Cell evaluation device

Abstract

A cell evaluation device has a short circuit detection portion to detect an internal short circuit within a test cell that has been subjected to nail penetration or crushing using the pressure from a pressurization portion, a pressure control portion to halt the operation of the pressurization portion on detection of a short circuit, and a cell information detection portion to collect and record cell information such as the cell temperature. By using such a cell evaluation device, the location of an internal short circuit during an abuse test is specified, and variations in the cell temperature increase accompanying the internal short circuit is minimized.

Description

technical field [0001] The present invention relates to a battery evaluation device for evaluating the safety of a battery from battery information obtained by deliberately short-circuiting the inside of the battery through a nail penetration test, a crush test, or the like. Background technique [0002] Batteries using flammable organic electrolytes such as lithium-ion secondary batteries are equipped with safety functions such as protection circuits to prevent high heat inside the battery due to incorrect use or failure of connected equipment, but they cannot cope with extreme wrong use. However, in order to ensure that the battery will not cause rupture or ignition due to thermal runaway in the case of extreme misuse, safety standards are set. The safety standard requires that even if the battery is subjected to battery evaluation tests under extremely severe conditions, it will not cause rupture or ignition. ignition. The battery evaluation test is specified in, for exa...

AI Technical Summary

Problems solved by technology

[0004] However, since the previous nail penetration test or crush test is only a test in which the nail penetrates the test cell or penetrates to a predetermined depth, and is pressed and crushed with a predetermined pressure, there is a change in the short circuit caused by the nail piercing or crushing. , The problem of unstable temperature changes caused by Joule heat generated by the specific or short-circuit current at the short-circuit place

[0005] In addition, the short-circuit current that flows due to internal short-circuit caused by nailing or crushing is determined by the internal resistance of the battery. Therefore, when evaluating various batteries, the Joule heat caused by the short-circuit current is different from the heat generated by the chemical reaction of the battery structural material. Therefore, it is impossible to correctly examine the cause of the battery temperature change.

In addition, in a battery pack, etc., where a plurality of batteries are assumed to be connected in parallel, if an internal short circuit occurs in one battery, it is impossible to evaluate the rise in battery temperature due to the short-circuit current flowing from other parallel-connected batteries.

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