Battery Module Weld Validation via Interconnect Temperature

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Solution Overview

Problem

Existing battery module weld joints often fail to exhibit desired characteristics, leading to high temperatures during discharge or charge cycles, which can be detrimental to the module's performance and safety.

Innovation Solution

A weld validation system that includes a gripping device with temperature sensors to measure the temperature of interconnect members during discharge or charge cycles, determining if the weld joints meet threshold temperature values for validation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If weld joint characteristics are poor (low impedance), then temperature at weld joint increases during discharge/charge, but weld validation requires temperature measurement capability

Engineering Contradiction:
Improvetemperature measurement capabilityVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a temperature sensor as an intermediary device that indirectly measures weld joint quality by monitoring temperature at the weld joint during battery discharge/charge cycles. This mediator approach allows validation of weld characteristics without directly measuring electrical impedance, simplifying the measurement system while maintaining effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex electrical measurement systems with a thermal measurement approach. Instead of using sophisticated electrical impedance measurement equipment to assess weld quality, the system uses temperature sensing (thermal field) to substitute for direct electrical characterization, reducing device complexity.

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

2Reliability

If temperature monitoring is implemented during battery operation, then weld joint validation is achieved, but additional sensing and control components are required

Engineering Contradiction:
Improveweld joint validationVSAvoidsensing and control components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system utilizes the battery's own operational heat generation during normal discharge and charge cycles to validate weld joints. The battery module serves itself by providing the thermal conditions necessary for validation without requiring external heating equipment or separate test procedures, reducing overall system complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements a feedback mechanism where temperature sensor data is fed back to a controller that compares measured temperatures against predetermined thresholds. This automatic feedback loop enables real-time weld joint validation during battery operation, improving reliability while keeping the control system relatively simple through threshold-based decision making.

Inventive Principle:
Principle #23Feedback

3Productivity

If temperature thresholds are used for weld validation, then quick assessment is possible, but measurement precision must be sufficient to detect temperature differences

Engineering Contradiction:
Improvevalidation speedVSAvoidtemperature measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent transforms the validation criterion from direct electrical impedance measurement to temperature parameter measurement. By changing the measurement parameter to temperature (which naturally varies during battery operation), the system achieves quick assessment through simple threshold comparisons while maintaining sufficient precision through the use of standard temperature sensors and controlled measurement conditions.

Inventive Principle:
Principle #35Parameter changes

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 effectively validates weld joints by ensuring they maintain safe and optimal temperatures, thereby ensuring structural and functional integrity during battery operation.

Implementation Method 1

a temperature sensor disposed on one of the first and second gripping fingers. The temperature sensor is configured to generate a first signal indicative of a temperature of the interconnect member

Methodology Applied
Scientific EffectTemperature sensing: Thermocouple

Implementation Method 2

If the weld joint between the battery cell tabs and the interconnect member does not have desired weld joint characteristics (e.g., a low impedance), the inventors herein have recognized that a relatively high temperature may be obtained at the weld joint during discharging or charging of the battery module

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2481517B8Battery module welding verification system and method for same
Publication Date: 2018.10.17 LG CHEM LTD

AI summary

A weld validation system and method for a battery module are provided. The battery module has first and second battery cells and an interconnect member welded to first and second tabs of the first and second battery cells, respectively. The system includes a gripping device having first and second gripping fingers contacting the interconnect member. The system further includes a temperature sensor that generates a first signal indicative of a temperature of the interconnect member when a battery cycling device is discharging the battery module. The system further includes a computer that determines a first temperature value indicative of the temperature of the interconnect member based on the first signal.