The impact of solvents on properties of solution-cast poly(vinylidene fluoride) films for energy storage

The properties of solution-cast poly(vinylidene fluoride) (PVDF) films for energy storage are affected greatly by solvents used. In this letter, surface micrographs, crystalline phases, and energy storage properties of PVDF films crystallized from different solvents were studied. Under an electric field of 1000 kV/cm, the charge-discharge efficiency of the PVDF film crystallized from N,N-dimethylformamide (DMF) (with low vapor pressure) is 2.6 times higher than that of the PVDF film crystallized from N-methyl-2-pyrrolidone (NMP) (with high vapor pressure). Meanwhile, the resistivity of the former is up to 6.6 times higher than that of the latter.