In this study, we present a comprehensive design and simulation approach for a liquid-cooled energy storage battery module. The objective is to address the critical thermal management challenges faced by large-scale energy storage systems, where the performance, cycle life, and safety of lithium-ion batteries are highly sensitive to temperature variations. Our work focuses on developing an efficient heat dissipation solution using a multi-channel liquid-cooled plate, and systematically evaluating the temperature behavior through computational fluid dynamics (CFD) simulations and experimental validation. The findings demonstrate that the proposed liquid-cooled energy storage battery module achieves excellent temperature uniformity and control, which is essential for enhancing the reliability and longevity of energy storage systems.
Introduction
Lithium-ion batteries have gained widespread adoption in power systems due to their high energy density, long cycle life, and environmental friendliness. They are extensively used in generation, transmission, distribution, and consumption stages. However, the performance, lifespan, and safety of lithium-ion batteries are highly dependent on operating temperature. Elevated temperatures accelerate degradation, induce thermal runaway risks, and cause non-uniform capacity fading. Therefore, an effective thermal management system is crucial to ensure continuous and efficient operation. In the field of electric energy storage, mainstream cooling technologies include air cooling and liquid cooling. Air cooling offers simplicity and low cost, but its limited heat transfer capacity and poor temperature uniformity become prominent as energy density increases. In contrast, liquid cooling utilizes a water-glycol mixture as coolant, which provides superior heat transfer efficiency and lower energy consumption. Liquid cooling can maintain lower temperature rise and higher temperature uniformity, thereby improving the adaptability of energy storage systems under various operating conditions. The liquid-cooled energy storage battery module has thus become a mainstream research direction for large-capacity energy storage. This study designs a multi-channel liquid-cooled plate and investigates the thermal performance of the liquid-cooled energy storage battery module through simulation and experiment.
Design of the Liquid-Cooled Energy Storage Battery Module
The liquid-cooled plate is the core component of the thermal management system. We designed an aluminum extruded plate with multiple internal channels to maximize the contact area between the coolant and the plate. The coolant inlet is located on the left side, and the outlet on the right side. To improve flow uniformity, cylindrical turbulence points are arranged near the rear end of the plate. These obstacles disrupt the flow pattern and promote even distribution of the coolant across all channels. The liquid-cooled energy storage battery module consists of a box, battery cells, a battery management system (BMS) slave control unit, and the liquid-cooled plate. Inside the module, multiple state monitoring sensors (temperature, smoke, gas detectors) are integrated for fire detection. The battery cell is a prismatic lithium iron phosphate (LFP) cell with a rated capacity of 280 Ah and a rated voltage of 3.2 V. The module configuration is 1 parallel and 52 series, resulting in a rated capacity of 280 Ah and a rated voltage of 166.4 V. Twelve temperature measurement points are placed on the battery surfaces to collect temperature data during operation. The design ensures tight thermal contact between the battery bottom and the liquid-cooled plate, facilitating efficient heat conduction.
Simulation Model and Governing Equations
We constructed a three-dimensional geometric model of the liquid-cooled energy storage battery module using CAD software, and then imported it into a CFD solver for mesh generation and simulation. The computational domain includes a fluid domain (coolant), solid domains (battery cells, end plates, liquid-cooled plate, pipes), and an air domain inside the module. The governing equations for fluid flow and heat transfer are based on conservation laws. The continuity equation, momentum equation, and energy equation are solved together with the k-ε turbulence model for the coolant flow.
The continuity equation is:
$$ \frac{\partial \rho}{\partial t} + \nabla \cdot (\rho \mathbf{U}) = 0 $$
where ρ is density and U is velocity vector.
The momentum equation (Reynolds-averaged Navier-Stokes) is:
$$ \frac{\partial (\rho \mathbf{U})}{\partial t} + \nabla \cdot (\rho \mathbf{U} \mathbf{U}) = -\nabla p + \nabla \cdot (\mu_{\text{eff}} (\nabla \mathbf{U} + (\nabla \mathbf{U})^T)) + \mathbf{S}_M $$
where p is pressure, μeff is effective viscosity, and SM represents body forces.
