Fabrication of PVDF/BaTiO3/NiO nanocomposite film as a separator for supercapacitors

Abstract The PVDF/BaTiO3/NiO nanocomposite films of ~ 50 µm thickness are prepared via solution mixing method. The SEM images confirm the well incorporation of filler nanoparticles in the PVDF matrix with a highly porous mesh - like structure. The α → β phase transition in PVDF is observed by FTIR spectroscopic analysis. The dielectric constant of the proposed separator film is found to be ~ 24, which is much higher than the micro-porous Celgard Ez 2090 (dielectric constant ~ 2.2 at 60 kHz) and previously reported separators. A well maintained quasi rectangular shape of CV curves is observed at different scan rate, which offer the excellent capacitive properties of the PVDF/BaTiO3/NiO nanocomposite separator film. The bulk electrolyte resistance (Rbe) for the PVDF/BaTiO3/NiO separator film is found to be 0.6 Ω, which is much lower than the bulk electrolyte resistance for commercially available non-porous Celgard™ 2500 (88.2 Ω) and micro - porous Celgard Ez 2090 (47.1 Ω). Also, the ionic conductivity (σ) for the separator film is found 19.8 mS cm−1, which is higher than commercially available Cellulose (10 mS cm−1) and non-porous Celgard™ 2500 (4 mS cm−1) and previously reported separators. The fabricated PVDF/BaTiO3/NiO nanocomposite films are proposed to be used as a separator in supercapacitors.