Prismatic Battery Research Articles

Experimental study on the low-temperature preheating performance of positive-temperature-coefficient heating film in the prismatic power battery module

The performance of a power battery directly affects the thermal safety performance of the vehicle. Aiming at the improvement of thermal safety of lithium-ion batteries under low temperature condition, this study focuses on the effect of the positive-temperature-coefficient (PTC) heating film on the heating performance of batteries through experimental testing. First, the side and bottom of the cell were heated, and the heat transfer path and mode of the single cell were analyzed. The effects of different power densities and geometric positions on the heating effect were studied by testing the heating time and temperature consistency. Second, for the battery module, a low-temperature heating thermal management heat transfer model was built to analyze the heating mechanism of the heating film under different heating power densities. Finally, the results of these studies were synthesized to obtain the optimal heating power density. The results show that for the cell, the optimum power density of side heating and bottom heating is 0.5 W /cm2 and 0.4 W /cm2, respectively. The time required for side heating from −20 °C to 10 °C is 730 s lower than that of bottom heating, and the maximum temperature difference is 1.885 °C lower. For battery modules, a power density of 0.5 W/cm2 was appropriate for both bottom and side heating methods. Due to the existence of heat conduction between battery packs, the battery modules will be quickly and evenly preheated. Under the optimal power density, the time length for side heating from –20 °C to 10 °C was 1459 s, and the maximum temperature difference was 6.32 °C; bottom heating time required slightly more time (1783 s), and the maximum temperature difference was 6.221 °C. Side heating can be beneficial for the rapid preheating of the battery module. This study will contribute to improving the performance and safety of batteries in cold environments.

MnO2 nanowires modified reduced graphene oxide thick film cathode for aqueous zinc-ion prismatic battery

Aqueous zinc-ion batteries are an excellent alternative to lithium-ion batteries that can meet the energy requirements while also being safe and eco-friendly. However, developing a suitable cathode material with good energy density and high-rate capability is challenging. In this study, we developed an aqueous zinc-ion battery with a high surface area MnO2 nanowires modified reduced graphene oxide nanocomposite screen printed interdigitated array electrodes and a distinctive aqueous electrolyte comprising 1 M each of ZnSO4 and Na2SO4, 0.1 M MnSO4, and 0.8 mM sodium dodecyl sulfate. The charge-discharge curves reveal that the cathode material exhibits a high reversible storage capacity of 164 mAh g−1 at a current density of 50 mA g−1. The battery retained 99.59% of its Coulombic efficiency after 300 cycles when cycled at a high current rate of 300 mA g−1. The prismatic battery realized exhibited a calculated energy density of 505.5 Wh kg−1 which is higher than previously reported works. On account of the large energy density and high rate capability coupled with non-toxic components, low cost and facile fabrication method, the Zn||MnO2/rGO battery shows good promise for energy storage application.

Simulation study on heat dissipation of a prismatic power battery considers anisotropic thermal conductivity in air cooling system

Heat accumulation could be occurred due to low thermal conductivity in one direction inside the power battery, which may lead to the decrease charging performance and potential thermal runaway. In this study, the impact of the anisotropic thermal conductivity (kx, ky, kz) on the temperature of the battery was analyzed. The anisotropic thermal conductivity was divided into the flow direction, thickness direction and spanwise conductivity. Then, the variation regularityof surface temperature distribution and heat flux are revealed by changing the anisotropic thermal conductivity. The results show that the increase of kx improves the heat dissipation efficiency of the upstream battery by 24 %. The higher thermal conductivity allows additional heat to be transferred from upstream to downstream along the direction of flow. The increase of kx makes the temperature difference only about 3 K, which improves the temperature uniformity of the battery. In addition, the impact of kx on the battery heat dissipation process is more dominant than ky and kz. However, there is an upper limit to the impact of ky on the battery temperature. When the ky exceeds 10 times the value of kx, the maximum temperature and temperature uniformity of the battery are almost unaffected by the change of ky. Meanwhile, the increase of kz has the minor effect on the temperature distribution of the battery surface. The anisotropic thermal conductivity is adjusted to reduce heat accumulation in the battery and improve the temperature uniformity. This work is beneficial to the engineering application of battery thermal management technology.

