Abstract
Nickel-based compounds have gained significant attention as energy storage materials of battery-supercapacitor hybrids (BSHs) due to their high theoretical capacity and versatile redox properties. To improve energy storage performance, bimetallic compounds have been developed to provide abundant redox states and enhanced electrical conductivity. Vanadium compounds with their rich redox states are also considered promising battery-type materials for BSHs. In this study, novel nickel‑vanadium bimetallic compounds are synthesized using various ratios of nickel and vanadium through hydrothermal and annealing processes, serving as electroactive materials of BSHs. The nickel‑vanadium compound synthesized with a nickel-to‑vanadium ratio of 1:1 (NiV11) exhibits the highest specific capacitance (CF) of 1090.4 F/g and a specific capacity of 381.6 C/g at 20 mV/s, attributed to its favorable leaf-like aggregated structure and the high theoretical capacity of NiS2. A BSH is assembled with a NiV11 positive electrode and a reduced graphene oxide negative electrode. The BSH achieved a maximum energy density of 38.2 Wh/kg at the power density of 650 W/kg, and excellent cycling stability with the CF retention of 92.0% and Coulombic efficiency 91.4% after 10,000 cycles. This work provides a blueprint for designing efficient bimetallic compounds and insights into the effects of metal ratios on electrochemical performance.
Original language | English |
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Article number | 114971 |
Journal | Journal of Energy Storage |
Volume | 107 |
DOIs | |
Publication status | Published - Jan 30 2025 |
Keywords
- Battery-supercapacitor hybrids
- Bimetallic
- Coulombic efficiency
- Metal ratio
- Nickel‑vanadium compounds
- Redox states
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering