Amorphous carbon interweaved mesoporous all-carbon electrode for wide-temperature range supercapacitors

The wide-temperature operation of supercapacitors is important for stable power output and a long lifespan under harsh conditions. However, supercapacitors for extreme conditions are still a big challenge because of the inevitable decline of performance caused by sluggish ion diffusion and increased unusable surface area contributed by micropores. Here we report a strategy for modification of carbon for wide-temperature operating supercapacitor electrodes. The polyvinylpyrrolidone creates conductive carbon bridges between CNTs and mesoporous carbon spheres (MCS) and produces a well-interconnected carbon network. The high conductivity and thermostable features of the all-carbon electrode lead to high capacitance retention at the temperature range from -40 °C to 80 °C. The binder-free all-carbon electrodes have excellent long-term stability with high mechanical durability under continuous bending from 0 to 360° This work demonstrates the construction of amorphous carbon interweaved all-carbon electrodes for supercapacitors with high performance at both low and high temperatures.