LiCl-assisted polysiloxane electrolyte complexes for highly sensitive humidity sensing

Polyelectrolytes with hydrophilic and hydrophobic structures are widely employed in humidity sensors , but their response properties necessitate improvement. This paper introduces the development of crosslinked polysiloxane electrolytes via Zr 4+ coordination and LiCl assistance for humidity sensing applications. The composition , microstructure, thermal stability, and humidity response of polymer complexes based on ZrOCl 2 were thoroughly investigated. The resulting complexes exhibited porous structures and demonstrated excellent thermal stability. The ionic conductivity displayed an exponential change of 10 6 - 10 7 within the relative humidity (RH) range of 43–95 %. The polymer complexes with 5 mol% ZrOCl 2 exhibited the most favorable humidity sensing properties , including a response time of 90 s and a recovery time of 7 s. The addition of LiCl as an assistant further enhanced the humidity sensing properties of the polymer complexes. The optimal sensor exhibited high sensitivity, reaching 1175 throughout the entire RH range from 11 % to 95 %. It demonstrated good linearity, minimal humidity hysteresis (2.3 % RH), and rapid response/recovery time of 16/9 s. The development of LiCl-assisted polysiloxane polyelectrolyte-Zr complexes has provided a strategy for the creation of high-performance humidity sensors.