Advancements in thermal adhesives: enhancing battery cell-to-pack and cell-to-ribbon performance for EVs

Sponsored by Parker.

A key to the advancement of high energy-density, lithium-ion, battery packs is effective management of heat generated during charge and discharge cycles. Heat is often managed by connecting battery cells and/or modules to a cooling plate or pack via thermally conductive materials (gap fillers or adhesives). Typically, they are two-component polymeric resins with ceramic fillers. These promote heat conduction by displacing air from not only microscopic surfaces but large gaps as well. 

Electric Vehicle (EV) battery pack architecture is driven by cell form factor: Pouch, Cylindrical, and Prismatic. The cell type is the main guiding influence module/pack design and thermal management material needs. 

Pouch and cylindrical cells are typically constructed into modules, and modules are linked together in the pack. Pouch cells require this type of construction due to their lack of structural rigidity, whilst cylindrical cells need this due to the high piece count (>1000). Previously, prismatic cells were handled in the same manner, but with the advent of cell to pack/plate architecture, there is no longer a need for modules.

Generally, pouch cells stacks are formed into modules in three ways, typically using a thermal adhesive or gap filler and then either ambiently cooled or put in contact with a cooling system:

1. Inserted into a can with no adhesives or thermal management
2. Inserted into a can with thermal adhesives
3. Stacked with an aluminum heat spreader between each cell with and without thermal material

Cylindrical cell module designs fall into three categories prior to being inserted into the pack and connected to the cooling loop:

1. Inserted into plastic carriers using interference fit or structural adhesives
2. Side bonded to a cooling ribbon with thermal adhesives
3. Fixtured into an array and then the cell bottoms are bonded to a housing or cooling plate using a thermal adhesive

Prismatic cells are used to form modules or packs (modules are inserted into the pack) typically using a thermal adhesive or gap filler:

1. Modules are formed by grouping the cells into a stack and then either inserted into a module housing or onto a cooling plate, both using thermal adhesives or gap fillers
2. Packs are directly formed by bonding large format cells (~1m length) directly to the bottom plate using thermal adhesives or gap fillers

Opportunities and Challenges

Many design and manufacturing opportunities and challenges exist for each form factor.

Pouch cell challenges include:

1. Minimal structural rigidity, requiring additional housing
2. Use of low surface energy polyethylene films as the outermost layer of the foil pouch, which limits the ultimate strength of adhesive-based stack-ups
3. Marginal surface area for heat removal when stacked without heat spreaders (i.e., edge cooling)

Cylindrical cell challenges include:

1. Smaller cell size, requiring many cells to achieve vehicle range
2. High cell count necessitating exact positioning to ensure proper locating for downstream processes
3. Significant mechanical fixturing requirements
4. Nickel-plated steel surfaces that can be difficult to bond
5. A cell can live when PVC shrink-wrap sleeves are not used

Prismatic cell challenges include:

1. Higher individual cell surface area compared to cylindrical or pouch cells, leading to tolerance issues for both the cell and the cooling plate/pack
2. Use of low surface energy shrink-wrap films or tapes for dielectric protection, which limits the ultimate strength of adhesive-based stack-ups
3. Greater need for flexibility due to larger areas resulting in more tolerance stacking and larger stress from thermal expansion. 

Many of these challenges can be mitigated using thermal gap fillers or thermal adhesives.

Early EV battery pack applications relied on a small number of highly specialized formulations. Today, EV battery systems benefit from a broader portfolio of thermally conductive materials that are still engineered specifically for battery pack requirements but offer a wider range of performance and processing options.

At Parker Lord, the distinction between gap fillers and adhesives is based on strength. Gap fillers typically exhibit lap shear strengths below 7 MPa (1015psi), while adhesives are generally well above this threshold.

Thermal adhesives formulated for electric vehicle battery manufacturing

Two-component acrylic structural adhesives have been used for the last 50 years to bond automotive panels. Their ability to bond directly to various metals and finishes, along with room-temperature curing, has dramatically reduced the amount of mechanical fixturing and/or welding required. Likewise, two-component, thermally conductive potting and encapsulation materials have been used for the last 60 years to protect electronic components and remove heat.

As an industry leader in both categories, scientists at Parker Lord were able to combine these two technologies, creating a new class of adhesives: thermally conductive structural adhesives.

Parker Lord’s CoolTherm TC-2002 Thermally Conductive Structural Adhesive was the first commercial product in this category. Its high strength and thermal conductivity, combined with the ability to bond nickel-plated steel to powder-coated aluminum and cure at room temperature with a relatively short fixture time, enabled significant design freedom for cylindrical battery modules.

