Surface modification of electrode materials played an important role in tailoring their electrochemical performance. Here, surface amorphization or distortion, which was fairly common in material synthesis, was studied for its impact on potassium storage behavior. To this aim, contrast experiments were conducted on a series of NiS porous-hollow microspheres, whose shells were composed of interwoven NiS nanosheets. HRTEM characterization showed that each nanosheet comprised crystalline inner core and amorphous outer layer. By adjusting the thickness of this amorphous layer, potassium storage mechanism could be transformed from a diffusion-controlled type to a hybrid of capacitive and diffusive type, accompanied by an improvement in potassium storage performance. At the optimal layer thickness, NiS electrode could deliver a capacity of 182.4 mAh g^-1 at 5 A g^-1 as well as maintain 427.0 mAh g^-1 after 300 cycles at 0.2 A g^-1.

电极材料的表面改性在调整其电化学性能方面发挥了重要作用。在这里，研究了在材料合成中相当普遍的表面非晶化或变形对钾储存行为的影响。为此，对一系列 NiS 多孔空心微球进行了对比实验，其壳由交织的 NiS 纳米片组成。HRTEM 表征表明每个纳米片都包含结晶内核和非晶外层。通过调整非晶层的厚度，钾的存储机制可以从扩散控制型转变为电容和扩散的混合型，同时提高钾的存储性能。在最佳层厚度下，NiS 电极可提供 182.4 mAh g 的容量^-1在 5 A g ^-1以及在 300 个循环后在 0.2 A g ^{-1保持 427.0 mAh g -1}。