Synergistic Enhancement Effect of Al Doping and Highly Active Facets of LiMn2O4 Cathode Materials for Lithium-Ion Batteries

Abstract

To overcome the poor cycling stability of LiMn2O4 cathode materials without sacrificing the specific capacity, we demonstrate a new strategy for synergistically enhancing their electrochemical performance by combining the advantages of Al doping and the exposure of highly active facets. Specifically, Al doping can suppress Mn dissolution in the electrolyte, leading to an outstanding cycling stability. In addition, the exposure of highly active facets can greatly enhance the specific capacity and rate capability, while also compensating for the capacity loss caused by Al doping. As a consequence, the as-prepared Al-doped LiMn2O4 truncated octahedrons exhibit a far superior performance in both rate capacity and cycling stability than the pure LiMn2O4 octahedrons and the LiMn2O4 truncated octahedrons. Our work is meaningful not only for the synthesis of high-performance LiAl0.1Mn1.9O4 truncated octahedrons, but also for providing new insight into the development of high-performance LiMn2O4 cathode materials.