You’ve heard it before: optimizing battery power is challenging. With market competition of electric vehicles (EVs) on the rise, engineers are working hard to overcome batteries’ limitations—results so far are mixed.
A recent article in WIRED, “Why A New Crop Of Electric SUV Batteries Are Coming Up Short,” noted car manufacturers and researchers have optimistic targets for the range ratings new models will achieve, but many models are not performing as hoped and they are receiving disappointing ratings from the Environmental Protection Agency (EPA). The WIRED article highlighted the differences in performance which can be attributed to thermal management.
Thermal management is critically important in improving EV performance. Batteries need high energy and power density for longer range and faster charging. This leads to greater heat generation. That heat needs to be dissipated quickly and effectively, making thermal management materials decisions a key consideration.
Thermal Management Solutions on the Market Today
The role of thermal interface materials (TIMs) is to facilitate conduction between battery packs and cooling plates; good conduction is dependent on low interfacial impedance values. (Thermal impedance is a measure of the resistance to heat flow through the TIM assembly.)
Battery manufacturers face the choice of whether to use a cure-in-place, liquid-dispensed gap filler or a pre-cured thermal pad. Liquid gap fillers exhibit significantly lower values for thermal impedance, in large part because liquid gap fillers displace air—at both the microscopic and macroscopic level, as seen in the image below.
Steady state thermal analyses have shown CoolTherm liquid-dispensed gap fillers provide lower thermal impedance than thermal pads having comparable bulk thermal conductivity and thickness. However, improved impedance isn’t the only reason to use liquid-dispensed gap fillers. The table below shows six key performance comparisons between gap fillers and thermal pads.
Choosing the Right Solution for your EV Design
Battery pack design isn’t standardized; cells, modules and packs are specific to various vehicle makes and models. Because battery design is unique, thermal management strategies should also be unique. Sometimes off-the-shelf products don’t offer the best performance for a given design, especially considering the new chemistries in thermal management materials that are in development. In these instances, LORD works with you to customize a solution. Our application engineers work hand-in-hand with customers to create highly targeted, meticulously engineered thermal management systems that will improve your battery performance and ultimately, EV performance.