Lithium ion battery with thermal sensitive layer

Abstract

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.

Description

technical field

[0001] The present application relates to a lithium ion battery, in particular, it has a thermosensitive layer for blocking the passage of lithium ions at a predetermined temperature. Background technique

[0002] Li-ion batteries are usually designed with a pressure limiting valve and an external positive temperature coefficient (positive temperature coefficient, PTC) resistor equipped in the case. However, these external devices are not capable of responding when harmful reactions occur at very high rates.

[0003] Various mechanisms exist to improve the safety of Li-ion batteries under thermal runaway conditions, such as thermal fuses, PTC material external or internal fuses, and blocking separators. However, none of them can achieve automatic blocking of Li-ion batteries at a predetermined temperature.

[0004] Blocking separators are designed to perform thermally induced blocking of Li-ion batteries, and typically have a polyethylene (PE)-polypropylene...

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