US Patent 9711774 Lithium ion battery with thermal sensitive layer

The present application provides a lithium ion battery including a thermal sensitive layer comprising polymer particles. The thermal sensitive layer may be disposed between the electrodes and the separator. When the lithium ion battery is under thermal runaway condition and the internal temperature rises to a critical temperature, the polymer particles undergo a thermal transition process (melting) to form an insulating barrier on the electrodes, which blocks lithium ion transfer between the electrodes and shuts down the internal current of the battery.