Composite (bi‐)metallic oxides with heterostructure and heteroatom‐doped porous carbon as advanced potassium‐ion battery anodes

Abstract In this work, a scalable two‐step synthesis method was employed to develop transition metal oxide/carbon composites that exhibit excellent electrochemical performance as the anode of potassium‐ion batteries. The functionalized metal‐organic framework precursor was combined with molecular silicotungstic acid clusters (SiW9) during thermal conversion, and embedded into in‐situ formed porous carbon matrix to form a multi‐component CoWO 4 /WO 3 ‐C composite material with N‐doping. Benefiting from unique compositional and structural features, the resulting composite exhibits an appealing potassium‐ion storage performance, such as, large specific capacity of ca. 1500 mAh/g after 600 cycles and excellent rate capability, i. e., delivering reversible capacity over 200 mAh/g even at the high‐rate of 2.0 A/g.