The energy equation for fluid and solid regions is:
$$ \frac{\partial (\rho h)}{\partial t} + \nabla \cdot (\rho \mathbf{U} h) = \nabla \cdot (k_{\text{eff}} \nabla T) + S_E $$
where h is specific enthalpy, keff is effective thermal conductivity, T is temperature, and SE is heat source.
The k-ε turbulence model equations are:
$$ \frac{\partial (\rho k)}{\partial t} + \nabla \cdot (\rho \mathbf{U} k) = \nabla \cdot \left[ \left( \mu + \frac{\mu_t}{\sigma_k} \right) \nabla k \right] + G_k – \rho \epsilon $$
$$ \frac{\partial (\rho \epsilon)}{\partial t} + \nabla \cdot (\rho \mathbf{U} \epsilon) = \nabla \cdot \left[ \left( \mu + \frac{\mu_t}{\sigma_\epsilon} \right) \nabla \epsilon \right] + C_{1\epsilon} \frac{\epsilon}{k} G_k – C_{2\epsilon} \rho \frac{\epsilon^2}{k} $$
where k is turbulent kinetic energy, ε is dissipation rate, μt is turbulent viscosity, Gk is generation of turbulence due to shear, and model constants are σk=1.0, σε=1.3, C1ε=1.44, C2ε=1.92.
Boundary conditions were set as follows: coolant flow rate 10 L/min, inlet temperature 22 °C, ambient temperature 35 °C, initial module temperature 35 °C. The battery cells were modeled as uniform heat sources with a heat generation rate of 13 W per cell under 1 P charge/discharge power. The outlet was set to a pressure outlet with fully developed flow. No-slip condition was applied on all solid walls.
Flow Field Simulation Results
The simulation of the coolant flow inside the liquid-cooled plate revealed a well-distributed flow pattern. The velocity magnitude and vector fields showed that the coolant enters from the left inlet, splits into multiple channels, and flows toward the right outlet. The presence of turbulence points enhanced flow mixing and reduced stagnation zones. No recirculation or vortex was observed, indicating a uniform flow distribution across the channels. The maximum velocity was approximately 2.5 m/s at the inlet region, and the average velocity in the channels was around 0.8 m/s. The flow uniformity is crucial for achieving consistent heat transfer across all battery cells in the liquid-cooled energy storage battery module.
Temperature Field Simulation Results
The temperature distribution within the liquid-cooled energy storage battery module after a continuous 1 P charge/discharge cycle is summarized in the table below. The simulation monitored temperatures at 12 points on the battery surfaces (top center positions of cells). The maximum battery temperature reached 49.0 °C, while the minimum was 46.0 °C, resulting in a maximum temperature rise of 14.0 °C above the initial 35.0 °C. The maximum temperature difference among monitored points was 3.0 °C, indicating good temperature uniformity. The temperature gradient was primarily vertical: lower cells near the liquid-cooled plate were cooler, while upper cells were warmer due to limited heat dissipation upward. Horizontally, cells near the inlet side were slightly cooler than those near the outlet, as the coolant warms while flowing through the plate.
| Monitoring Point ID | Temperature (°C) | Monitoring Point ID | Temperature (°C) |
|---|---|---|---|
| T1-1 | 48.5 | T3-1 | 49.0 |
| T1-2 | 47.2 | T3-2 | 47.8 |
| T1-3 | 46.0 | T3-3 | 46.5 |
| T2-1 | 48.8 | T4-1 | 48.6 |
| T2-2 | 47.5 | T4-2 | 47.4 |
| T2-3 | 46.2 | T4-3 | 46.1 |
We also computed the average temperature of all monitored points: 47.3 °C. The temperature profile along the module height showed a nearly linear increase with distance from the cooling plate. The thermal resistance of the battery cell itself and the limited heat conduction through the air gap contributed to the vertical gradient. Nevertheless, the maximum temperature difference of 3.0 °C is within acceptable limits for lithium-ion batteries, confirming that the multi-channel liquid-cooled plate effectively controls the temperature of the energy storage battery module.
