固态金属锂电池研究进展:外部压力和内部应力的影响

Recent advances in solid-state lithium metal batteries:the role of external pressure and internal stress

固态锂金属电池具有理论能量密度高、安全性高等优势,是极有前景的下一代储能系统。然而,固体电极与固体电解质之间有限的固–固接触严重阻碍了界面离子的传输。因此,增加外部压力是增加固–固接触及延长电池循环寿命的重要途径。同时,在充放电过程中,电极体积变化产生的内应力也将影响电池界面特性。通过介绍两种基本物理接触模型,结合硫化物、氧化物、聚合物电解质以及金属锂的物理性质,综述了外压和内部应力对电解质、电极及电池的影响。最后,对外压力与内应力在全固态金属锂电池中的作用进行了总结和展望。

The solid-state lithium metal battery has the advantages of high theoretical energy density and high safety,and is a very promising next-generation energy storage system.However,the limited solid–solid contact retards the migration of Li ions between solid electrolytes and electrodes.Consequently,applying external pressure is an effective route to enhance interfacial contacts and extend battery cycle life.At the same time,the internal stresses generated with the volume changes of electrodes during cycling will also hugely influence the interfacial contacts. In this paper, the mechanisms of external pressure and internal stresses on electrodes and electrolytes arereviewed by introducing two basic physical contact models and analyzing the physical properties of sulfide, oxide,polymer electrolytes and lithium metal anodes. Finally, the roles of external pressure and internal stresses in allsolid-state Li metal batteries are summarized and prospected.