Calorimetric Methods and Thermal Management of Lithium-ion batteries: A mini-review

Lithium-ion batteries can be employed in dissimilar applications, including grid integration, electric vehicles, grid support, and consumer electronics. Lithium-ion batteries are one of the most important tools for storing electrical energy. These tools are important because of their widespread use in industry. Therefore, modelling lithium-ion batteries and examining their temperature distribution and heat transfer is very important mostly for safety concerns. Therefore, the study of battery heat transfer helps designers to propose and develop a suitable cooling system. Different sources including overpotential contribute to heat generation. Different understandings were achieved from the previous modelling and experimental studies which involve the necessity for more accurate heat generation measurements of lithium-ion batteries, and improved modelling of the heat generation specifically comprehended at big discharge and charge rates for different applications including electric vehicles

A model-based approach for temperature estimation of a lithium-ion battery pack

Temperature is an essential factor that substantially impacts lithium-ion batteries\u27 cycle lifetime, capacity, safety, and heat loss. The present investigation analyses the influence of the lithium-ion battery cell\u27s current rate on its temperature and thermal behaviour. The experiments were fulfilled at different discharge and charge cycles with different current rates. In this study, the thermal behaviour of a lithium-ion battery was analyzed at different current rates by employing a model-based approach from MATLAB. A correlation was seen between the current rate of the lithium-ion battery and the most remarkable temperature growth. The results would produce a more robust understanding of the temperature evolution of the lithium-ion battery cell for various applications. A smaller temperature was seen on the upper part of the lithium-ion battery pack

A Regression-Based Technique for Capacity Estimation of Lithium-Ion Batteries

Electric vehicles (EVs) and hybrid vehicles (HEVs) are being increasingly utilized for various reasons. The main reasons for their implementation are that they consume less or do not consume fossil fuel (no carbon dioxide pollution) and do not cause sound pollution. However, this technology has some challenges, including complex and troublesome accurate state of health estimation, which is affected by different factors. According to the increase in electric and hybrid vehicles’ application, it is crucial to have a more accurate and reliable estimation of state of charge (SOC) and state of health (SOH) in different environmental conditions. This allows improving battery management system operation for optimal utilization of a battery pack in various operating conditions. This article proposes an approach to estimate battery capacity based on two parameters. First, a practical and straightforward method is introduced to assess the battery’s internal resistance, which is directly related to the battery’s remaining useful life. Second, the different least square algorithm is explored. Finally, a promising, practical, simple, accurate, and reliable technique is proposed to estimate battery capacity appropriately. The root mean square percentage error and the mean absolute percentage error of the proposed methods were calculated and were less than 0.02%. It was concluded the geometry method has all the advantages of a recursive manner, including a fading memory, a close form of a solution, and being applicable in embedded systems

Thermal Characteristics and Safety Aspects of Lithium-Ion Batteries: An In-Depth Review

This paper provides an overview of the significance of precise thermal analysis in the context of lithium-ion battery systems. It underscores the requirement for additional research to create efficient methodologies for modeling and controlling thermal properties, with the ultimate goal of enhancing both the safety and performance of Li-ion batteries. The interaction between temperature regulation and lithium-ion batteries is pivotal due to the intrinsic heat generation within these energy storage systems. A profound understanding of the thermal behaviors exhibited by lithium-ion batteries, along with the implementation of advanced temperature control strategies for battery packs, remains a critical pursuit. Utilizing tailored models to dissect the thermal dynamics of lithium-ion batteries significantly enhances our comprehension of their thermal management across a wide range of operational scenarios. This comprehensive review systematically explores diverse research endeavors that employ simulations and models to unravel intricate thermal characteristics, behavioral nuances, and potential runaway incidents associated with lithium-ion batteries. The primary objective of this review is to underscore the effectiveness of employed characterization methodologies and emphasize the pivotal roles that key parameters—specifically, current rate and temperature—play in shaping thermal dynamics. Notably, the enhancement of thermal design systems is often more feasible than direct alterations to the lithium-ion battery designs themselves. As a result, this thermal review primarily focuses on the realm of thermal systems. The synthesized insights offer a panoramic overview of research findings, with a deeper understanding requiring consultation of specific published studies and their corresponding modeling endeavors

Simulation, Set-Up, and Thermal Characterization of a Water-Cooled Li-Ion Battery System