Cooling performance enhanced by integrating multicomponent phase change material and compression spring into air-cooled battery module

In order to improve the cooling efficiency and temperature consistency of the air-cooled prismatic battery module, a novel multicomponent phase change material-spring plate (MPCM-SP) was developed in this work. The MPCM was formed by combining lauric acid (LA), polyethylene glycol (PEG), palmitic acid (PA), and carboxylated multi-walled carbon nanotubes (MWCNT-COOH). The melting temperature of MPCM can be adjusted within the range 37 °C to 65 °C, and the associated latent heat of phase change varied from 159 J∙g−1 to 209 J∙g−1. The optimized proportions of LA, PEG, PA, and MWCNT-COOH achieved through multiple-objective optimization were 65.55 %, 7.07 %, 25.38 %, and 2.00 %, respectively. The cooling performance of the MPCM-SP was examined by experimental verification and numerical evaluation. The inclusion of MPCM-SP in the air-cooling system resulted in a reduction of 3.41 °C, 3.74 °C, and 3.32 °C in the maximum temperatures of the U-shaped, Z-shaped, and I-shaped battery modules, respectively. Moreover, the temperature difference was decreased by 3.60 °C, 3.16 °C, and 2.42 °C, respectively. Additionally, in comparison to a single battery, a battery equipped with MPCM-SP had a 32.8 % reduction in thermal deformation in the thickness direction under a thermal expansion coefficient of 4.06 × 10-6 K−1.

Numerical Investigation of the Thermal Performance of Air-Cooling System for a Lithium-Ion Battery Module Combined with Epoxy Resin Boards

Lithium-ion batteries (LIBs) have the lead as the most used power source for electric vehicles and grid storage systems, and a battery thermal management system (BTMS) can ensure the efficient and safe operation of lithium-ion batteries. Epoxy resin board (ERB) offers a wide range of applications in LIBs due to its significant advantages such as high dielectric strength, electrical insulation, good mechanical strength, and stiffness. This study proposes an air-cooled battery module comprised of sixteen prismatic batteries incorporating an ERB layer between the batteries. To compare the performance of the ERB-based air-cooling system, two other air-cooling structures are also assessed in this study. Three-dimensional numerical models for the three cases are established in this paper, and the heat dissipation processes of the battery module under varying discharge rates (1C, 2C, and 5C) are simulated and analyzed to comprehensively evaluate the performance of the different cooling systems. Comparative simulations reveal that incorporating ERB into the battery assembly significantly reduces battery surface temperatures and promotes temperature uniformity across individual batteries and the entire pack at various discharge rates. Notably, under 5C discharge conditions, the ERB-based thermal management system achieves a maximum battery surface temperature increase of 16 °C and a maximum temperature difference of 8 °C between batteries. Additionally, this paper also analyzes the impact of battery arrangement on air-cooling system performance. Therefore, further optimization of the structural design or the integration of supplementary cooling media might be necessary for such demanding conditions.

Performance Evaluation of a Novel Cold Plate with Double-Layer Interdigitated Flow Channels for Battery Thermal Management

Working temperature is a non-negligible factor that determines the operating performance of lithium-ion batteries which are extensively used in vehicles and the energy storage industry. Therefore, it is essential to maintain the battery temperature within an acceptable range while minimizing power consumption and ensuring uniform temperature distribution. To achieve these goals, a novel cold plate design with double-layer interdigitated flow channels is proposed in this study for efficient prismatic battery thermal management. The newly proposed cold plate design outperforms the serpentine-channel based cold plate under the same working conditions, resulting in significant improvements in both battery temperature and pressure drop. Specifically, the maximum temperature and temperature difference were reduced by over 10%, while the power cost was reduced by approximately 50%. By considering different arrangements of inlet and outlet locations, 32 non-repeating designs of the cold plate flow paths were examined. Relatively good inlet and outlet layouts are determined by comparing battery thermal management metrics including the maximum temperature, temperature difference, uniform index, and pressure drop, as well as the overall performance factors that consider both the battery temperature and power cost. In addition, the effects of the inlet flow velocity are examined to determine the optimal design.

