A self-improving triboelectric nanogenerator with improved charge density and increased charge accumulation speed.

Charge density is one of the most important parameters of triboelectric nanogenerators since it directly determines performance; unfortunately, it is largely restricted by the phenomenon of air breakdown. Here, we design a self-improving triboelectric nanogenerator with improved charge density. A maximum effective charge density of 490 μC m is obtained, which is about two times higher than the highest reported charge density of a triboelectric nanogenerator that operates in an air environment. At the beginning of the working process, the charge accumulation speed is increased 5.8 times in comparison with a triboelectric nanogenerator that is incorporated into the self-improving device. The self-improving triboelectric nanogenerator overcomes the restriction of air breakdown and exhibits an increased effective charge density, which contributes to the improvement of the output performance, and the increase of charge accumulation speed will accelerate the increase of the output power at the start of operation.