Oil-Immersed Battery Module Cooling Beyond Air Temperature Limits

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Typical air-cooled battery packs struggle to maintain battery cells within a desired temperature range due to ambient air temperatures often exceeding the maximum operating temperature of the cells.

Innovation Solution

A battery module utilizing a housing filled with non-conductive oil and a cooling manifold that receives a refrigerant or coolant to conduct heat energy from the oil or oil to cool the battery cells, with a compressor and condenser system to manage refrigerant flow and a heat exchanger to extract heat energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If air cooling is used for battery cells, then the cooling system is simple, but the battery cells cannot be maintained within desired temperature range when ambient air temperature exceeds maximum operating temperature

Engineering Contradiction:
Improvecooling system complexityVSAvoidbattery cell temperature control
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent introduces non-conductive oil as an intermediary cooling medium between the battery cells and the refrigerant system. The oil circulates through channels surrounding the battery cells, absorbing heat from the cells and transferring it to the refrigerant, enabling effective temperature control when ambient air temperature exceeds battery operating limits

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the cooling medium from air to non-conductive oil, which has superior heat transfer properties. This parameter change allows the cooling system to maintain battery cells within desired temperature range even when ambient temperature exceeds maximum operating temperature, while the refrigerant cycle system provides adjustable cooling capacity through compression and expansion processes

Inventive Principle:
Principle #35Parameter changes

2Temperature

If refrigerant is used to cool the non-conductive oil, then effective cooling is achieved, but the system complexity increases with compressor, condenser, and expansion device

Engineering Contradiction:
Improvebattery cell temperature controlVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent employs a refrigerant cycle system utilizing phase change principles where refrigerant evaporates to absorb heat from the non-conductive oil and condenses to release heat externally. This pneumatic-hydraulic approach provides efficient heat transfer and adjustable cooling capacity, achieving effective battery temperature control despite the added system complexity of compressor, condenser, and expansion devices

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

Effectively maintains battery cells within a desired temperature range (e.g., 15° Celsius - 35° Celsius) by efficiently transferring heat energy from the battery cells to the non-conductive oil or coolant, ensuring stable operation.

Implementation Method 1

The cooling manifold is configured to receive a refrigerant therethrough and to conduct heat energy from the non-conductive oil into the refrigerant to cool the battery cell

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

The condenser is configured to receive the refrigerant from the battery module and to extract heat energy from the refrigerant

Methodology Applied
Scientific EffectHeat extraction: Heat Exchanger

Implementation Method 3

the evaporator is cooled by the vaporized heat of the refrigerant supplied to the evaporator, and the cooled evaporator cools up the battery via the insulated oil

Methodology Applied
Scientific EffectEvaporative cooling: Evaporative Cooler

Data Source

PatentEP2426779B1Battery system, battery module, and a method for cooling the battery module
Publication Date: 2015.07.08 LG CHEM LTD
  • EP2426779B1 patent drawingFigure 1~2
  • EP2426779B1 patent drawingFigure 3~4
  • EP2426779B1 patent drawingFigure 5~8

AI summary

Battery systems, a battery module, and a method for cooling the battery module are provided. The battery module includes a housing having a non-conductive oil disposed therein. The battery module further includes a battery cell disposed in the housing. The battery module further includes a cooling manifold disposed in the housing that contacts the non-conductive oil. The cooling manifold is configured to receive a fluid therethrough and to conduct heat energy from the non-conductive oil into the fluid to cool the battery cell.