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BATTERY ELECTRODE ADDITIVE WITH POSITIVE TEMPERATURE COEFFICIENT OF RESISTANCE

IP.com Disclosure Number: IPCOM000242233D
Publication Date: 2015-Jun-26
Document File: 1 page(s) / 212K

Publishing Venue

The IP.com Prior Art Database

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BATTERY ELECTRODE ADDITIVE WITH POSITIVE TEMPERATURE COEFFICIENT OF RESISTANCE

Li-ion batteries have the potential to generate large amounts of heat when subjected to abusive crush conditions, such as those possible during an automotive crash. Although the presence of the separator between electrodes provides some measure of safety for moderate crush conditions, it is still prone to failure during extreme degrees of crush since it is not an intrinsic part of the electrode structure.

The proposed invention incorporates a positive temperature coefficient (PTC) of resistance ceramic into the battery active material slurry, thus modifying the bulk electrical properties of the electrode active material. In the event of an internal short circuit, the rapid rise in resistance caused by the PTC effect would cause the current passing through an internal short circuit to decrease suddenly once a critical temperature is reached. This reduction in current flow would interrupt the heat generation process at an early stage, thus achieving a moderate temperature throughout the battery cell that falls short of the onset temperatures required to activate the additional
exothermic processes that define thermal runaway.

The most effective switching (Curie) temperature
for the PTC material is chosen based on
knowledge of the onset temperatures for
the key exothermic reactions. The standard
decomposition reactions for the solid-
electrolyte interphase layer on graphite
begin to release significant amounts of heat
at a...