A strategy of adding LDPE particles to enhance the high-temperature endurance of PMMA-based GPE for lithium-ion battery

Replacing liquid electrolyte (LE) with gel polymer electrolyte (GPE) can significantly improve the safety and long-term stability of lithium-ion batteries. However, the traditional pure polymethyl methacrylate (PMMA)-based GPE after immersion in the electrolyte has the problem of poor mechanical properties and easy damage. In this article, PMMA was used as the matrix, and low-density polyethylene particles were mixed to prepare a kind of structure-enhanced and heat-resistant GPE by phase inversion method. The prepared GPE has high ionic conductivity at room temperature. It can slow down the temperature rise of the battery by reducing the ionic conductivity at high temperatures, thereby improving the safe application performance of the battery. In addition, the symmetrical battery made of this material can maintain ultra-low overvoltage and run stably for at least 800 h in the overpotential test when the current density is 1 mA cm−2. This study provides new insights for the preparation of high-temperature safety GPE.