The growing demand of electric vehicles (EVs) attracts many researchers to work on the battery thermal management to maintain the temperature of battery package in the desired temperature. In this regard, the present work aims to use the numerical and experimental approaches in order to perform the battery thermal management. The lattice Boltzmann method is used to simulate the fluid flow and heat transfer during free convection in a rectangular cavity included with seven battery cylinders. The battery package and battery are simplified with rectangular cavity and circle cylinder, respectively. The top and bottom walls are kept at constant cold temperature with three different configurations (Smooth, Jagged and Zigzag). In addition, the cavity is filled with SLG (Single Layer Graphene)/water nanofluid which the thermal conductivity and dynamic viscosity are measured experimentally using modern devices. Furthermore, the second law analysis is carried out in order to find the influence of governing parameters including Rayleigh number, nanoparticle concentration (?? = 0.2, 0.4, 0.6, 0.8 and 1.0 mg/ml) and configuration of cavity on the local/total entropy generation. The flow structure, temperature field, local maps of heat transfer irreversibility and fluid friction irreversibility, volumetric magnitude of total entropy generation and average Nusselt number are presented.

电动汽车（EV）不断增长的需求吸引了许多研究人员从事电池热管理工作，以将电池封装的温度保持在所需温度。在这方面，本工作旨在使用数值和实验方法来执行电池热管理。格子Boltzmann方法用于模拟在自由对流过程中在包含七个电池缸的矩形腔体中的流体流动和热传递。电池封装和电池分别简化为矩形腔体和圆形圆柱体。顶壁和底壁通过三种不同的配置（平滑，锯齿形和锯齿形）保持恒定的低温。此外，空腔中充满了SLG（单层石墨烯）/水纳米流体，其导热系数和动态粘度是使用现代设备通过实验测量的。此外，进行第二定律分析是为了发现控制参数的影响，包括瑞利数，纳米颗粒浓度（Δε= 0.2、0.4、0.6、0.8和1.0 mg / ml）以及腔的形状对局部/总的影响熵产生。给出了流动结构，温度场，不可逆传热和流体摩擦不可逆的局部图，总熵产生的体积大小以及平均Nusselt数。纳米粒子的浓度（Δε= 0.2、0.4、0.6、0.8和1.0 mg / ml）和腔体在局部/总熵产生上的构型。给出了流动结构，温度场，不可逆传热和流体摩擦不可逆的局部图，总熵产生的体积大小以及平均Nusselt数。纳米粒子的浓度（Δε= 0.2、0.4、0.6、0.8和1.0 mg / ml）和腔体在局部/总熵产生上的构型。给出了流动结构，温度场，不可逆传热和流体摩擦不可逆的局部图，总熵产生的体积大小以及平均Nusselt数。