Carbon nitride nanotube for ion transport based photo-rechargeable electric energy storage

To resolve the fluctuation and storage issues renewable energy is facing, photo-rechargeable electric energy storage systems may contribute by immediately storing the generated electricity locally. Complementing the various conventional chemical-reaction-based photo-rechargeable electric energy storage systems, we propose here a physical ion transport-based photo-rechargeable electric energy storage system to harvest solar energy and then store it in place as ionic power, which can be reconverted into electric energy later but momentarily. The new solar energy conversion and storage approach is based on a carbon nitride nanotube membrane, which can be fabricated by chemical vapor deposition method. The charging and discharging current peaks can reach to 1.8 μA/cm2, which can be scaled up through parallel (current) and series (voltage) connections. Our findings provide possibilities in advancing the design principles for a combined, easy and efficient solar energy conversion and storage system.