Bi@hollow carbon tube enabled high performance potassium metal batteries

Potassium (K) metal batteries are attractive alternatives beyond lithium-ion batteries because of the large abundance, high theoretical specific capacity and low electrochemical potential of the K metal. However, K metal anode have been restrained by the uncontrollable K dendrite growth. A high-activity K metal anodes achieved by confining K metal into a Bismuth compound hollow carbon tube (Bi@CNT) freestanding matrix is reported. The homogeneous K ionic flux and reduced local current density during plating/stripping processes are enabled by the high electronic transport in the Bi@CNT matrix. Moreover, the "K-philic" Bi in the Bi@CNT can induce the nucleation of K metal and induce K to uniformly distribute in the electrode during cycling. Therefore, the obtained Bi@CNT composite K anode shows more excellent electrochemical performance in electroplating/stripping, greatly improves the stability (500 h at 0.5 mA cm(-2) 0.5 mA h cm(-2) and a low overpotential of 53 mV), and provides more choices for the development of potassium metal batteries. Furthermore, K@Bi@CNT||PTCDA full batteries exhibit excellent electrochemical performance with good rate capability and long cycling stability (103.3 mA h g(-1) after 150 cycle at 0.1 A g(-1)). (c) 2022 Elsevier B.V. All rights reserved.