Spatio‐Temporal Coupling Direct‐Current Triboelectric Nanogenerator by Harvesting Residual Charge of Tribo‐Materials

Direct‐current triboelectric nanogenerators (DC‐TENGs) have attracted increasing attention in ambient energy harvesting, as such systems enable direct power delivery to electronics without rectification. However, in leakage‐based configurations, the millimeter‐scale thickness of PU foam constrains internal charge transport and electrostatic induction, leaving residual tribo‐charges underutilized. To address this limitation, a spatio‐temporal coupling direct‐current triboelectric nanogenerator (STC‐DTENG) is proposed to enhance charge conversion efficiency. This strategy leverages the residual tribo‐charges to establish periodic time‐varying potentials at electrode 3 during operation. Meanwhile, electrode 3 forms intermittent electrical coupling with electrode 1 or 2, which strengthens the capture of both leaked and induced charges. Following systematic optimization, the device delivers an output charge density of 8.58 mC m −2 , 1.35 times higher than the counterpart without spatio‐temporal coupling. Moreover, the high output voltage of STC‐DTENG is sufficient to drive carbon‐fiber emitters for negative air ion generation. Subsequent optimization of emitter parameters, integrated with an E‐mesh, enhances the charge utilization efficiency of the negative‐end output, reaching 92.07%. Accordingly, the wind‐driven STC‐DTENG demonstrates excellent potential for self‐powered air purification and ultraviolet excitation. More broadly, this spatio‐temporal coupling strategy provides a viable pathway for advancing DC‐TENG performance and supports solid implementation in sustainable energy and environmental applications.