In situ healing of dendrites in a potassium metal battery
Prateek Hundekar, Swastik Basu, Xiulin Fan, Lu Li, Anthony Yoshimura, Tushar Gupta, Varun Sarbada, Aniruddha S. Lakhnot, Rishabh Jain, Shankar Narayanan, Yunfeng Shi, Chunsheng Wang, Nikhil Koratkar
Abstract
The use of potassium (K) metal anodes could result in high-performance K-ion batteries that offer a sustainable and low-cost alternative to lithium (Li)-ion technology. However, formation of dendrites on such K-metal surfaces is inevitable, which prevents their utilization. Here, we report that K dendrites can be healed in situ in a K-metal battery. The healing is triggered by current-controlled, self-heating at the electrolyte/dendrite interface, which causes migration of surface atoms away from the dendrite tips, thereby smoothening the dendritic surface. We discover that this process is strikingly more efficient for K as compared to Li metal. We show that the reason for this is the far greater mobility of surface atoms in K relative to Li metal, which enables dendrite healing to take place at an order-of-magnitude lower current density. We demonstrate that the K-metal anode can be coupled with a potassium cobalt oxide cathode to achieve dendrite healing in a practical full-cell device.