The symmetrical configuration is attractive for electrochemical energy storage devices due to using one electrode material, but it is difficult to achieve for a rechargeable battery. Here, we propose an electrochemical activity modulation method to construct a quasi-symmetrical rechargeable battery with decoupled conversion reactions of the anionic/cationic counterparts of covalent transition metal sulfides. The modulated process contains potential window and electrolyte modulation, followed by a predesigned conversion reaction. For molybdenum disulfide (MoS₂), after cathodic modulation the sulfur redox (S⁰ to S²⁻) inside MoS₂ was activated as redox center of cathode, resulting in a capacity increase of one order of magnitude and high cycling stability. Meanwhile, an anodic-modulated MoS₂ anode displayed high capacity due to the reversible conversion between Mo^x+ and Mo⁰. Coupling this cathode and anode, a quasi-symmetrical battery is fabricated and opens up a new direction for building high-energy electrochemical systems.

对称构造由于使用一种电极材料而对于电化学能量存储装置具有吸引力，但是对于可再充电电池而言难以实现。在这里，我们提出了一种电化学活性调节方法，以构造具有共价过渡金属硫化物的阴离子/阳离子对应物的解偶联转化反应的准对称可充电电池。调制过程包括电位窗和电解质调制，然后进行预先设计的转化反应。对于二硫化钼（MoS ₂），在阴极调制后，MoS ₂内部的硫氧化还原（S ⁰至S ²⁻）被活化为阴极的氧化还原中心，导致容量增加一个数量级和高循环稳定性。同时，由于Mo ^{x +}和Mo ⁰之间的可逆转换，阳极调制的MoS ₂阳极显示出高容量。耦合此阴极和阳极，制造了一个准对称电池，并为构建高能电化学系统开辟了新的方向。