Battery Explosion-Proof Sheet for Controlled Pressure Release

Solution Overview

Problem

Existing explosion-proof sheets in secondary batteries detach from the top cover as a whole during pressure release, posing safety risks to users and surrounding components.

Innovation Solution

An explosion-proof sheet with a pressure release portion, fixing portion, and connecting portion, where the connecting portion includes weakened and strengthened regions, ensuring partial separation and controlled venting to prevent complete detachment from the top cover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the explosion-proof sheet is made as a single integral structure, then it provides uniform strength and sealing, but it detaches completely from the top cover during pressure release, causing safety hazards

Engineering Contradiction:

Improveuniform strengthVSAvoidsafety during pressure release

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The explosion-proof sheet is divided into three functional regions: a fixing portion with greater thickness for strong attachment to the top cover, a pressure release portion with smaller thickness for controlled rupture, and a connecting portion that links them. This segmentation allows different parts to serve different functions during normal operation and during pressure release events.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the explosion-proof sheet are given different thicknesses and material properties tailored to their specific functions. The fixing portion has greater thickness for strength and sealing, while the pressure release portion has smaller thickness for controlled rupture at a lower pressure threshold.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If the explosion-proof sheet is made with uniform thickness, then it is simple to manufacture, but it cannot achieve controlled partial separation during pressure release

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidstructural complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The explosion-proof sheet is divided into three functional regions: a fixing portion with greater thickness for strong attachment to the top cover, a pressure release portion with smaller thickness for controlled rupture, and a connecting portion that links them. This segmentation allows different parts to serve different functions during normal operation and during pressure release events.

Inventive Principle:

Principle #1Segmentation

3Speed

If the connecting portion has small thickness, then pressure release is achieved quickly, but the explosion-proof sheet detaches completely from the top cover

Engineering Contradiction:

Improvepressure release speedVSAvoidattachment stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The explosion-proof sheet is divided into three functional regions: a fixing portion with greater thickness for strong attachment to the top cover, a pressure release portion with smaller thickness for controlled rupture, and a connecting portion that links them. This segmentation allows different parts to serve different functions during normal operation and during pressure release events.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the explosion-proof sheet are given different thicknesses and material properties tailored to their specific functions. The fixing portion has greater thickness for strength and sealing, while the pressure release portion has smaller thickness for controlled rupture at a lower pressure threshold.

Inventive Principle:

Principle #3Local quality

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

Enhances safety by allowing controlled pressure release without complete detachment of the explosion-proof sheet, thereby preventing injury and damage to users and components.

Implementation Method 1

when a pressure inside the battery reaches a threshold, a part with a smaller thickness of the connecting portion will crack first

Methodology Applied

Scientific EffectPressure: Pressure Increase

Implementation Method 2

a part with a smaller thickness of the connecting portion will crack first, and a part with a greater thickness of the connecting portion will remain connected

Methodology Applied

Scientific EffectFracture: Fracture Mechanics

Data Source

PatentUS12555850B2Explosion-proof sheet, top cover assembly of secondary battery, and secondary battery

Publication Date: 2026.02.17 HITHIUM TECH HK LTD

AI summary

An explosion-proof sheet, a top cover assembly of a secondary battery, and a secondary battery are provided. The explosion-proof sheet has a pressure release portion arranged oppositely to the explosion-proof hole, a fixing portion surrounding the pressure release portion and connected to the top cover, a connecting portion located between the pressure release portion and the fixing portion for connecting the pressure release portion to the fixing portion. A thickness of a part of the connecting portion is greater than a thickness of the remaining part of the connecting portion.