Thermal Resistance

Thermal Path

Heat rejection depends directly upon the total thermal resistance accumulated across multiple layers separating the jelly roll from the module housing. Conduction barriers arise from current collectors, separator films, aluminum pouch foils and the microscopic air gaps residing between adjacent cylindrical cans and cold plates. Engineering teams minimize these cumulative restrictions by applying high thermal conductivity interface pads that displace trapped air and lower interfacial transfer barriers.

Interface Resistance

Contact resistance dominates total heat dissipation performance whenever solid surfaces meet with microscopic roughness preventing complete physical contact. Pressure applied during module compression reduces this boundary penalty by forcing microscopic peaks to deform and enlarge the actual conductive contact area. Thermal greases and phase change materials fill remaining voids to establish continuous solid state conduction paths across mechanical interfaces.

Thermal Gradient

Internal temperature rises concentrate heavily near active material zones where high C rate discharges generate intense Joule heating and reaction entropy shifts. Excessive thermal resistance forces internal core temperatures to outpace external cooling capacities by wide margins, accelerating electrolyte decomposition and aging mechanisms. Cell architectures must balance electrical conductivity requirements against boundary resistance limits to prevent localized thermal runaways during rapid charging cycles.