金属锂负极的关键技术与研究进展

综述了近几年科研工作者基于金属锂负极本身的改性的最新研究进展。金属锂的理论质量比容量达3860 mAh/g,密度为0.534 g/cm^3,标准还原电位为-3.045 V,这些优势使得金属锂成为下一代理想的锂二次电池(如锂硫、锂空气电池等)的负极材料。然而,锂离子的不均匀沉积导致的锂枝晶生长、体积膨胀及其随之带来的电池安全隐患和循环寿命的降低等缺陷严重困扰着金属锂电池的发展。本文从机械地增加锂负极的表面积、锂合金负极及混合锂负极、锂负极表面层以及二维三维基底四个方面对金属锂负极的改性进行分析。最后提出要实现金属锂电池的产业化,应从解决锂枝晶和体积膨胀两个方面,通过结合不同改性方法进行研究探索。

Key technology and research progress of lithium metal anode

The latest research progress based on lithium metal anode modification is reviewed.It makes lithium metal become the ideal anode material for the next generation of lithium secondary batteries(such as lithium sulfur and lithium air batteries)due to the theoretical mass specific capacity 3860 mAh/g,density 0.534 g/cm3 and standard reduction potential of-3.045 V.However,the development of lithium metal batteries has been seriously hindered by and volume expansion and the growth of lithium dendrites which is caused by the uneven deposition of lithium ions,and the resulting battery safety risks and reduced cycle life.The modification of lithium anode is analyzed from four aspects:mechanically increasing the surface area of the lithium anode,lithium alloy anode and mixed lithium anode,surface layer of lithium anode,and two-dimensional and three-dimensional substrate.Finally,it is proposed that the industrialization of lithium metal battery should be solved from two aspects of dendrite and volume expansion,and research and exploration should be carried out by combining different modification methods.