Polyurethane adhesives are widely used in the field of new energy, especially in the two core scenarios of power batteries and photovoltaics. They are the key materials that ensure safety, enhance performance and achieve lightweighting.
1.Power Battery: The Core Link Between Structure and Thermal Management
In the power batteries of new energy vehicles, polyurethane adhesives play multiple crucial roles. Two-component polyurethane structural adhesives are used for the assembly fixation of battery cells, with a bonding strength of up to 15 MPa. Combined with its low modulus property, it can absorb vehicle vibrations and impacts, preventing cell displacement and delamination. In CTP/CTC integration technologies, it replaces some mechanical fasteners to achieve lightweight battery packs and maintain structural stability at 120°C. At the same time, polyurethane thermal conductive adhesives with adjustable thermal conductivity (0.8–1.5 W/m·K) are used for the bonding of battery cells and liquid cooling plates, efficiently transferring heat and supporting the battery thermal management system. Combined with UL94 V0 flame retardant performance, they build a solid safety barrier. The outer layer of pouch batteries also relies on polyurethane adhesives for high tensile bonding and resistance to humidity and heat, ensuring the reliability of battery encapsulation.
2. Photovoltaic Modules: Long-term Solutions for Weather Resistance and Sealing
The demand for polyurethane adhesives in the photovoltaic field focuses on long-term weather resistance and reliable sealing. MDI-based polyurethane adhesives are resistant to UV rays and hydrolysis, have a low yellowing rate under long-term outdoor service, significantly reducing the risk of module delamination. Their weather resistance is more than five times that of traditional EVA adhesives, suitable for power station lifespans of 25 years or more. It is used for backsheet lamination, frame bonding, and junction box sealing, maintaining excellent bonding strength and sealing performance in high-temperature, high-humidity, and salt spray environments. Solvent-free polyurethane adhesives can also be used for PO/PET layering of solar backplates, maintaining high peel strength even after "double 85" aging tests, meeting the strict outdoor requirements.
3. Technical Advantages and Application Expansion
The core advantage of polyurethane adhesives lies in their flexible formulation - by adjusting the ratio of soft segments to hard segments and adding thermal conductive/combustion-resistant fillers, they can meet the strength, thermal conductivity and combustion resistance requirements of different working conditions. At the same time, their flexibility effectively buffers thermal expansion and contraction stresses, enhancing the structural durability of components and battery packs. Besides power batteries and photovoltaics, polyurethane adhesives are also used in the fixation of energy storage cells, the bonding of heat dissipation modules in 5G base stations, and other new energy scenarios. They are an important supporting material for promoting the industry towards safety, efficiency and lightweighting.
