Electrospinning fabrication of flexible, foldable, and twistable Sb2S3/TiO2/C nanofiber anode for lithium ion batteries

Flexible batteries are one of the key components of flexible electronic devices. To develop flexible batteries with excellent mechanical durability and electrochemical performance, electrode design is the critical part. Electrospinning technology is a popular strategy for producing flexible electrodes. However, the nanofiber membranes prepared by traditional electrospinning methods without additives have poor mechanical flexibility due to the collapse of the fiber structure during heat treatment caused by the incompatibility and low adhesion of the interface between the polymer and transition metal ions. Herein, we propose a method of using titanium (IV) isopropoxide as coupling agent to enhance the thermotolerant and mechanical properties of nanofibers. The porous Sb2S3/TiO2/C nanofiber membrane is prepared by adding an appropriate amount of titanium (IV) isopropoxide as the coupling agent. The prepared nanofiber membranes remain intact and crease-free after 4-folded manipulation. The porous Sb2S3/TiO2/C nanofiber membranes are cut into electrodes and directly assembled into lithium-ion half-cells or full-cells without slurry coating processes. In lithium-ion half-cells, the porous Sb2S3/TiO2/C nanofiber membranes could cycle 800 times at a current density of 2000 mA g−1. In lithium-ion full-cells, a high discharge capacity of 261.6 mAh g−1 can obtained after 100 cycles when cycled at 50 mA g−1. More importantly, the fully charged full-cell can turn on 16 red light-emitting diodes, demonstrating the practical utility of the porous Sb2S3/TiO2/C nanofiber membrane in flexible lithium-ion batteries.