The widespread use of lithium-ion batteries (LIBs) is increasingly challenged by their vulnerability to thermal conditions, particularly when directly exposed to adverse or dynamically varying environments. To address this issue, a multifunctional battery thermal management (BTM) design is proposed, integrating phase change materials (PCMs), thermoelectric modules (TEMs) and heat pipes (HPs), with HPs bridging TEMs and LIBs to facilitate direct heat transfer. The design employs PCM phase change as the primary cooling means, supplemented by TEM-refrigeration for high-temperature scenarios. Meanwhile, it utilizes solidified PCM to mitigate heat loss from batteries under sub-zero conditions and applies TEM-heating to preheat LIBs before cold starts. Experiments were conducted by discharging NCM prismatic batteries with the proposed design under continuous and pulsed profiles across various thermal conditions. At the ambient temperatures and , the maximum battery-surface temperatures successfully remained within ; the maximum temperature differences were less than . Under the high-temperature circumstance, TEM-refrigeration outperformed both air- and liquid-cooling in identical continuous discharge and input power conditions. At , solidified PCM effectively prevented a plunge in battery temperatures, and TEM-heating achieved a preheating rate of . It is also revealed that the proposed BTM design can electrically control TEM on-off through a set of logic rules, enabling instantaneous regulation of the battery temperature rise and distribution in response to ambient temperature surges and drops. All these findings demonstrate the superior efficacy of the proposed BTM design, whose multifunctional capabilities, including cooling, insulation and preheating, can fulfil diverse thermal requirements of LIBs in various conditions.