A constant and homogenous temperature control of Li-ion batteries is essential for a good performance, a safe operation, and a low aging rate. Especially when operating a battery with high loads in dense battery systems, a cooling system is required to keep the cell in a controlled temperature range. Therefore, an existing battery module is set up with a water-based liquid cooling system with aluminum cooling plates. A finite-element simulation is used to optimize the design and arrangement of the cooling plates regarding power consumption, cooling efficiency, and temperature homogeneity. The heat generation of an operating Li-ion battery is described by the lumped battery model, which is integrated into COMSOL Multiphysics. As the results show, a small set of non-destructively determined parameters of the lumped battery model is sufficient to estimate heat generation. The simulated temperature distribution within the battery pack confirmed adequate cooling and good temperature homogeneity as measured by an integrated temperature sensor array. Furthermore, the simulation reveals sufficient cooling of the batteries by using only one cooling plate per two pouch cells while continuously discharging at up to 3 C

Progress in thermal management and safety of cells and packs by testing in battery calorimeters

With increasing energy density the safety and the thermal management of Li-ion batteries is becoming more and more important, because the thermal runaway can cause an ignition or even explosion of the battery with simultaneous release of toxic gases. In the last nine years we have established battery calorimetry as a powerful and versatile electrochemical-thermal characterization technique, which allows both advancements for the thermal management and the safety of batteries. With six adiabatic Accelerating Rate Calorimeters (ARC) of different sizes and two sensitive Tian-Calvet calorimeters, all of them combined with cyclers, the IAM-AWP now operates Europe’s largest battery calorimeter center, which enables the evaluation of thermodynamic, thermal and safety data on material, cell and pack level under quasiadiabatic and isoperibolic environments for both normal and abuse conditions (thermal, electrical, mechanical). It will be shown how sophisticated battery calorimetry allows finding new and quantitative correlations between different critical thermally and safety related parameters that will help to design safer systems. For an optimized design with regard to safety cells and packs have to be characterized not only for their temperature behavior but also for the heat dissipation and the pressure development in a quantitative manner. Calorimetry allows the collection of quantitative data required for optimum battery performance and safety. This information can then be used to define the requirements for cooling and thermal management and adapt them accordingly. The battery calorimeters can be used for studies on heat generation and dissipation of Li-ion cells and are coupled to a battery cycler in order to perform the measurements during charging and discharging of the cells under defined thermal conditions. Isoperibolic (constant temperature of the calori-meter) or quasiadiabatic (no heat exchange with the calorimeter) ambient conditions are adjusted by heaters and thermocouples that are located in lid, bottom and side walls of the calorimeter chamber, in which the cell is inserted. For improving the thermal management system, the measured temperature data are converted into generated and dissipated heat data [1] by determination of specific heat capacity and heat transfer coefficient using heat flux sensors. Concerning safety aspects it will be presented how battery calorimeters provide thermal stability data on materials level, e.g. of anodes, cathodes or electrolytes or there combinations and to perform safety tests on cell and pack level by applying thermal [2], mechanical or electrical [3] abuse conditions. The studies on materials level are especially important for Post-Li cells, which make use of more abundant materials, such as sodium or magnesium instead of Li, nickel and cobalt, because these data help to develop safe cells from the beginning all along the value chain. For the advanced Li-ion technology, a holistic safety assessment is in the focus, because the thermal runaway can have multiple interacting causes and effects. A test in the calorimeter is much more sensitive than a hotbox test and reveals the entire process of the thermal runaway with the different stages of exothermic reactions. Self-heating, thermal stability and thermal runaway are characterized and the critical parameters and their thresholds for safe cell operation are determined. As a result of the different tests quantitative and system relevant data for temperature, heat and pressure development of materials and cells are provided. In addition it will be explained how calorimeters allow studying the thermal runaway propagation in order to develop and qualify suitable countermeasures, such as heat protection barriers, which is currently becoming a very hot topic, because a global technical regulation (GTR) on electric vehicle safety is being developed, which includes thermal propagation. There is still the open question, which is the best initialization method to become a standard. We hope that the research in the Calorimeter Center will help to make progress in this field as well. References: [1] C. Ziebert et al., in: L.M. Rodriguez, N. Omar, eds., EMERGING NANOTECHNOLOGIES IN RECHARGABLE ENERGY STORAGE SYSTEMS, Elsevier Inc., ISBN 978032342977, 195-229. 2017. [2] B. Lei, W. Zhao, C. Ziebert, et al., Experimental analysis of thermal runaway in 18650 cylindrical cells using an accelerating rate calorimeter, Batteries 3 (2017) 14, doi:10.3390/batteries3020014.. [3] A. Hofmann, N. Uhlmann, C. Ziebert, O. Wiegand, A. Schmidt, Th. Hanemann, Preventing Li-ion cell explosion during thermal runaway with reduced pressure, Appl. Thermal Eng. 124 (2017) 539-544

