Battery Pack Spray Pipeline for Thermal Runaway Containment

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Solution Overview

Problem

High-energy density batteries in electric vehicles are prone to spontaneous combustion due to thermal failures, leading to heat flow that can spread and cause adjacent battery units to burn, posing a safety risk to passengers and drivers.

Innovation Solution

A spray system for battery packs that includes a spray pipeline connected to each battery unit's vent, storing a fluorinated liquid that is discharged when the battery overheats, using a driving device with an elastic component to ensure continuous flow and prevent heat spread, thereby enhancing safety by forming an opening to release the heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the energy density of the battery is increased, then the volume of the battery unit is reduced, but the risk of thermal failure and heat flow spreading increases

Engineering Contradiction:
Improvebattery unit volumeVSAvoidheat flow spreading risk
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The spray system is pre-configured with spray pipelines extending through the battery pack, with spray nozzles positioned at strategic locations. The system is pre-filled with spray liquid and the driving device is pre-charged, so that when thermal failure occurs, spray can immediately begin without delay. This preliminary preparation ensures rapid response to prevent heat flow spreading from high-energy-density battery units.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A non-flammable spray liquid is introduced as an intermediary substance between the thermal failure source and the surrounding environment. The spray liquid forms a protective barrier that intercepts and suppresses heat flow, preventing it from spreading to adjacent battery units. This intermediary substance directly addresses the harmful thermal effects while allowing the high energy density battery design to continue.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a spray system is added to prevent heat flow spreading, then the safety of the battery pack is improved, but the device complexity increases

Engineering Contradiction:
Improvebattery pack safetyVSAvoidspray system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spray system is merged with the existing battery pack structure. Spray pipelines are integrated into the battery housing, and the driving device utilizes the battery pack's existing spatial arrangement. This merging approach incorporates safety functionality without creating a completely separate complex system, thereby improving reliability while controlling device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driving device is designed to automatically activate and control the spray system without requiring external complex control systems. The system self-regulates spray delivery based on thermal conditions, eliminating the need for additional sensors, controllers, and power management circuits. This self-service capability improves safety while minimizing the added device complexity.

Inventive Principle:
Principle #25Self-service

3Reliability

If the spray pipeline is damaged during thermal failure, then the spray effect is reduced, but the driving device can still drive spray liquid to flow into the spray pipeline to maintain safety

Engineering Contradiction:
Improvespray safety functionVSAvoidspray pipeline integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The driving device is pre-charged with sufficient pressure and the system is designed with redundant spray pathways. If the spray pipeline is damaged, the pre-charged driving device can immediately drive spray liquid through alternative routes or repaired sections. This beforehand cushioning ensures that safety function is maintained even when pipeline integrity is compromised during thermal failure events.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 prevents heat flow from spreading to adjacent battery units, improving safety by ensuring continuous discharge of the spray liquid, even when the spray pipeline is damaged, and maintaining safety during high-temperature thermal failures.

Implementation Method 1

a driving device configured to drive the spray liquid in the liquid storage device to flow into the spray pipeline... The driving device includes two driving plates, an elastic component and a limiting component... In the first working state, the limiting component acts on the two driving plates to limit a distance between the two driving plates in such a manner that the elastic component is brought to a compressed state

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

spray liquid in the spray pipeline can be discharged through the opening, preventing the heat flow from spreading... after the spray liquid in the spray pipeline is discharged through the opening, the driving device can drive the spray liquid stored in the liquid storage device to flow into the spray pipeline and to be discharged through the opening of the spray pipeline, further preventing the heat flow from spreading

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

spray liquid in the spray pipeline can be discharged through the opening, preventing the heat flow from spreading... further preventing the heat flow from spreading

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP3675214B1Battery pack and spray system for the same
Publication Date: 2024.12.25 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP3675214B1 patent drawingFigure 1~2
  • EP3675214B1 patent drawingFigure 3~4
  • EP3675214B1 patent drawingFigure 5~6

AI summary

The present disclosure provides a spray system for a battery pack and a battery pack. The spray system includes a spray pipeline configured to circulate a spray liquid and form an opening when being heating, a liquid storage device communicating with the spray pipeline, and a driving device including a driving component and an elastic component connected to the driving component. The driving component, under an elastic force applied by the elastic component, drives the spray liquid in the liquid storage device to flow into the spray pipeline. In the present spray system, the spray liquid not only in the spray pipeline but in the liquid storage device can be discharged to spray, thereby improving the spray effect, preventing the heat flow generated when the one battery unit is thermally out of control from spreading to the adjacent battery units, and improving the safety of the battery pack.