Battery Pack Liquid Cooling Plate

The Battery Pack liquid cooling plate is a core component for thermal management of batteries in new energy vehicles, energy storage systems, and other industries. It achieves efficient temperature equalization of the battery pack through a high thermal conductivity metal substrate and microchannel flow channel structure. Its core technologies include double-sided cooling design (contact area ≥ 80%), microchannel flow resistance optimization (pressure drop ≤ 50kPa), phase change material composite (heat capacity increased by 30%), etc., adapted to the heat dissipation needs of high-energy density batteries (such as NCM811, LFP) in fast charging (≥ 3C) and high-power discharging (≥ 200kW) scenarios, ensuring that the temperature difference of the battery pack is ≤ 5 ℃ and the lifespan is extended by 20%.

2、 Core Features

1. Efficient heat conduction and temperature control

Thermal conductivity:

Data: The substrate is made of 6061-T6 aluminum alloy (thermal conductivity 167 W/m · K) or copper aluminum composite structure (copper layer thickness 1.5mm, thermal conductivity 398 W/m · K), which is 74% -315% higher than traditional die cast aluminum (96 W/m · K).

Case: Ningde Era CTP 3.0 liquid cooling plate adopts copper aluminum composite substrate, and the contact thermal resistance is reduced to 0.005 ℃ · in ²/W, which is matched with nano thermal conductive gel (thermal resistance 0.003 ℃ · in ²/W) to achieve the thermal resistance between the battery module and the liquid cooling plate ≤ 0.01 ℃ · in ²/W.

Temperature uniformity performance:

Data: By using dual inlet and dual outlet channels (channel width 0.8-1.2mm, depth 1.5-2mm) and wavy deflectors (wave height 3mm, wave distance 5mm), the temperature difference of the battery pack is controlled within ± 2 ℃ (at 2C discharge rate), which is 60% lower than the single inlet and single outlet channel scheme.

Test: When 3M coolant (FC-72, specific heat capacity 1.2 kJ/kg · K) is circulated at a flow rate of 1.5m/s, the convective heat transfer coefficient reaches 8000-12000 W/m ² · K, and the highest surface temperature of the battery is reduced by 25 ℃ compared to natural cooling.

2. Lightweight and structural strength

Density optimization:

Data: The density of aluminum alloy liquid cooled plate is 2.7g/cm ³, which is 69.7% lighter than that of copper liquid cooled plate (8.9g/cm ³). Taking the Tesla Model 3 liquid cooled plate as an example, the weight of a single piece has been reduced from 8.5kg in the copper solution to 2.6kg, resulting in a weight reduction of over 50kg and a 3-5% increase in range.

Composite material: Using carbon fiber reinforced polymer (CFRP) substrate (thermal conductivity of 5 W/m · K, density of 1.5g/cm ³) and metal flow channel composite, the weight is further reduced by 40%, suitable for ultra lightweight scenarios such as drone battery packs.

Mechanical properties:

Data: Yield strength ≥ 240MPa (T6 state), impact resistance (Charpy V-notch) ≥ 25J/cm ², passing cold and hot impact tests (1000 cycles) from -40 ℃ to 120 ℃ without cracks, suitable for harsh working conditions of battery pack vibration acceleration 15g (continuous for 10 hours).

Sealing: Laser welding flow channel is used (weld strength ≥ 80% of substrate strength), helium mass spectrometer leak detector detects leakage rate ≤ 1 × 10 ⁻⁹ Pa · m ³/s, reducing the risk of coolant leakage by 99%.

3. Corrosion resistance and reliability

Surface treatment:

Data: The substrate surface is coated with nickel phosphorus coating (thickness 5-10 μ m) or nano ceramic coating (hardness HV 800-1000), and the salt spray test (ASTM B117) shows no corrosion after 2000 hours, which is 6.7 times more corrosion-resistant than ordinary painting (300 hours).

Case: The BYD Han EV liquid cooling plate adopts nickel phosphorus coating and organic silicon sealing treatment, which is suitable for extreme environments such as high humidity in Hainan and saline alkali land in the north. The maintenance cost is reduced by 70% during the 10-year service life.

Frost resistance:

Data: The flow channel design reserves 5% expansion space, combined with ethylene glycol based coolant (freezing point -40 ℃), and has passed temperature cycling tests (500 cycles) from -50 ℃ to 120 ℃ without deformation. Compared with pure water cooling systems, the frost resistance is increased by 20 times.

Anti clogging design: A 200 mesh stainless steel filter screen is installed at the inlet of the flow channel, combined with a cooling liquid online filtration device (filtration accuracy of 10 μ m), with an impurity removal rate of ≥ 99%, to avoid microchannel blockage.

4. Cost effectiveness and mass production capability

Manufacturing cost:

Data: The cost of a single aluminum alloy liquid cooled plate is $15-25 (batch size of over 100000 pieces), which is 60% lower than the copper solution and 40% lower than the stamping+brazing process. The mold development cycle is 20-30 days, with a production capacity of 5000 pieces per day (8 hours), suitable for large-scale production.

Process comparison: Friction Stir Welding (FSW) replaces traditional brazing, increasing welding efficiency by three times, reducing energy consumption by 50%, and increasing weld strength by 40%. It is suitable for complex channel structures.

Customization flexibility:

Data: Supports customized design with channel width of 0.5-2mm and depth of 1-3mm, with a complexity factor of ≤ 8 (circumference ²/area). It can achieve gradient channel (inlet width 1.2mm → outlet 0.8mm), 3D curved channel and other irregular structures, adapting to different battery module layouts.

3、 Typical application scenarios and solutions

1. New energy vehicle power battery

Pure electric vehicle (BEV):

Structure: Double layer microchannel liquid cooling plate (channel spacing of 1.5mm, depth of 2mm), integrated with explosion-proof valve installation holes, battery module fixing slots, and insulation layer (thickness of 0.1mm).

Performance: Suitable for 800V high voltage platform, with a battery pack temperature difference of ≤ 3 ℃ and a thermal resistance of 0.02 ℃/W during fast charging (≥ 3C), meeting the requirement of a lifespan of 10 years/1.2 million kilometers.

Hybrid Electric Vehicle (HEV):

Structure: Copper aluminum composite liquid cooled plate (copper layer 1mm+aluminum layer 5mm), surface nickel plated electromagnetic shielding, built-in phase change material (PCM) heat absorbing layer (melting point 45 ℃).

Case: Toyota Prius battery pack liquid cooled plate, IGBT junction temperature ≤ 120 ℃ at peak power of 150kW, reduced by 20 ℃ compared to pure aluminum solution, and thermal runaway risk reduced by 80%.