Rapid synthesis of nickel‑copper phosphate electrode by microwave-assisted hydrothermal reaction for supercapattery. (May 2023)

• Record Type: Journal Article
• Authors: Gerard, Ong; Numan, Arshid; Abdah, Muhammad Amirul Aizat Mohd; Khalid, Mohammad; Ramesh, S.; Ramesh, K.
• Is Part Of: Journal of energy storage. Volume 61(2023)
• Publication Date: 2023-05
• Subjects: Supercapattery -- Nickel‑copper phosphate -- Binder-free -- Battery-type electrode -- Microwave-assisted hydrothermal synthesis; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2023.106813
• Languages: English
• ISSNs: 2352-152X

Abstract

Abstract: This study reports the fabrication of binder-free nickel‑copper phosphate (NCP) battery-type electrode via microwave-assisted hydrothermal method for the first time. This fabrication method involved microwave heating which significantly reduced the reaction time compared to the conventional hydrothermal method. The NCP electrodes with different precursor ratios (Ni:Cu of 4:0, 3:1, 1:1, 1:3, and 0:4) were fabricated at 90 °C for 12.5 min. Among all NCP binder-free electrodes, Ni3-Cu-P electrode (Ni:Cu of 3:1) exhibited superior electrochemical performance by showing the highest specific capacity of 1030.8 C/g and areal capacity of 0.72 C/cm 2 at 3 A/g, and the lowest charge transfer (25.9 Ω) and ion diffusion resistances. These can be explained by the fact that Ni3-Cu-P electrode had a small-sized microsphere electrode material with an amorphous structure deposited on the nickel foam. The small-sized microsphere provided a larger surface area for faradaic reaction. Besides, the amorphous structure offered more electrochemical sites for faradaic reaction. Therefore, it was selected as the battery-type electrode for supercapattery. The Ni3-Cu-P//AC supercapattery delivered a higher energy density of 51.6 Wh/kg at 2.25 kW/kg power density, and outstanding stability with 91.3 % capacity retention after 3000 cycles. Graphical abstract: Unlabelled Image Highlights: Nickel-copper phosphate (NCP) electrodes were prepared by microwave method. NCP was used as electrode material for battery-type electrode in supercapattery. Ni3-Cu-P electrode showed the highest specific capacity of 1030.8 C/g at 3 A/g. Ni3-Cu-P//AC supercapattery provided the maximum energy density of 51.6 Wh/kg. Ni3-Cu-P//AC retained 91.3 % of its initial specific capacity after 3000 cycles.