Simultaneously suppressing lithium dendrite growth and Mn dissolution by integration of a safe inorganic separator in a LiMn2O4/Li battery

Lithium metal is considered an ideal anode material for next-generation rechargeable batteries with high energy density due to its high theoretical capacity and the lowest electrode potential among metals. However, the practical application of Li metal coupled with some traditional cathode materials like spinel LiMn2O4 is hindered by Li dendrites on the anode surface and the dissolution of metal (Mn) ions in the electrolyte. In this work, we introduce a safe inorganic separator based on hydroxyapatite (HAP) nanowires into a LiMn2O4|Li battery. The HAP separator can not only suppress Li dendrite growth, but also help to reduce Mn-ion dissolution, which dramatically improves the cycle stability and safety of the battery. The improved mechanism is carefully investigated. With the integration of the safe inorganic HAP separator, high energy density batteries with Li metal anodes coupled with LiMn2O4 or other cathode materials are promising for practical application.