Rechargeable Battery Cap Plate Short-Circuit and Valve Mechanism

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Solution Overview

Problem

High-capacity rechargeable batteries are prone to explosion or fire due to overcurrent, which existing safety mechanisms fail to adequately prevent, especially in high-power applications like electric vehicles.

Innovation Solution

A rechargeable battery design featuring a short-circuit tab and member that contacts each other upon deformation, coupled with a valve member that opens at a predetermined pressure higher than the deformation pressure, to safely discharge excess current and prevent internal pressure buildup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a deformable plate is used to connect both electrodes upon pressure increase, then electrical connection is maintained under pressure, but safety against overcurrent and explosion is compromised

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidexplosion and fire risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cap plate is segmented into functionally distinct regions: a first region with a through-hole for pressure equalization and a second region with the short-circuit tab for safety protection. This segmentation allows the plate to simultaneously maintain electrical connection reliability while preventing overcurrent-induced explosions by separating the pressure relief function from the electrical connection function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The short-circuit tab acts as an intermediary safety mechanism between the deformable plate and the electrodes. When internal pressure causes the plate to deform, the short-circuit tab contacts the short-circuit member to create a controlled short-circuit, preventing dangerous pressure buildup and potential explosion while the deformable plate maintains normal electrical connection during operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If internal pressure is allowed to build up to drive motors, then high power output is achieved, but explosion risk increases

Engineering Contradiction:
Improvemotor driving powerVSAvoidexplosion risk
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The through-hole in the cap plate provides a preliminary pressure relief path that prevents dangerous pressure buildup before it can lead to explosion. This preliminary action allows the battery to achieve high power output for motor driving while simultaneously protecting against the harmful effect of pressure-induced explosion by providing advance pressure equalization.

Inventive Principle:
Principle #10Preliminary action

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 prevents explosions and fires by ensuring safe discharge of excess current and maintaining internal pressure within safe limits, enhancing the safety of high-capacity rechargeable batteries.

Implementation Method 1

The short-circuit member and the short-circuit tab are formed to contact each other when the short-circuit member is deformed into the second shape

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

The valve member may be set to be opened at a predetermined pressure and the opening pressure of the valve member may be set to be higher than a deformation pressure of the short-circuit member

Methodology Applied
Scientific EffectPressure-dependent valve opening: Valve

Data Source

PatentEP2533326B1Rechargeable battery
Publication Date: 2014.04.02 ROBERT BOSCH GMBH
  • EP2533326B1 patent drawingFigure 1
  • EP2533326B1 patent drawingFigure 2
  • EP2533326B1 patent drawingFigure 3

AI summary

According to the present invention, there is provided a rechargeable battery including an electrode assembly having a positive electrode and a negative electrode; a case in which the electrode assembly is installed; and a cap plate coupled with the case. A short-circuit member is provided in a short-circuit hole formed in the cap plate. The short-circuit member is electrically connected to one of the electrodes. Further, a valve member is provided under the short-circuit hole.