摘要
固态锂金属电池是最具潜力的下一代高能量密度储能技术,但其面临的一个最迫切问题是锂枝晶的不均匀生长.目前低模量复合固态电解质,特别是低模量多相复合固态电解质,抑制锂枝晶生长的机制还没有被完全明确.因此,本文通过相场法构建了力学-化学模型,研究了复合固态电解质不同弹性模量对于锂枝晶生长的影响,结果表明电解质模量越高,锂金属的应力越大,易使锂枝晶发生塑性形变,从而抑制锂枝晶的生长.本文的研究加深理解了低模量多相复合固态电解质抑制锂枝晶的机制,并为复合固态电解质的设计提供了指导.
Abstract
Lithium metal is a highly promising anode material due to its high theoretical capacity and low reduction/oxidation potential,and has received extensive attention.However,the formation and growth of lithium dendrites poses the biggest challenge to its commercialization.The use of solid-state e-lectrolyte,instead of liquid electrolyte,has become a potential path to inhibit the growth of lithium den-drites.However,issues such as poor metal-lithium interface contact and low ionic conductivity in solid-state electrolytes persist.Composite solid-state electrolytes,prepared by combining polymers with inor-ganic ceramic electrolytes,have shown effectiveness in inhibiting the growth of lithium dendrites.Al-though these composite solid electrolytes typically have high ionic conductivity,their elastic moduli are low.Currently,the mechanism of dendrite suppression by low-modulus composite solid-state electrolytes,especially low-modulus multiphase composite solid-state electrolytes,remains incompletely clarified.Therefore,this paper considers the mechanical effects of solid electrolytes and builds a mechanical-chemical model using the phase field method.By taking poly(ethylene oxide)(PEO)-based composite-state electro-lyte as an example,the study investigates the influence of composite solid electrolyte modulus on dendrite growth.The results show that the higher the electrolyte modulus,the greater the stress on the lithium metal,leading to a more uniform distribution of lithium ions on the interface between the electrolyte and the lithium anode electrode.The higher stress also tends to cause the plastic deformation of lithium den-drites,thus inhibiting their growth.This research deepens the understanding of the mechanism of inhibi-tion of lithium dendrites by low-modulus multiphase composite solid electrolytes,and provides guidance for the design of composite solid electrolytes.
基金项目
重庆市技术创新与应用发展专项重点项目(Z20230084)
河北省创新群体项目(A2020202002)
河北省重点研发项目(202030507040009)
天津市科技计划项目(20ZYJDJC0030)
维普
万方数据