Void space expanded hierarchical battery-type composite material for high-capacity hybrid supercapacitors

• Published in: Materials today chemistry 2024-04, Vol.37, p.101990, Article 101990
• Main Authors: Goli, Hemachandra Rao, Bharat, Lankamsetty Krishna, Nagaraju, Goli, Al-Asbahi, Bandar Ali, Pallavolu, Mohan Reddy, Yang, Hyun Kyoung, Alvi, Parvez Ahmad, Rama Raju, Ganji Seeta
• Format: Article
• Language: English
• Subjects: Energy density; Hybrid composite; Hybrid supercapacitor; Metal oxysulfides; Redox behavior
• ISSN: 2468-5194; 2468-5194
• DOI: 10.1016/j.mtchem.2024.101990

Synergetic modulation of battery-type materials with excellent electrochemical activity is an important feature to elevate the energy storage performance in the hybrid supercapacitors (HySCs). In this study, we synthesized a void space expanded nickel sulfide@nickel molybdenum oxysulfide on Ni foam (NixSy@NiMoOx-1Sy/Ni foam) using wet-chemical sulfurization technique. The growth solution, composed of sulfur ions, partially converts NiMo DHs into NiMoOx-1Sy and the Ni foam substrate into NixSy, resulting in the formation of a hybrid-composite. Increased mass-loading growth of NixSy@NiMoOx-1Sy/Ni foam and multi-oxidation states of nickel species in the composite were confirmed using the X-ray photoelectron spectroscopy analysis. The binder-free NixSy@NiMoOx-1Sy/Ni foam electrode was electrochemically cycled in aqueous KOH electrolyte, demonstrating battery-type redox behavior with enhanced capacity (310.6 mAh/g) compared to the NixSy/Ni foam (221.1 mAh/g) and NiMo DHs/Ni foam (142.5 mAh/g) electrodes, which could be ascribed to the improved electrical conductivity, adequate electrolyte diffusivity, and fast charge transfer properties. Furthermore, a two-electrode system based HySC was assembled using the battery-type NixSy@NiMoOx-1Sy/Ni foam and capacitive-type activated carbon, enabling a maximum energy density (58.8 Wh/kg) and power density (2666.7 W/kg) with good cycling stability and coulombic efficiency. The high-performance HySCs were used to power-up portable lighting devices, demonstrating their practical use in real-time applications. [Display omitted] •Void space expanded NixSy@NiMoOx-1Sy/Ni foam was developed using simple wet chemical and sulfurization method.•The synergetic effect of dual structures enhanced the electrochemical properties.•The NixSy@NiMoOx-1Sy//AC delivered a high-energy density at a high-power density.•The NixSy@NiMoOx-1Sy//AC used to demonstrate and operate portable electronic devices.