State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Northwest University, 710069, PR China; Shaanxi Joint Lab of Graphene (NWU), Xi'an 710127, PR China.
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), College of Chemistry & Materials Science, Northwest University, Xi'an 710127, PR China; Shaanxi Joint Lab of Graphene (NWU), Xi'an 710127, PR China.
J Colloid Interface Sci. 2019 Dec 1;557:216-226. doi: 10.1016/j.jcis.2019.08.071. Epub 2019 Aug 21.
Among an enormous variety of electrode materials for lithium and sodium storage, transition metal-oxides/sulfides stand out on account of their widespread availability and high theoretical charge capacity. However, these anodes still undergo poor capacity retention and limited cycle life. Herein, we present a simple approach to synthesize one-dimensional (1D) porous FeO@C and FeS@C nanofibers in which ultra-small active nanoparticles are first distributed in the internal porous carbon matrix and further encapsulated in the external nano-carbon walls. The 1D porous nano-architecture effectively alleviates the pulverization or aggregation induced by huge volume changes during cycling as well as provides a short ion/electron diffusion path in the crystal. Furthermore, the internal porous carbon matrix and the external nano-carbon layers keep the structural and mechanical stability of the entire electrode. The as-synthesized FeO@C and FeS@C nanofibers show high specific capacities, robust cycling stability as well as desirable rate capability for LIBs and SIBs. Simultaneously, the FeS@C nanofibers achieve better lithium and sodium storage properties due to good electrical property and fast ion diffusion kinetics compared with FeO@C nanofibers. This novel architecture design may open an avenue to seeking out high performance electrodes for advanced energy storage.
在用于锂和钠存储的大量电极材料中，过渡金属氧化物/硫化物因其广泛的可用性和高理论比容量而脱颖而出。然而，这些阳极仍然存在较差的容量保持率和有限的循环寿命。在此，我们提出了一种简单的方法来合成一维（1D）多孔 FeO@C 和 FeS@C 纳米纤维，其中超小的活性纳米颗粒首先分布在内部多孔碳基质中，然后再包裹在外部纳米碳壁中。1D 多孔纳米结构有效缓解了循环过程中巨大体积变化引起的粉碎或团聚，以及在晶体中提供了短的离子/电子扩散路径。此外，内部多孔碳基质和外部纳米碳层保持了整个电极的结构和机械稳定性。合成的 FeO@C 和 FeS@C 纳米纤维表现出高的比容量、稳健的循环稳定性以及对 LIB 和 SIB 的良好倍率性能。同时，与 FeO@C 纳米纤维相比，FeS@C 纳米纤维由于良好的导电性和快速的离子扩散动力学，具有更好的锂和钠存储性能。这种新颖的结构设计可能为寻找先进储能用高性能电极开辟了一条途径。