Research Progress of Microchannel Liquid Cooling Technology in the Application of Thermal Management of Prismatic Lithium Batteries (Withdrawn)

Lithium-ion batteries have significant advantages such as high energy density, long cycle life and low self-discharge rate. Therefore, they are ideal for energy storage in electric vehicles. However, lithium-ion batteries are very sensitive to temperature, which affects the battery's cycle life, efficiency, reliability and safety. During the charging and discharging process, a large amount of heat is generated inside the battery due to the electrochemical reaction and resistance, causing the battery temperature to rise. When the temperature gets too high, thermal runaway, electrolyte fire and explosions may occur. As battery energy density increases, the demand for efficient thermal management continues to increase, and a compact and efficient battery thermal management system is essential. This paper introduces the development status of different thermal management technologies, reviews the application of microchannel liquid-cooling technology in the thermal management of prismatic lithium batteries, discusses the current research direction and status of microchannel technology, and finally looks forward to the future research and development direction of microchannel technology.

High-Energy Aqueous S-MnO2 Batteries with Redox Charge Carriers.

The energy densities of conventional aqueous batteries are often unsatisfactory due to the limited capacities of electrode materials. Therefore, the design of creative aqueous batteries has to be considered. Herein, aqueous S-MnO2 batteries are constructed by matching S/Cu2S redox couples and MnO2 deposition/dissolution. In such batteries, S/Cu2S redox couples undergo the solid-solid conversion reaction with four-electron transfer, ensuring a high specific capacity of 2220 mAh g-1 in S anodes. Furthermore, the conversion reaction of S/Cu2S redox couples can take place stably in acidic electrolyte that is essential for the MnO2 deposition/dissolution. As a result, the S/Cu2S redox couples can match MnO2 deposition/dissolution well, which endow the batteries with a membrane-free configuration. As a proof of concept, Ah-level prismatic and single-flow batteries were assembled and could operate stably for over 1000 h, demonstrating their great potential for large-scale energy storage. This work broadens the horizons of aqueous batteries beyond metal-manganese chemistry.

Study on Thermal Runaway Behavior and Jet Characteristics of a 156 Ah Prismatic Ternary Lithium Battery

Ternary lithium batteries have been widely used in transportation and energy storage due to their high energy density and long cycle life. However, safety issues arising from thermal runaway (TR) need urgent resolution. Current research on thermal runaway in large-capacity ternary lithium batteries is limited, making the study of hazard indicators during the thermal runaway ejection process crucial. This study places a commercial 156 Ah prismatic battery (positive electrode material: Li(Ni0.8Mn0.1Co0.1)O2, negative electrode material: graphite) in a nitrogen-filled sealed container, triggering thermal runaway through lateral heating. The experimental results show that the battery’s maximum surface temperature can reach 851.8–943.7 °C, exceeding the melting point of aluminum. Temperature surge inflection points at the battery’s bottom and near the small side of the negative electrode coincide with the inflection point on the heated surface. The highest jet temperatures at three monitoring points 50 mm, 150 mm, and 250 mm above the safety valve are 356.9 °C, 302.7 °C, and 216.5 °C, respectively. Acoustic signals reveal two ejection events. The average gas production of the battery is 0.089 mol/Ah, and the jet undergoes three stages: ultra-fast ejection (2 s), rapid ejection (32 s), and slow ejection (47 s). Post-thermal runaway remnants indicate that grooves from internal jet impacts are mainly located at ±45° positions. This study provides valuable insights for the safety design of batteries and the suppression of thermal runaway propagation.

