Novel Li2MnO3 nanowire anode with internal Li-enrichment for use in a Li-ion battery

Abstract

Anode materials which undergo a conversion reaction can achieve larger specific capacities than conventional carbon-based materials. They can even achieve higher energy densities when used at low voltages. However, the large amounts of Li₂O generated in the interior of these structures when Li ions are inserted can cause volume expansion and mechanical fracturing from the inside out. This leads to a poor cycling performance and limits their commercial application. To overcome this limitation, we introduced Li ions into the interior of the cells of manganese oxide materials and successfully synthesized a novel Li-rich anode material (Li₂MnO₃). The reversible capacity reached 1279 mA h g⁻¹ after 500 cycles, much higher than that of pure MnO₂ or other commercial anodes. This optimization of the internal Li-enrichment and its application in Li₂MnO₃ nanowires used as low voltage anodes in Li-ion batteries have rarely been reported. Further investigations by X-ray diffraction and photoelectron spectroscopy suggested that the strategy of optimizing the internal Li-enrichment of this novel Li₂MnO₃ anode is a promising development for Li-ion batteries.