*Article* **A Thermal Investigation and Optimization of an Air-Cooled Lithium-Ion Battery Pack**

### **Xiongbin Peng 1, Xujian Cui 1, Xiangping Liao 2,\* and Akhil Garg 3**


Received: 6 May 2020; Accepted: 5 June 2020; Published: 9 June 2020

**Abstract:** An e ffective battery thermal managemen<sup>t</sup> system (BTMS) is essential to ensure that the battery pack operates within the normal temperature range, especially for multi-cell batteries. This paper studied the optimal configuration of an air-cooling (AC) system for a cylindrical battery pack. The thermal parameters of the single battery were measured experimentally. The heat dissipation performance of a single battery was analyzed and compared with the simulation results. The experimental and simulation results were in good agreement, which proves the validity of the computational fluid dynamics (CFD) model. Various schemes with di fferent battery arrangements, di fferent positions of the inlet and outlet of the cooling system and the number of inlets and outlets were compared. The results showed that an arrangemen<sup>t</sup> that uses a small length-width ratio is more conducive to promoting the performance of the cooling system. The inlet and outlet configuration of the cooling system, which facilitates fluid flow over most of the battery pack over shorter distances is more beneficial to battery thermal management. The configuration of a large number of inlets and outlets can facilitate more flexible adjustment of the fluid flow state and can slow down battery heating to a greater extent.

**Keywords:** thermal managemen<sup>t</sup> system; optimal configuration; air-cooling; lithium-ion battery