Modeling and Simulation the Thermal Runaway Behavior of Cylindrical Li-Ion Cells—Computing of Critical Parameter

The thermal behavior of Li-ion cells is an important safety issue and has to be known under varying thermal conditions. The main objectives of this work is to gain a better understanding of the temperature increase within the cell considering different heat sources under specified working conditions. With respect to the governing physical parameters, the major aim is to find out under which thermal conditions a so called Thermal Runaway occurs. Therefore, a mathematical electrochemical-thermal model based on the Newman model has been extended with a simple combustion model from reaction kinetics including various types of heat sources assumed to be based on an Arrhenius law. This model was realized in COMSOL Multiphysics modeling software. First simulations were performed for a cylindrical 1860 cell with a -cathode to calculate the temperature increase under two various simple electric load profiles and to compute critical system parameters. It has been found that the critical cell temperature [Math Processing Error] , above which a thermal runaway may occur is approximately [Math Processing Error] , which is near the starting temperature of the decomposition of the Solid-Electrolyte-Interface in the anode at [Math Processing Error] . Furthermore, it has been found that a thermal runaway can be described in three main stages

Thermophysical Properties of Lithium Aluminum Germanium Phosphate with Different Compositions

The NASICON system LAGP (Li$_{1+x}$Al$_{x}$Ge$_{2-x}$ (PO$_{4}$)$_{3}$ was studied, which is a candidate material for solid state electrolytes. LAGP substrates with different compositions (x = 0.3–0.7) were prepared using a melt quenching route with subsequent heat treatment. In order to develop a better understanding of the relationships between the structure and the ionic as well as the thermal conductivity, respectively, the samples were characterized by X-ray diffraction. The ionic conductivity was measured using impedance spectroscopy while the thermal diffusivity and the specific heat were determined by Laser Flash technique and differential scanning calorimetry, respectively. Additionally, thermal analysis was performed in order to evaluate the thermal stability a higher temperatures and, also to identify the optimum temperature range of the thermal post-processing. The measured values of the ionic conductivities were in the range of 10$^{-4}$Ω$^{-1}$·cm$^{-1}$ to 10$^{-3}$ Ω$^{-1}$·cm$^{-1}$ at room temperature, but exhibited an increasing behavior as a function of temperature reaching a level of the order 10$^{-2}$ Ω$^{-1}$· cm$^{-1}$ above 200 °C. The thermal conductivity varies only slowly as a function of temperature but its level depends on the composition. The apparent specific heat depends also on the composition and exhibits enthalpy changes due to phase transitions at higher temperatures for LAGP samples with x > 0.5. The compositional dependencies of the ionic and thermal transport properties are not simply correlated. However, the compound with the highest Li-doping level shows the highest ionic conductivity but the lowest thermal conductivity, while the lowest doping level is associated with highest thermal conductivity but the lowest ionic conductivity

A Review on Temperature-Dependent Electrochemical Properties, Aging, and Performance of Lithium-Ion Cells

Temperature heavily affects the behavior of any energy storage chemistries. In particular, lithium-ion batteries (LIBs) play a significant role in almost all storage application fields, including Electric Vehicles (EVs). Therefore, a full comprehension of the influence of the temperature on the key cell components and their governing equations is mandatory for the effective integration of LIBs into the application. If the battery is exposed to extreme thermal environments or the desired temperature cannot be maintained, the rates of chemical reactions and/or the mobility of the active species may change drastically. The alteration of properties of LIBs with temperature may create at best a performance problem and at worst a safety problem. Despite the presence of many reports on LIBs in the literature, their industrial realization has still been difficult, as the technologies developed in different labs have not been standardized yet. Thus, the field requires a systematic analysis of the effect of temperature on the critical properties of LIBs. In this paper, we report a comprehensive review of the effect of temperature on the properties of LIBs such as performance, cycle life, and safety. In addition, we focus on the alterations in resistances, energy losses, physicochemical properties, and aging mechanism when the temperature of LIBs are not under control