LiMn2O4电池的高温贮存胀气成因及解决方法

考察了有机官能团对LiMn2O4的表面修饰作用,以及对电性能的影响。通过优化水性粘合剂的组成,使之既起到LiMn2O4粘接作用,又能改善LiMn2O4电芯高温贮存性能的目的。实验结果表明:LiMn2O4材料在电池体系中高温循环容量稳定性与高温贮存稳定性是不同的电化学反应过程。引起电芯胀气的本质是电解液发生分解所致。因此,解决LiMn2O4电芯高温贮存胀气的技术途径,应设法降低锰离子悬挂键催化活性。合成了一种LiMn2O4专用水性粘合剂—LA138,由其制备的电芯不仅提高了高温贮存性能,且改善了电芯的高温循环性能,在60℃贮存40天无胀气,高温循环100周还有接近89%的容量保持率。

Cause and solution of high-temperature storage flatulence of LiMn2O4 cell

The surface modified function of organic functional group on LiMn2O4 was investigated,and the effect of organic functional group on LiMn2O4 electrical performance was also studied.By optimizing the composition of water-based binder,LiMn2O4 material was bonded,and the storage performance of LiMn2O4 cell under elevated temperature was improved.The test results show that the recycling capacitance stability and high temperature storage stability of LiMn2O4 in the system of battery is different electrochemical reaction processes.The essence of cell flatulence is caused by electrolyte decomposition.Therefore,the technological approach to solve the storage flatulence of LiMn2O4 cell under high temperature is to reduce the catalytic activity of manganese ion dangling bond.A kind of water-based binder-LA138 for LiMn2O4 was synthesized;both the high temperature storage performance and cycle performance of the cell prepared by LiMn2O4 with this binder were improved.Under 60 ℃ and for 40 days,there was no flatulence of the cell,and the capacity retention was 89% after 100 cycles.