Wei Xu, Yinghai Zhang, Wei He, Haopeng Shi, Tingwen Ruan, Yannan Xie, Chen Zhu, Qingyun Chen, Qingying Ren, Linwei Yu, Wei Li
Most triboelectric nanogenerators (TENGs) rely on surface electrostatic induction and require external rectification for DC output, introducing energy loss and circuit complexity. Existing DC-TENGs based on semiconductor junctions or ionic media that bypass rectifiers suffer from critically low output voltages (typically < 5 V). Here, we introduce a materials-driven paradigm that shifts TENG design from surface-limited induction to bulk-charge migration. By constructing a percolating conductive network within a doped polymer composite, interfacial triboelectric charges travel directly through the bulk, forming a continuous unidirectional current loop. The resulting device delivers a substantially higher cumulative open-circuit voltage (∼ 88 V per cycle) and a short-circuit current of ∼ 4.1 μA. Demonstrations include significantly enhanced capacitor-charging efficiency compared to rectified conventional TENGs and a self-resetting alarm system based on voltage-cumulative air breakdown. This work establishes a new design route for high-performance DC-TENGs, where material-level control of charge transport unlocks previously inaccessible performance headroom in mechanical energy harvesting.