Selective potassium deposition enables dendrite-resistant anodes for ultra-stable potassium metal batteries.

Instability at the solid electrolyte interface (SEI) and uncontrollable growth of potassium dendrites have been pressing issues for potassium-ion batteries. Herein, a self-supporting electrode composed of bismuth and nitrogen-doped reduced graphene oxide (Bi 80 /NrGO) is designed as an anode host for potassium metal batteries. Following the molten potassium diffusion into Bi 80 /NrGO, the resulting K@Bi 80 /NrGO exhibits unique hollow pores that provide K + diffusion channels and deposition space to buffer volume expansion, thus maintaining the electrode structure and SEI stability. The K@Bi 80 /NrGO also provides a controlled electric field that promotes uniform K + flux, abundant potassiophilic N sites, and Bi alloying active sites, collectively enabling precise nucleation and selective deposition of potassium to achieve dendrite-resistant anodes. With the K@Bi 80 /NrGO-based optimized electrodes, the assembled K@Bi 80 /NrGO symmetrical cells could sustain stable cycling over 3000 h at a current density of 0.2 mA cm -2 . The Prussian blue cathode and K@Bi 80 /NrGO anode-based full cells exhibited high stability (with no degradation for 1960 cycles at 1000 mA g -1 ) with 99% Coulombic efficiency. This work led to the design of anodes with the triple attributes of precise nucleation, smooth diffusion, and dendrite inhibition, ideal for developing stable potassium metal anodes and beyond. This article is protected by copyright. All rights reserved.