Co_0.5Ni_0.5MoO₄ Double-Shelled Hollow Spheres with Enhanced Electrochemical Performance for Supercapacitors and Lithium-Ion Batteries

Transition metal molybdates represent a promising family of electrode materials for supercapacitors and lithium-ion batteries (LIBs). Herein, Co_0.5Ni_0.5MoO₄ double-shelled hollow spheres (DSHSs) are synthesized using a simple and scalable spray-drying method followed by calcination in air. Benefited from the unique hollow structure as well as the coexistence of Co and Ni, the as-synthesized Co_0.5Ni_0.5MoO₄ DSHSs exhibit an improved pseudocapacitive property with a specific capacitance of 731 F g⁻¹ at 0.5 A g⁻¹ and a high capacitance retention of 91% (10 A g⁻¹) after 5000 cycles. In addition, the obtained Co_0.5Ni_0.5MoO₄ DSHSs also manifest a high specific capacity (900 mAh g⁻¹ at 0.2 A g⁻¹ after 50 cycles) and an excellent cyclability (756 mAh g⁻¹ at 1 A g⁻¹ after 1000 cycles) for lithium storage. This rational design on both component and structure provides an effective strategy to achieve high-performance supercapacitors and LIBs.