Thermal runaway front propagation characteristics, modeling and judging criteria for multi-jelly roll prismatic lithium-ion battery applications

Large-format prismatic Li-ion batteries (LIBs) are prominent energy storage devices in electric transportation applications. However, large-format LIB induces severe thermal runaway (TR) disasters. Battery failure commonly initiates from a local point of one jelly roll and then propagates to the whole cell, called thermal runaway front (TRF) propagation. This study investigates the TRF propagation mechanism of multi-jelly roll-based LIBs through experiments, modeling, and theoretical analysis for thermal runaway propagation (TRP) mitigation. Experiments prove that battery venting changes along the jelly roll-safety valve directions during the TRF boundary movement. Besides, TRF propagation speed is found to be accelerated inside each cell (from 3.6 to 10.6 mm/s) during TRP, driven by a significant temperature gradient, chemical reactions, and gas flow along the TRP direction. The in-cell TRF acceleration behavior is more noticeable for batteries with more jelly rolls. The TRF speed-jelly roll index equations are proposed to reveal the propagation acceleration principle mathematically. Furthermore, a thermal-physical model is developed to precisely simulate in-cell TRF propagation behavior, which is validated by experimental data. Moreover, the TRF boundary temperature equation and “No TRP” judging criteria are proposed through theoretical analysis. This study proposes promising strategies for potential TRP suppression, contributing to future safe battery system design.

Venting particle-induced arc of lithium-ion batteries during the thermal runaway

Thermal runaway of lithium-ion batteries will release a large amount of particles with elevated temperature and high velocity, probably resulting in arc failures. In this study, we adopted an 117Ah fully-charged prismatic battery with Li(Ni0.8Co0.1Mn0.1)O2 cathode to collect the vented particles in an inert atmosphere after thermal runaway. All settled particles were classified into six groups to investigate the influence of electrode spacing, particle size and load resistance on the critical breakdown voltage as well as arc characteristics. As a result, a novel breakdown arc failure called venting particle-induced arc was firstly revealed and verified in the battery system. These settled particles significantly decrease the critical breakdown voltage for arc failure. The critical breakdown voltage exhibits a positively quadratic correlation with electrode spacing within 1–8 mm, while it is negatively correlated with particle sizes. Furthermore, a critical voltage map for breakdown arc under various particle sizes and electrode spacing was proposed. The results provide guidance to electrical hazards prevention in the battery system.

Editor's Note for article entitled “An electrochemical-thermal coupling model for heat generation analysis of prismatic lithium battery”

Editor's Note for article entitled “An electrochemical-thermal coupling model for heat generation analysis of prismatic lithium battery”

A hybrid battery thermal management system composed of MHPA/PCM/Liquid with a highly efficient cooling strategy

Hybrid battery thermal management system (BTMS) has received a lot of attention lately because of its excellent heat dissipation. However, the performance of hybrid BTMS is impacted by several elements, including basic technologies, structural design, and control methods. To improve the temperature and temperature uniformity of prismatic batteries, a novel hybrid BTMS composed of the U-shaped micro heat pipe array (U-MHPA) and the liquid cold plate filled with composite phase change material (cPCM) was proposed. Furthermore, a performance evaluation method and delayed cooling strategy were proposed and used to optimize the hybrid BTMS. Results showed that adhering a U-MHPA to the surface of the battery can effectively mitigate temperature non-uniformity in the prismatic battery. The cold plate filled with cPCM addressed the issue of significant temperature gradients parallel to the long flow direction of the cold plate. Compared to the single liquid cooling, the hybrid BTMS exhibited outstanding cooling performance under extreme operating conditions, reducing the Tmax of the battery module by 4.2 °C and the ΔTmax by 8.39 °C. The delayed cooling strategy based on the principles of phase change reduced the energy consumption of the hybrid thermal management system by 41.7%.

