In this study,a series of soybean protein isolate(SPI)membranes were prepared with triethanolamine(TEA)as plasticizer.The supercapacitor single cells(SSCs)were fabricated with the SPI membranes and commercial membrane as separators,activated carbon(AC)as electrode materials and Li2SO4 as neutral aqueous electrolyte.The performance of each SSC was investigated systematically.The SSC exhibits excellent double layer capacitance characteristics in a 0~1.5Voperating potential.The SSC EDLC-1.6with TEA/SPI-1.6memb...