Enhancing the capacity of Mn-rich cathodes by kinetics control for lithium-ion batteries

Abstract

High energy density cathodes have been widely explored in recent years in the area of lithium-ion batteries, which suffer from sluggish kinetics and structural degradation. Herein, the kinetics of the charge transfer process on the cathode material was accelerated via synergistic lanthurizing and Li/Mn optimization method, thereby delivering layered-spinel biphase and improved electrochemical performance. The available capacity was greatly enhanced from 57.4 mA h g⁻¹ for the pristine material to 233.4 mA h g⁻¹ for the modified material with a voltage of 1.5–4.8 V. Based on the electrochemical and structural characterization, the improved capacity and rate performance were attributed to the engineered structural design with enhanced electrochemical kinetics. Electrochemical impedance spectroscopy results indicated that modification tuning could effectively lower the activation energy of the charge transfer process by nearly 45%. This synergistic approach widens the method for enhancing the energy density of oxide cathodes.