Ternary Electrification for Efficient Charge Accumulation and Synergetic Charge Collection

A direct current triboelectric nanogenerator (DC-TENG) based on corona discharge has a high efficiency in collecting electrification charges. However, enhancing the constant current output with an ultra-low crest factor and average power density of DC-TENG through a rational structure design is still a great challenge. Herein, a novel ternary dielectric electrification TENG (TDE-TENG) is proposed with Kapton/electrode/Polytetrafluoroetylene (PTFE) on the slider and Polyurethane (PU) modified by PTFE powder on the stator. The PTFE powder is coated on PU film to regulate its triboelectricity and realize its electropositivity/electronegativity under friction with PTFE/Kaption, which is an important discovery for tribomaterials. The collecting electrode on the slider can synergistically capture charges generated from its adjacent two tribo-materials. This structure of TDE-TENG can further realize multiple unit integration to fully capture the tribo-charges. TDE-TENG achieves a charge density of 5.5 mC m(-2) and a constant current output with an ultra-low crest factor of 1.02 at 30 rpm. Moreover, the sliding TDE-TENG has an average power density of 12.4 W m(-2), which breaks the record for all sliding DC-TENGs. The direct connection of the 4-unit TDE-TENG with the PMC generates an output charge of 1.17 mC s(-1). This work provides a novel strategy for enhancing DC-TENG output performance.