Bipolar Battery Elastic Metal Contact for Pressure Safety

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Solution Overview

Problem

Bipolar batteries face excessive temperature rises due to external short circuits, leading to electrolyte gasification and increased internal pressure, which can cause excessive current flow.

Innovation Solution

Incorporating an elastic metal portion that contacts the power generation element, allowing surface contact when external forces are applied and point or line contact otherwise, with an outer covering material maintaining internal air pressure lower than atmospheric pressure to limit current flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the bipolar battery operates under normal conditions with point or line contact between the elastic metal portion and power generation element, then the current flow is sufficient for power generation, but when temperature rises excessively due to abnormalities, the electrolyte gasifies and internal pressure increases leading to excessive current flow

Engineering Contradiction:
Improvepower generation capabilityVSAvoidsafety under abnormal conditions
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The elastic metal portion is designed to dynamically change its contact state with the power generation element based on internal pressure conditions. Under normal operation, it maintains point or line contact for sufficient current flow. When abnormal temperature rise causes electrolyte gasification and internal pressure increase, the elastic metal portion deforms to reduce contact area, automatically limiting excessive current flow without requiring external control systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention utilizes the elastic properties of the metal portion to change the contact parameter (contact area) in response to pressure changes. The elastic metal portion's contact area with the power generation element varies as a function of internal pressure, which changes based on temperature and electrolyte state. This automatic parameter adjustment resolves the contradiction between maintaining sufficient power generation and preventing excessive current under abnormal conditions.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the elastic metal portion maintains surface contact with the power generation element, then uniform current distribution is achieved, but this requires continuous external force application which increases device complexity

Engineering Contradiction:
Improveuniform current distributionVSAvoidforce application mechanism
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The elastic metal portion automatically adjusts its own contact state with the power generation element based on internal pressure conditions without requiring external control. The elastic deformation of the metal portion itself provides the mechanism to achieve surface contact under normal conditions for uniform current distribution, and automatically reduces to point or line contact when pressure increases, eliminating the need for external force application mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the force application function from external mechanisms and incorporates it into the elastic metal portion itself. The elastic properties of the metal portion inherently provide the necessary contact force under normal conditions, and the same elastic properties enable automatic force reduction when pressure increases. This eliminates complex external force application mechanisms while maintaining the desired contact states.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Prevents excessive current flow by deforming to separate from the power generation element when internal pressure increases, ensuring uniform current distribution and preventing pressure buildup.

Implementation Method 1

an outer covering material provided to accommodate the power generation element and the elastic metal portion, an internal air pressure of which is set to be lower than an atmospheric pressure such that the elastic metal portion is caused to contact the power generation element in surface contact by a pressure difference between the internal air pressure and the atmospheric pressure

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

an elastic metal portion provided in contact with the power generation element so as to contact the power generation element in point or line contact when no external force is exerted thereon and contact the power generation element in surface contact when external force is exerted thereon

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2600442B1Bipolar battery
Publication Date: 2018.01.03 NISSAN MOTOR CO LTD
  • EP2600442B1 patent drawingFigure 1(A)~1(C)
  • EP2600442B1 patent drawingFigure 2(A)~2(B)
  • EP2600442B1 patent drawingFigure 3(A)~3(C)

AI summary

A bipolar battery includes: a power generation element formed by stacking a plurality of bipolar electrodes, in which an electrode layer is formed on a front and a rear of a collector, via an electrolyte layer; an elastic metal portion provided in contact with the power generation element so as to contact the power generation element in point or line contact when no external force is exerted thereon and contact the power generation element in surface contact when external force is exerted thereon; and an outer covering material provided to accommodate the power generation element and the elastic metal portion, an internal air pressure of which is set to be lower than an atmospheric pressure such that the elastic metal portion is caused to contact the power generation element in surface contact by a pressure difference between the internal air pressure and the atmospheric pressure.