Electrochemical performance of nano-fibrous selenium cathode synthesized by reverse solvent method for rechargeable li-batteries

Nano-fibrous selenium of high purity and crystallinity with a diameter of 100 nm were synthesized by the reverse solvent method. The structure and morphology of products were characterized by X-ray diffraction and scanning electron microscope, respectively. Since the size of elemental selenium is reduced, the inactivaton effect induced by the coverage of fully insulated discharge product Li2Se on Se particles surface is mitigated, thus greatly improving the utilization coefficient of active materials and alleviating the capacity fading of lithium-selenium batteries. Compared with the pristine selenium cathode, Se fiber electrode presents higher specific capacity and better cycling stability which delivers an initial specific discharge capacity of 465 mAh/g at 0.1C (1C=675 mAh/g) and maintains a capacity of 213 mAh/g after 40 cycles. Meanwhile, Se fiber electrode shows higher electrochemical activity than pristine Se electrode due to its shorter lithium ion diffusion path, resulting in a substantially enhanced rate capability of Se fiber electrode. ©, 2015, Science Press. All right reserved.