Calcium Molybdenum Bronze as a Stable High-Capacity Cathode Material for Calcium-Ion Batteries

Calcium-ion batteries (CIBs) are gaining increasing attention due to their theoretically high capacity, owing to the divalency of calcium, and low cost. However, only a few calcium insertion electrode materials are reported, and most of them exhibit low capacity or poor cyclability in nonaqueous electrolytes. Herein, we demonstrated high-performance calcium molybdenum bronze Ca 0.13 MoO 3 ·(H 2 O) 0.41 as a potential CIB cathode material at room temperature, with a reversible discharge capacity of 192 mAh g –1 at 86 mA g –1, an average voltage of 2.4 V (vs Ca/Ca 2+ ), and excellent cyclability. This work provides the feasibility of developing high-capacity CIB cathode materials.