Orderly arranged three-dimensional porous S/Ti3C2/NC potassiphilic scaffold enabling dendrite-free K metal deposition for potassium metal batteries

Potassium (K) metal battery is a promising future electrochemical energy storage system owing to the low electrochemical potential, high theoretical specific capacity, and inexhaustible K resources. However, the K metal anodes prematurely defeat due to the inescapable dendrites growth and volume variation, which severely hindered the practical application of K metal battery. To tackle these issues, we propose a S-modified Ti3C2chitosan aerogel (S-TNC) with orderly arranged 3D porous structure and high potassiphilicity to construct K metal anode (S-TNC@K) by molten infusing with K metal. S-TNC scaffold buffers the internal volume variation via large porous voids during the plating/stripping, and accelerates electron/ion transport by interconnected conductive skeleton, inducing uniform K deposition. The monodispersed S and N sites in S-TNC improve the potassiphilicity of scaffold, reducing K nucleation barrier and inhibiting K dendrites growth. Benefiting from the above outstanding properties of S-TNC scaffold, the S-TNC@K//PTCDA full battery realizes excellent cycling stability with a boosted specific capacity of 90.2 mA h g-1 after 100 cycles at 1 C. This work solves the dendrites growth and volume variation problems in K metal batteries, which laid foundation for the further development of K metal battery.