Co-activation for enhanced K-ion storage in battery anodes

The relative natural abundance of potassium and potentially high energy density has established potassium-ion batteries as a promising technology for future large-scale global energy storage. However, the anodes' low capacity and high discharge platform lead to low energy density, which impedes their rapid development. Herein, we present a possible co-activation mechanism between bismuth (Bi) and tin (Sn) that enhances K-ion storage in battery anodes. The co-activated Bi-Sn anode delivered a high capacity of 634 mAh g(-1), with a discharge plateau as low as 0.35 V, and operated continuously for 500 cycles at a current density of 50 mA g(-1), with a high Coulombic efficiency of 99.2%. This possible co-activation strategy for high potassium storage may be extended to other Na/Zn/Ca/Mg/Al ion battery technologies, thus providing insights into how to improve their energy storage ability. A co-activated Bi-Sn material was designed as anode for potassium ion batteries, and the co-activation of Bi and Sn led to the formation of K3Sn, thus overcoming the traditional limit of one Sn atom storing only one K ion.

Automated summary

The co-activation of Bi and Sn in the anode of potassium-ion batteries enhances K-ion storage, leading to a high capacity and extended cycling life. This co-activation strategy can also be applied to other ion battery technologies, improving their energy storage ability.