Structural superlubricity triboelectric nanogenerator with negligible wear and high triboelectrification efficiency

Triboelectric nanogenerators (TENGs) can efficiently convert weak mechanical energy into electricity, making them suitable for small-scale and distributed power supply demanded by the Internet of Things. However, the inevitable friction and wear not only cause high energy dissipation and low triboelectrification efficiency but also severely limit the device's lifetime and reliability. Here, a wear-free structural superlubricity TENG (SSL-TENG) is designed using the graphite-SiO₂ pair. By achieving an atomic-level friction interface via micromachining, the device operates in a stable SSL state with a near-zero coefficient of friction (0.0034). As compared to mosaic charge distribution in previous studies, the intimate contact at the SSL interface suppresses air breakdown, enabling a unipolar charge distribution, which yields a high charge density of 0.47 mC/m² and a 10⁶-fold enhancement in triboelectrification efficiency. Simultaneously, the SSL-TENG demonstrates stable output performance for over $1.1\times {10}^5$ cycles without wear. This work provides a fundamental strategy to eliminate interfacial friction and the air-breakdown limit, paving the way for ultra-reliable and high-output energy harvesting.