A host potassiophilicity strategy for unprecedentedly stable and safe K metal batteries

Creating high-performance host materials for potassium (K) metal anodes remains a significant challenge due to the complex preparation process and poor K reversibility. In our work, we developed a potassiophilicity strategy using an oxygen-modified carbon cloth (O-CC) network as a host for K metal anodes. The O-CC network exhibited superior potassiophilic ability, and this improvement was also observed in other carbon hosts using the same process. The oxygen-induced epoxy group in the carbon network regulates interface electrons and enables strong binding of K adatoms through orbital hybridization, resulting in fewer side reactions with the electrolyte and promoting K-ion desolvation and uniform deposition. These factors result in unprecedented stability of the carbon network host, with a long lifespan of over 5500 hours at 0.5 mA cm(-2)/0.5 mA h cm(-2) and 3500 h at 1 mA cm(-2)/0.5 mA h cm(-2) in symmetric cells for K metal anodes, surpassing the cycle life of all previously reported K metal anodes. Furthermore, a high average coulombic efficiency of over 99.3% is demonstrated in O-CC//K cells during 210 cycles. The O-CC also exhibited a stable electrochemical performance, with a capacity retention of 73.3% in full cells coupled with a perylene-3,4,9,10-tetracarboxylic dianhydride cathode. We believe that this new strategy holds great promise for metal anodes in battery applications.

Automated summary

In this work, a potassiophilicity strategy using an oxygen-modified carbon cloth network as a host for potassium metal anodes was developed. The carbon network exhibited superior potassiophilic ability, resulting in unprecedented stability and long lifespan for potassium metal anodes. This new strategy shows great promise for metal anodes in battery applications.