A hybrid spherical triboelectric nanogenerator (S-TENG) with both solid-solid and solid-liquid contact modes is successfully constructed to collect wave energy for highly efficient cathodic protection of metals in marine. The S-TENG simultaneously captures friction energy from inside and outside, achieving a short circuit current density of 186 mA m⁻³ and open circuit voltage of 88.9 V. It demonstrates cathodic protection of stainless steel (304SS) and organically coated carbon steel (Q235CS) with potential drops of about 410 mV and 930 mV, respectively. This low-cost, environmentally friendly approach effectively converts wave energy for electrochemical cathodic protection in marine environments.