Thermal management lithium-ion battery for electric vehicles with using cold plate

Lithium-ion batteries are widely employed as the primary energy storage solution for electric vehicles (EVs). Effective thermal management of these batteries within EVs is important to ensure their safety, optimal performance, and longevity. Lithium-ion batteries are sensitive to fluctuations in temperature, and if not managed correctly, these temperature variations can lead to issues like overheating, reduced efficiency, and even safety risks. This study aims to investigate the effectiveness of a cooling method for a prismatic NMC battery used in electric vehicles. It emphasizes the significance of maintaining the battery's temperature within a specific range, typically between 15 °C and 35 °C, to prevent capacity loss and extend the battery's life. The design of the minichannel cold plate allows for precise thermal control with the 7 °C temperature difference. It efficiently absorbs heat generated during battery operation and releases it, preventing the battery from reaching undesirable temperature levels. Furthermore, the study underscores the importance of optimizing the contact area between the coolant and the battery stack for superior performance of the liquid cooling system. At higher discharge rates of the battery, a greater flow rate is required to achieve efficient cooling, with certain limitations due to the cooling system's efficiency. Overall, the study highlights the advantages of employing a liquid cooling system for proficient temperature regulation and effective heat dissipation in battery stacks for EVs.

Lithium-Ion Battery Thermal Runaway: Experimental Analysis of Particle Deposition in Battery Module Environment

In this paper, a novel experimental setup to quantify the particle deposition during a lithium-ion battery thermal runaway (TR) is proposed. The setup integrates a single prismatic battery cell into an environment representing similar conditions as found for battery modules in battery packs of electric vehicles. In total, 86 weighing plates, positioned within the flow path of the vented gas and particles, can be individually removed from the setup in order to determine the spatial mass distribution of the deposited particles. Two proof-of-concept experiments with different distances between cell vent and module cover are performed. The particle deposition on the weighing plates as well as the particle size distribution of the deposited particles are found to be dependent on the distance between cell vent and cover. In addition, the specific heat capacity of the deposited particles as well as the jelly roll remains are analyzed. Its temperature dependency is found to be comparable for both ejected particles and jelly roll remains. The results of this study help researches and engineers to gain further insights into the particle ejection process during TR. By implementing certain suggested improvements, the proposed experimental setup may be used in the future to provide necessary data for simulation model validation. Therefore, this study contributes to the improvement of battery pack design and safety.

A thermal management design using phase change material in embedded finned shells for lithium-ion batteries

Phase change material (PCM) has recently been regarded as a promising thermal management means for lithium-ion (Li-ion) batteries. However, solid-liquid phase change of many current PCMs occurs in a narrow temperature range, and the cooling performance of their liquid phase is rather poor. To tackle these issues, this article presents a battery thermal management (BTM) design which injects PCM into an aluminum shell around each cell, and machines the shell inner surfaces into a row of straight rectangular fins immersed into the PCM and its outer surfaces into a plain-fin shape exposed in the air. In the mild thermal conditions, the finned shells of two adjacent cells can be embedded and passive PCM cooling is employed. Once the PCM completely melts, the shells will move apart and an airflow will be driven through the gap between them. The BTM design can also protect Li-ion batteries in a freezing environment, by taking advantage of PCM solidification when the finned shells return to their embedded configuration. A series of experiments were conducted to examine its effectiveness on two 50Ah lithium nickel cobalt manganese oxide (NCM) prismatic batteries, which were discharged at a capacity-rate of 2C and at room temperatures of T0=25∘C, 40∘C and −10∘C. It is shown that in the battery discharge at T0=25∘C, PCM in the embedded finned shells effectively reduced the average battery-surface temperature (T¯) and the maximum temperature difference (ΔTmax) by 21% and 36.7%, respectively, compared to bare batteries. At T0=40∘C, this BTM design successfully limited the growth of T¯ to 9.0∘C and led to ΔTmax no more than 1.5∘C. As to the low-temperature scenario, it maintained the batteries at temperatures above T0 for 55.2% longer than those without any BTM protections. Its cooling performance was also compared with that of the conventional liquid-cooling scheme using a bottom serpentine-channel cooling plate. All these results clearly demonstrate that the BTM design in this article can compensate for the deficiencies of conventional PCM-based BTM schemes. Regardless of whether the PCM phase change is available, it has well coped with different thermal management demands of Li-ion batteries.

