In situ synthesized SnSe nanorods in a SnOx@CNF membrane toward high-performance freestanding and binder-free lithium-ion batteries

The poor reversibility of the first conversion reaction (SnO2 + 4Li+ + 4e− → Sn + 2Li2O) and the inferior electrical conductivity of the resulting Li2O make tin oxides not make full use of their lithium storage performance. In this study, various amounts of SnSe nanorods were in situ incorporated into SnOx@CNFs via electrospinning and thermal treatment processes. Binder-free SnSe/SnOx@CNFs exhibit a greatly enhanced lithium-ion storage performance due to their higher electrical conductivity, faster Li-ion diffusivity, and better reversible ability. The optimal SnSe/SnOx@CNFs exhibited a higher initial coulombic efficiency (86.5%) and better reversible capacity (740.7 mA h g−1 at 200 mA g−1 after 70 cycles) than pristine SnOx@CNFs (68.1%, 552 mA h g−1 at 200 mA g−1 after 70 cycles). Moreover, the high capacity of the SnSe/SnOx@CNF electrode can be maintained as high as 345 mA h g−1 at 1 A g−1 over 1000 cycles, demonstrating its robust long-term stability. This work provides new insights for designing high-performance tin-based anode materials for lithium-ion batteries.