A textile-based SnO₂ ultra-flexible electrode for lithium-ion batteries

The advancements in wearable electronic devices make it urgent to develop high-performance flexible lithium-ion batteries (LIBs) with excellent mechanical and electrochemical properties. Herein, we design a new 3D hierarchical hybrid sandwich flexible structure by anchoring SnO₂ nanosheets (SnO₂-NSs) on flexible carbon cloth and coating with thin amorphous carbon (AC) layer (CF@SnO₂-NS@AC). The carbon cloth substrate works as the backbone and the current collector, while the thin AC layer provides extra support during the electrode expansion. The new architecture can be utilised as a binder-free electrode and presents extraordinary mechanical flexibility and outstanding electrical stability under external stresses. The new electrode can deliver a specific capacity as high as 968.6 mA h g⁻¹ after 100 cycles at 85 mA g⁻¹, which also shows remarkable rate capability and an excellent high current cycling stability. The outstanding electrochemical performances combined with the high mechanical flexibility and invariable electrical conductivity during/after different bending cycles make the new structure a promising oxide anode for flexible batteries. With the possibility of using a similar approach to design flexible cathode, the present work opens the door to empower the next-generation wearable devices and smart clothes with a robust and reliable battery.