Wuhu Huishi New Material Technology Co., Ltd.

Wuhu Huishi New Material Technology Co., Ltd.

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Dry goods, new energy vehicle power battery glue classification, glue points and market analysis.


Release time:

2022-06-28

At present, the use of cars is increasing. New energy electric vehicles are a mainstream trend to solve the problems of energy, environment and urban transportation, and are also a major direction for the development of the automobile industry in the future.

At present, the use of cars is increasing. New energy electric vehicles are a mainstream trend to solve the problems of energy, environment and urban transportation, and are also a major direction for the development of the automobile industry in the future.

The power battery is the "heart" of new energy vehicles, and the adhesive is the "muscle membrane tissue" to achieve the "heart" lasting power ". At present, the wave of electrification is sweeping the world, the demand for power batteries is "blowout" explosive growth, and the size of the adhesive market is also simultaneously enlarged.

This paper will introduce the glue and application of new energy vehicle power battery in detail.

It is understood that the CTP structure battery pack for new energy vehicles saves or greatly saves the intermediate module components in design, and instead uses a large amount of glue to connect and fix the battery cells.The application of these glue mainly has two major demand points:The first type is structural adhesiveThat is, the structure is mainly bonded, taking into account a certain thermal conductivity;The second category is thermal adhesiveThat is, the purpose of adhesive application is to export the heat generated by the battery core to the external heat dissipation components, to achieve part of the function of thermal management, taking into account the structural bonding requirements.

  structural adhesiveIt refers to the adhesive used in the bonding of stressed structural parts, which can bear large dynamic load and static load and can be used for a long time. Instead of bolts, rivets or welding, used to join metal, plastic, glass, wood and other structural parts, are adhesives that withstand large loads for a long time and still have reliable performance.

  thermal conductive adhesiveIt is mainly used to complete the heat conduction between the battery core and the battery core and the liquid cooling pipe. The specific use forms of the glue include gasket, potting, filling, etc.

1 Structural adhesive

The structural adhesive should play a role in reliably connecting and fixing the battery core and the pack shell, replacing the mechanical connection of the original module structure, and put forward higher performance requirements for strength, flexibility, aging resistance, flame retardant insulation and thermal conductivity.

The power battery pack structural adhesives mainly include polyurethane structural adhesive, acrylic structural adhesive, silica gel, epoxy structural adhesive, UV adhesive and high temperature resistant hot melt adhesive, which are applied to different scenes according to their different characteristics.

For different types of structural adhesives, there are three specific indicators to evaluate their bonding performance: the strength of the joint, the form of failure (cohesive failure is the most ideal form, reaching the maximum strength of the material at the joint) and the elongation at break of the adhesive (reflecting colloidal elasticity).

2 Thermal conductive adhesive

Thermal conductive adhesive is mainly composed of resin matrix (epoxy resin, silicone and polyurethane, etc.) and thermal conductive filler (to improve thermal conductivity, aluminum nitride (AlN), boron nitride (BN) and silicon nitride (Si3N4), alumina (Al2O3), magnesium oxide (MgO), zinc oxide (ZnO), etc.). Under the development trend of CTP for battery packs, battery manufacturers have a large demand for thermal conductive adhesives and a continuous demand for cost reduction. At the same time, the design of reducing structural parts also produces a higher strength (greater than 10Mpa) bonding and fixing demand for adhesives. Therefore, polyurethane thermal conductive structural adhesives, which are superior in bonding strength and economic cost, have become the mainstream thermal conductive adhesive selection.

Since the optimal operating temperature band of the battery cell is narrow (20-40 ℃), the thermal conductive adhesive under the CTP structure achieves balanced heat dissipation between the cells and between the cells and the liquid cooling plate, thus reducing the temperature difference between the cells and the cells by 1-2 ℃, which is greatly beneficial to the battery thermal management system.

 3 Analysis of glue points for power batteries

Adhesive in the power battery on the four major role:

1. Provide protective effect for power battery;

2. Realize safe and reliable lightweight design;

thermal management;

4. Help the battery to cope with more complex use environment.

 

Bonding between 3.1 cells-structural bonding

Substrate: aluminum plate and outer PET film

Requirements: bonding positioning, thermal conductivity, good adhesion with PET film and aluminum plate

Solution: two-component polyurethane structural adhesive, one-component silicone, two-component silicone

 

 Bonding of 3.2 Conductive Sheet to Module Shell

Substrate: PC sheet and nickel sheet/aluminum sheet nickel sheet/aluminum sheet and ABS/PC

Requirements: bonding positioning, temperature resistance -40 ℃ ~ 85 ℃ fast positioning;

Recommended products: two-component acrylic structural adhesive, high temperature resistant hot melt adhesive

 

 3.3 cell potting

Requirements: Thermal Conductivity, Fixed Cell, Shock Absorption, Flame Retardant, Increased Safety, Low Density

Product recommendation: two-component thermal silica gel

 

 Adhesive fixation of the bottom of a 3.4 cylindrical cell

Application: wire harness isolation plate, solder joint position protection glue

Requirements: Flame retardant, low odor, non-corrosive to copper/aluminum/PVC/PP/silicone materials, as fast as possible to cure

Product recommendation: flame retardant yellow glue, UV glue, epoxy protective glue

 

  3.5 cylindrical battery bracket fixed

Performance requirements: excellent aging resistance, good flexibility

Product recommendation: acrylic structural adhesive

 

 Heat conduction between 3.6 base plate and cell

Requirements: environmental protection, with thixotropy, good thermal conductivity, fast solid at room temperature;

Product recommend: Thermal conductive epoxy structural adhesive, two-component acrylic structural adhesive

 

  Thread locking of 3.7 battery

Requirements: Can meet the requirements of vibration, mechanical shock, drop, flip, simulation of the collision test.

Product recommend: Anaerobic Thread Locking Adhesive

 

 3.8 nameplate bonding

Substrate: most of the aluminum alloy and surface treated steel parts.

Requirements: vibration resistance, the adhesive layer has toughness, strong initial adhesion, adhesive has a certain degree of thixotropy, good adhesion to the substrate.

Product recommendation: acrylic structural adhesive, low temperature curing epoxy adhesive.

4 Market conditions

With the application of CTP and blade battery technology, the requirements and dosage of adhesives have increased, and the dosage of a single PACK package adhesive will increase from the current1-2kgshow a higher multiple of growth, the amount of single pack value will also increase from200-300 yuan increased to 400-900 yuan.

It is worth noting that due to the product characteristics of new energy vehicles and power batteries, the performance requirements of adhesives and adhesive materials are also different from traditional adhesive materials. Power battery technology is in the process of rapid iterative upgrading, and new products are constantly emerging. The development of new adhesive materials adapted to it is indispensable to improve the energy density, safety, cycle life and lightweight of power batteries.

in recent years,The special functional adhesive film and adhesive industry is developing rapidly, and the overall trend is towards specialization, differentiation and high performance,In particular, the rapid development of the power battery industry has also driven the technological innovation and product innovation speed of domestic enterprises in this field.

Source: The Gum World