Experimental study on flame morphology, ceiling temperature and carbon monoxide generation characteristic of prismatic lithium iron phosphate battery fires with different states of charge in a tunnel

Lithium-ion battery (LIB) fire in a tunnel can generate a high-temperature environment, massive toxic and harmful smoke in a short period. This work carried out a series of thermal runaway (TR) experiments on large prismatic lithium cells in a model tunnel. Results showed that the flame height of LIBs with above 50 % SOC was above 40 cm for much time of the stage (Ⅰ) and (Ⅱ). The average flame height is further proposed to quantify the flame profile at different phases. The greater the SOC was, the higher the ceiling temperature and peak CO concentration were also relatively. For example, while decreasing the distance to the fire source from 0 m to -0.7 m, the peak ceiling temperature of 25 Ah batteries with 100 % SOC decreases from 309 °C to 118 °C, with a decay rate of 62 %. The CO concentration showed a comparable variation pattern to the tunnel ceiling temperature. Finally, a dimensionless relationship was employed to describe the ceiling temperature decay. Meanwhile, the ceiling maximum temperature rise for different capacity battery fires in a tunnel was integrated into a relational correlation. The study results are expected to further understand the battery fire hazards in tunnel.

Effects of the cold plate with airfoil fins on the cooling performance enhancement of the prismatic LiFePO4 battery pack

To maintain the optimal battery performance, it is essential to develop an efficient battery thermal management system for keeping the battery operation temperature within the appropriate range. In this work, a novel design of cold plate featuring airfoil fin channel is developed as a highly effective cooling module of a prismatic LiFePO4 battery pack. The thermal performance of battery and the thermo-hydraulic performance of the cooling module for the cold plate featuring airfoil fin channel, U-type channel and serpentine channel are numerically investigated and compared to reveal the superiority of the novel cold plate. The results indicate that compared with the U-type channel and the serpentine channel, the airfoil fin channel can enhance the total heat dissipation amount by 3.47% and 4.64%, respectively. Besides, the airfoil fin channel can provide the smallest battery maximum temperature and temperature difference under the same coolant flow rate. The airfoil fin channel provides the smallest pressure loss and heat transfer coefficient but the largest overall thermo-hydraulic performance indictor in terms of j/f factor. Under the same requirement of battery cooling performance, the remarkably smaller power consumption is required for the airfoil fin channel compared with the U-type channel and serpentine channel.

Revealing the electrochemical-mechanical correspondence between electrode films and 20 Ah prismatic Li-ion batteries via optical fiber monitoring

Revealing the connections and corresponding relationships between changes in the electrodes and cell-level strain variation can enhance the accurate estimation of state of charge (SOC), state of health (SOH), cycling life, safety and other key factors of the large capacity prismatic batteries. By utilizing Fiber Bragg Grating (FBG) sensors and a “Zero-strain” lithium titanate (LTO) electrode, we directly monitored the strain behaviors of LiFePO4 (LFP) and graphite electrodes. These strain measurements were further connected to the non-monotonic strain variation observed in a 20 Ah LFP||Graphite prismatic cell monitored by surface-implanted FBGs, whicih confirms that the strain variation results from electrode deformation. Furthermore, we demonstrate the feasibility of accurately estimating SOC and SOH of the prismatic cell based on strain profiles, achieving an absolute error below 3% and a relative error below 10% for SOC estimation, as well as the ability to indicate capacity degradation method for SOH monitoring. These results encourage the utilization of FBG strain monitoring in actual engineering applications.

Study on multi-channel air cooling thermal management of prismatic power battery pack

Study on multi-channel air cooling thermal management of prismatic power battery pack