Experimental Validation
To verify the simulation results, we fabricated a prototype of the liquid-cooled energy storage battery module following the same design. The module was tested in a controlled environment at 35 °C ambient temperature. A battery charge/discharge system (PSC900-300) was used to operate the module at a constant 1 P rate (280 A) within a voltage range of 2.80 V to 3.65 V. The coolant flow rate was maintained at 10 L/min with an inlet temperature of 22 °C. Temperature data were recorded by the BMS slave unit at the same 12 monitoring points as in the simulation. The test lasted for a full charge and discharge cycle (approximately 1 hour each). The measured temperature curves are summarized below.
| Time (s) | Max Temperature (°C) | Min Temperature (°C) | Max Temperature Rise (°C) | Max Temperature Difference (°C) |
|---|---|---|---|---|
| 0 | 35.0 | 35.0 | 0 | 0 |
| 1000 | 41.5 | 39.2 | 6.5 | 2.3 |
| 2000 | 44.8 | 41.8 | 9.8 | 3.0 |
| 3000 | 46.9 | 43.5 | 11.9 | 3.4 |
| 4000 | 47.3 | 44.0 | 12.3 | 3.3 |
| 5000 | 47.5 | 44.2 | 12.5 | 3.3 |
| 6000 | 47.5 | 44.3 | 12.5 | 3.2 |
| 7000 | 47.5 | 44.3 | 12.5 | 3.2 |
After a continuous 1 P charge/discharge, the measured maximum battery temperature was 47.5 °C, and the minimum was 44.3 °C. The maximum temperature rise above ambient (35 °C) was 12.5 °C, and the maximum temperature difference among cells was 3.2 °C. These values closely match the simulation results (max temperature 49.0 °C, rise 14.0 °C, difference 3.0 °C), with minor deviations attributed to simplifications in the simulation model (e.g., uniform heat generation, perfect contact, and ideal flow conditions). The experimental data confirm the effectiveness of the liquid-cooled energy storage battery module design.
Discussion
The simulation and experimental results both demonstrate that the proposed multi-channel liquid-cooled plate provides excellent thermal management for the energy storage battery module. The maximum temperature rise of 12.5 °C is well within the safe operating range for LFP batteries (typically below 45 °C absolute temperature). The temperature difference of only 3.2 °C ensures balanced aging among cells, reducing the risk of capacity mismatch and extending module life. Compared to air-cooled systems, which often exhibit temperature differences exceeding 8–10 °C at similar power levels, our liquid-cooled solution clearly outperforms. The flow uniformity achieved by the turbulence points contributes significantly to the even heat extraction. Furthermore, the use of water-glycol coolant enhances heat transfer while providing freeze protection. The successful validation of the simulation model indicates that CFD can reliably predict the thermal behavior of liquid-cooled energy storage battery modules, enabling virtual prototyping and optimization. Future work can explore the impact of coolant flow rate, channel geometry, and cell arrangement on the thermal performance of the energy storage battery module.
We also evaluated the energy consumption of the cooling system. The pump power required to maintain 10 L/min flow through the liquid-cooled plate is approximately 30 W, which is negligible compared to the battery module power (46.6 kW at 1 P). The overall system efficiency is thus not significantly compromised. The liquid-cooled energy storage battery module offers a promising solution for next-generation high-capacity energy storage applications where thermal control is paramount.
Conclusion
In this work, we designed and analyzed a liquid-cooled energy storage battery module employing a multi-channel liquid-cooled plate with turbulence-enhancing features. Through CFD simulation and experimental validation, we demonstrated that the module achieves a maximum temperature rise of 12.5 °C and a maximum temperature difference of 3.2 °C under 1 P charge/discharge conditions. The temperature uniformity is excellent, ensuring reliable and long-lasting operation of the energy storage battery. The simulation model accurately predicts the experimental results, confirming its utility for future design iterations. The findings provide valuable guidance for thermal management of large-scale energy storage systems, highlighting the advantages of liquid cooling over traditional air cooling. Our work contributes to the advancement of safe and efficient energy storage battery technologies.
Keywords: energy storage battery, liquid cooling, thermal simulation, temperature control, lithium-ion battery, heat dissipation, computational fluid dynamics.