Carbon fiber cloth@VO2 (B): excellent binder-free flexible electrodes with ultrahigh mass-loading

Abstract

Flexible batteries have attracted much attention in recent years due to their promising applications in flexible displays, portable consumer electronic devices, and thin-film-based electronics. However, their practical applications are still limited by their low active material mass-loading in flexible electrodes and poor lithium storage performances. In this work, we have successfully grown highly crystalline VO₂ nanobelt arrays on carbon fiber cloth (CFC) for the first time. The strategy only involves a facile one-pot solvothermal method. As binder-free flexible electrodes for LIBs, even with active material mass loading dramatically reaching up to 5.2 mg per square centimeter, such a novel CFC@VO₂ (B) nanobelt array cathode electrode still exhibits a specific capacity of 145 mA h g⁻¹ (90% of theoretical capacity), excellent cyclability with capacity retention over 90% after 200 cycles at ∼9C (1000 mA g⁻¹), and high rate capability at high current densities up to ∼20C (2000 mA g⁻¹). Such an excellent cathode material is very desirable in high-power flexible LIBs. The effective combination of CFC and a high areal mass loading of active materials described in this paper is a feasible and effective solution to design high-performance flexible batteries, especially high-power flexible batteries.