Mitigating Gas Evolution in Electron Beam‐Induced Gel Polymer Electrolytes Through Bi‐Functional Cross–Linkable Additives

Abstract The current high‐capacity lithium‐ion batteries (LIBs), reliant on flammable liquid electrolytes (LEs) and nickel‐rich cathodes, are plagued by safety hazards, especially the risk of hazardous gas release stemming from internal side reactions. To address these safety concerns, an electron beam (E‐beam)‐induced gel polymer electrolyte (E‐Gel) is introduced, employing dipentaerythritol hexaacrylate (DPH) as a bi‐functional cross–linkable additive (CIA). The dual roles of DPH are exploited through a strategically designed E‐beam irradiation process. Applying E‐beam irradiation on the pre‐cycled cells allows DPH to function as an additive during the initial cycle, establishing a protective layer on the surface of the anode and cathode and as a cross–linker during the E‐beam irradiation step, forming a polymer framework. The prepared E‐Gel with CIA has superior interfacial compatibility, facilitating lithium‐ion diffusion at the electrode/E‐Gel interface. The electrochemical assessment of 1.2 Ah pouch cells demonstrates that E‐Gel substantially reduces gas release by 2.5 times compared to commercial LEs during the initial formation stage and ensures superior reversible capacity retention even after prolonged cycling at 55 °C. The research underscores the synergy of bifunctional CIA with E‐beam technology, paving the way for large‐scale production of safe, high‐capacity, and commercially viable LIBs.