Charged EVs | Optimizing the thermal administration ecosystem in EV batteries

Sponsored by Avery Dennison.

Continued optimization of battery design means addressing thermal runaway and different points. Stress-sensitive adhesive (PSA) tapes could also be an essential a part of the answer.

By Max VanRaaphorst—Market Supervisor, Power Storage for Avery Dennison North America.

It is a dynamic time for the electrical car (EV) market. In line with an April 2025 report by Cox Automotive, EV gross sales rose 11.4% within the first quarter of 2025 in comparison with the primary quarter of 2024. Many long-term forecasts predict continued double-digit development. 

The near-term outlook for the trade, nevertheless, is volatility. As of this writing, the Trump administration’s tariff plan stays in flux. No matter their closing kind, tariffs appear more likely to stir the worldwide provide chains that producers rely on.

Regardless, engineers tasked with making EV batteries safer, extra sturdy, and extra energy-dense should stay targeted on the duty at hand. Really transformative applied sciences, comparable to solid-state batteries, are nonetheless years off. So, continued progress means additional optimization of present know-how platforms. Stress-sensitive adhesive (PSA) tapes, built-in with purposeful supplies, are a flexible, easy-to-use, and cost-effective materials answer for a lot of of in the present day’s EV battery engineering challenges. 

The thermal administration ecosystem

A key problem on this story of optimization is that of thermal administration.

A battery is a posh ecosystem requiring temperature regulation for optimum cell efficiency throughout regular use in addition to throughout excessive occasions. On the most simple stage, which means cells ought to be warmed after they’re too chilly and cooled after they’re too heat.

Batteries thus have three forms of thermal necessities:

1. Thermal insulation
Low thermally conductive (insulating) supplies are used to guard usually working cells from overheating, thus stopping thermal runaway occasions. 

2. Thermal conductivity
Excessive thermally conductive supplies, comparable to thermal interface supplies (TIMs), are used to attach cells to cooling elements and facilitate warmth switch.

3. Venting
Venting methods permit sizzling gases to flee a malfunctioning cell whereas defending adjoining cells. These methods can incorporate numerous thermal supplies. 

To know thermal conductivity … go for a hike within the woods

Evaluate the concept of thermal conductivity to a hike within the woods. Think about attempting to bushwhack via a dense forest of timber, low-lying scrub, roots and rocks, and maybe some mud. It’s troublesome, you’re respiration onerous, sweating and possibly cursing a bit! Now evaluate that to a stroll on a flat, well-maintained, tree-lined path. It’s simpler and possibly extra pleasurable. From warmth’s perspective, a low conductivity materials is like that dense forest — troublesome to traverse. A excessive conductivity materials is the light path. 

One other essential consideration is the size of the hike itself. A brief hike via a dense forest might not be a lot of an impediment. It’s the lengthy slog that in the end slows you down.

That brings us to PSA tape options for thermal administration. Tapes, by design, are very skinny. So whereas they don’t have a tendency to supply excessive thermal conductivity, they do provide only a brief path for warmth to journey. However as a consequence of their super versatility, tapes will also be built-in with low thermal conductivity supplies, thus making them appropriate for a variety of thermal administration purposes inside a battery pack.

Thermal runaway barrier options

Thermal runaway begins when an overheating cell combusts. That fireplace grows to the purpose at which sizzling gases and supplies burst from the cell. The escaping matter causes different cells to overheat, catch hearth and burst in flip. A module-level thermal runaway occasion can then unfold to different modules in a pack, inflicting full destruction of the battery pack and sure the car. 

Tapes can be utilized to encapsulate insulating (low warmth conductivity) barrier supplies, comparable to mica, ceramic paper or aerogels. These can then be positioned between cells, modules, and/or on the within of the pack lid. Due to tapes’ skinny profiles, they’re a really perfect selection for these slender areas — offering the mandatory bond whereas permitting for the utmost potential thickness of the insulating materials given the area constraints. 

In some circumstances, these PSA-based options can forestall cell- or module-level thermal runaway propagation. However normally, they will at the very least sluggish the unfold of thermal runaway, offering helpful time for passengers to exit the car.

Thermal runaway venting options

As famous above, thermal runaway is underway when sizzling gases and supplies erupt from a single cell. Cell producers thus combine venting methods into their designs. 

A vent is just a port that permits sizzling, increasing gases and burning materials to flee the cell’s confines, making a extra managed stress launch. The issue lies in the truth that as these escaped rush via the module, they will infiltrate different cells via their vent ports, and thus provoke a thermal runaway occasion. 

What’s wanted is a venting technique that permits that stress launch whereas defending wholesome cells from these sizzling gases and supplies. Once more, PSA tapes provide a chic answer: On this case, it’s tapes with an anisotropic service—only one aspect of the tape affords flame resistance.

These PSA tapes are utilized to battery cells throughout meeting, protecting the vent ports. The anisotropic service then permits flames to flee via the port of a burning cell. However because the flames then flow into via the module, the flame-retardant aspect of the tape protects the vent ports of wholesome cells. 

PSA-based anisotropic tapes may help shield wholesome cells and inhibit thermal runaway.

Flame retardance isn’t everlasting. Finally, the tape is compromised, and flames can have an effect on wholesome cells. However once more, that is about mitigating and delaying full thermal runaway, and giving passengers helpful time for a secure escape.

Dielectric safety options

Electrical arcing in a high-voltage atmosphere can typically result in hearth, and thus is one other difficulty that may have an effect on a battery ecosystem’s thermal administration. Once more, PSA tapes are stepping as much as the problem. 

Polymer movie tapes can be utilized inside the pack and module for bonding or to encapsulate important components. These tapes provide excessive dielectric energy per unit thickness and have a tendency to inhibit warmth movement, making them a most popular different to many conventional dielectric coatings. 

A brand new PSA tape know-how is a dielectric tape that may be utilized to flat steel blanks previous to stamping and forming. It’s an easy-to-use answer that optimizes each dielectric energy and meeting flows, because it eliminates curing and cleansing, and different processes wanted for conventional coatings. Avery Dennison has lately printed a whitepaper explaining how stampable dielectric PSA tape know-how can profit producers. 

PSA tape options can be found now

All the PSA tape options mentioned on this article are at present out there. In truth, the Avery Dennison EV Battery Portfolio incorporates a variety of PSA tape-based options engineered to assist producers deal with points comparable to thermal runaway and dielectric safety. And these tapes are straightforward to include into both handbook or automated meeting processes, serving to EV battery producers optimize each workflow and design. 

Tape options will be reduce and stamped to spec and offered at scale by native converters. These third-party suppliers work carefully with Avery Dennison and the battery producer to make sure the precise options are offered on the volumes wanted, even in a risky time for the automotive trade. 

A vivid future for EVs

No matter volatility the close to time period would possibly maintain, the long run is vivid for EVs. Through the use of options comparable to PSA tapes, producers will be assured their merchandise will meet shoppers’ wants for security, reliability and sturdiness.