Mild aqueous Zn–MnO₂ battery attracts lots of attention in energy storage filed due to its low cost, high safety and environmental friendliness. To achieve high-performance in battery, phase evolution processes of MnO₂ during synthesis and electrochemical reactions need to be understood. Herein, the phase evolution during microwave hydrothermal and correlated battery performance of β-MnO₂ are studied. The results demonstrate a phase evolution mechanism from an initial mixture of vernadite, nsutite, and pyrolusite (β-MnO₂) to a final single β-MnO₂ phase, along with enhanced structure stability, increased Mn valence, and decreased BET surface area. It is found that only when microwave hydrothermal time (MHT) ≥ 120 min, β-MnO₂ showing both high capacity and excellent cycling performance can be obtained. β-MnO₂ prepared under a MHT of 120 min shows a high reversible capacity of 288 mA h g⁻¹ with a median voltage of 1.36 V vs. Zn/Zn²⁺, and high capacity retentions of 91.8% after 200 cycles at 0.5C and 84.3% after 1000 cycles at 4C, respectively. In addition, the formation of inactive ZnMn₂O₄ during cycling is observed, which contributes to the capacity fading of β-MnO₂ after long-term cycling. This research makes a step forward to the practical application of Zn–MnO₂ batteries, and contributes to the large-scale energy storage field.

温和的Zn-MnO ₂水性电池由于其低成本，高安全性和环境友好性而在能量存储领域引起了很多关注。为了在电池中实现高性能，需要了解MnO ₂在合成和电化学反应过程中的相变过程。在此，微波水热和β-的MnO相关的电池性能在相位演化₂进行了研究。结果表明从（β-MnO的水羟锰矿，nsutite，和软锰矿的初始混合物的相位演化机构₂）至最终单β-MnO的₂相，以及增强的结构稳定性，增加的锰价和减少的BET表面积。据发现，只有当微波水热时间（MHT）≥120分钟，β-MnO的₂可以得到表示高容量和优异的循环性能。β-的MnO ₂下120个分钟节目288毫安ħg的高可逆容量一个MHT制备^-1与1.36 V的中值电压相对于锌/锌²⁺，和以0.5C 200次循环后的91.8％高容量维持率在4C下经过1000次循环后分别为84.3％和84.3％。此外，不活动ZnMn形成₂ ö ₄循环期间观察到，这有助于容量衰减的β-MnO的₂长期骑车之后。这项研究为Zn-MnO ₂电池的实际应用迈出了一步，并为大规模的储能领域做出了贡献。