Aqueous rechargeable Zn/MnO₂ batteries are attractive due to their low-cost, high safety and use of non-toxic materials. In term of electrolyte materials, it is anticipated that an aqueous electrolyte with a wider electrochemical window will improve the stability and energy density. In this work, we investigated salt-concentrated electrolytes based on relatively inexpensive acetate salts. An electrochemical window of 3.4 V was achieved in salt-concentrated 1 m Zn(OAc)₂+31 m KOAc electrolyte. Its total ionic conductivity is 2.96 × 10^-2 S cm^-1 while the ionic conductivity of Zn²⁺ ions is 7.80 × 10^-3 S cm^-1, estimated by a current interrupt method. This electrolyte is regarded as a mild alkaline environment with a pH value of 9.76, causing the different storage mechanism for anode with Zn²⁺ ions and, cathode with OH^- ions as the charge carriers respectively. A Zn-MnO₂ battery was assembled using 1 m Zn(OAc)₂+31 m KOAc electrolyte, self-supported α-MnO₂-TiN/TiO₂ cathode and Zn foil anode. The Zn/MnO₂ battery can be charged to 2.0 V versus Zn/Zn²⁺ and delivers discharge capacity and energy density of 304.6 mAh·g^-1 and 368.5 Wh·kg^-1 in first cycle which is then reduced to 243.1 mAh·g^-1 and 277.8 Wh·kg^-1 after 600 cycles when charged/discharged under a current density of 100 mA g^-1 (∼C/3). During cycling, the coulombic efficiency can be maintained around 99% and reached 99.9% during the 14-340th cycles. After the cycling tests, almost no dendrites were observed on the Zn foil anode attributing to the super-high salt concentration in that acetate-based electrolyte, which will benefit the stability of aqueous zinc batteries.

水性可充电Zn / MnO ₂电池因其低成本，高安全性和使用无毒材料而具有吸引力。就电解质材料而言，预期具有更宽的电化学窗口的水性电解质将改善稳定性和能量密度。在这项工作中，我们研究了基于相对便宜的醋酸盐的盐浓缩电解质。在盐浓度为1 m的Zn（OAc）₂ +31 m KOAc电解质中，电化学窗口为3.4V 。总离子电导率为2.96×10 ^-2  S cm ^-1，而Zn ²⁺离子的电导率为7.80×10 ^-3  S cm ^-1由当前的中断方法估算。该电解液被认为是具有9.76的pH值的弱碱性环境，造成用于与锌阳极中的不同存储机制²⁺离子和被OH，阴极^-分别离子作为电荷载体。甲锌的MnO ₂电池使用1M的Zn（OAc）组装₂ 31米的KOAc电解质，自支撑的α-MnO的₂ -锡/二氧化钛₂阴极和Zn箔阳极。与Zn / Zn ²⁺相比，Zn / MnO ₂电池可充电至2.0 V，并在第一循环中提供304.6 mAh·g ^-1和368.5 Wh·kg ^-1的放电容量和能量密度，然后降低至243.1 mAh· G在100 mA g ^-1（〜C / 3）的电流密度下充电/放电600个循环后的^-1和277.8 Wh·kg ^-1。在循环过程中，在第14-340个循环中，库仑效率可保持在99％左右并达到99.9％。循环测试后，在锌箔阳极上几乎没有观察到树突，这归因于该醋酸盐基电解质中的超高盐浓度，这将有利于水性锌电池的稳定性。