成膜添加剂对硅碳体系高温性能的影响

Influence of propenyl-1,3-sultone and methylene methanedisulfonate on high temperature performance of silicon carbon system

选用丙烯基-1,3-磺酸内酯(PST)与甲烷二磺酸亚甲酯(MMDS)作为硅碳负极体系电解液的添加剂,重点论证了两种添加剂对该体系高温性能的影响。采用DFT密度泛函理论计算了两种添加剂的成膜性,实验结果表明:丙烯基-1,3-磺酸内酯(PST)添加剂的使用具有更加优异的成膜性,使其具有相对添加剂甲烷二磺酸亚甲酯(MMDS)更优异的高温循环与存储性能。甲烷二磺酸亚甲酯(MMDS)的使用不利于高温循环性能的提升。但丙烯基-1,3-磺酸内酯(PST)与甲烷二磺酸亚甲酯(MMDS)添加的使用都可以降低电池的ACIR与DCIR的增长率,抑制电池的热膨胀率与冷膨胀率,提高电池的容量保持率与容量恢复率,显著提升硅碳体系电池的高温存储性能。

The propenyl-1,3-sultone(PST)and methylene methanedisulfonate(MMDS)were selected as the additives for the electrolyte of the silicon-carbon anode system,and the effects of the two additives on the high temperature performance of the system were mainly demonstrated.The film-forming properties of the two additives were calculated using DFT density functional theory.The experimental results show that the use of propenyl-1,3-sultone(PST)additive has more excellent film-forming properties,which makes it have better high temperature than the additive methyl methanedisulfonate(MMDS)cycle and storage performance.The use of methylene methane disulfonate(MMDS)is not conducive to the improvement of high temperature cycle performance.The addition of propenyl-1,3-sultone(PST)and methylene methanedisulfonate(MMDS)can reduce the growth rate of ACIR and DCIR of the battery,and inhibit the thermal expansion rate and cold expansion rate of the battery,improve the capacity retention rate and capacity recovery rate of the battery,and significantly improve the high temperature storage performance of the silicon carbon system battery.