Electrochemical Cathodic Protection Powered by Triboelectric Nanogenerator

Metal corrosion is universal in the nature and the corrosion prevention for metals plays an important role everywhere in national economic development and daily life. Here a disk triboelectric nanogenerator (TENG) with segmental structures is introduced as power source to achieve a special cathodic protection effect for steels. The output transferred charges and short-circuit current density of the TENG achieve 1.41 mC/min and 10.1 mA/m², respectively, when the rotating speed is 1000 revolutions per minute (rpm). The cathodic protection potential, Tafel polarization curves and electrochemical impedance spectra (EIS) measurements are measured to evaluate the corrosion protection effect for the 403 stainless steel (403SS). The cathodic protection potential range from -320 mV to -5320 mV is achieved by changing rotation speeds and external resistance when the steel is coupled in a 0.5 m NaCl solution to the negative pole of the disk TENG. The corrosion tests results indicate that the TENG can produce 59.1% degree of protection for Q235 steels in 0.5 m NaCl solution. Furthermore, an application of marine corrosion prevention is presented by mounting the TENG onto a buoy. This work demonstrates a versatile, cost-effect and self-powered system to scavenging mechanical energy from environment, leading to effectively protect the metal corrosion without additional power sources.