A High‐Power‐Density and Durable Stacked Triboelectric Nanogenerator‐Based Self‐Stabilized Device for Omnidirectional Wave Energy Harvesting

ABSTRACT Triboelectric nanogenerators (TENGs) for water wave energy harvesting, known for high efficiency at low frequency, high environmental compatibility, and adaptability, can overcome key limitations of conventional wave energy systems and support sustainable ocean development and carbon neutrality. However, current devices still face challenges such as water‐induced dielectric shielding, mechanical wear, and reduced longevity under prolonged water exposure. Herein, a high‐performance stacked TENG (HPS‐TENG) device is proposed that overcomes the challenges through three key innovations. First, by optimizing the motion mode and geometry of the dielectric rollers, the peak output voltage reaches 4000 V and the power density increases to 52.83 W m ⁻³ , with only a 3% voltage drop after 277.8 h of continuous operation (1 000 000 cycles). Second, a two‐stage full degree‐of‐freedom buoy‐linkage transmission system, designed as a self‐stabilized rocker, converts omnidirectional wave energy into unidirectional rotation, improving energy conversion efficiency by 40% over conventional designs. Finally, a non‐immersed wave‐energy harvesting design eliminates the water shielding; under a 0.40 Hz wave excitation, a superior power density of 141.90 W m ⁻³ Hz ⁻¹ is achieved. The device has successfully powered specialized equipment such as a nuclear radiation detector, providing a reliable solution for the large‐scale development and industrialization of ocean energy.