Battery Inner Case Venting Structure for Cooling Relief Gas

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Solution Overview

Problem

Existing power supply devices with secondary battery cells face challenges in safely managing high-temperature and high-pressure gases ejected from relief valves, particularly in larger devices with increased capacity, as they lack efficient mechanisms to reduce pressure and temperature before the gases are released outside the outer case.

Innovation Solution

A power supply device with a laminated inner case structure featuring a gas-exhaust duct formed by recesses in the inner and outer plates of the inner case, allowing gases to be guided through a long, closed path that reduces pressure and temperature before exit, and includes multiple ducts and openings to enhance exhaust efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the battery device uses a conventional exhaust structure without a long closed path, then the device size can be smaller, but the pressure and temperature of ejected gases cannot be effectively reduced before release

Engineering Contradiction:
Improvetemperature of ejected gasVSAvoidcomplexity of exhaust structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The gas-exhaust duct is formed by creating recesses in both the inner-side plate and outer-side plate of the inner case, which nest together to form a closed duct structure. This nested construction allows the exhaust path to be integrated within the existing case structure rather than adding external components, effectively reducing gas temperature and pressure while avoiding significant increases in device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The exhaust path is extended by utilizing the thickness dimension of the case walls. By forming recesses that extend into the plates and creating a three-dimensional closed duct, the patent achieves a long exhaust path without increasing the external footprint of the device, thus reducing gas temperature and pressure effectively.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Power

If the battery device accommodates more battery cells to increase capacity, then the power and capacity increase, but the amount of ejected materials increases requiring more efficient pressure and temperature reduction

Engineering Contradiction:
Improvepower of power supply deviceVSAvoidamount of ejected gas
Core Design Contradiction:
PowerVSQuantity of substance

Solution Approach 1:

The closed gas-exhaust duct is nested within the inner case structure by forming recesses in the inner-side and outer-side plates. This integrated design provides an efficient exhaust path capable of handling large volumes of ejected gas from multiple battery cells, reducing both pressure and temperature effectively without requiring separate external exhaust systems.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The exhaust system is segmented into distinct components: the inner-side opening, the closed gas-exhaust duct with its recesses, and the outer-side opening. This segmentation allows the system to efficiently process large amounts of ejected gas by providing a dedicated closed path that can handle high volumes while maintaining effective pressure and temperature reduction.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If the battery device releases high-temperature gas directly outside the outer case, then the exhaust structure can be simpler, but flame emission and thermal damage may occur

Engineering Contradiction:
Improveflame emission and thermal damageVSAvoidcomplexity of exhaust structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The closed gas-exhaust duct is formed by nesting recesses within the inner case structure, creating a protected enclosed path for gas exhaust. This nested design effectively contains and cools the ejected gas, preventing flame emission and thermal damage to external components while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The closed gas-exhaust duct acts as an intermediary structure between the battery cells and the external environment. It provides a controlled path that mediates the exhaust process, allowing high-temperature gas to be cooled and pressure-reduced before any potential release, thereby preventing harmful effects while adding minimal structural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 device effectively exhausts high-temperature and high-pressure gases to the outside while maintaining safety by reducing pressure and temperature, preventing ignition and enhancing the structural integrity of the inner case.

Implementation Method 1

a structure in which the gas and other ejected materials are allowed to pass through a maze-like exhaust path inside the outer case to gradually reduce the pressure and temperature

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The recess constituting a gas-exhaust duct... The gas-exhaust duct communicates with an inside of the inner case through an inner-side opening... and communicates with an outside of the inner case through an outer-side opening

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4704240A1Power supply device
Publication Date: 2026.03.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4704240A1 patent drawingFigure 1
  • EP4704240A1 patent drawingFigure 2
  • EP4704240A1 patent drawingFigure 3

AI summary

In a power supply device, an inner case accommodating secondary battery cells each including a relief valve is covered with an outer case. The inner case includes an inner-side plate and an outer-side plate which constitute an outer circumferential wall of the inner case. Portions of the inner-side plate and the outer-side plate overlap each other at a laminated portion constituting a laminated structure of the inner case. The laminated portion has a recess partially provided in one or both of a surface of the inner-side plate and a surface of the outer-side plate which face each other. The recess constitutes a gas-exhaust duct closed between the inner-side and outer-side plates. The gas-exhaust duct communicates with an inside of the inner case through an inner-side opening formed in the inner-side plate and communicates with an outside of the inner case through an outer-side opening formed in the outer-side plate. The inner-side opening and the outer-side opening are disposed at opposite ends of the gas-exhaust duct.