A novel strategy of enhanced thermal performance in air cooled lithium-ion battery by wavy walls

•A novel air-cooled BTMS is proposed based on the wavy (undulated) walls.•Undulations enhance heat transport by increasing local velocity in narrow passages.•Significant reduction (∼10 K) in temperature is seen in presence of undulations.•The more is the surface waviness, the better is the thermal uniformity.•Optimum number of undulations is required to foresee the best thermal performance.