Liquid Cooling Systems for EV Batteries

Electric vehicles (EV) are advancing rapidly, with increasing demand for enhanced technological support. One of the key challenges EVs is ensuring adequate power storage, a critical parameter being battery pack's ability to support high discharge rate. Achieving rate requires proper cell design and efficient heat management within pack. During discharge, generation becomes significant, necessitating an effective cooling system. Battery Thermal Management Systems (BTMS) employed regulate temperatures, optimal performance. Among various methods, liquid-based BTMS demonstrates superior performance compared phase-change materials (PCM) air cooling. However, weight liquid coolers, due volume coolant required, can add substantial battery, impacting overall vehicle efficiency. This paper investigates potential use mini channels integrated into plates applications. The study utilizes finite element method (FEM) simulate fluid flow processes in systems operating at C-rates. findings show that this novel effectively maintains temperatures below 40C, offering promising solution current limita... Read More

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This study presents an experimental investigation of a novel hybrid battery thermal management system (BTMS) that integrates solenoid-actuated Peltier-based heat sink with CuO/ethylene glycol (EG) nanofluid coolant loop. The delivers on-demand cooling through time-controlled thermoelectric operation, enhancing temperature regulation during surges. Experiments were conducted CuO nanoparticle concentrations ranging from 0.5% to 2.0% (vol.) and flow rates 1 5 LPM, at inlet 50C ambient 26C. Performance metrics such as drop, transfer rate, overall coefficient analyzed. Results showed maximum enhancement 40.63% (tube-side) 38.64% (air-side) CuO. Compared conventional liquid system, the setup demonstrated 7.01% higher rate improved variation control (up 28.53%). Life Cycle Cost (LCC) analysis demonstrates 25%30% reduction in long-term costs 36% life extension, supporting systems economic viability. scalable, energy-efficient BTMS offers promising solution for advanced electric vehicles requiring high-precision control.

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Battery cooling system for electric vehicles that prevents delays in cooling the battery pack when switching from cold to hot environments. The system uses a thermosiphon cooling circuit with condensers and coolers. If circulation stops due to liquid filling the circuit, it enters a vapor phase temperature rise control mode. This raises the condenser temperature to lower the liquid level, allowing circulation to restart sooner than waiting for natural evaporation. It also uses higher target refrigerant temperatures during circulation restart to further lower liquid levels. This prevents the condenser and coolers from fully filling with liquid when switching environments.

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Lithium-ion batteries have become a prominent ultimate choice due to their inherent advantages. However, performance is susceptible, especially at high temperatures arising out of fast charging and discharge rates. A good battery thermal management overcome runaway the temperature sensitivity power batteries. Liquid cooling with water as coolant has emerged an integral part electric vehicle-related research. For effective liquid cooling, use min-channel cold plates explored but complicated circuits flow. Present work deals with, two simple designs- Design 1 2, efficacy been tried by varying numbers channels, cross- section profile channels inlet mass flow rate under 3C 5C rates for prismatic pack. systematic extensive simulations are performed, using ANSYS FLUENT 2023 R1, maintaining uniform initial boundary conditions ambient pressure temperature, 300 K. To begin with,simulations performed on single cell extended up pack without mini-channel plate. It observed that 2 yielded better in terms lowest peak difference across cells marginally high-pressure drop zig-zag compared straight a... Read More

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Abstract Lithium-ion batteries (LiBs) are extensively used in stationary and transportation energy storage applications because of their high power densities. However, performance is temperature dependent, presenting challenges related to thermal management runaway risks. Direct liquid or immersion cooling provides a heat transfer rate by allowing direct contact with the LiBs. In contrast, single-phase dielectric fluids improve safety, reducing parasitic consumption space requirements. This work combines experimental numerical analysis assess an immersion-cooled 4S4P battery module, focusing on effects position fluid inlet outlet, flow type maximum temperature, rise uniformity. Although outlet positions had minimal impact rise, more substantial increase was observed when positioned at top compared center module. Among tested, highest 9.28 C mineral oil, while NOVEC 7000 showed lowest 6.24 C. As increased from 0.003 kg/s 0.010 kg/s, module decreased 4.02 non-uniformity dropped 3.41 Higher needed move through higher pressure drops. general, demonstrated superior among tested.

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Cooling device for electrical components like batteries that uses disruption elements inside the cooling channels to improve heat exchange. The channels have disruption elements like projecting protrusions on the sidewalls and bottom. These elements disrupt the fluid flow to create turbulence and acceleration. The elements are spaced with specific distances to optimize the heat transfer. The disruption elements are arranged on straight sections or bends of the channels. This design provides higher heat exchange coefficient compared to smooth channels for cooling electrical components like batteries.

