Tang Wei, Yin Xuesong, Kang Sujin, Chen Zhongxin, Tian Bingbing, Teo Siew Lang, Wang Xiaowei, Chi Xiao, Loh Kian Ping, Lee Hyun-Wook, Zheng Guangyuan Wesley
Institute of Materials Research and Engineering, A*STAR, 2 Fusionopolis Way, Innovis, Singapore, 138634, Singapore.
School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
Adv Mater. 2018 Jul 5:e1801745. doi: 10.1002/adma.201801745.
The propensity of lithium dendrite formation during the charging process of lithium metal batteries is linked to inhomogeneity on the lithium surface layer. The high reactivity of lithium and the complex surface structure of the native layer create "hot spots" for fast dendritic growth. Here, it is demonstrated that a fundamental restructuring of the lithium surface in the form of lithium silicide (Li Si) can effectively eliminate the surface inhomogeneity on the lithium surface. In situ optical microscopic study is carried out to monitor the electrochemical deposition of lithium on the Li Si-modified lithium electrodes and the bare lithium electrode. It is observed that a much more uniform lithium dissolution/deposition on the Li Si-modified lithium anode can be achieved as compared to the bare lithium electrode. Full cells paring the modified lithium anode with sulfur and LiFePO cathodes show excellent electrochemical performances in terms of rate capability and cycle stability. Compatibility of the anode enrichment method with mass production process also offers a practical way for enabling lithium metal anode for next-generation lithium batteries.
锂金属电池充电过程中锂枝晶形成的倾向与锂表面层的不均匀性有关。锂的高反应活性和原生层复杂的表面结构为快速枝晶生长创造了“热点”。在此，证明了以硅化锂（LiSi）形式对锂表面进行根本性重构可有效消除锂表面的不均匀性。进行原位光学显微镜研究以监测锂在LiSi修饰的锂电极和裸锂电极上的电化学沉积。观察到，与裸锂电极相比，LiSi修饰的锂阳极上锂的溶解/沉积更加均匀。将修饰后的锂阳极与硫和LiFePO阴极配对的全电池在倍率性能和循环稳定性方面表现出优异的电化学性能。阳极富集方法与大规模生产工艺的兼容性也为下一代锂电池启用锂金属阳极提供了一条实用途径。
