Superhigh charge density and direct-current output in triboelectric nanogenerators via peak shifting modified charge pumping

Due to the great potentials in self-powered sensors and micro-nano power sources, triboelectric nanogenerator (TENG) has attracted numerous attentions. However, enhancing charge density and realizing direct-current (DC) are long-term significant issues for TENGs. In this work, we investigated a DC TENG with outstanding electricity generation characteristics based on quasi- synchronous double-stage self-charge pumping. The TENG works in a contact-separation mode with a four-layered parallel structure. The TENG possesses a high open-circuit voltage of 2300 V, a high short-circuit current of 3 mA, a high power of 150 mW and a superhigh transferred charge of 20 μC at 4 Hz, which are significantly enhanced from those in single-stage pumping and non pumped counterpart TENGs. The property-improving mechanism lies in that through the unidirectional self-charge pump with a slight time difference among TENGs, negative halves are moved to the adjacent positive halves, leads to the widening, higher and DC outputs at the final terminal, which employs the Plancherel theorem for peak shifting in framework of energy conservation law. The TENG can power light emitting diodes, electronic devices and an electrophoretic deposition of pigment coatings. This work provides a method for developing high-performance DC TENGs with superhigh transferred charge for various applications.