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Abstract Inspired by leaf vein structures, this study presents a bioinspired channel liquidcooled plate designed to enhance thermal management performance. Topological optimization and crosssectional design are employed reduce flow resistance improve heat transfer efficiency. Among various shapes (rectangular, pentagonal, hexagonal, elliptical), the elliptical section exhibited superior Specifically, it achieves 31.7% improvement in temperature reduction capability (T) compared rectangular section, while also demonstrating 20.7% increase average velocity better uniformity. The material demonstrates excellent electrical properties suitable for hightemperature applications, as evidenced FTIR analysis, conductivity measurements (4.489 W m 1 K at 25 C 5.557 150 C), specific capacity (1.000 J g 1.276 resistivity (1.06 G cm with stability elevated temperatures). Infrared thermography shows significant reductions under initial temperatures, its being twice that of conventional straight channels. This highlights fluid efficiency, dissipation, structural plate, promi... Read More

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Thermal management system for electric vehicle batteries that allows individual cooling or heating of different zones within the battery to optimize performance and lifespan. The system uses multiple distinct circuits, each associated with a cooling zone, with independent flow control valves. A controller ranks the zones by temperature and adjusts the valves to balance cooling and heating based on the hottest and coldest zones. This provides customized cooling/heating to prevent hot spots and improve overall battery temperature management.

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Liquid immersion cooling (LIC) system for battery packs that uses stacked perforated separator plates between cell rows to distribute coolant fluid vertically upward between the cells. The separator plates have interconnected coolant channels with angled grooves on one plate aligned with opposite angled grooves on the other plate. This zigzag channel pattern creates a pressure differential that forces coolant to flow vertically between the cells. The perforated plates with angled channels stacked between cell rows improve LIC cooling by distributing the coolant fluid over and between the cells.

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Abstract Efficient thermal management of highpower lithiumion batteries (LiBs) is critical for ensuring safety, longevity, and performance in electric vehicles (EVs). Battery systems (BTMS) play a crucial role regulating temperature, as LiBs are highly sensitive to fluctuations. Excessive heat generation during charging discharging can degrade battery performance, reduce lifespan, pose safety risks. Traditional cooling methods, such air liquid cooling, often require additional power complex components, making them less effective highenergydensity batteries. As result, recent advancements focus on immersion, indirect, hybrid solutions. Among these, phase change material (PCM)based BTMS has emerged promising passive approach. PCMs efficiently absorb store heat, maintaining optimal temperature without external power. Their further enhanced by integrating expanded graphite (EG) fillers, metal foams, or fins, improving dissipation. This review examines progress (20192024) technologies, with particular PCM applications fastcharging conditions. It also discusses under e... Read More

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ABSTRACT This paper proposes an optimal control strategy for SOC balancing and introduces a framework analyzing the spatial temperature distribution in multipack battery energy storage system (BESS) composed of multiple modules. While various techniques exist to distribute power among parallelconnected systems, their influence on within modules is often neglected, despite being critical factor accelerating health degradation. To bridge this research gap, integrates 1D thermal simulation stateofhealth (SoH) estimation with split strategies. showcase application framework, comparative study two powersharing methods conducted: (i) Model Predictive Control (MPC) based State Charge (SoC) balancing, (ii) RuleBased (RBC) strategies, highlighting impact aging. Results show that MPC maintains more uniform profile, limiting peak temperatures 300 K minimizing SoH degradation, whereas RBC results higher (314 K) accelerated In summary, primarily intends to: Enable researchers further develop healthaware strategies BESS. Equip BESS operators detailed insights optimize manageme... Read More

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Battery cooling plate design to improve cooling uniformity and battery performance in electric vehicles. The cooling plate has a unique flow path configuration to distribute coolant flow more evenly across the plate surface. The coolant enters and exits along one edge, with a main section of the flow path extending along the other three edges. This main section separates the coolant flow from the plate edges. This prevents coolant heating progression that can cause temperature gradients. The plate also has turbulating inserts between the walls to further mix and distribute the coolant flow.

