As electric vehicles (EVs) continue to push the boundaries of range, acceleration, and efficiency, one critical piece of the engineering puzzle often gets overlooked: battery cooling. As experts in lean design and manufacturing teardown, the science of EV battery cooling methods isn’t just an academic discussion—it’s a real-world performance driver. At Munro & Associates, we explore the leading cooling strategies used in EV battery cells, modules, and packs, and provide practical insight into how manufacturers are evolving their thermal management systems.
Understanding the Basics of Heat Transfer
Before diving into the methods, it’s important to grasp the fundamentals of thermal management. Heat transfer occurs in three primary forms:
- Conduction – Direct heat transfer through solid materials (e.g., heat sinks).
- Convection – Heat movement via fluids like air or glycol-based coolants.
- Radiation – Heat transfer through electromagnetic waves (e.g., sunlight heating the Earth).
In EV battery cooling, conduction and convection dominate. Battery thermal systems typically rely on engineered combinations of both—conducting heat from the cell and convecting it away using a coolant medium.
Thermal Interface Materials (TIMs): The Hidden Heroes
A key element in battery cooling design is the use of thermal interface materials, or TIMs. These materials serve to bridge the thermal gap between battery cells and cooling systems. Two metrics are essential:
- Thermal Conductivity (watts per meter-Kelvin): Higher is better for heat transfer.
- Thermal Impedance: Resistance to heat flow, where lower is better.
The ideal TIM is thin, highly conductive, and flexible—especially important for pouch cells that expand and contract during charge/discharge cycles.
Cooling by Cell Type: Cylindrical, Pouch, and Prismatic
Cylindrical Cells (Tesla, Lucid, Rivian)
Tesla’s popular 18650, 2170, and now 4680 cylindrical cells showcase how thermal management has evolved over the years:
- Early Models (Model X/S): Featured straight-line coolant pipes that only touched the tangent of each cell, limiting surface area for heat extraction.
- Updated Designs: Later models like the Model Y adopted serpentine cooling tubes that weave between cells, increasing contact surface and improving heat dissipation.
- Structural Battery Pack: Tesla’s structural packs consolidate cooling with inlets and outlets on a single end, circulating coolant in a U-shaped loop to even out temperature gradients.
Pouch Cells (Ford, Hyundai, Ionic 5)
Pouch cells are known for their cost-effectiveness and flexibility, but they introduce thermal challenges due to their shape and movement:
- Chevy Volt: Used expensive dual-plate cooling with ethylene glycol plumbing.
- Ford Lightning: Leverages edge cooling via bottom-mounted cold plates and thick TIMs.
- Hyundai Ionic 5: Utilizes a full aluminum enclosure as the cold plate, enhancing efficiency but risking thermal runaway exposure in extreme climates.
Prismatic Cells
These use a rigid metal shell, combining aspects of pouch and cylindrical cells. Cooling can occur on multiple surfaces—bottom, side, or edge—providing design flexibility. Their structure minimizes expansion but allows for robust thermal contact across flat surfaces.
Comparing Cooling Architectures: Ford vs. Tesla vs. Lucid
Tesla‘s serpentine coolers and advanced loop designs show a relentless pursuit of thermal uniformity. By maximizing surface contact and managing coolant paths, Tesla minimizes temperature gradients and supports burst power output—critical for features like Ludicrous and Plaid modes.
Lucid opts for ultra-thin TIMs and bottom cooling on its 2170 cells. This reduces resistance to heat flow while preserving high electrical isolation. The result? Class-leading acceleration in the Lucid Air Sapphire—besting even Tesla’s Plaid performance.
Ford’s Lightning sits somewhere in between, using edge cooling with moderate TIM thickness. It favors steady-state performance over short-term power bursts, suiting towing and grade-climbing more than drag-strip dominance.
The Role of Cold Plates and Composite Materials
Cold plates, essential for convection-based cooling, vary widely:
- Modular Cold Plates: Used by Rivian and Ford, these are plumbed per module, allowing easier replacement and thermal zoning.
- Integrated Cold Plates: Hyundai’s solution merges the battery enclosure with the cold plate—efficient but less flexible.
Composite enclosures, like those developed in Munro’s concept tray, introduce thermal insulation advantages. They help isolate batteries from extreme ambient temperatures and reduce the risk of runaway propagation during failure events.
Heat Pipes and Phase Change Materials
Though rare in automotive applications due to cost, heat pipes and vapor chambers offer promising thermal performance. These systems rely on fluid phase changes—boiling and condensing—to regulate temperature uniformly across surfaces.
Their inclusion might be limited to high-performance applications, but the concept remains compelling: precise thermal control without massive coolant flow systems.
Cooling for Performance vs. Stability
Not all EVs require Ludicrous Mode. Cooling designs typically serve one of two philosophies:
- Power Performance: Prioritizes rapid heat extraction for short bursts (e.g., Tesla Plaid, Lucid Sapphire).
- Thermal Stability: Focuses on long-term heat balance for sustained driving (e.g., Rivian R1T, Ford Lightning).
Each strategy carries cost and complexity tradeoffs, especially when trying to scale for production.
EV Battery Cooling Methods: Key Takeaways
- High K, Low Thickness: For TIMs, maximize conductivity and minimize thickness for best results.
- Cooling Direction Matters: Bottom vs. side cooling influences surface area and thermal response.
- Composite Enclosures Rise: Future battery packs will likely use composites to balance insulation, cost, and safety.
- Design for Use Case: Match your cooling system to your performance requirements—steady driving vs. high-speed performance.
- Serpentine Wins: Tesla’s serpentine loops provide some of the best thermal performance through clever engineering.
Final Thoughts
Battery cooling isn’t just a back-end engineering task—it’s a performance enabler. Whether you’re an EV startup, OEM engineer, or automotive investor, understanding electric vehicle battery cooling methods can give you a competitive edge.
Want more?
At Munro & Associates, we specialize in deep-dive teardowns, cost breakdowns, and custom engineering solutions. If you’re designing your next EV or analyzing an existing pack, our team offers the insights that move technology forward.
Watch the full teardown breakdown on Munro Live or explore our battery benchmarking services today.