Immersion-Cooled Battery Cell Aging Monitoring via Coolant Sensors

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Solution Overview

Problem

Existing battery monitoring systems lack precision and reliability in assessing cell aging, particularly in battery devices with immersed cells, as they primarily rely on temperature and pressure sensors that do not fully capture the complex interactions between coolant parameters and cell degradation.

Innovation Solution

Incorporating coolant property sensors, such as pressure, flow, and temperature sensors, to monitor the aging of battery cells by correlating coolant parameter evolution with cell aging, including measuring pressure drops and fluid temperature, and using a monitoring device to analyze these parameters for improved precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional temperature and pressure sensors are used to monitor cell aging, then the monitoring system is simple, but the precision and reliability of cell aging assessment deteriorates

Engineering Contradiction:
Improvecell aging assessment precisionVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces coolant as an intermediary medium that directly contacts the battery cells. By monitoring the physical parameters of this intermediary (coolant) rather than directly measuring the cells, the system achieves improved measurement precision while maintaining reasonable system complexity. The coolant acts as a mediator that transfers information about cell aging through changes in its own properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The monitoring system implements feedback by continuously measuring coolant parameters and comparing them against reference values to detect cell aging. The system uses the measured pressure drop and temperature changes of the coolant as feedback signals to assess the state of the battery cells, enabling dynamic monitoring and assessment of cell aging throughout the battery lifecycle.

Inventive Principle:
Principle #23Feedback

2Reliability

If coolant property sensors are added to monitor additional parameters, then the reliability of cell aging monitoring improves, but the device complexity increases

Engineering Contradiction:
Improvecell aging monitoring reliabilityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coolant serves multiple functions simultaneously: it cools the battery cells, acts as a monitoring medium for cell aging, and provides a means to detect multiple parameters (pressure, temperature, flow). By making the coolant multi-functional, the system achieves improved reliability through multiple measurement parameters without proportionally increasing device complexity, as the same coolant handles multiple tasks.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system monitors changes in physical parameters of the coolant (pressure, temperature, flow rate) to detect cell aging. By tracking parameter changes in the coolant rather than adding complex direct cell measurement systems, the patent achieves improved monitoring reliability through multiple parameters while keeping the device complexity manageable through the use of standard sensor technologies.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If direct immersion cooling is used, then the cooling efficiency improves, but the difficulty of detecting cell aging increases due to complex fluid-cell interactions

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcell aging detection difficulty
Core Design Contradiction:
TemperatureVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces direct mechanical/electrical measurement systems with a fluid-based measurement approach. Instead of using complex sensors to directly measure cell properties, the system uses the coolant's physical parameters (pressure drop, temperature change) to indirectly detect cell aging. This substitution simplifies the detection mechanism while maintaining high cooling efficiency through direct immersion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enhances the monitoring of battery cell aging by leveraging additional coolant parameters, providing more accurate and reliable assessments of cell degradation through comprehensive analysis of coolant properties and fluid dynamics.

Implementation Method 1

a cooling circuit (14) configured to circulate a cooling fluid in contact with the cells (13)

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

the at least one property sensor comprises a first pressure and/or flow sensor (22) arranged on the cooling circuit (14), at the outlet of the corresponding module (12)... a second pressure and/or flow sensor (24) arranged on the cooling circuit (14), at the inlet of the corresponding module (12)... the monitoring device (30) is configured to take into account a pressure drop in each module (12)

Methodology Applied
Scientific EffectPressure Drop: Pressure Drop

Implementation Method 3

The at least one property sensor comprises at least one temperature sensor (26) measuring the temperature of the fluid

Methodology Applied
Scientific EffectThermal Conduction: Conduction (thermal)

Data Source

PatentEP4632871A1Battery device with cells immersed in cooling liquid
Publication Date: 2025.10.15 AUTOMOTIVE CELLS CO SE
  • EP4632871A1 patent drawingFigure 1
  • EP4632871A1 patent drawingFigure 2
  • EP4632871A1 patent drawingFigure 3

AI summary

The battery device (10) comprises at least one module (12) of cells (13), and a cooling circuit (14) intended to circulate a cooling fluid in contact with the cells (13), the battery device (10) comprising a device (30) for monitoring the cells (13). The monitoring device (30) comprises at least one sensor (22, 24, 26) for the property of the cooling fluid.