The characteristics of the core insulation material: the key to ensure the safety and performance of the battery
Cell insulation materials have a variety of important characteristics, which play a decisive role in the normal operation and safety of the battery.
The first is the excellent insulation performance, which is the most basic and most important characteristic of the cell insulation material. It can effectively isolate the positive and negative electrodes of the battery, prevent current short circuit and leakage, and ensure the stable operation of the battery during charging and discharging. For example, PET insulating film once occupied a mainstream position in the field of power batteries with good insulation performance2.
The second is good high temperature resistance. The battery will generate heat during operation, especially in the process of high-power charging and discharging, and the temperature will increase significantly. Therefore, the insulation material needs to maintain a stable insulation effect in a high temperature environment to ensure the safe operation of the battery. Materials such as high temperature resistant polymers designed specifically for the insulation of the end plates of electric vehicle battery modules can maintain good insulation properties at high temperatures.
Chemical resistance is also one of the important characteristics of the core insulation material. The electrolyte inside the battery is usually corrosive, and the insulation material needs to be able to resist the erosion of chemical substances such as acid and alkali to maintain long-term insulation performance. For example, the polypropylene insulation material used in the lithium battery termination tape has strong electrolyte resistance and can well resist the corrosion of the chemical substances inside the battery 2.
Wear resistance can not be ignored. During the use of the battery, the battery cell may be squeezed by various external forces, friction, etc., and the insulating material needs to have excellent wear resistance, which can withstand long-term use and is not easy to break, so as to maintain the stability of the battery component.
In addition, some new types of cell insulation materials also have other advantages. Such as UV coated insulating materials, not only high breakdown voltage resistance, cell bonding shear strength, but also very fast curing speed, high production efficiency, no VOCs volatiles, more environmentally friendly. Powder coating is simple in construction, a spray molding, compared with the traditional blue film, no air gap, good adhesion, not easy to damage, and insulation, corrosion resistance, humidity and heat stability and other excellent properties.
In short, these characteristics of the cell insulation material are essential to ensure the safe, stable and efficient operation of the battery. With the continuous development of new energy technology, the performance requirements for cell insulation materials are also constantly improving, and the future cell insulation materials will develop in the direction of higher performance, more environmentally friendly and more adaptable to complex working conditions.