A high-performance electrochemical power generation humidity sensor based on LiCl/MoS₂ composite

Developed a LiCl-doped MoS₂ composite for self-powered humidity sensing. • Exhibits wide sensing range, fast response, low hysteresis, and high repeatability. • Enables capacitor charging, LED lighting, breath monitoring & noncontact sensing. Humidity sensors are widely used in environmental monitoring and human-related applications. Electrochemical power generation humidity (ECH) sensors have gained considerable attention owing to their zero external power requirement, compact size, and battery-like power generation capability. In this study, we propose an ECH sensor based on LiCl-doped MoS₂ microspheres as the humidity-sensing material. MoS₂ microspheres were synthesized by a hydrothermal method in an ionic liquid/water binary emulsion, combined with LiCl solution to form the sensing slurry, and coated across planar Cu and Zn foil electrodes to construct a humidity-activated galvanic device. The material was characterized by SEM, EDS, FTIR, XPS, and contact-angle measurements, and its humidity-sensing and power-generation performance was systematically evaluated in saturated-salt humidity chambers. The sensor achieves a wide detection range (11%–97% RH) with fast response/recovery (4.6/40.1 s), good repeatability (RSD = 0.44% over 10 cycles), and low hysteresis (6.4%). The average sensitivity is approximately 5.2 mV/%RH over the 11%–97% RH range. A single device outputs 0.70 V at 97% RH, and a series array of five sensors can charge a capacitor to light a red LED, demonstrating its power generation capability. Applications in respiratory-pattern detection and contactless finger-proximity sensing are further demonstrated, highlighting the practical potential of this ECH sensor. Download: Download high-res image (193KB) Download: Download full-size image