The electrochemical performance of manganese oxoborate cathodes for lithium-ion batteries: Effect of synthesis method

Abstract

Cathodes for lithium-ion batteries (LIBs) present stability and performance issues; therefore, searching for alternative novel electrode materials or modifications of known ones is one of the main issues. Warwickite-type Mn2OBO3 samples synthesized by hydrothermal (HT), solid-state (SS), and solution combustion (SC) methods were investigated for the first time as cathode materials for LIBs. The prepared Mn2OBO3 electrodes were analyzed using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in order to correlate the surface properties and electrochemical behaviour. X-ray photoelectron spectroscopy (XPS) revealed the existence of +2 and + 3 oxidation states of Mn in the electrodes. The band gaps (Eg) for all electrodes were calculated between 1.75 and 2.04 eV. The electrochemical performance of the Mn2OBO3 electrodes (E) prepared with the SC method was significantly improved. The E-SC electrode showed the highest initial discharge capacity of about 155 mAhg-1 and found to be more stable at a current density of 30 mAg-1. The results presented here provide a new approach to the utilization of manganese oxoborate compounds as promising cathode materials for high-performance energy storage systems and emphasize that homogeneously structured cathode electrodes with a high surface area are desirable for LIBs. © 2021 Elsevier Ltd and Techna Group S.r.l.