What is the core insulation material? Read the key points
In the huge system of new energy batteries, the core insulation material is an indispensable key part. Although it is not "large", it plays a pivotal role in ensuring the safe and stable operation of the battery.
Cell insulation material, in simple terms, is a special material used to isolate the positive and negative electrodes of the battery cell to prevent short circuit and current leakage. In the process of battery charging and discharging, the battery cell will produce a large amount of current, if there is no effective insulation material for isolation, there may be a short circuit between the positive and negative electrodes, which will not only affect the battery performance, but also may cause serious safety accidents, such as fire, explosion, etc. Therefore, the core insulation material is the first line of defense to ensure the safety of the battery.
There are many types of common cell insulation materials. PET insulating film is once the mainstream product, it takes PET as the substrate, backed by pressure sensitive adhesive (PSA) made of single-sided tape, because of its good insulation performance, chemical resistance and tensile strength is also relatively excellent, in the past for a long time, in the field of power battery electrical insulation and physical protection occupy a dominant position. However, with the development of new energy technology, its shortcomings gradually emerged. The PSA back adhesive has limited bonding properties, and it is easy to fall off and peel off when it is impacted by external force. At high voltage, the breakdown resistance voltage is also difficult to meet the requirements.
Uv-coated insulation materials are the "new stars" that have risen in recent years. Its breakdown resistance voltage can reach 2800-6000V, which is much higher than the highest breakdown resistance voltage of PET blue film 2500V; The shear strength of the cell bonding is as high as 9-15Mpa, which is also far higher than the 3-4Mpa of the blue film. Its curing speed is extremely fast, a single cell spray time is only 2-4S, can achieve 15-30PPM production efficiency, a yield of 99%, ink utilization rate of 100%, the entire production process can also achieve a high degree of automation and intelligence, and no VOCs volatiles, more environmentally friendly.
In addition to the above two types, PC insulation is also a commonly used cell insulation material. It is based on the insulation and flame retardant PC film die-cut molding, with insulation, flame retardant, fire prevention and efficient resistance characteristics, between the cell insulation, to prevent short circuit, its flame retardant performance can also slow the spread of fire when the battery thermal control. There are silicone elastomer insulation sheets, such as pure boron nitride filled silicone elastomer materials, with high thermal conductivity, super voltage resistance, low density, low dielectric properties, and ultra-thin, soft, strong toughness, can be backed by glue, with its own viscosity, can well meet the thermal insulation needs of new energy vehicle batteries and electronic packaging applications.
The insulating material of the cell generally needs to have good insulation performance and can effectively isolate the current; It should have good high temperature resistance to adapt to the heat generated when the battery is working; It also needs to have certain chemical corrosion resistance and wear resistance to ensure long-term stable work in complex environments.
With the rapid development of new energy vehicles and energy storage equipment, the performance requirements for core insulation materials are becoming higher and higher. In the future, cell insulation materials will develop in the direction of higher performance, more environmentally friendly, and more adaptable to complex working conditions, and continue to promote the progress of new energy battery technology.