MOF‐Derived Potassiophilic CuO Nanoparticles on Carbon Fiber Cloth as Host for Stabilizing Potassium Metal Anode

Abstract Potassium (K) metal anodes suffer the main obstacle of uncontrollable dendrite growth. One of the best ways to overcome this challenge is to build a stable potassiophilic host. Herein, we designed a Metal‐Organic Frameworks (MOF)‐derived CuO nanoparticles on carbon fiber cloth (CC) as a high potassiophilic host to prestore molten potassium for dendrite‐free K metal anode. The three‐dimensional host has a relatively large surface area and excellent mechanical strength, which helps to lower the local current density as well as buffer the volume expansion during the plating/stripping of K. The highly potassiophilic CuO nanoparticles could provide abundant nucleation sites for K, thereby guiding uniform K deposition with a low nucleation overpotential and inhibits the growth of dendrites. The CC@CuO@K anode could cycle for 2000 h at a current of 0.5 mA cm −2 , which exceeds K metal anodes mentioned in other reports. Last but not least, by using the composite K metal as the anode to assemble the full cell, highly boosted performance can be achieved. Our result provides a tempting method for realizing dendrite‐free K metal anodes in PIBs, and also provides an opportunity for the application of other MOF‐based materials in the field of high‐performance K metal anodes.