The latest view suggests the inactive core, surface pulverization, and polysulfide shuttling effect of metal sulfides are responsible for their low capacity and poor cycling performance in sodium-ion batteries (SIBs). Whereas overcoming the above problems based on conventional nanoengineering is not efficient enough. In this work, erythrocyte-like CuS microspheres with an elastic buffering layer of ultrathin polyaniline (PANI) were synthesized through one-step self-assembly growth, followed by in situ polymerization of aniline. When CuS@PANI is used as anode electrode in SIBs, it delivers high capacity, ultrahigh rate capability (500 mAh g⁻¹ at 0.1 A g⁻¹, and 214.5 mAh g⁻¹ at 40 A g⁻¹), and superior cycling life of over 7500 cycles at 20 A g⁻¹. A series of in/ex situ characterization techniques were applied to investigate the structural evolution and sodium-ion storage mechanism. The PANI swollen with electrolyte can stabilize solid electrolyte interface layer, benefit the ion transport/charge transfer at the PANI/electrolyte interface, and restrain the size growth of Cu particles in confined space. Moreover, finite element analyses and density functional simulations confirm that the PANI film effectively buffers the volume expansion, suppresses the surface pulverization, and traps the polysulfide.

最新观点表明，金属硫化物的惰性核心、表面粉碎和多硫化物穿梭效应是导致钠离子电池 (SIB) 容量低和循环性能差的原因。而基于传统的纳米工程克服上述问题效率不够。在这项工作中，通过一步自组装生长，然后苯胺原位聚合，合成了具有超薄聚苯胺 (PANI) 弹性缓冲层的类红细胞 CuS 微球。当 CuS@PANI 在 SIB 中用作阳极电极时，它具有高容量、超高倍率能力（500 mAh g ^-1在 0.1 A g ^-1和 214.5 mAh g ^-1在 40 A g ^{-1), 以及在 20 A g −1}下超过 7500 次循环的卓越循环寿命。应用了一系列原位/非原位表征技术来研究结构演变和钠离子储存机制。电解质溶胀的聚苯胺可以稳定固体电解质界面层，有利于聚苯胺/电解质界面的离子传输/电荷转移，抑制限制空间内铜颗粒的尺寸增长。此外，有限元分析和密度泛函模拟证实聚苯胺薄膜有效地缓冲了体积膨胀，抑制了表面粉碎，并捕获了多硫化物。