Battery Pack Venting Structure for Gas Relief and Liquid Blocking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Battery packs face safety issues due to gas pressure buildup, leading to potential swelling and short circuits, as existing technologies fail to effectively manage gas pressure and prevent liquid ingress.

Innovation Solution

A battery pack design featuring a housing with hermetically connected sidewalls and a bottom wall, including a through-hole for gas exhaust and a detachable filler to balance gas pressure and prevent liquid entry, enhancing safety by allowing gas escape while restricting liquid access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a through-hole is provided for gas exhaust, then gas pressure is relieved and swelling is prevented, but liquid may enter through the same hole causing short circuits

Engineering Contradiction:
Improvesafety of battery packVSAvoidliquid ingress risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The filler material is positioned specifically at the lower portion of the through-hole to block liquid entry while allowing gas to pass through the upper portion. This creates different functional zones within the same hole: the lower zone prevents liquid ingress while the upper zone maintains gas exhaust capability, resolving the contradiction between safety and liquid protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The filler material acts as an intermediary element inserted into the through-hole. It selectively interacts with different substances: gas molecules can pass through the gaps in the filler, while liquid droplets are blocked by the filler's physical structure. This intermediary component enables the through-hole to simultaneously achieve gas exhaust and liquid prevention functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the housing is hermetically sealed, then liquid entry is prevented, but gas pressure builds up causing swelling

Engineering Contradiction:
Improveliquid entry preventionVSAvoidgas pressure inside battery pack
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The hermetic seal is applied to the overall housing structure to prevent liquid entry, while a localized opening (through-hole) is created specifically for gas exhaust. The filler material further refines this by creating a liquid-blocking zone at the bottom of the through-hole while maintaining gas flow paths in the upper region. This localized differentiation resolves the contradiction between hermetic sealing and pressure relief.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The through-hole is segmented into different functional zones using the filler material. The lower portion blocks liquid while the upper portion allows gas passage. This segmentation enables the single through-hole structure to simultaneously provide both liquid prevention and pressure relief functions, resolving the contradiction between hermetic sealing and gas exhaust.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If a filler is placed in the through-hole to block liquid, then liquid entry is reduced, but gas exhaust capability may be compromised

Engineering Contradiction:
Improveliquid entry reductionVSAvoidgas exhaust function
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The filler material is positioned only in the lower portion of the through-hole, creating a localized liquid barrier. The upper portion of the through-hole remains open to allow gas exhaust. This spatial differentiation of functions within the same hole ensures that liquid blocking does not compromise gas exhaust capability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The filler material is designed with a porous or mesh structure that copies the selective permeability needed: it replicates the ability to block liquids while allowing gases to pass through its structure. This structural copying enables the filler to maintain both liquid blocking and gas exhaust functions simultaneously.

Inventive Principle:
Principle #26Copying

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 effectively balances gas pressure within the battery pack, reducing the risk of swelling and short circuits, thereby improving safety and reliability.

Implementation Method 1

The first filler can restrict a liquid from entering the first through-hole, thereby reducing entry of the liquid into the first space from the first through-hole

Methodology Applied
Scientific EffectPhysical barrier blocking:

Implementation Method 2

A second clearance exists between the first filler and the first through-hole. The second clearance is configured to allow a gas to escape. The gas in the first space is exhausted through the first through-hole, so as to balance the gas pressure in the first space

Methodology Applied
Scientific EffectGas pressure differential driven flow: Pressure Gradient

Data Source

PatentEP4404347A1Battery pack and electrical device
Publication Date: 2024.07.24 XIAMEN AMPACK TECH LTD
  • EP4404347A1 patent drawingFigure 1
  • EP4404347A1 patent drawingFigure 2
  • EP4404347A1 patent drawingFigure 3

AI summary

A battery pack (100) includes a housing and a cell assembly (20). The housing includes a first housing and a second housing. The first housing is connected to the second housing. A first space (101) is formed in the first housing (11). The first housing (11) includes a plurality of sidewalls and a bottom wall (115) connected to the plurality of sidewalls. The plurality of sidewalls and the bottom wall form the first space (101). The cell assembly (20) is accommodated in the first space (101). A first clearance (11a) is formed between the cell assembly (20) and the plurality of sidewalls. The plurality of sidewalls are hermetically connected to the bottom wall. A first through-hole (11b) is disposed on at least one of a sidewall or the bottom wall (115). The first through-hole (11b) extends through the sidewall or the bottom wall (115). The first through-hole (11b) is in communication with the first clearance (11a). The first filler (30) is detachably disposed in the first through-hole (11b). A second clearance (10b) exists between the first filler (30) and the first through-hole (11b). The second clearance (10b) is configured to allow a gas to escape. The battery pack can balance a gas pressure in the first space, improve safety of the battery pack, reduce entry of a liquid into the first space from the first through-hole, and reduce the short-circuit risk.