Manganese dioxide (MnO₂) is considered as a potential cathode material for aqueous magnesium-ion batteries (MIBs) owing to the high theoretical capacity of 308 mAh g⁻¹, low cost and high abundance. However, the essentially poor electrical conductivity of MnO₂ leads to low rate performance and short lifespan in the dated MnO₂ electrodes prepared by the traditional slurry coating route. In present study, the binder-free ε-MnO₂ nanoflakes as a robust cathode for aqueous MIBs is reported. This method provides the direct contact of ε-MnO₂ with the current collector, and thus remarkably improves the electrical conductivity. The binder-free ε-MnO₂ delivers a high specific capacity of 259.3 mAh g¹ at 0.5 A g¹, excellent rate capability, and a long cycling stability of 94.3% retention after 400 cycles. Further, a full cell MIB incorporated with the ε-MnO₂ cathode delivers high rate capability and high energy density of 98.6 Wh kg¹.

由于308 mAh g ^-1的高理论容量，低成本和高丰度，二氧化锰（MnO ₂）被认为是水性镁离子电池（MIB）的潜在正极材料。但是，MnO _2的电导率本质上较差，这导致通过传统浆料涂覆方法制备的陈旧的MnO ₂电极的速率性能较低且寿命较短。在本研究中，无粘合剂的ε-的MnO _2个报道纳米片作为用于水性MIB的健壮阴极。这种方法提供了ε-的MnO的直接接触₂与集电体，从而显着提高导电性。无粘接剂的ε-的MnO ₂在400 A循环后，在0.5 A g ¹时具有259.3 mAh g ¹的高比容量，出色的倍率性能和94.3％的保留率。此外，在ε-MnO的方式并入一个全电池MIB ₂阴极提供高倍率性能和98.6瓦公斤高能量密度¹。