High entropy spinel metal oxide (CoCrFeMnNi)3O4 nanoparticles as a high-performance supercapacitor electrode material

High entropy spinel oxides (HEO) are a new type of material stabilized by contributions from configurational entropy, and they are expected to show interesting electrochemical energy storage properties. In this study, the first spinel (CrMnFeCoNi)(3)O-4 HEO nanoparticle-based supercapacitor electrode material is synthesized using a reverse co-precipitation approach. The X-ray diffraction analysis confirmed the phase-pure spinel structure. The X-ray photoelectron spectroscopy is used to identify the oxidation states of the cations in spinel HEO. Scanning electron microscopy and electron dispersive X-ray spectroscopy revealed smooth spherical morphology with uniform distribution of cations in HEO nanoparticles. Electrochemical energy storage properties were further studied on spinel HEO-based supercapacitor electrode material. The HEO electrode showed capacitance of 239 F g(-1) and specific energy of 24.1 Wh kg(-1) at a current density of 0.5 A g(-1). A rate capability of 38% is observed from 0.5 to 25 A g(-1). Capacitance retention is found to be 76% after 1000 cycles. The columbic efficiency is remained 86% for 1000 cycles which indicates that HEO has good charge-discharge reversibility. The solution resistance (R-s) and a charge transfer (R-ct) of HEO electrodes are found to be 0.96 Omega and 1.56 Omega, respectively. This is the first report on the deployment of pristine spinel-type HEO nanoparticles in supercapacitors, and it opens up possibilities for further exploration of other HEOs.

Automated summary

The study synthesized a supercapacitor electrode material based on high entropy spinel oxides (HEO), showing excellent electrochemical energy storage properties including high capacitance, good rate capability, and cycling stability. Additionally, this study opens up possibilities for further exploration of other HEO materials.