As new cell-to-pack and cell-to-plate designs are commercialized in electric vehicle (EV) powertrains, the role of thermal adhesives has become increasingly critical. There is a growing need for innovative thermal adhesives that effectively bond battery cells to pack components while addressing performance and manufacturing challenges.

Key improvements in acrylic and urethane thermal adhesives include:

• Tailorable bond strength for structural or reworkable pack designs
• Increased elongation for enhanced durability
• Adapted cure speeds
• Methods to facilitate high-throughput manufacturing.

The latest release from Parker Lord is CoolTherm TC-850 Thermally Conductive Acrylic Adhesive, which builds on the capabilities of CoolTherm TC-2002. Leveraging recent structural adhesive innovations has enabled four times higher elongation, as well as increased adhesion to plastics and coatings.

One note regarding bondline – in general, adhesives provide higher levels of strength with thinner bondlines. A standard bondline is 250 µm, but when reducing thermal resistance is critical, thinner bondlines are always better. For these products, 100 µm was determined to be ideal. This thickness allows for sufficient breakdown strength, reduces material usage, and lowers the required thermal conductivity.

See below for an illustration demonstrating that a 0.5 W/m∙K with a 100um bondline achieves lower thermal resistance compared to a 1 W/m∙K material with a 250um bondline.

Wrapping it up

In conclusion, selecting a thermal adhesive that aligns with specific cell-to-pack designs and needs will equip battery pack designers and material engineers with the knowledge to optimize pack performance, reliability, and cost-effectiveness.

Parker Lord has a wealth of expertise and knowledge to help you with your EV battery design. If you want to connect with one of their application engineers to get started, then reach out today.

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California bill aims to enforce electric truck pricing transparency

A common criticism of subsidy programs is that sellers may simply raise their prices by part or all of the subsidy amount, capturing taxpayer money as additional profit instead of passing on savings to buyers.

In California, which is expanding its already substantial support for electric commercial vehicles, a bill before the Senate would require vehicle OEMs to publicly reveal the prices they’re charging customers.

SB-1213, “Zero- and near-zero-emission medium- and heavy-duty vehicles: incentives: transparency,” which is now making its way through the state legislature, is intended to bring down the price of electric trucks by tying state funding under the Clean Truck and Bus Voucher Incentive Project (HVIP) to “full pricing transparency” of electric trucks by manufacturers.

Unlike passenger vehicles, truck prices are not always publicly available—companies may set different prices for different customers. Electric truck advocacy organization Idle Giants reports that electric truck prices remain high in the US and have increased, despite falling prices in Europe.

It’s been widely reported that the Tesla Semi, which has now gone into volume production, is priced significantly lower than Class 8 tractors from legacy OEMs, but reliable information about pricing is not easy to find.

Volvo Group, Daimler Truck and Traton continue to work on multiple fronts to stall or delay the shift to clean technologies. Could keeping the prices of their electric trucks uncompetitive be part of their slow-walking strategy?

The California legislation can’t force OEMs to lower their prices, but it aims to ensure that accurate pricing information is available to all interested parties—dealers, buyers and taxpayers (and don’t forget the press).

“SB 1213 passed three Senate committees without a single ‘no’ vote because it puts California first,” said Guillermo Ortiz, Senior Clean Vehicles Advocate at the Natural Resources Defense Council. “Governor Newsom [has just committed] $1 billion to accelerate clean truck adoption, and this bill makes sure that money actually delivers. Pricing transparency is the tool that holds manufacturers to their promise of delivering affordable clean trucks.”

“By requiring greater disclosure of truck pricing information for vehicles receiving public incentives, SB 1213 would give state agencies the tools they need to hold manufacturers accountable for selling electric trucks in California at the prices they offer abroad, and ensure that our state incentive dollars go as far as possible to provide air pollution relief,” said Jakob Evans, Senior Policy Strategist at Sierra Club California. “SB 1213 is a commonsense reform that will help ensure every dollar committed to clean trucks delivers maximum public benefit.”

Source: Idle Giants

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Blink Charging to deploy Kempower’s distributed EV charging systems at 14 new sites

EV charging provider Blink Charging has announced an expansion of its EV charging empire. This round of installations includes 14 sites in total. Two locations—Vasa Fitness in Colorado and Idaho Falls in Idaho—have already opened. Additional sites are set to roll out across multiple states along the US East Coast throughout 2026.

The new sites will be in high-traffic areas near convenience stores and will feature Kempower Power Units and Satellite fast chargers. The deployment of distributed charging systems may represent a new direction for Blink, which until now has mostly favored all-in-one chargers.

