Semi-solid-state high specific energy battery enabled by in situ construction of gel electrolyte

The pursuit of higher energy density in lithium-ion batteries (LIBs) often pushes safety limits, primarily due to the flammability of liquid electrolytes, which poses significant hazards. This study presents an in situ curing process for the fabrication of high-density pouch cells with gel electrolyte. The electrochemical performance of these pouch cells was evaluated using galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS), linear voltammetry, and hot box tests. The results show that the electrochemical performance of Ni-rich/silicon-graphite pouch cells with gel electrolyte is comparable to that of pouch cells with traditional liquid electrolyte. After 500 cycles, the pouch cells with gel electrolyte retained 87.59% residual capacity retention, outperforming the 85.40% retention observed in pouch cells with liquid electrolyte. Additionally, the gel electrolyte significantly enhanced the thermal stability of the pouch cells, delaying the thermal runaway by approximately 25 minutes during the 180 °C hot box test. These findings provide valuable insights for the further application and development of high specific energy batteries.