Self-healing battery separator

Safety separator that repairs cracks using self-healing monomers and Grubbs catalysts within micro-conduits

This technology embeds micro-conduits or capsules containing self-healing monomers within the separator body and places catalysts on the surface. When a crack occurs, the monomer moves to the damaged area via capillary action or thermal melting, where it hardens through ring-opening metathesis polymerization (ROMP) to seal the gap.

Previously, if a separator was torn or cracked due to overcharging, over-discharging, or external impact, the anode and cathode could come into direct contact, causing a short circuit. Such short circuits posed a high risk of safety accidents, including battery overheating and explosions.

This technology incorporates a self-healing unit made of fluid thermoplastic elastomers, such as dicyclopentadiene (DCPD), and a Grubbs catalyst into the separator. When a crack occurs, the self-healing unit flows into the area to harden it; in the event of severe overheating, it shuts down the separator function to prevent overcurrent-induced explosions. It can be applied to pouch cells for electric vehicle battery packs, drones, and wearable devices subject to frequent vibration and impact, acting as a passive safety device that self-seals micro-damage before it can escalate into an internal short circuit.

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Key Features:

• Separator body with internal three-dimensional micro-conduits for storing self-healing components
• Coating layer formed on the body surface to detect the occurrence of cracks upon external damage
• Liquid self-healing unit contained within the micro-conduits that flows into the cracked area of the coating layer via capillary action
• Grubbs-based catalyst formed on the body surface that reacts with the incoming self-healing unit to harden it and seal the crack

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