Power Battery Vent and Cap Assembly with Protective Sheath

Solution Overview

Problem

Power battery vents in existing designs face premature bursting under manufacturing or operational conditions due to reduced strength from drawing forces, leading to potential explosions when the bursting pressure is too low, and increased risk of delayed pressure release when it's too high, compromising safety.

Innovation Solution

A vent and cap assembly design featuring a vent body with a protective sheath and cap plate connection, which stabilizes bursting pressure within a specific range, enhancing the vent's strength and ensuring timely pressure release, incorporating a vent protective sheet for additional protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the vent bursting pressure is set low (≤0.2 MPa) to ensure timely pressure release, then battery safety is improved, but the vent bursts prematurely during manufacturing or normal operation causing production failures

Engineering Contradiction:

Improvebattery safetyVSAvoidventing pressure control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The venting system is segmented into two independent pressure control mechanisms: a first venting hole for low-pressure venting (≤0.2 MPa) during normal operation, and a second venting hole for high-pressure emergency relief (>0.2 MPa). This segmentation allows each venting channel to be optimized for its specific function without interference from the other, resolving the contradiction between premature venting and safety.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A flexible membrane acts as an intermediary element that selectively opens different venting holes based on pressure levels. The membrane remains closed at low pressures, preventing premature venting during manufacturing, but deflects at high pressures to open the emergency venting hole, ensuring safety when needed.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the vent bursting pressure is set high to prevent premature venting, then manufacturing stability is improved, but the vent fails to release pressure timely in abuse conditions causing battery explosion

Engineering Contradiction:

Improvemanufacturing stabilityVSAvoidbattery explosion risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The venting system is segmented into two independent pressure control mechanisms: a first venting hole for low-pressure venting (≤0.2 MPa) during normal operation, and a second venting hole for high-pressure emergency relief (>0.2 MPa). This segmentation allows each venting channel to be optimized for its specific function without interference from the other, resolving the contradiction between premature venting and safety.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the pressure parameter threshold for different venting modes. The first venting hole operates at low pressure (≤0.2 MPa) for normal gas release, while the second venting hole activates at high pressure (>0.2 MPa) for emergency relief. The flexible membrane enables this parameter transition based on actual pressure conditions.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If the case and cap assembly wall thicknesses are reduced to increase capacity density, then energy density is improved, but the drawing force from case expansion greatly reduces vent strength and bursting pressure

Engineering Contradiction:

Improvebattery capacity densityVSAvoidvent strength

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The venting system is segmented into two independent pressure control mechanisms: a first venting hole for low-pressure venting (≤0.2 MPa) during normal operation, and a second venting hole for high-pressure emergency relief (>0.2 MPa). This segmentation allows each venting channel to be optimized for its specific function without interference from the other, resolving the contradiction between premature venting and safety.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flexible membrane provides beforehand cushioning by being pre-installed to cover the venting holes. It cushions against premature venting during manufacturing and normal operation by remaining closed at low pressures, while still allowing timely venting when high pressures occur during abuse conditions.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS9853266B2Vent and cap assembly of power battery

Publication Date: 2017.12.26 DONGGUAN POWERAMP TECH LTD

AI summary

The present disclosure provides a vent and a cap assembly of a power battery. The vent comprises a vent body and a vent body protective sheath having a wall portion and a hollow portion, the vent body is fixedly connected to a lower portion of the wall portion and sealing the hollow portion from below, an upper portion of the wall portion is fixedly connected to a cap plate for sealing a vent hole. The cap assembly of the power battery comprises a cap plate provided with a vent hole and an electrolyte-injection hole; a first electrode post connected to the cap plate; a second electrode post connected to the cap plate; and a vent fixedly provided to the vent hole; wherein the vent is the above vent.