability. On the basis of ab initio molecular dynamics simulations, we further reveal that the unexpected activation of the otherwise inert species in the interphase formation is due to the FEC-Li coordinated environment that altered the electronic states of reactants. The nonsacrificial additive on CEI formation opens up alternative avenues for the interphase design through the use of the commonly overlooked, anodically stable compounds.
固态电解质界面对于可充电电池的稳定循环至关重要。传统的界面设计方法是在主体电解质之前使添加剂分解，然而，受热力学规则支配，这固有地限制了可行的添加剂。在此，我们报道了一种使用非牺牲性添加剂的替代方法。以局部高浓度电解质为例，其中氟代碳酸乙烯酯（FEC）在修饰阴极 - 电解质界面（CEI）层的化学性质、结构和形成机制以增强循环稳定性方面起着非牺牲性作用。基于从头算分子动力学模拟，我们进一步揭示，在界面形成过程中原本惰性的物种意外地被激活，这是由于FEC - Li配位环境改变了反应物的电子态。CEI形成上的非牺牲性添加剂通过使用通常被忽视的阳极稳定化合物为界面设计开辟了替代途径。
