1D-Thermal Analysis and Electro-Thermal Modeling of Prismatic-Shape LTO and NMC Batteries (original) (raw)
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2021
Li-ion batteries are nowadays widely used in electric vehicles, portable devices and smart grids. They are commercialized in different geometries, capacities and serval technologies depending on users' requirements. During operating time, heat is generated inside Li-ion batteries due to chemical reactions which causes temperature rise. Noncontrollable thermal behavior of these batteries may lead to the deterioration of their performance and may also cause a thermal runaway. In this study, A comparison of the thermal behavior of five li-ion batteries is performed. Used batteries are: LFP (lithium iron phosphate) prismatic (72Ah,60Ah,20Ah), NMC (Nickel Manganese Cobalt) prismatic (53Ah) and NMC cylindrical (3Ah). All batteries are tested under different climate conditions (0°C,10°C,20°C,30°C) and consecutive charge/discharge cycles were applied. The application of consecutive charge/discharge cycles aims to describe the temperature profiles and difference with the ambient in quasistationary regime. Constant current was used during each charge/discharge cycle, maximum and minimum voltage recommended by manufactures were chosen as cutoff voltage. T-type thermocouples are used to measure the temperature. The results show a 'V' shape during a cycle in quasi-stationary regime for all tested batteries. Moreover, the temperature difference increases for decreasing ambient temperature. The batteries specific heat capacity and thermal conductivities were experimentally measured. The results show a linear increase of the specific heat capacity for increasing ambient temperature while no dependency of thermal conductivity to ambient temperature was observed.
Heat generation in high power prismatic Li-ion battery cell with LiMnNiCoO 2 cathode material
While in use, battery modules and battery packs generate large amounts of heat, which needs to be accounted for. The main challenge in battery thermal management is the correct estimation of heat generation in the battery cell during charging/ discharging. In this paper, a method to calculate accurate heat generation in one individual cell is provided. The heat generation is calculated by measuring the overpotential resistances with four different methods and entropic heat generation in the cell. The effect and contribution of entropic heat generation towards the total heat generation in the cell are also calculated and measured. Finally, calorimeter tests are carried out to compare the calculated and measured heat generation.
In this experiment-based research, the performance and behaviour of a pouch type Li-ion battery cell are reported. The commercial test cell has a Lithium Titanate Oxide (LTO) based anode with 13Ah capacity. It is accomplished by measuring the evolution of surface temperature distribution, and the heat flux of the battery cell at the same time. Temperatures on the surface of the cell are measured using contact thermocouples, whereas, the heat flux is measured simultaneously by the isothermal calorimeter. This heat flux measurement is used for determining the heat generation inside the cell. Consequently, using the heat generation result the important performance constituent of the battery cell efficiency is calculated. Those are accomplished at different temperature levels (-5°C, 10°C, 25°C and 40°C) of continuous charge and discharge constant current rate (1C,2C,4C,8C,10C (maximum)). There is a significant change in heat generation in both charge and discharge events on different temperature and Crate. The heat flux change level is non-linear. This nonlinear heat flux is responsible for the nonlinear change of efficiency in different Crate in a particular temperature. The presented experimental technique is a very precise determination to profile the battery cell. The result of the research can be incorporated in constructing a precise datasheet for a battery cell which can assist the researchers, engineers, and different stakeholders to enhance different aspects of battery research. Keywords— Surface temperature; spatial distribution; Isothermal Calorimeter; Lithium Titanate Oxide (LTO), Battery thermal management, battery efficiency, heat Generation, key performance indicator (KPI), battery behaviour.
Measurements of heat generation in prismatic Li-ion batteries
Journal of Power Sources, 2014
h i g h l i g h t s Developed a calorimeter for heat generation measurement of prismatic batteries. Measured battery heat generation from À10 C to 40 C and 0.25Ce3C discharge rates. Observed endothermic heat flow at low discharge rates and 30 Ce40 C temperatures. Observed non-negligible heat of mixing at discharge rates as low as 0.25C. Observed a double plateau in battery discharge curve for 30 Ce40 C temperatures.
Thermal behavior of a commercial prismatic Lithium-ion battery cell applied in electric vehicles
Journal Paper, 2018
This paper mainly discusses the thermal behavior and performance of Lithium-ion batteries utilized in hybrid electric vehicles (HEVs), battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) based on numerical simulations. In this work, the battery’s thermal behavior is investigated at different C-rates and also contour plots of phase potential for both tabs and volume-monitored plot of maximum temperature inside the computational domain are illustrated. The numerical simulation is done via ANSYS Fluent traditional software package which utilizes the dual potential multi-scale multi-dimensional (MSMD) battery model to analyze the cell discharge behavior and investigate the thermal performance and potential variation(s). The results show that the maximum temperature of battery surface is proportional to the battery discharge rate, i.e., the higher the C-rate, the greater the cell surface temperature. Moreover, an increasing symmetric pattern is noticed for volume monitor of maximum temperature over the simulation period. Finally, it is worth noting that the battery tab potential varies more quickly if the C-rate becomes greater. In fact, the lowest and highest rate of changes are observed for 1C and 4C rate of discharging, respectively.
Batteries
Temperature prediction of a battery plays a significant role in terms of energy efficiency and safety of electric vehicles, as well as several kinds of electric and electronic devices. In this regard, it is crucial to identify an adequate model to study the thermal behavior of a battery. This article reports a comparative study on thermal modeling approaches by using a LiCoO2 26650 lithium-ion battery, and provides a methodology to characterize electrothermal phenomena. Three approaches have been implemented numerically—a thermal lumped model, a 3D computational fluid dynamics model, and an electrochemical model based on Newman, Tiedemann, Gu and Kim formulation. The last two methods were solved using ANSYS Fluent software. Simulations were validated with experimental measurements of the cell surface temperature at constant current discharge and under a highway driving cycle. Results show that the three models are consistent with actual temperature measurements. The electrochemical ...
2018
This paper represents a simulation model for a 2D-thermal model applied on a Lithium-ion pouch battery. This model is able to describe the transient response of the thermal distribution accurately. The heat generation parameters used in this model have been obtained experimentally from dedicated estimation technique. The experimental and simulation are performed at different charge and discharge current rates. The experimental results are in good agreement with the developed model. The battery thermal distributions using natural and forced convection cooling are studied.
Electro-thermal modeling and experimental validation for lithium ion battery
Journal of Power Sources, 2011
Thermal management is crucial for improving the charge-discharge efficiency and cycling life of lithium ion battery. In this paper, a mathematical model coupling electronic conduction, mass transfer, energy balance and electrochemical mechanism is developed. Lithium ion diffusivity and chemical reaction rate of cathode material are estimated by comparing simulated results with experimental data of pulse test at various current charge-discharge rates (0.2C, 0.5C, 1C, 2C) and operating temperatures (0 • C, 10 • C, 25 • C, 55 • C). The modeling results are further validated in aspects of electrochemical performance, thermal performance and electrochemical-thermal coupling effects, which show well agreement between the modeling results and experimental results. The modeling results show that lithium ion concentration gradient in both liquid phase and solid phase are greatly affected by temperature, and the lithium ion concentration gradient increase when temperature decrease. This phenomenon results in the capacity losses and power loses of lithium ion battery during low temperature operation. The reversible heat generation during charging process is equal with the heat consumption during discharging process. It is also indicated that the reversible heat is dominant at low rate discharging process and irreversible heat is dominant at high rate discharging process. Proper cooling system should be added to keep battery temperature within safety range during high rate current charging/discharging.