Spinel Ferrite-Based Electrode Materials for Supercapacitors: A Review

Abstract

Transition metal ferrites (MFe2O4, M = Co, Ni, Mn, Zn, Mg, Cu) and their composites are a very promising family of pseudocapacitive electrode materials for supercapacitors and asymmetric supercapacitors (ASCs) because of their multi-electron redox activity, wide operating potential windows up to 1.8 V, chemical stability and low cost. The crystallite size, surface area and morphology progress are vital in synthesis routes such as hydrothermal/solvothermal processing, binder-free electrodeposition, co-precipitation and sol-gel auto-combustion. Hybridization of ferrites with conducting polymers and conductive carbon matrices and direct growth on 3D conductive substrates are effective ways to overcome the intrinsic limitations such as low electrical conductivity and structural degradation during cycling. This review provides a real-world guide to the material design, key performance indicators and the standardization requirements for high-energy and high-power next-generation energy storage devices