长寿命高能量密度钛酸锂电池设计

Design of high energy density Li4Ti5O12 based Li-ion batteries with long cycle life

钛酸锂电池在轨道交通领域具有非常大的潜在应用空间。对比研究了同容量不同面密度设计钛酸锂电池的性能,结果表明:随正、负极面密度增加,电池能量密度增加趋缓,当正、负极面密度分别超过300、260 g/m^2时,电池大电流充放电能力及循环寿命显著下降。其性能下降主要是正极极化所致,并且长时间循环后存在一定程度的不可逆衰减。综合考虑电池能量密度、倍率性能及循环寿命需求,钛酸锂电池正极面密度设计应控制在260~220 g/m^2。该研究成果对于开发高性能钛酸锂电池具有重要的参考意义。

Li4Ti5O12 based lithium ion batteries(LTO-LIBs)have great potential in the applications of rail transit.A comparative study of LTO-LIBs with designed capacity of different surface density was done.The results show that the increase of energy density slows down gradually with the increases of positive and negative surface density.When the positive and negative surface density are more than 300,260 g/m^2,there is a significant reduction in the rate capacity and cycle life of the battery.The performance reduction is mainly caused by the positive polarization,and in the meantime,there is a certain degree of irreversible decline after long cycle.Therefore,considering the battery’s energy density,rate performance and cycle life requirements,the design of positive electrode surface density are suggested to be controlled between 260 g/m^2 and 220 g/m^2 for the LTO-LIBs.This research is of great significance for the development of high-performance LTO-LIBs.