Battery Module Thermal Cable for Accurate Vent Burst Detection

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Solution Overview

Problem

Existing battery modules and packs lack effective and accurate methods to detect thermal runaway in battery cells, which can lead to high temperatures and fires, posing significant safety risks.

Innovation Solution

A battery module with a thermal cable integrated into the circuit board, featuring a thermal circuit that short-circuits when the vent of a battery cell bursts, providing a prompt signal to the battery management system (BMS) to indicate thermal runaway, thereby enhancing safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If only voltages and temperature signals of some battery cells are collected for sampling, then the sampling system remains simple, but the ability to effectively and accurately detect thermal runaway is insufficient

Engineering Contradiction:
Improvethermal runaway detection accuracyVSAvoidsampling system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a thermal cable as an intermediary component that physically connects to the battery cell vent. This thermal cable contains a thermal circuit that acts as a mediator between the battery cell's thermal state and the detection system, enabling accurate thermal runaway detection through thermal conduction from the vent to the circuit board.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex electronic sensing systems with a simpler thermal conduction-based detection mechanism. Instead of using multiple temperature sensors and complex signal processing, the invention uses the thermal cable to conduct heat directly from the vent to the circuit board, where a simple thermal circuit detects the thermal state through resistance changes.

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

2Reliability

If a thermal cable with thermal circuit is integrated into the circuit board to detect vent bursting, then thermal runaway detection accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvethermal runaway signal detection reliabilityVSAvoidcircuit board integration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the thermal cable with the circuit board by integrating the thermal circuit directly into the circuit board structure. The thermal cable is fixedly coupled to the circuit board, combining the thermal conduction function with the electrical detection function in a single integrated component, thereby improving reliability without proportionally increasing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The circuit board serves multiple functions: it collects voltage and temperature signals from battery cells, and simultaneously hosts the thermal circuit from the thermal cable for thermal runaway detection. This multi-functionality reduces the need for separate dedicated detection circuits, balancing reliability improvement with complexity management.

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

3Measurement precision

If the insulating layer of the thermal cable melts to short-circuit the thermal circuit when the vent bursts, then the prompt signal generation is achieved, but the response time may be delayed

Engineering Contradiction:
Improvevent bursting detection accuracyVSAvoidsignal response time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent utilizes the phase transition (melting) of the insulating layer as the detection mechanism. When the vent bursts and releases high-temperature gas or liquid, the insulating layer melts from solid to liquid state, causing the thermal circuit to short-circuit and generate a detectable signal. This phase transition provides a clear, unambiguous detection point for vent bursting.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent detects vent bursting by monitoring changes in electrical parameters of the thermal circuit. When the insulating layer melts, the electrical resistance of the thermal circuit changes dramatically (short-circuiting), providing a clear electrical signal that can be detected by the battery management system with minimal delay.

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 solution enables accurate and timely detection of thermal runaway, allowing for swift alarm signals to be sent to vehicle systems, thereby improving safety and preventing accidents.

Implementation Method 1

the insulating layer of the thermal cable is melted when the vent of any of the battery cells bursts, so as to short-circuit the thermal circuit and provide the prompt signal

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

a thermal cable, located between the battery assembly and the circuit board and fixedly coupled to the circuit board, wherein a thermal circuit is formed inside the thermal cable

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3734692B1Battery module and battery pack
Publication Date: 2021.08.25 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3734692B1 patent drawingFigure 1~2
  • EP3734692B1 patent drawingFigure 3~5
  • EP3734692B1 patent drawingFigure 6~8

AI summary

The present disclosure relates to a battery module and a battery pack. The battery module comprises a battery assembly (11), including a plurality of battery cells (111) arranged in an array, wherein each of the battery cells (111) includes a vent (1111); a circuit board (12), including a plurality of sampling terminals (122) connected to the battery cells (111) and being capable of collecting electrical parameters and/or temperature parameters of the battery cells (111); and a thermal cable (13), located between the battery assembly (11) and the circuit board (12) and fixedly coupled to the circuit board (12), wherein a thermal circuit is formed inside the thermal cable (13), and the thermal circuit can provide a prompt signal indicating a bursting of the vent (1111) of any of the battery cells (111). When a thermal runaway of any of the battery cells occur, the corresponding vent bursts to heat the thermal cable, and the thermal cable can quickly sense a temperature change. When the temperature exceeds a predetermined threshold, the thermal circuit inside the thermal cable is short-circuited or open-circuited. A short-circuit signal or an open-circuit signal can be used as a prompt signal, and can accurately and effectively transmit an information that the thermal runaway of the battery cell occurs, to the outside, thereby improving the safety of the battery module.