Self-heating–induced healing of lithium dendrites

作者：Lu Li, Swastik Basu, Yiping Wang, Zhizhong Chen, Prateek Hundekar, Baiwei Wang, Jian Zhong Shi, Yunfeng Shi, Shankar Narayanan, Nikhil A. Koratkar · 发表于：Science · 年份：2018 · DOI：10.1126/science.aap8787 · 被引用次数：530 · 研究领域：Advanced Battery Materials and Technologies、Advancements in Battery Materials、Advanced Battery Technologies Research

Lithium (Li) metal electrodes are not deployable in rechargeable batteries because electrochemical plating and stripping invariably leads to growth of dendrites that reduce coulombic efficiency and eventually short the battery. It is generally accepted that the dendrite problem is exacerbated at high current densities. Here, we report a regime for dendrite evolution in which the reverse is true. In our experiments, we found that when the plating and stripping current density is raised above ~9 milliamperes per square centimeter, there is substantial self-heating of the dendrites, which triggers extensive surface migration of Li. This surface diffusion heals the dendrites and smoothens the Li metal surface. We show that repeated doses of high-current-density healing treatment enables the safe cycling of Li-sulfur batteries with high coulombic efficiency.