Iron sulfides are promising anode materials for lithium ion batteries (LIBs) owe to their high theoretical capacity and low cost. However, unsatisfactory electronic conductivity, dissolution of polysulfides, and severe agglomeration during the cycling process limit their applications. To solve these issues, a ternary FeS₂/Fe₇S₈@nitrogen-sulfur co-doping reduced graphene oxide hybrid (FeS₂/Fe₇S₈@NSG) was designed and synthesized through a facile hydrolysis-sulfurization strategy, in which the FeS₂/Fe₇S₈ could be well distributed upon the NSG. The NSG was believed to buffer the volume change and augment the electronic conductivity of the electrode, and the nano-dimensional FeS₂/Fe₇S₈ particles with a diameter of 50–100 ​nm could shorten the ion-diffusion paths during the lithiation/delithiation process. Benefiting from synergistic contributions from nano-dimensional FeS₂/Fe₇S₈ and flexible NSG, the FeS₂/Fe₇S₈@NSG hybrid displayed a high initial capacity of ~1068 ​mAh g⁻¹ at 200 ​mA ​g⁻¹, good cycling stability (~898 ​mAh g⁻¹ at 500 ​mA ​g⁻¹ after 200 cycles) and high-rate performance. Further kinetic analysis corroborated that the introduction of NSG boosted the capacitive behavior. Above results indicate the potential applications of FeS₂/Fe₇S₈@NSG hybrid in LIBs with low-cost and high energy density.

硫化铁由于其高的理论容量和低成本而成为锂离子电池（LIB）的有希望的负极材料。然而，在循环过程中，令人满意的电子电导率，多硫化物的溶解以及严重的团聚限制了它们的应用。为了解决这些问题，设计了三元FeS ₂ / Fe ₇ S ₈氮-硫共掺杂还原氧化石墨烯杂化物（FeS ₂ / Fe ₇ S ₈ @NSG），并通过一种简便的水解-硫化策略进行了合成。 FeS ₂ / Fe ₇ S ₈可以很好地分布在NSG上。人们认为NSG可以缓冲体积变化并增加电极的电子电导率，直径为50–100 nm的纳米尺寸FeS ₂ / Fe ₇ S ₈粒子可以缩短锂化过程中的离子扩散路径/去石化过程。受益于纳米级FeS ₂ / Fe ₇ S ₈和柔性NSG的协同作用，FeS ₂ / Fe ₇ S ₈ @NSG杂化物在200 mA g ^−下显示出约1068 mAh g ^-1的高初始容量^{- 1}，良好的循环稳定性（〜898 mAh g ^-1200个周期后在500 mA g ^-1时）和高速率性能。进一步的动力学分析证实，NSG的引入增强了电容性能。以上结果表明，FeS ₂ / Fe ₇ S ₈ @NSG杂化材料在低成本和高能量密度的LIB中的潜在应用。