Potassiophilic skeleton achieving highly stable potassium metal anode

Abstract

K metal batteries are one of the most promising designs for high energy density storage. However, dendrite growth and volume expansion of K metal anode severely lower their cycling stability. In this work, Ag nanoparticles/micropores semi-yolk/shell structure on carbon cloth (Ag-CC) is constructed in situ by a facile method. As a 3D potassiophilic skeleton, the uniformly distributed micropores can effectively reduce the local current density, and then the Ag nanoparticles induce homogeneous nucleation of metallic K. Moreover, the unique semi-yolk/shell structure can promote a special deposition mode of “first root-later grow” for K. The composite anode prepared by electrodepositing K on Ag-CC (K@Ag-CC) exhibits excellent dendrite suppression ability and high electrochemical properties in both symmetric and full cells. This design strategy is expected to be a way to promote the commercial application of K metal batteries.