Electrolyte for lithium secondary batteries containing a pre-polymer electrolyte and a lithium secondary battery comprising the same

Gel polymer electrolyte penetrating deep into electrodes via in-situ polymerization of TSEMA monomers

This technology forms a gel-type polymer electrolyte network by adding 2-(trimethylsilyloxy)ethyl methacrylate (TSEMA) monomer and an AIBN initiator to a lithium secondary battery electrolyte, then inducing in-situ polymerization within the electrode through 45°C aging after cell assembly.

Conventional liquid electrolytes suffer from poor thermal stability and leakage risks. Solid or polymer electrolytes intended to replace them have faced limitations in performance due to low ionic conductivity and poor electrode interface characteristics.

This technology involves mixing a pre-polymer electrolyte (PPE) consisting of a carbonate-based electrolyte, TSEMA monomer, and AIBN initiator, allowing it to diffuse evenly into the cell, and then performing thermal aging at 45°C to create a gel-like ion-conductive network that penetrates deep into the porous electrodes. It can be applied to pouch-type cells using existing liquid electrolyte injection lines or to wearable power sources where leakage prevention is critical, providing a pathway to transition to semi-solid batteries without the burden of equipment changes.

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Key Features:

• Pre-polymer electrolyte (PPE) composed of a solvent, TSEMA monomer, and AIBN initiator
• Gel-type electrolyte that absorbs solvent after polymerization, showing Si-O-C and Si-CH3 peaks in FT-IR
• Step of injecting the pre-polymer electrolyte into a cell containing porous electrodes and diffusing it into the electrodes
• Step of aging the cell at 45°C for 12 hours to form a gel-type in-situ ionic polymer electrolyte

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