Enhanced electrochemical performance of a composite made of core-shell structured ZnMn2O4@TiO2 and soft carbon as an anode material for lithium-ion batteries

Abstract

The utilization of green energy requires efficient large-scale energy storage, with high-energy-density lithium-ion batteries playing a pivotal role. ZnMn₂O₄ (ZMO), a ternary transition metal oxide, is known for its abundance of component elements, cost-effectiveness, non-toxicity, and high theoretical capacity (∼1000 mAh g^-1). However, its low electrical conductivity and substantial volume expansion during cycling lead to particle fracture and rapid capacity degradation. In this study, a core-shell ZnMn₂O₄@TiO₂ composite anode material incorporating soft carbon was developed. The TiO₂ layer enables to mitigate ZMO volume expansion and provide a rapid charge transfer pathway, while the incorporation of soft carbon can enhance the surface area and increase lithium storage sites. The optimized composite anode ([email protected]) exhibits pseudo-capacitive behavior, which achieves a high discharge capacity of 1170 mAh g^-1 in the 100th cycle and exceeds the initial capacity by over 250 mAh g^-1. Furthermore, it demonstrates promising rate performance, retaining 85 % of its capacity at 1000 mA g^-1 compared to 100 mA g^-1. This work presents a viable strategy for developing high-energy-density lithium-ion batteries with enhanced cycling and rate performances.