FeS₂ has been widely studied and is considered as a promising Li-free cathode for the next generation high-energy-density lithium metal batteries. However, it has a fast capacity decay due to large volume expansion. Herein, with the aim to pre-expand the particle, a mild chemical prelithiation strategy is applied to obtain Li_xFeS₂ cathode. It alleviates the electrode's volume variation during cycling process by keeping a well electrical contact between the conductive additive and the active material. In addition, partially amorphous Li₂S, generated in situ by the reaction of FeS₂ + 4Li-Bp → Fe + 2Li₂S + 4Bp, achieves rapid interfacial Li⁺ transportation and low solubility of polysulfides. As a result, the prelithiated FeS₂ electrode material exhibits an alleviated volume variation and an improved cycling performance. This work can be extended to other conversion reaction materials with large volume expansion for better electrochemical performance.

FeS ₂已被广泛研究，被认为是下一代高能量密度锂金属电池的有前途的无锂正极。但由于体积膨胀较大，容量衰减较快。在此，为了预膨胀粒子，应用温和的化学预锂化策略来获得 Li _x FeS ₂正极。它通过保持导电添加剂和活性材料之间良好的电接触来减轻循环过程中电极的体积变化。此外，部分非晶态 Li ₂ S，由 FeS ₂  + 4Li-Bp → Fe + 2Li ₂ S + 4Bp反应原位生成，实现快速界面 Li ⁺多硫化物的运输和低溶解度。结果，预锂化的FeS ₂电极材料表现出减小的体积变化和改进的循环性能。这项工作可以扩展到其他具有大体积膨胀的转化反应材料，以获得更好的电化学性能。