High-temperature insulating coating for battery and preparation method thereof

Abstract

The invention discloses a high-temperature insulating coating for a battery and a preparation method of the high-temperature insulating coating, and relates to the technical field of lithium ion batteries. The high-temperature insulating coating comprises a third prepared solution and a binder; the third prepared solution comprises a first prepared solution containing expanded particles, and a second prepared solution containing a graphite component, wherein the graphite component is graphene or graphite. The mass percentage of the expanded particles, the graphite component and the binder is as follows: 1%-15% of the expanded particles; 40%-90% of the graphite component; 8%-30% of the binder. The polymer expansion material and graphene are creatively combined and applied to a battery coating, the characteristics of the polymer expansion material and graphene are fully utilized to realize automatic control of the heat of a battery, and therefore, the reaction to the internal temperatureof the battery is more sensitive, the safety performance is more excellent; and besides, a normal electric path in a normal temperature state is also considered, so that the service life of the battery is prolonged; and daily normal use is not influenced.

Description

technical field [0001] The present application relates to the technical field of lithium-ion batteries, in particular to a high-temperature insulating coating for batteries and a preparation method thereof. Background technique [0002] The main direction of development of lithium-ion batteries, especially vehicle batteries, is to maximize the energy storage effect and shorten the charging time in a limited space, that is, to increase the unit energy density and speed up the charging efficiency. [0003] Among them, the improvement of unit energy density can be divided into two main directions, one is to seek materials for high-voltage platforms, which may have problems such as high internal resistance and structural instability; the other direction is to change the proportion of electroactive materials. Ratio or adjust the battery space structure, through the adjustment of the ratio is mainly to reduce the thickness of the current collector, but the conductive cross-section...

AI Technical Summary

Problems solved by technology

However, for a bulky vehicle battery, the general thermistor cannot effectively respond to the heating inside the battery at the first time, and cannot sense the local heating inside the battery at the first time, and make a corresponding response. There is a time difference in induction

In addition, common PTCs are divided into two categories. The first category is the gradual increase in internal resistance. Due to the inherent problems of the material, this type of PTC will cause more heat generation as the temperature rises. It is easy to cause adverse effects in vehicle-mounted projects and accelerate battery deterioration; The second type is the use of direct phase change materials such as BaTiO3, but its initial internal resistance is too high, which does not meet the internal resistance requirements of the battery. If the conductive agent is added to increase its conductivity, its internal current will also be affected by Kerschhoff The law chooses the path with the lowest resistance to move, so its performance will be greatly reduced

[0005] The BMS (battery management system) also isolates the internal resistance boosting components, so in addition to using the BMS to control the battery, with the wide application of soft-pack batteries and hard-shell batteries, the volume of the single cell increases. It is more difficult for us to control the behavior inside the battery

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