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It is seen from this figure that the maximum temperature rise of the cell module decreases as the increasing rate of fluid flow. The maximum temperature rise of the cell module is under 40 °C and 36 °C respectively since the flow rate is 0.40 × 10−3 L·s−1 and 1.20 × 10−3 L·s−1, indicating that increasing flow rate increases the cooling capability of the LCP. • A new cooling plate is developed for controlling undesirable cell temperature field. • Inlet and outlet of cooling plate have big impact on cell temperature distribution. • Increasing flow rate decreases cell temperature rise markedly. • Cooling plate channel width has weak impact on cell temperature distribution. • Channel width has great effect on ratio of power consumption of cooling plate. The thermal management for a lithium ion battery cell plays a pivotal role in enhancing the cell performance and reliability for electric vehicles. In this work, a novel serpentine-channel liquid cooling plate with double inlets and outlets is developed for better managing an undesirable temperature distribution of a cell module. With a simplified model for the cell module, numerical analyses are implemented using the software of FloEFD to study effects of flow directions, flow rates and channel widths of the cooling plate on cell temperature distribution under different operating conditions; Likewise, a ratio of power consumption as a non-dimensional number is defined to analyze the hydraulic performance of the developed cooling plate. Results show that locations of the inlet and the outlet as well as flow directions have great impacts on the cell temperature distribution and the ratio of power consumption of the cooling plate. Increasing fluid flow rate substantially decreases the maximum temperature rise of the cell module while it has little effect on the temperature distribution. Moreover, the channel width of the cooling plate has a strong influence on its ratio of power consumption as well as the cell temperature distribution but it has a weak influence on the cell maximum temperature rise. Interestingly, the developed serpentine-channel cooling plate offers one a new method to design a lithium ion battery thermal management system for controlling temperature distribution of a cell module. [ABSTRACT FROM AUTHOR]

It is seen from these two figures that the battery temperature and SOC have a minor effect on its thermal conductivity. Battery thermal conductivity vary with the battery types heavily. • A novel method for determining thermal parameters of lithium ion cells is presented. • Temperature has a linear effect on thermal conductivity and specific heat of cells. • Cell temperature has a higher effect on its specific heat than thermal conductivity. • Cells' thermal conductivity and specific heat vary with the battery types. • The method is more effective to test thermal conductivity and specific heat of cells. Characterizing thermal parameters of a lithium ion battery is a key step to predict the temperature distribution of battery cell modules. In this work, a novel method is developed based on the quasi-steady state heat transfer analysis to determine the thermal conductivity and the specific heat simultaneously. Both prismatic lithium iron phosphate cells and pouch cells with different electrode materials are used in this experimental test. A constant heat flux is applied to the cell surface whereas the heat loss is estimated based upon the temperature drop curve. As such, the quasi-steady state heat transfer can be attained to determine cell thermal parameters. It is observed that cell thermal parameters increase linearly with the increase of the operating temperature. Furthermore, the operating temperature has a more significant influence on the cell specific heat than the thermal conductivity, while the effect of the state of charge has a minimal effect on these two parameters. The current method demonstrates an effective and practical way to determine the thermal conductivity and specific heat of the cell simultaneously. [ABSTRACT FROM AUTHOR]

Thermal characteristics of lithium-ion battery cells are crucial in the thermal design of power battery packs for electric vehicles. In this paper, a calibration calorimetry method of considering the heat loss is proposed to investigate the thermal characteristics of a commercial cylindrical 21700 cell. In the meantime, an existing heat-flux meter method is employed to analyze the present method effectiveness. Furthermore, a cell thermal model by considering the physical specifications and thermal parameters is established to predict the cell's temperature rise during its operation. It is shown that the proposed calibration calorimetry method matches well with the existing heat-flux meter method in determining the cell heat generation rate. The cell heat generation rate increases as the decreasing temperature and the increasing discharge rate, and there exists a quadratic-relationship in them between each other. The established thermal model to predict the cell temperature rise is effective with accuracy of within 3.0 °C. This work is fast and cost-effective in characterizing the thermal characteristics of the commercial cylindrical cells, without resorting to the specialized instruments. • A calibration calorimetry method to analyze cell thermal characteristics is proposed. • The present method is compared with the heat flux meter method. • Cell heat generation is increased at ascending discharge rate and lower temperature. • The established thermal model predicts cell temperature profile is highly feasible. [ABSTRACT FROM AUTHOR]

