What are the relevant methods to improve the needle penetration rate?

The recent Beijing XieDao NK 800 electric cars on fire explosion will once again power battery security of the pushed to the forefront, the lithium battery security become lithium battery to the bottleneck of energetic materials, large-scale development, under normal circumstances, the abuse test internal short circuit occurs in the biggest risk, the battery temperature rise sharply, and may eventually lead to thermal runaway, therefore in the laboratory on the risk of internal short circuit and improve the method of the research is valuable.

Power battery standardization technology committee of Guangdong province is Guangdong province pledges inspect bureau under the leadership of the organization for standardization, the new energy automotive power battery standard of acupuncture at home and abroad were studied. China's main power battery acupuncture standard from GB/T31485-2015 "electric car battery with dynamic safety and test method, batteries and battery test method is as follows:

Power battery acupuncture standards abroad mainly comes from SAEJ2464 electric vehicle battery abuse testing, test standard is as follows:

According to the standard content analysis, mainly in China standard reference standard of the society of automotive engineers are consistent with that from abroad. Acupuncture project is more difficult in power battery standard through project, Guangdong power battery standard council according to relevant data sorting the improvement method of acupuncture.

1, the diaphragm

The diaphragm in lithium ion battery is mainly used for separating the battery in the cathode, prevent short circuit in the contact between. Diaphragm of the obturator and rupture in temperature has a decisive role for cell can through acupuncture project, we will try to control the battery diaphragm retaining low obturator and high rupture in temperature. Development of PE and PP composite membrane and ceramic membrane are the trend and direction of the development of the diaphragm.

2, electrolyte

Lithium ion battery electrolyte used for the combination of conductive lithium salts and organic solvents, these low flash point of organic solvent, made of lithium ion battery electrolyte after exposure to air, easy to burn when heated, flame retardant additives added can improve the stability and safety of the battery itself, is an effective way to improve acupuncture pass rate. Currently the most used one of the most widely for organic phosphorus flame retardant additives.

3, conductive agent and caking agent

After acupuncture short-circuit, conductive agent, binder and electrolyte reaction, release a lot of calories, currently using DSC method, choose according to the initial decomposition temperature and the heat conductive agent and caking agent type, the high temperature heat production reduction is an effective method.

4, battery structure design

Batteries, you can consider the appropriate gap between increasing is negative, increase the ductility of the diaphragm, adding explosion-proof valve on the top of the battery cover plate at the same time, to prevent the explosion and leakage of electrolyte, enhance the probability of battery by acupuncture.

Related introduction: Guangdong power battery standard council in September 2013 by the bureau of quality and technical supervision of Guangdong province approved the establishment, will be entirely responsible for Guangdong province lithium batteries, lead-acid batteries, battery materials, light electric vehicles and related standardization work, the secretariat to undertake unit has established UN38.3, GB31241, CB62133, electric business platform in inspection ability.

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