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With the rapid development of battery energy storage technology, issue thermal runaway (TR) in lithium-ion batteries has become a key challenge restricting their safe application. This study presents an innovative protection strategy that integrates liquid cooling with sodium acetate trihydrate (SAT)-based composite phase change materials (CPCM) to mitigate TR and its propagation prismatic modules. Through numerical simulation, this systematically investigates mechanism optimization pathways for The results indicate pure SAT exhibits poor latent heat performance due low conductivity. In contrast, incorporation expanded graphite (EG) significantly enhances conductivity improves overall performance. Compared traditional paraffin-expanded (PA-EG), SAT-EG, 4.8 times higher than PA-EG, demonstrates more six effectiveness delaying (TRP). When combined cooling, effect is further enhanced, will not be triggered when initial abnormal generation rate relatively low. Even if experiences TR, prevented thickness SAT-EG exceeds 12 mm. Ambient temperature influences both peak timing occurrence modu... Read More

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Direct liquid cooling technology has the potential to enhance thermal management performance of electric motors with continuously increasing energy density. However, direct practical limitations for full-scale commercialization. In addition, conventionally used indirect imposes higher resistance cope increased high power density motors. Therefore, this study proposes a hybrid directindirect oil system as next-generation strategy enhanced The heat transfer characteristics, including maximum winding, stator and motor housing temperatures, coefficient, friction factor, pressure drop, evaluation criteria (PEC), are investigated different spray hole diameters, coolant volume flow rates, loss levels. computational model was validated experimental results within 5% error developed evaluate characteristics. show that diameter significantly influences performance, larger (1.7 mm) reducing hydraulic while causing slight increase in temperatures. rate major impact on dissipation, an from 10 20 L/minute (LPM) stator, temperatures by 22.05%, 22.70% 24.02%, respectively. rates also resulted emp... Read More

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Thermal management system for electric vehicle battery packs that provides efficient cooling and heating without adding significant weight or cost. The system uses a network of flexible tubes connecting intake and exhaust manifolds with channels tuned for even fluid flow distribution. It allows direct contact cooling/heating of individual battery cells by conforming tubes passing between them. The system connects to a pump and heat exchanger for circulating fluid through the pack. The flexible tubes fill and bleed easily for installation. The manifold design prevents fluid bypassing and ensures full inflation.

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Battery pack design for electric vehicles that improves energy density, mechanical rigidity, and space utilization compared to conventional packs. The pack has a unique arrangement of battery modules inside a case. Each module has battery cells arranged in one direction, enclosed in a case with beams between the cells. The modules are fixed to the cover of the pack instead of a separate tray. This eliminates gaps, beams, and covers inside the pack. Cooling is integrated into the module base plate. The pack cover has a water channel to circulate cooling fluid around the modules. This reduces heat transfer path, parts, and space compared to separate heatsinks.

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Battery temperature regulating apparatus for vehicles that uses a heat exchanger and a radiator to regulate the temperature of an onboard battery while reducing power consumption. The apparatus has an onboard battery, a temperature regulating plate, a heat exchanger, a radiator, valves, and a control device. The heat exchanger has a heat source that allows heat exchange without using vehicle power. The control device determines if the battery temperature is above a threshold and if the heat source is mounted. If so, it opens valves to circulate the battery heat through the heat exchanger and radiator to lower temperature. This uses the heat source as a passive coolant source instead of active cooling.

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Electric vehicles (EVs) are pivotal in reducing greenhouse gas emissions and achieving sustainable transportation goals. However, lithium-ion batteries (LIBs), the primary energy source for EVs, face critical thermal management, safety, long-term efficiency challenges. This study proposes an integrated battery management system that combines a waterethylene glycol-based liquid cooling mechanism with high-conductivity copper tubing to enhance LIB performance, longevity, safety. Through COMSOL multiphysics simulations, this examines behavior under varying operational conditions. The results indicate 20% reduction temperature peaks, maintaining optimal range of 15C 35C, thus mitigating risks runaway. Experimental validation using infrared thermography imaging confirms system's efficiency, showing maximum recorded 43.48C load conditions, significantly lower than unmanaged systems. Beyond work integrates advanced strategies, including state-of-charge estimation, predictive fault diagnostics, active optimization, cell balancing. analysis further reveals proposed improves heat diss... Read More

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A thermal management system for battery packs in electric vehicles that provides uniform cooling to prevent overheating and improve battery life. The system uses a circulation pump, a cooling device, and a network of cooling pipes within the battery pack. The pipes have a first row below the pack, a second row above, and heat exchange pipes between. Coolant enters the lower row, flows through the pack, then exits the upper row. This slow flow time fully cools the pack. The cooling device cools the returning coolant. The lower row below the pack ensures complete cooling.

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Thermal management system for electric vehicles that allows both battery cooling and heating using a single chiller component. The system has a battery circuit, drive circuit, and refrigerant circuit. The chiller can operate in cooling mode to extract heat from the battery during charging or discharging, and in heating mode to provide heat to the battery during cold weather starts. This eliminates the need for a separate battery heater component. The chiller can switch between cooling and heating using a combination valve to redirect the refrigerant flow path.

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