Electrochemistry of polyvinyl acetate gel electrolytes

This paper describes the first example of polyvinyl acetate (PVAc) used as a gel electrolyte with a short-chain polyethylene glycol (MPEG-400) as a plasticizer. The polymer films are solid and sticky. Background cyclic voltammetry (CV) shows a potential window between +0.4 and −0.7 V vs. AgQRE. The voltammetry of ferrocene, 7,7,8,8-tetracyanoquinodimethane (TCNQ) and tris(2,2′-bipyridyl)cobalt(II) indicates that diffusion coefficients are in the range of 10−8–10−9 cm2/s. Ionic conductivities are approximately 10−6 S/cm. Similar films using dimethyl sulfoxide (DMSO) as a plasticizer instead of MPEG-400 have demonstrated ionic conductivities of 10−4 S/cm and reversible voltammetry. However, UV spectrophotometry shows that 70% of the DMSO is lost under vacuum, indicating the difficulty in quantifying the DMSO content when exposed to vacuum.