Current collectors play a critical role in the thermal management of lithium-ion batteries by facilitating heat dissipation from the electrodes. Their thermal conductivity directly impacts the efficiency of heat transfer, influencing battery performance, safety, and longevity. Among the most commonly used materials, copper and aluminum dominate due to their balance of electrical and thermal properties. However, emerging composite materials offer potential improvements in thermal management. Understanding these materials and their thermal characteristics is essential for optimizing battery design.

Copper is widely used as a current collector for anodes due to its high electrical conductivity and excellent thermal properties. With a thermal conductivity of approximately 398 W/m·K, copper efficiently transfers heat away from active materials, reducing localized hot spots. This property is particularly beneficial in high-power applications where heat generation is significant. The high thermal conductivity of copper ensures uniform temperature distribution, minimizing thermal gradients that can accelerate degradation. However, copper’s density and cost are drawbacks, leading to exploration of alternatives in some applications.

Aluminum, the preferred current collector for cathodes, has a lower thermal conductivity of around 237 W/m·K compared to copper. While this is still sufficient for many applications, the difference becomes notable in high-energy-density cells where heat dissipation is critical. Aluminum’s lighter weight and lower cost make it attractive, but its thermal performance may require supplementary thermal management strategies in demanding environments. The choice between aluminum and copper often involves trade-offs between thermal efficiency, weight, and cost.

Composite materials are being developed to enhance the thermal and mechanical properties of current collectors while addressing the limitations of pure metals. For example, copper-aluminum laminates or metal matrix composites reinforced with carbon fibers can offer tailored thermal conductivities. These composites aim to combine the high thermal conductivity of copper with the lightweight nature of aluminum. Some experimental composites incorporate graphene or carbon nanotubes to further improve heat transfer, achieving thermal conductivities exceeding those of pure metals in specific configurations. However, challenges such as interfacial resistance and manufacturing scalability must be resolved before widespread adoption.

The thermal conductivity of current collectors is closely linked to the design of battery thermal management systems. Effective heat dissipation relies on integrating high-conductivity materials with the overall cell architecture. For instance, thicker current collectors can improve heat spreading but add weight and reduce energy density. Thin coatings or foils with high thermal conductivity can mitigate this trade-off. Additionally, the arrangement of current collectors within the cell influences heat flow pathways. Optimal designs ensure that heat generated during charge and discharge is efficiently conducted to the cell casing or external thermal interfaces.

In pouch and prismatic cells, current collectors are often bonded to tabs that serve as thermal conduits to the external environment. The thermal resistance at these interfaces must be minimized to prevent bottlenecks in heat dissipation. Techniques such as ultrasonic welding or conductive adhesives are employed to enhance thermal contact. In cylindrical cells, the spiral-wound configuration leverages the current collectors’ thermal conductivity to distribute heat radially, though axial heat transfer remains a challenge without active cooling.

The role of current collectors extends beyond electrical conduction to thermal stabilization, particularly under high-stress conditions. During fast charging or high discharge rates, uneven heat generation can lead to localized overheating. Current collectors with high thermal conductivity help mitigate this by redistributing heat more evenly. This is especially important in large-format cells used in electric vehicles, where thermal runaway risks are heightened. Materials with anisotropic thermal properties, such as laminated or textured foils, can be engineered to direct heat flow preferentially toward cooling surfaces.

Thermal modeling and simulation are valuable tools for evaluating the impact of current collector materials on battery performance. Multiphysics models that couple electrochemical and thermal behavior can predict temperature distributions under various operating conditions. These simulations guide material selection and geometry optimization to balance thermal management with other design constraints. For example, models may reveal that a composite current collector with moderate thermal conductivity but superior mechanical strength is preferable in applications where vibration or mechanical stress is a concern.

Future advancements in current collector technology will likely focus on multifunctional materials that integrate thermal, electrical, and mechanical benefits. Innovations such as nanostructured coatings or hybrid metal-polymer foils could push the boundaries of heat dissipation efficiency. As battery systems evolve toward higher energy densities and faster charging, the thermal role of current collectors will become even more critical. By leveraging material science and engineering insights, next-generation current collectors can contribute to safer, more efficient energy storage solutions.

In summary, the thermal conductivity of current collectors is a key factor in battery thermal management. Copper and aluminum remain the standard materials, but composites offer promising avenues for improvement. The interplay between material properties, cell design, and thermal management strategies determines the effectiveness of heat dissipation. Continued research and development in this area will support the advancement of high-performance, thermally stable battery systems.