Address EV Battery Trends With Thermal Management Adhesives

When manufacturing electric vehicle (EV) batteries, you're likely aiming to increase the battery’s energy density, sustainability and range to optimize battery effectiveness. 

However, achieving these goals simultaneously can be difficult, as there can be complexities in trying to create compact and optimized systems with effective thermal management. This is where thermal management adhesives can help. 

Learn about important industry trends and which thermal management adhesives can be the right choice for your EV battery needs to address them.

How Thermal Management Adhesives Can Help:

In redesigning battery packs to fit more cells into tighter spaces, thermal management adhesives, such as thermally conductive adhesives (TCAs), help enable increased energy density by replacing traditional mechanical fasteners or cell holders that would take up space and reducing gaps between cells. Further, TCAs used in EV battery packs provide both structural bonding and thermal control. Formulated with thermally conductive fillers, such as ceramic particles or metal oxides, TCAs create efficient pathways for heat dissipation through the adhesive layer. The base polymer is formulated to maintain strong adhesion and flexibility, accommodating the thermal expansion and contraction of battery components. This balance of thermal conductivity, electrical insulation and mechanical strength helps TCAs meet EV battery design requirements for large vehicles where increased energy density is critical. 

In particular: 

• Two-component, epoxy (EP) TCAs are non-silicone solutions known for their high-strength bonding and customizable properties tailored to specific battery design needs. With thermal conductivity up to 3W/m.K*, they offer a range of viscosities suitable for fast joining and automated processes along with excellent chemical resistance to support long-term battery durability.  
• Two-component, polyurethane (PUR) TCAs are also non-silicone solutions valued for providing thermal conductivity up to 1.5 W/m.K or higher* as well as high elongation, which provides elasticity to handle thermal cycling. These adhesives bond to substrates such as nylon, PET, PI,  aluminum and steel; they maintain electrical insulation to help reduce the risk of electrical faults.

Additionally, you may also want to consider customized TCA formulations that meet the specific thermal and mechanical requirements of your battery design to help ensure high performance and long battery life.  

How Thermal Management Adhesives Can Help:  

Certain thermal management adhesives, such as alternative, silicone-free gap fillers, are designed for removability to address repair needs and end-of-life disassembly as well as provide thermal conductivity and density to help prevent hot spots. 

Available in one and two-component options, they help contribute to less waste production compared to other gap fillers: 

• One-component, non-reactive gap fillers are non-curing, silicone-free materials that remain pliable over time. With a low oil separation (~0.3%), they maintain the same liquid viscosity throughout their lifespan, helping to ensure long-term stability with easy removability at the battery’s end of life.  
• Two-component silyl-modified polymer (SMP) gap fillers are designed for automated, high-volume production. These gap fillers maintain a low bond strength with controlled viscosity and low compression forces. This aids in removal, allowing you to disassemble the battery module down to its sub-parts and reuse them if needed to reduce overall waste generation. Additionally, these SMP gap fillers are VOC-free to further enhance sustainability in the EV battery and remove hazardous materials.  

How Thermal Management Adhesives Can Help:  

As previously mentioned, both TCAs and gap fillers help transfer heat away from a battery cell, helping to minimize imperfections and enhance efficient thermal performance outside the battery cell. This allows for more ease in switching to sodium-ion inside the cell, as you have the assurance the components outside the cells will be able to keep up with the extensive battery life compared to what was necessary for lithium-ion. 

Thermally Conductive Adhesives (TCAs), as mentioned above, are formulated to be non-reactive with metals, ceramics, and plastics, helping to prevent corrosion or material breakdown. In particular, they provide: 

• Thermal Stability: TCAs are built to perform across a wide temperature range, from -40°F to 302°F (-40°C to 150°C), helping to ensure reliable performance during charging, discharging and everyday driving conditions. 
• Long-Term Durability: TCAs resist degradation from chemicals and humidity, helping to reduce the need for repairs or replacements. 
• Flexibility: If desired, some TCAs can retain flexibility after curing, which allows them to absorb stress caused by thermal expansion and contraction. This flexibility helps prevent mechanical failures.  

Gap Fillers, as previously mentioned, play a crucial role in optimizing thermal performance by eliminating air pockets that can impact heat transfer. Their ability to conform to surfaces and fill voids enhances battery efficiency and longevity: 

• Hot Spot Mitigation: By filling the space between battery cells and heat sinks, gap fillers can prevent the formation of hot spots that can lead to overheating or damage. This helps with consistent thermal flow and protects sensitive components. 
• Surface Conformability: Liquid gap fillers adapt to microscopic surface irregularities, creating a more uniform thermal interface. This improves heat dissipation and overall system performance.