Abstract
Electrolytes play a pivotal role to determine the electrode performances in lithium-ion batteries (LIBs). However, understanding the function of electrolyte components at the molecular scale remains elusive (e.g., salts, solvents, and additives), particularly how they arrange themselves and affect properties of the bulk, liquid-solid interfaces, and electrolyte decomposition, rendering a bottleneck for improving the electrolytes. Herein, the function of electrolyte components is thoroughly studied, from Li+ solvation structure in the bulk electrolyte, Li+ (de-)solvation behaviors at the electrolyte-solid interfaces, until the formation of solid electrolyte interphase (i.e., SEI) layer on the electrodes. Furthermore, a detailed model by taking into account the effects of solvent, additive, lithium salt, and concentration on the electrochemical properties of the Li+-solvent-anion complex to elucidate the electrode performances are depicted. As the ultimate benefit of this study, a completely new non-flammable ether-based electrolyte and stabilizing the promising antimony (Sb) anodes can be designed. Remarkably, a high-performance Sb anode that is superior to previous reports is obtained. This work provides a graphical model to unravel interfacial and interphasial behaviors of electrolyte components in LIBs, which is also significant for developing other metal-ion batteries.