Nickel/Cobalt Molybdate Hollow Rods Induced by Structure and Defect Engineering as Exceptional Electrode Materials for Hybrid Supercapacitor

Abstract

Oxygen defects and hollow structures positively impact pseudocapacitive properties of diffusion/surface-controlled processes, a component of critical importance when building high-performance supercapacitors. Hence, we fabricated hollow nickel/cobalt molybdate rods with O-defects (D-H-NiMoO₄ @CoMoO₄ ) through a soft-template and partial reduction method, enhancing D-H-NiMoO₄ @CoMoO₄ 's electrochemical performance, yielding a specific capacitance of 1329 F g^-1 , and demonstrating excellent durability with 95.8 % capacity retention after 3000 cycles. D-H-NiMoO₄ @CoMoO₄ was used as the positive electrode to construct an asymmetric supercapacitor, displaying an energy density of up to 34.13 Wh kg^-1 and demonstrating good predisposition towards practical applications. This work presents an effective approach to fabricate and use hollow nickel/cobalt molybdate rods with O-defects as pseudocapacitor material for high-performance capacitive energy storage devices.

Keywords: Hollow structure; Oxygen defects; Partial reduction; Soft template; Supercapacitor.