Abstract: With the upsurge of the energy revolution, secondary battery as a new way of energy storage has been widely concerned owing to their efficient energy conversion. As we all know, lithium-ion batteries (LIBs) have high operating voltage and high energy density, they can be used in various application scenarios, such as electrical vehicles (EV), portable electronic devices, and large-scale energy storage systems. However, due to the shortage of lithium resources and rising prices of raw materials, many battery companies are observed to undergo cost pressure and bankruptcy risk. Given this, sodium-ion batteries (SIBs) work similarly to lithium-ion batteries, but they have great advantages in terms of resource reserve, low cost, low temperature, rate performance, and safety, thus have received strong attention from researchers and engineers. In the sodium-ion battery system, it is also composed of the positive electrode, negative electrode, electrolyte, separator, and other key components. The electrolyte, as the intermediate bridge connecting the positive and negative electrode material system, plays a vital role to undertake the transport of sodium ions, which mainly consists of organic solvent, sodium salt, and additives. The introduction of a small number of functional additives can significantly improve the overall performance of the battery because it constructs a solid electrolyte interface (SEI) between electrolyte and electrode. Different kinds of additives can exhibit specific properties to meet different conditions. This review focuses on the use of electrolyte additives, including unsaturated carbonates, sulfur compounds, phosphorus compounds, silicon compounds, inorganic sodium salts, and other types of components. Meanwhile, the research progress and related mechanisms of this addition agent in the electrolyte of sodium-ion batteries in recent years were summarized as a reference for subsequent research. Finally, the future study of electrolyte additives prospects from the science idea and practical application, for example, density functional theory, AI for science, and in-situ analysis method for SIBs.

Key words: sodium-ion batteries, eletrolysis solution, additive, film, solid electrolyte interface (SEI)

摘要： 随着能源革命的高涨，二次电池作为新型储能方式受到人们的广泛关注。钠离子电池与锂离子电池工作原理相似，且在资源储备、成本低廉、低温、倍率及安全性能方面具有极大优势。钠离子电池体系中，电解液作为衔接正负极材料体系的中间桥梁，发挥着至关重要的作用，而添加少量的功能性分子可以使电池整体性能实现显著提升。本工作围绕电解液添加剂进行介绍，综述了近年来不饱和碳酸酯、含硫化合物、含磷化合物、含硅化合物、无机钠盐及其他类型组分在钠离子电池电解液中的研究进展和相关机理。最后从科学理念和实际应用的角度出发，对电解液添加剂的未来研究进行展望。

关键词: 钠离子电池, 电解液, 添加剂, 成膜, 固体电解质界面