In this work, via in situ F doping induction, multilayer hierarchical heterostructures of FeS₂@CoS encapsulated with carbon shell (F-FeS₂@CoS@C) were rationally designed for lithium-ion batteries. Strongly synergistic coupling interactions among the F-FeS₂@CoS and CoS@C interface accelerated electron and ion migration throughout the F-FeS₂@CoS@C nanorods. The uniform carbon shell relieved volume expansion and maintained structural stability during the lithiation/delithiation process. In addition, the hierarchical heterostructures of FeS₂@CoS@C and introduction of F atoms further improved electrical conductivity and provided more active sites to heighten electrochemical reaction kinetics. As a result, the F-FeS₂@CoS@C nanorods delivered a good rate performance (633 mAh/g at 5.0 A/g) and stable long-cyclic performance of 597.1 mAh/g at 2.0 A/g after 800 cycles with the capacity retention ratio of 83.6%. The strategy of constructing hierarchical heterostructures via heteroatomic doping will be beneficial to design novel electrode materials for alkali metal ion batteries.

在这项工作中，通过原位F 掺杂诱导，为锂离子电池合理设计了碳壳封装的 FeS ₂ @CoS多层分层异质结构（F-FeS _{2 @CoS@C）。F-FeS 2} @CoS 和 CoS@C 界面之间的强协同耦合相互作用加速了整个 F-FeS ₂ @CoS@C 纳米棒中的电子和离子迁移。在锂化/脱锂过程中，均匀的碳壳减轻了体积膨胀并保持了结构稳定性。此外，FeS ₂ @CoS@C 的分级异质结构和 F 原子的引入进一步提高了电导率并提供了更多的活性位点来提高电化学反应动力学。结果，F-FeS ₂ @CoS@C 纳米棒在 800 次循环后表现出良好的倍率性能（633 mAh/g，5.0 A/g）和稳定的长循环性能（597.1 mAh/g，2.0 A/g）。容量保持率为83.6%。通过杂原子掺杂构建分级异质结构的策略将有利于设计用于碱金属离子电池的新型电极材料。