Transition metal sulfides are considered to be a promising material for energy storage due to their abundant structure and excellent electrical conductivity. However, the neglect of the activation process of these materials in some specific situations may hinder our understanding of the intrinsic mechanism and capacity in the energy storage process. Here, cobalt sulfide is taken as the object of study to reveal the transformation during electrochemical activation. Graphene-loaded cobalt sulfide nanoparticles were prepared by calcination and in situ transformed into defect-rich CoOOH nanosheets by rapid electrochemical activation. Notably, the activation process is inevitable for cobalt sulfide in an alkaline environment under operating conditions, which enables cobalt sulfide to exhibit energy storage capacity. Moreover, other battery-type metal sulfides also undergo activation with similar electrochemical features indicating the universality of this activation process. Meanwhile, the materials exhibit superior performance after sufficient activation. Typically, the activated Co-OH/G exhibits a specific capacity of 511C g⁻¹ at 1 A g⁻¹ and capacity retention of 65.9% at 50 A g⁻¹. More significantly, the new insights and in-depth research of the activation process make it possible to design advanced materials utilizing activation processes.

过渡金属硫化物因其丰富的结构和优异的导电性而被认为是一种很有前途的储能材料。然而，在某些特定情况下忽视这些材料的活化过程可能会阻碍我们对储能过程的内在机制和容量的理解。这里以硫化钴为研究对象，揭示电化学活化过程中的转变。通过煅烧制备石墨烯负载的硫化钴纳米颗粒，并通过快速电化学活化原位转化为富含缺陷的CoOOH纳米片。值得注意的是，硫化钴在碱性环境下操作条件下的活化过程是不可避免的，这使得硫化钴具有储能能力。而且，其他电池型金属硫化物也经历类似的电化学特征的活化，表明该活化过程的普遍性。同时，材料在充分活化后表现出优异的性能。通常，活化的 Co-OH/G 的比容量为 511C g^-1在 1 A g ^-1和 65.9% 在 50 A g ^-1的容量保持率。更重要的是，对活化过程的新见解和深入研究使得利用活化过程设计先进材料成为可能。