The sluggish reaction kinetics and poor structure stability of transition metal dichalcogenides (TMDs)-based anodes in potassium-ion batteries (KIBs) usually cause limited rate performance and rapid capacity decay, which seriously impede their application. Herein, we report a vacancy engineering strategy for preparing a class of Te-doped 1T’-ReSe anchored onto MXene (Te-ReSe/MXene) as an advanced anode for KIBs with high performance. By taking advantage of the synergistic effects of the defective Te-ReSe arrays with expanded interlayers and the elastic MXene nanosheets with self-autoadjustable function, the Te-ReSe/MXene superstructure exhibits boosted K ion storage performance, in terms of high reversible capacity (361.1 mA h g at 0.1 A g over 200 cycles), excellent rate capability (179.3 mA h g at 20 A g), ultra-long cycle life (202.8 mA h g at 5 A g over 2000 cycles), and steady operation in flexible full battery, presenting one of the best performances among the TMDs-based anodes reported thus far. The kinetics analysis and theoretical calculations further indicate that satisfactory pseudocapacitive property, high electronic conductivity and outstanding K ion adsorption/diffusion capability corroborate the accelerated reaction kinetics. Especially, structural characterizations clearly elaborate that the Te-ReSe/MXene undergoes reversible evolutions of an initial insertion process followed by a conversion reaction.

过渡金属二硫族化合物(TMDs)用作钾离子电池(KIBs)负极时存在反应动力学缓慢及结构稳定性不足等难题,导致其循环和倍率性能差,使得其应用严重受限.在本文中,我们将Te掺杂的1T′-ReSe₂负载在MXene上构建了高性能KIBs负极(Te-ReSe₂/MXene).该超结构利用缺陷化的Te-ReSe₂与自调节弹性MXene的协同效应,表现出高可逆容量(0.1 A g^-1电流密度下循环200圈后为361.1 m A h g^-1),优异的倍率性能(20 A g^-1电流密度下为179.3 m A h g^-1)和超长的循环寿命(5 A g^-1电流密度下循环2000圈后为202.8 m A h g^-1),并能实现柔性全电池的稳定运行,是目前所有TMDs基负极展示的最好性能之一.动力学分析和理论计算表明,该材料具有出色的赝电容特性,高电导率和优异的K⁺吸附/扩散能力,显著提升了其反应动力学