Flexible anodes with carbonized cotton covered by graphene/SnO₂ for advanced lithium-ion batteries

Recent attention has been focused on the synthesis and application of flexible lithium-ion battery electrodes for the development of high-performance and durable electronic devices. Herein, we synthesize a novel composites with carbonized cotton covered by graphene/SnO₂ (CGN/SnO₂), in which SnO₂ nano-particles grow in-situ on the cotton fibers covered with graphene oxide (CGO) under the following thermal annealing process. The conductivity of the composites and the sizes of the SnO₂ particles in the composites could be expediently adjusted by changing the thermal annealing temperatures. The as-prepared flexible CGN/SnO₂ composites can be directly used as an anode for lithium-ion batteries without the addition of conductive additive, binder and current collector. The CGN/SnO₂ composites prepared at 500 °C have exhibited a good reversible specific capacity (calculated by the weight of whole electrode) of 406 mAh·g^− 1 (1.70 mAh·cm^− 2) after 80 cycles. This work provides an effective way for the metal oxide composed with flexible carbon framework, promising to develop a new portable electrochemical energy-storage electrode.