Non-aqueous electrolyte liquids such as carbonate solvents have been widely employed in the commercial lithium-ion batteries and in the development of next-generation rechargeable batteries. The decomposition products of the organic electrolyte and additive molecules contribute to the formation of solid electrolyte interphases (SEIs) on the electrode surface, which have key impacts on battery's electrochemical performance. The rational engineering of electrolyte systems demands precise understanding of the electrochemical reaction pathways as well as the decomposition products of the electrolytes. Mass spectrometry (MS) is a well-established molecular analytical approach that can provide critical information for unambiguous structure assignment based on its mass-resolving power. In recent years, the application of MS for battery research has been expanding rapidly, providing valuable insights about the chemical species generated during battery operation and electrolyte evolution. This review aims to summarize the recent advances of MS technique-based analysis of electrolyte decomposition products as well as SEIs, and thus to demonstrate the high utility of MS methods for characterization of battery systems.

非水电解质液体如碳酸酯溶剂已广泛用于商业锂离子电池和下一代可充电电池的开发。有机电解质和添加剂分子的分解产物有助于在电极表面形成固体电解质界面（SEI），这对电池的电化学性能有关键影响。电解质系统的合理工程需要精确了解电化学反应途径以及电解质的分解产物。质谱 (MS) 是一种成熟的分子分析方法，可以根据其质量分辨能力为明确的结构分配提供关键信息。最近几年，MS 在电池研究中的应用一直在迅速扩大，为电池运行和电解质演变过程中产生的化学物质提供了宝贵的见解。本综述旨在总结基于 MS 技术的电解质分解产物以及 SEI 分析的最新进展，从而证明 MS 方法在电池系统表征方面的高实用性。