EVSE experts have been telling Charged that distributed charging is the wave of the future. All-in-one units have their advantages (compact footprints, ease of installation), but a distributed system offers more flexibility, as it can allocate charging power intelligently among vehicles.

The Kempower Power Unit can deliver 600 kW, or even 1,200 kW, of power. One cabinet can supply power to up to 12 Kempower Satellite dispensers.

Blink cited the reliability and uptime of Kempower technology as key factors in selecting the company’s charging systems.

“Reliable charging infrastructure depends on more than the equipment itself,” said Blink Senior VP of Global Business Engineering Alex Calnan. “The training we’ve received through Kempower has helped our teams approach installation and commissioning with confidence and consistency. That foundation shows up in smooth deployments and strong long-term site performance.”

Sources: Kempower, EV Charging Stations

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Download trend paper: Supercharging data connectivity to meet next-generation automotive expectations

Sponsored by TTI & TE Connectivity.

Automotive consumers demand more personalization, autonomy and connectivity from their driving experience. To make this a reality, connectivity plays a pivotal role in vehicle innovation design requirements.

The next generation of vehicles needs more cameras to support advanced driver-assistance system (ADAS) and autonomous driving (AD) functionalities.​ The cameras need to be smaller in size while also providing a higher resolution for more detailed views for the driver. For these newer compact yet powerful cameras, the connectors used will be required to support higher bit rates while also offering a new level of physical integration into the device itself.

Download this trend paper to learn about the future of vehicle technology and the connectivity solutions that enable this evolution of superior mobility.

Download now.

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Maui Kapalua Airport commissions a new NEVI DC fast charging site

Remember the National Electric Vehicle Infrastructure program? It’s alive and well, funding public EV charging sites around the country.

Sustainability Partners, a provider of Electric Vehicles as a Service, supported the Hawaiʻi Department of Transportation in the development of a new DC fast charging site at Maui Kapalua Airport. This is the third NEVI-funded location commissioned by HDOT.

Community leaders recently participated in a commissioning and blessing ceremony celebrating the opening of the new charging facility.

The new site includes four 150 kW DC fast chargers with both NACS and CCS connectors. It’s open 24 hours a day, and features canopy lighting and security cameras.

“Expanding Hawaiʻi’s EV charging infrastructure is an important step toward supporting cleaner transportation and improving connectivity across the islands,” said Ed Sniffen, Director of the Hawaiʻi Department of Transportation. “This new NEVI-funded fast-charging site at Kapalua Airport helps provide residents and visitors with more reliable access to public charging infrastructure while supporting the state’s broader transportation electrification and sustainability goals.”

Source: Sustainability Partners

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Download the guide to multi-gig automotive ethernet validation

Sponsored by Pickering Interfaces.

Applications for 10GBASE-T1 MEMS Fault Insertion.

As EV architectures evolve to support ADAS, autonomy, and high-bandwidth in-vehicle communications, validating 10GBASE-T1 Automotive Ethernet links is becoming increasingly complex.

This white paper explores how automated MEMS-based fault insertion can help test engineers move beyond time-consuming road testing and simulate real-world connectivity faults in the lab. Learn practical approaches for improving repeatability, protecting signal integrity, accelerating HIL validation, and building greater confidence in high-speed automotive network performance.

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New Zealand EV charging provider Meridian hits 500 charging point milestone

New Zealand EV charging provider Meridian has installed its 500th public charging point. The company has deployed charging stations at locations across the country, including Roxburgh, Haast, Mossburn, Dunedin South, Oamaru, Culverden, Rakaia, Rangiora, Punakaiki and Tokoroa.

Meridian has focused on expanding charging access in the South Island over the past 12 months, and is now planning additional expansion in the central and upper North Island. Potential North Island locations include Manawatū, Hawke’s Bay, Bay of Plenty, Waikato, Auckland and Northland.

The company plans to roll out an additional 900 public charge points by 2030.

Meridian sees plenty of potential for expansion—according to the company, New Zealand currently has about 80 EVs per charge point, compared with a global average of 11 EVs per charge point.

The company also finds that uncertainty around global fuel supplies has increased interest in EVs. Weekly users have increased by 75% and weekly app registrations have increased by 70% since December 2025.

“We want to build New Zealand’s largest EV charging network, and we’re continuing to expand coverage,” said Richard Sandford, Head of Energy at Meridian. “We’ve focused on filling gaps across New Zealand’s charging network. The case for EVs has never been stronger, and electric journeys are getting easier almost by the day.”

Source: Meridian

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