Synergistic effect of soy protein isolate and montmorillonite on interface stability between polymer electrolyte and electrode of all-solid lithium-ion battery

In response to the safety performance of liquid electrolytes in traditional lithium-ion batteries, we have prepared a new type of polymer electrolyte. In this paper, PVDF is used as the polymer electrolyte matrix, bio-based filler soybean protein isolate (SPI), and inorganic filler montmorillonite (MMT) as additional groups. In addition, the effects of the addition of soybean protein isolate (SPI) and montmorillonite (MMT) on the polymer electrolyte ion conductivity, lithium ion migration number, and electrode interface performance were investigated. After the test, it was found that the polymer electrolyte membrane with MMT and SPI had an ion conductivity of 2.56 × 10 −4 S cm −1 at room temperature, an electrochemical stability window of 5.1 V, and a Li + transfer number of 0.77. When assembling Li/LiTFSI-MMT-SPI-PVDF/Li batteries, the symmetric battery has a stable electrode interface because it can circulate stably for more than 100 h at a very small polarization voltage. Graphical Abstract