CoMoO4 nano-architecture-based supercapacitors: Tunable properties, performance optimization, and prospective applications

Abstract

Supercapacitors (SCs) are emerging as promising energy storage technology, thanks to their high-power density, rapid charging/discharging capabilities, and extended cycle life. The quest for enhanced performance, particularly in terms of energy density, has driven extensive exploration into innovative electrode materials to bolster performance. This study focuses on recent advancements in CoMoO₄ (CMO) with engineered architectures serving as electrodes for high-performance SCs. A distinct advantage lies in the ability of Co and Mo ions to exist in a range of oxidation states, promising increased energy density, enhanced cycling stability, and prolonged discharge time for SCs. These advancements encompass α, β, and hydrated (H)-CMO with adjusted electronic structures and adopting unique morphologies. Despite the longstanding study of CMO architectures, their inherent low conductivity and volume fluctuations during operation hinder further SC applications. To overcome these challenges, the integration of various materials has been explored. Concurrently, incorporating conductive materials (polymers, metal elements, amorphous carbon, graphene, carbon nanotubes, etc.) and introducing metals, heteroatoms, and defects into the electrode matrix (oxygen vacancies, heterojunctions) have proven effective in enhancing electrochemical performance. This review aims to provide recommendations for optimizing the performance of CMO-based SC electrode materials by manipulating the conductivity and reactivity of CMO. As a guiding principle, optimizing crystallite size, morphology, and synthesis and deposition strategies is crucial for the sustainable development of CMO-based nano-architecture designs for thick and flexible electrodes in prospective practical electronic storage devices.