Intricate Ionic Behaviors in High‐Performance Self‐Powered Hydrothermal Chemical Generator Using Water and Iron (III) Gate

Abstract Utilizing the ionic flux to generate voltage output has been confirmed as an effective way to meet the requirements of clean energy sources. Different from ionic thermoelectric (i‐TE) and hydrovoltaic devices, a new hydrothermal chemical generator is designed by amorphous FeCl₃ particles dispersing in MWCNT and unique ferric chloride or water gate. In the presence of gate, the special ion behaviors enable the cell to present a constant voltage of 0.60 V lasting for over 96 h without temperature difference. Combining the differences of cation concentration, humidity and temperature between the right and left side of sample, the maximum short‐circuit current and power output can be obtained to 168.46 µA and 28.11 µW, respectively. The generator also can utilize the low‐grade heat to produce electricity wherein Seebeck coefficient is 6.79 mV K⁻¹. The emerged hydrothermal chemical generator offers a novel approach to utilize the low‐grade heat, water and salt solution resources, which provides a simple, sustainable and low‐cost strategy to realize energy supply.