FEC、PST、MMDS、DTD对高电压NCM523电池性能的影响

Effect of FEC,PST,MMDS and DTD on high voltage NCM523 battery performance

单晶NCM523/人造石墨电池可以在高压4.4 V和高温45℃下具有出色的长期寿命。本研究的重点是开发用于单晶NCM523/人造石墨电池的新电解质,这种电池寿命长并支持更高的充电速率。考察了电解液中FEC(氟代碳酸乙烯酯)、PST(1,3丙烯磺酸内酯)、MMDS(甲烷二磺酸亚甲酯)、DTD(硫酸乙烯酯)组合添加剂含量对锂离子电池初始容量、阻抗和化成时候的产气量,70℃储存7天电池的容量恢复和容量保持,1 C、2 C、3 C不同倍率下的放电性能,低温下放电性能和高温下循环寿命的影响。电解液中PST、MMDS添加剂含量对电池初始容量及内阻影响比较大。FEC对于化成过程中产气影响比较大,但可以提高电池的循环性能,DTD综合性能比较好。含有1%FEC+1%DTD添加剂(百分数均代表质量分数)的电解质产生具有长寿命的单晶NCM523/石墨电池,常温下倍率性能较好。

The cells using monocrystal NCM523/C batteries have excellent long life up to 4.4 V high voltage and 45℃high temperature.This paper focuses on the development of new electrolytes for single-crystal NCM523/C batteries that has long lifetimes and support higher charging rates.The effects of FEC(Fluoroethylene carbonate),PST(Prop-1-ene-1,3-sultone),MMDS(1,5,2,4-dioxadithiane-2,2,4,4-tetraoxide)and DTD(Ethylene sulfate/1,3,2-dioxathiolane-2,2-dioxide)content on initial capacity of lithium-ion battery,impedance of the battery,gas production during formation,capacity recovery and capacity maintenance of the battery stored at 70℃for 7 days,discharge performance at 1 C,2 C and 3 C,discharge performance at low temperature,and cycle life at high temperature were investigated.The contents of PST and MMDS additives in the electrolyte have a great influence on the initial capacity and internal resistance of the battery.FEC has a great influence on the gas generation in the formation process,but it can improve the cycle performance of the battery,and DTD has a better comprehensive performance.The electrolyte containing 1%FEC+1%DTD additive produced single-crystal NCM523/C batteries with long life,and the rate performance was better at room temperature.