A novel all-fiber-based LiFePO₄/Li₄Ti₅O₁₂ battery with self-standing nanofiber membrane electrodes

Electrodes with high conductivity and flexibility are crucial to the development of flexible lithium-ion batteries. In this study, three-dimensional (3D) LiFePO₄ and Li₄Ti₅O₁₂ fiber membrane materials were prepared through electrospinning and directly used as self-standing electrodes for lithium-ion batteries. The structure and morphology of the fibers, and the electrochemical performance of the electrodes and the full battery were characterized. The results show that the LiFePO₄ and Li₄Ti₅O₁₂ fiber membrane electrodes exhibit good rate and cycle performance. In particular, the all-fiber-based gel-state battery composed of LiFePO₄ and Li₄Ti₅O₁₂ fiber membrane electrodes can be charged/discharged for 800 cycles at 1C with a retention capacity of more than 100 mAh·g^-1 and a coulombic efficiency close to 100%. The good electrochemical performance is attributed to the high electronic and ionic conductivity provided by the 3D network structure of the self-standing electrodes. This design and preparation method for all-fiber-based lithium-ion batteries provides a novel strategy for the development of high-performance flexible batteries.