Numerous materials have been considered as promising electrode materials for rechargeable batteries; however, developing efficient materials to achieving good cycling performance and high volumetric energy capacity simultaneously remains a great challenge.¹ Considering the appealing properties of iron sulfides, which include low cost, high theoretical capacity, and favorable electrochemical conversion mechanism.^2,3 In this work, we demonstrate the feasibility of carbon-free micro-size Fe_1–xS as high-efficiency anode materials for rechargeable batteries by designing hierarchical intertexture architecture. The as-prepared intertexture Fe_1–xS microspheres constructed from nanoscale units show advantage of both the long cycle life of nanoscale units and the high tap density (1.13 g cm^–3) of the micro-intertexture Fe_1–xS. As a result, high capacities of 1089.2 mA h g^–1 (1230.8 mA h cm^–3) and 624.7 mA h g^–1 (705.9 mA h cm^–3) were obtained after 100 cycles at 1 A g^–1 in Li-ion and Na-ion batteries, respectively, demonstrating one of the best performances for iron sulfide-based electrodes. Even after deep cycling at 20 A g^–1, satisfactory capacities could be retained. Related results promote the practical application of metal sulfides as high-capacity electrodes with high rate capability for next-generation rechargeable batteries.

References

1. J.-Y. Hwang, S.-T. Myung and Y.-K. Sun, Soc. Rev., 2017, 46, 3529–3614.
2. Y. Xiao, J.-Y. Hwang, I. Belharouak and Y.-K. Sun, Nano Energy, 2017, 32, 320–328.
3. Y. Xiao, S.H. Lee and Y.-K. Sun, Adv. Energy Mater., 2017, 7, 1601329.