Immersion Liquid Cooling for Uniform Battery Pack Temperature

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Solution Overview

Problem

Conventional indirect contact liquid cooling methods for batteries, such as cold plate liquid cooling, suffer from high thermal resistance and limited heat exchange areas, leading to uneven temperature distribution and inefficient cooling of high-heat generating parts like battery tabs, affecting the performance and safety of lithium batteries.

Innovation Solution

An immersion liquid cooling system where batteries are directly immersed in a heat transfer medium, with heat dissipation and management modules to regulate temperature through direct contact, using heat transfer fins and a valve system to control heat exchange paths, allowing for efficient heating or cooling based on temperature needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If indirect contact liquid cooling (cold plate liquid cooling) is used to cool the battery, then the structure is simple and easy to implement, but the thermal resistance for heat transfer is high and the heat exchange area is limited

Engineering Contradiction:
Improveease of implementationVSAvoidthermal resistance
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent introduces a heat transfer medium as an intermediary substance that directly contacts the battery to facilitate heat transfer. The heat transfer medium serves as a mediator between the battery and the cooling system, enabling direct heat exchange without requiring complex thermal contact interfaces, thus reducing thermal resistance while maintaining system simplicity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a liquid heat transfer medium circulating through the system to transfer heat from the battery. By utilizing hydraulic principles with the circulating liquid medium, the system achieves efficient heat removal from the battery tabs and surfaces without requiring direct solid-to-solid thermal contact, thereby reducing thermal resistance

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of manufacture

If indirect contact liquid cooling is used to cool the battery, then the structure is simple, but the area of heat exchange between the battery module and the liquid cooling plate is limited

Engineering Contradiction:
Improvestructural simplicityVSAvoidheat exchange area
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The heat transfer medium acts as an intermediary that extends the heat exchange interface throughout the battery structure. Rather than being constrained to a limited plate surface area, the liquid medium can penetrate and contact multiple surfaces including battery tabs, edges, and internal structures, effectively increasing the heat exchange area while keeping the overall structure simple

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transitions from two-dimensional plate-to-surface heat exchange to three-dimensional immersive heat transfer. The heat transfer medium surrounds and contacts the battery from multiple directions and dimensions, including top, bottom, sides, and internal surfaces, thereby dramatically increasing the effective heat exchange area without complicating the structural design

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If indirect contact liquid cooling is used, then the cooling system is simple to implement, but it is difficult to directly cool high-heat generating parts such as battery tabs, resulting in high temperature of the battery tab

Engineering Contradiction:
Improveease of implementationVSAvoidbattery tab temperature
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The heat transfer medium serves as a direct intermediary contact with the battery tabs, which are high-heat generating parts. The liquid medium can directly wet and contact the tab surfaces, providing efficient heat removal from these critical high-temperature zones without requiring complex targeted cooling structures

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies local quality by allowing the heat transfer medium to selectively contact and cool different regions of the battery with varying thermal requirements. The medium can directly reach and cool the battery tabs and other high-heat generating parts more intensively, while maintaining appropriate cooling for other battery surfaces, thus addressing local thermal management needs effectively

Inventive Principle:
Principle #3Local quality

4Ease of manufacture

If indirect contact liquid cooling is used, then the system structure is simple, but the overall temperature uniformity of the battery is poor

Engineering Contradiction:
Improvesystem simplicityVSAvoidtemperature uniformity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The heat transfer medium acts as a unifying intermediary that distributes thermal energy uniformly across all battery surfaces it contacts. By immersing or surrounding the battery, the medium ensures consistent heat exchange across different battery regions, promoting uniform temperature distribution while maintaining system structural simplicity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies homogeneity by using a uniform heat transfer medium that provides consistent thermal interaction across all battery surfaces. The medium ensures homogeneous heat exchange conditions throughout the battery structure, eliminating temperature gradients and achieving uniform temperature distribution across different battery regions

Inventive Principle:
Principle #33Homogeneity

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves uniform temperature distribution and improved thermal efficiency, ensuring batteries operate at optimal temperatures, enhancing performance and safety by reducing thermal resistance and effectively cooling or heating critical components.

Implementation Method 1

the battery exchanges heat with the second heat transfer medium through direct contact, so that thermal resistance for heat transfer is low

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the first heat transfer medium circulates among the energy storage module, the thermal management module, and the heat dissipation module

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the thermal management module is configured to heat or cool the first heat transfer medium

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

when the battery has a high temperature and needs to dissipate heat, the first heat transfer medium may be cooled by using the thermal management module

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 5

the heat dissipation module is configured to dissipate heat generated by the immersion liquid cooling energy storage system to an external environment

Methodology Applied
Scientific EffectHeat dissipation: Thermal Radiation

Data Source

PatentEP4697452A1Immersion liquid-cooling energy storage system
Publication Date: 2026.02.18 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4697452A1 patent drawingFigure 1
  • EP4697452A1 patent drawingFigure 2~3
  • EP4697452A1 patent drawingFigure 4~5

AI summary

This application provides an immersion liquid cooling energy storage system. The immersion liquid cooling energy storage system includes an energy storage module, a thermal management module, a heat dissipation module, a pipe system, and a valve module. The energy storage module includes a battery liquid-collecting tank, a battery capsule, and a battery. The battery liquid-collecting tank is configured to accommodate the battery capsule, the battery liquid-collecting tank is filled with a first heat transfer medium, and the first heat transfer medium is configured to heat or cool the battery capsule. The battery capsule is configured to accommodate the battery, the battery capsule is filled with a second heat transfer medium, and the second heat transfer medium is configured to heat or cool the battery. The thermal management module is configured to heat or cool the first heat transfer medium. The heat dissipation module is configured to dissipate heat generated by the immersion liquid cooling energy storage system to an external environment. The valve module and the pipe system are configured to connect the energy storage module, the thermal management module, and the heat dissipation module, and the first heat transfer medium circulates among the energy storage module, the thermal management module, and the heat dissipation module. The immersion liquid cooling energy storage system provided in this application can improve temperature uniformity of the battery.