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Minichannel technology has been shown to be a promising solution for the battery thermal management system (BTMS). Since the design space of the BTMS using minichannel technology consists a large number of parameters, performing parametric study and optimization of such a system is challenging. To overcome this challenge, a simplified numerical model is developed. In this model, effective convective heat transfer (heff) boundary condition is used at the cell-minichannel interface to circumvent simulating conjugate heat transfer and fluid flow in the minichannel. After validation with past work based on a three-dimensional conjugate heat transfer model, the simplified model is used to conduct a parametric study to determine the effect of various design and operation parameters on the performance of the BTMS. For the proposed BTMS, it is found that cooling half of the cell surface on single side of the cell is enough to keep the maximum temperature difference in the pack to be less than 3 °C at 2C discharge rate. At module level, it has been found that minichannel cooling on only one side of the cell or on every other cell can significantly increase the system level energy density. The results from the parametric study would be useful in designing a robust, effective, and economical minichannel-based BTMS for Electrical Vehicles.

Thermal management on lithium-ion batteries is a crucial problem for the performance, lifetime, and safety of electric vehicles (EVs) and hybrid electric vehicles (HEVs). Fire and explosions can be triggered by thermal runaway if the temperature of the lithium-ion batteries is not maintained properly. This work describes a minichannel cooling system designed at the battery module level and the investigation on its efficacy on the mitigation of thermal runaway. Nail penetration was employed to simulate the internal short circuits, which in reality may be caused by vehicle collisions and/or manufacturing defects. Two integrated models were utilized to study thermal runaway: the conjugate heat transfer model and the reaction kinetics model. Numerical simulations were conducted to understand the thermal runaway process and the effects of flow rate, thermal abuse reactions, nail penetration depth, and nail diameter. It is concluded that minichannel cooling at cell level cannot cease thermal runaway in a single cell, but it can prevent battery fratricide due to thermal runaway propagation between cells.

Lithium-ion batteries are widely used for battery electric (all-electric) vehicles (BEV) and hybrid electric vehicles (HEV) due to their high energy and power density. An battery thermal management system (BTMS) is crucial for the performance, lifetime, and safety of lithium-ion batteries. In this paper, a novel design of BTMS based on aluminum minichannel tubes is developed and applied on a single prismatic Li-ion cell under different discharge rates. Parametric studies are conducted to investigate the performance of the BTMS using different flow rates and configurations. With minichannel cooling, the maximum cell temperature at a discharge rate of 1C is less than 27.8 °C, and the temperature difference across the cell is less than 0.80 °C using flow rate at 0.20 L/min, at the expense of 8.69e-6 W pumping power. At higher discharge rates, e.g., 1.5C and 2C, higher flow rates are required to maintain the same temperature rise and temperature difference. The flow rate needed is 0.8 L/min for 1.5C and 2.0 L/min for 2C, while the required pumping power is 4.23e-4 W and 5.27e-3 W, respectively. The uniform temperature distribution (

Thermal runaway is the top safety concern for Li-ion electrochemical energy storage systems. There are multiple abuse conditions that may cause thermal runaway in Li-ion cells. Although thermal runaway has been extensively studied, the runaway mechanisms due to external short circuit and ultra-high discharge rates (>10C) are relatively less studied. In the present work, an analytical thermal runaway model is developed to predict thermal runaway in prismatic and pouch Li-ion cells due to either external short circuit or ultra-high discharge rates. The heat generation data corresponding to the ultra-high discharge rates considered in the thermal runaway model have been obtained separately using an electrochemical-thermal coupled model. The analytical thermal runaway model is validated against experiments as well as COMSOL, a finite element-based commericial solver. Using the analytical model, the effects of key parameters on cell safety have been analyzed. Finally, the analytical model has been used to evaluate effectiveness of a thermal runaway prevention strategy based on boiling in minichannels of a water-cooled minichannel based battery thermal management system.