Secondary Battery Vent Plate Structure for Controlled Pressure Release

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Solution Overview

Problem

Existing lithium secondary batteries face challenges in managing internal pressure buildup during overcurrent conditions, which can lead to potential safety hazards without effective venting mechanisms.

Innovation Solution

A secondary battery design featuring a vent plate with an inclined surface and varying thicknesses, including a notch and guide notch, along with a contact part and extension, to facilitate controlled pressure release and enhance safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a vent plate is added to manage internal pressure, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vent plate is divided into multiple functional regions: a first rupture part with a first thickness and a second rupture part with a second thickness greater than the first thickness. This segmentation allows different portions of the vent plate to serve different pressure management functions, enabling controlled venting while maintaining overall structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The vent plate features non-uniform thickness distribution, with the second rupture part having greater thickness than the first rupture part. This local quality variation creates regions with different mechanical properties, allowing the thinner first rupture part to fail at lower pressures for controlled venting while the thicker second rupture part maintains structural strength.

Inventive Principle:
Principle #3Local quality

2Strength

If the vent plate thickness is increased to prevent rupture, then strength is improved, but pressure release capability deteriorates

Engineering Contradiction:
ImprovestrengthVSAvoidpressure release capability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The vent plate features non-uniform thickness distribution, with the second rupture part having greater thickness than the first rupture part. This local quality variation creates regions with different mechanical properties, allowing the thinner first rupture part to fail at lower pressures for controlled venting while the thicker second rupture part maintains structural strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The vent plate is divided into multiple functional regions: a first rupture part with a first thickness and a second rupture part with a second thickness greater than the first thickness. This segmentation allows different portions of the vent plate to serve different pressure management functions, enabling controlled venting while maintaining overall structural integrity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4672438A1Secondary battery and battery pack including the same
Publication Date: 2025.12.31 SAMSUNG SDI CO LTD
  • EP4672438A1 patent drawingFigure 1
  • EP4672438A1 patent drawingFigure 2
  • EP4672438A1 patent drawingFigure 3

AI summary

A secondary battery (2) includes a case (100) having an opening, an electrode assembly (200) accommodated in the case, a cap-up (310) disposed in the opening, a cap-down (320) disposed to face the cap-up and connected to the electrode assembly, a vent plate (330) disposed between the cap-up and the cap-down, an extension part (340) extending from the vent plate and connected to the cap-up, and a contact part (350) that protrudes from the vent plate toward the cap-down and is in contact with the cap-down, wherein a thickness of at least a portion of the vent plate increases toward a central axis of the case.