The lithium- and manganese-rich layered oxide (LMR) holds great promise as a cathode material for lithium-ion battery (LIB) applications due to its high capacity, high voltage and low cost. Unfortunately, its poor initial Coulombic efficiency (ICE) and unstable electrode/electrolyte interface with continuous growth of the solid electrolyte interphase leads to high impedance and large overpotential. These effects cause severe capacity loss and safety issues. In this work, we have developed a novel approach to fabricate a stable LMR cathode with a uniform thin layer of aluminum oxide (Al₂O₃) coated on the surface of the LMR particles. This synthesis approach uses the microemulsion method that is environment-friendly, cost-effective and can be easily scaled. Typically, an 8-nm layer of Al₂O₃ is shown to be effective in stabilizing the electrode/electrolyte interface (enhanced ICE to 82.0% and moderate impedance increase over 200 cycles). Moreover, the phase transformation from layered to spinel is inhibited (96.3% average voltage retention) and thermal stability of the structure is significantly increased (heat release reduced by 72.4%). This study opens up a new avenue to address interface issues in LIB cathodes and prompts the practical applications of high capacity and voltage materials for high energy density batteries.

富锂和锰的层状氧化物（LMR）由于其高容量，高电压和低成本而作为锂离子电池（LIB）应用的正极材料具有广阔的前景。不幸的是，其较差的初始库仑效率（ICE）和不稳定的电极/电解质界面以及固体电解质相间的连续增长会导致高阻抗和大的超电势。这些影响会导致严重的容量损失和安全问题。在这项工作中，我们开发了一种新颖的方法来制造具有均匀氧化铝薄层（Al ₂ O ₃）涂在LMR颗粒的表面上。这种合成方法使用了环境友好，具有成本效益且易于扩展的微乳液方法。通常，显示8nm的Al ₂ O ₃层可有效稳定电极/电解质界面（ICE增强至82.0％，并且在200个周期内阻抗适度增加）。此外，抑制了从层状到尖晶石的相变（平均电压保持力为96.3％），并且结构的热稳定性显着提高（热量释放减少了72.4％）。这项研究为解决LIB阴极中的界面问题开辟了一条新途径，并促进了高能量密度电池的高容量和高电压材料的实际应用。