Theoretical Specific Capacity and Metal Ion Diffusion Pathway of NiMoO 4 Microspheres for Hybrid Supercapacitors

Abstract Transition metal molybdates are one of the most prominent materials for energy storage devices. The present investigation establishes a strong correlation between the structure and electrochemical performance of NiMoO 4 through Density Functional Theory (DFT). Initially, the NiMoO 4 microspheres are directly deposited on nickel foam using a hydrothermal method by tuning experimental parameters. When employed as electrode materials, the NiMoO 4 microspheres deliver a specific capacity of 168.9 mAh g −1 at 1 A g −1 . In addition, the material retains 80% capacity over 7000 charge‐discharge cycles with 98.3% coulombic efficiency, implying its excellent stability. DFT calculations are used to determine specific capacity and potassium ion diffusion for 5 layers of [110] planes of NiMoO 4 . The potential energy landscape is created for [110] plane using the potassium atom minimum hopping algorithm and atomic simulation environment. The DFT results clearly align with the theoretical capacity of 203 mAh g −1 close to the experimental results. A hybrid supercapacitor (HSC) is also developed with NiMoO 4 //AC cell delivers a specific energy of 56.3 Wh kg −1 at a specific power of 421 W kg −1 with negligible capacity loss over 15 000 cycles. This investigation offers the development of battery‐type electrodes for hybrid supercapacitors using the fundamental understanding of ion‐diffusion in the materials’ structure.