• Develops a lightweight liquid cooling solution to cool a prismatic hard cased cell. • Effect of fluid flowing on cell thermal distribution is studied numerically. • Dimensionless analysis of cooling performance in cooling plate is performed. • Effectiveness of the lightweight solution was authenticated by an experimental test. The lightweight thermal design is a critical factor that must be taken into consideration during the lithium-ion battery pack manufacturing for electric vehicles. This work develops a lightweight liquid cooling solution to cool a prismatic hard-cased cell from its small lateral surfaces. The effects of fluid flow directions, flow rates, channel dimensions, and cooling mediums on the cell′s thermal distribution were studied. Meanwhile, a dimensionless analysis for the cooling plate performance was imposed. The simulation effectiveness was corroborated through experiments. Simulations show that the lightweight thermal design has a similar cooling effect with the conventional thermal design; crucially, the former can lower the cooling plate weight by 57% compared with the later. Effect of increasing fluid flow rate on minimizing the cell′s temperature rise and difference is positive and negative, respectively. Increasing fluid flow rate and channel width can promote the cooling plate performance. The glycol aqueous solution outperforms the liquid water to weaken the cell′s temperature difference. Experiments authenticating that an excellent effectiveness residing in the current lightweight thermal design to control the cell thermal profile within a desirable level. This work would be valuable for one to design a lightweight cooling system for a battery pack consists of prismatic hard-cased cells. [ABSTRACT FROM AUTHOR]

Purposing to the thermal profile management of typical format 21700 lithium-ion battery cells, this study develops a cellular liquid cooling jacket to meet their requirements. To this end, the effects of fluid flowing, channel dimension, and cooling medium on the cell thermal profile were investigated numerically, and then the simulation effectiveness was authenticated experimentally as per a constructed test bench. Meanwhile, a non-dimensional analysis for the optimum design of cellular cooling jacket was implemented. The results show that the interlaced flow directions can capture a lower temperature standard deviation and a more even thermal distribution. The non-dimensional analysis reveals that the increasing fluid flow rate and channel size can effectively promote the performance of high-efficiency and low-impedance in the designed cellular cooling plate. The glycol aqueous solution to minimize cell's temperature difference and temperature standard deviation is under a stronger capability than that of the liquid water. Experimental verification indicates that the developed cellular cooling jacket is of great control effectiveness to the thermal profile of the cylindrical 21700 cells. A benefit inside this study for the thermal management system designing for the power battery pack of composing with the cylindrical 21700 cells. • A cellular cooling jacket is developed to control thermal profile of a 21700 cell. • Impact of fluid flowing on 21700 cell thermal profiles is studied numerically. • Dimensionless analysis of the cellular cooling jacket performance is conducted. • The effectiveness of battery pack thermal design is verified by a built test bench. • The thermal design is of great effectiveness to control 21700 cell thermal field. [ABSTRACT FROM AUTHOR]

The thermophysical parameters such as thermal conductivity and specific heat play a vital part in the thermal design of the power battery pack composed of cylindrical lithium ion battery cells. This work proposes a quasi steady state method with considering heat loss to measure the thermophysical parameters of two classes of 21700 and 18650 cylindrical cells, respectively. To this end, the theoretical model and the corresponding measurement method were developed in consideration of the heat loss, and the two cells' thermophysical parameters were experimentally determined over a wide operating temperature range of −20–60 °C. The results show that both of the thermal conductivity and the specific heat of the cells increase linearly with the increase of the operating temperature. In comparison, the cell temperature has a greater influence on the specific heat than that of the thermal conductivity. The experimental verification reveals that the measurement error is behind 5.1%. Having a short measurement time within 930s, the present work provides a fast and convenient solution on determining the thermophysical parameters of the cylindrical cells without resorting to the costly instruments. • Proposes a quasi steady state method to measure cylindrical cell thermal parameters. • Cost-effectiveness and fast in current method to derive the cell thermal parameters. • Cell thermal parameters linearly increase as increasing temperature of −20–60 °C. • Experimental verification reveals that the current method is highly feasible. [ABSTRACT FROM AUTHOR]