Battery Pack Venting Geometry to Limit Air Ingress

Solution Overview

Problem

Existing battery packs face challenges in safely venting electrolyte gas while preventing external air from entering, which can lead to pressure buildup, deformation, and external flame spread due to turbulent flow and oxygen ingress.

Innovation Solution

A venting member with a cross-sectional area design that narrows from the inlet to the outlet, reducing external air inflow and maintaining smooth gas discharge, featuring a first region with a constant cross-sectional area and a second region with a smaller cross-sectional area, optionally with a truncated conical shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a venting hole with open structure is used to discharge gas, then gas discharge is effective, but external air flows into the battery pack causing explosion risk

Engineering Contradiction:

Improvegas discharge efficiencyVSAvoidexternal air inflow and explosion risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The venting member employs different cross-sectional areas at different locations: a larger inlet cross-sectional area for efficient gas discharge and a smaller outlet cross-sectional area to prevent external air inflow. This local variation in geometric properties optimizes both gas discharge efficiency and protection against harmful air ingress.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of using a conventional open venting hole that allows free bidirectional flow, the invention inverts the approach by creating a restricted passage with decreasing cross-sectional area from inlet to outlet. This inverted flow control mechanism prioritizes preventing harmful air inflow over maximizing discharge area.

Inventive Principle:

Principle #13The other way round (Inversion)

2Object-affected harmful factors

If the venting hole size is reduced to prevent external air inflow, then explosion risk is reduced, but pressure buildup causes deformation and damage

Engineering Contradiction:

Improveexternal air inflow preventionVSAvoidbattery pack structural integrity

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The venting member employs different cross-sectional areas at different locations: a larger inlet cross-sectional area for efficient gas discharge and a smaller outlet cross-sectional area to prevent external air inflow. This local variation in geometric properties optimizes both gas discharge efficiency and protection against harmful air ingress.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If a uniform cross-sectional area is used throughout the venting member, then manufacturing is simple, but turbulent flow occurs causing external flame spread

Engineering Contradiction:

Improveventing member fabricationVSAvoidturbulent flow and flame spread

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The venting member employs different cross-sectional areas at different locations: a larger inlet cross-sectional area for efficient gas discharge and a smaller outlet cross-sectional area to prevent external air inflow. This local variation in geometric properties optimizes both gas discharge efficiency and protection against harmful air ingress.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of using a conventional open venting hole that allows free bidirectional flow, the invention inverts the approach by creating a restricted passage with decreasing cross-sectional area from inlet to outlet. This inverted flow control mechanism prioritizes preventing harmful air inflow over maximizing discharge area.

Inventive Principle:

Principle #13The other way round (Inversion)

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

Effectively delays flame spread and reduces pressure buildup by minimizing external air ingress, ensuring safe venting of electrolyte gas without causing deformation or damage.

Implementation Method 1

a venting member configured to discharge the gas generated in the internal space externally, wherein a cross-sectional area of an outlet side of the venting member connected to an external space of the pack housing is smaller than a cross-sectional area of an inlet side of the venting member connected to the internal space

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS20250329861A1Battery pack

Publication Date: 2025.10.23 SK ON CO LTD

AI summary

A battery pack includes a pack housing having an internal space in which a plurality of battery modules are installed or a plurality of battery cells are installed directly without being modulized; and a venting member installed in the pack housing and configured to discharge gas generated in the internal space externally, wherein the venting member is configured such that a cross-sectional area A1 of an outlet side of the venting member connected to an external space of the pack housing is smaller than a cross-sectional area A1 of an inlet side of the venting member connected to the internal space.