Fig. 4: Comparison of CEC performance between pristine polymers and fluorinated oxides under elevated temperatures.

a Evolution of transferred charges per cycle for fluorinated ethylene propylene (FEP) and F-SiO2 during their contacts with deionized water under different temperatures. b Corresponding electron paramagnetic resonance (EPR) diagrams for FEP and F-SiO2 during CEC under different temperatures. c Comparison of contact-electrification (CE) abilities among various conditions of FEP membrane. d In-situ FTIR spectroscopy of F-SiO2 when the temperature varies from 30 to 200 °C. e Simulated distribution of hydrogen bond networks at the adjacent of F-SiO2 and water interface when the temperature is increased to 350 K. Error bars represent the standard deviation based on three replicate data. Source data are provided as a Source Data file.