高比能锂离子电池高电压电解液的设计

Design of Electrolyte for High Specific Energy Lithium Ion Batteries Working at High Voltage

自便携式电子设备以及电动汽车问世后,锂离子电池储能设备已经难以满足当前的生活与生产需求.锂离子电池作为商业储能设备市场的主要占有者,正朝着更高的能量密度、更长久的使用寿命以及更高的安全性能等方向发展.虽然通过提高锂离子电池的截止电压可以达到提升电池重量密度和体积密度的效果,但电池体系在高电压下将非常不稳定,这将导致锂离子电池的循环性能迅速衰减.同时,大量的电解液分解产物的堆积,导致电池的界面阻抗上升.另一方面,气体的生成形成了电池的安全隐患.本文针对高电压电解液的溶剂设计和电解液添加剂设计两个方面,回顾了过去一段时间里高电压电解液的发展.根据当前的理论研究基础,提出了高比能锂离子电池电解液的设计重心和未来该领域的主要研究方向.

The current energy storage devices of lithium ion batteries can hardly satisfy people’s work and living since the advent of portable electronics and electric vehicles.Lithium ion batteries,with their market superiority of commercial energy storage devices,are being researched and developed in the aspects of higher specific energy,longer cycle life and safer performance.The gravimetric and volumetric energy densities of lithium ion batteries can be increased at high-voltage conditions on which the battery systems are unstable.This will attenuate the batteries’capacity rapidly.Simultaneously,the interface impedance of batteries rises when amounts of decomposition products accumulate.In addition,the generation of harmful gas threatens the safety of the batteries.This paper reviews the development of high voltage electrolyte in allusion to the design of solvent and additive of electrolyte for working at high voltage.Based on the current theoretical researches,this paper also indicates the design focus and future research directions of multifunctional electrolyte for high specific energy lithium ion batteries.