A flexible Li-CO2 batteries with enhanced cycling stability enabled by a IrO2/carbon fiber self-standing cathode

Rechargeable Li-CO2 batteries provide a very promising approach to simultaneously solve energy shortage and the greenhouse effect. However, Li-CO2 batteries are facing several shortcomings, especially the slow CO2 oxidation and reduction kinetics, which deteriorate the energy efficiency and cycling life. Herein, IrO2/carbon fibers derived from kapok (IrO2/CK) are prepared via simple one-step carbonization and subsequent hydro -thermal reaction. Benefitting from the favorable CO2 reduction and evolution catalytic activities of the loaded IrO2 nanoparticles, the enhanced electron transfer and reactants diffusion kinetics derived by the unique cross -linked hierarchical porous structure and the ample space for Li2CO3 deposition, the fabricated Li-CO2 battery, IrO2/CK as the cathode, shows ultra-long operation time more than 4000 h. More importantly, the cathode exhibits excellent mechanical flexibility conferred by the kapok, which can maintain the original structure during bending. The pouch-type flexible Li-CO2 battery with IrO2/CK cathode can steadily operate for 300 h under different bending conditions. This work will advance the development of flexible Li-CO2 batteries in the field of wearing energy storage devices.