Bipolar Power Storage Module Sealing Against Alkaline Creep

Solution Overview

Problem

The alkaline creep phenomenon causes electrolytic solutions to seep out of power storage modules, leading to potential corrosion and short-circuits due to the interaction between alkaline solutions and metal plates in bipolar batteries.

Innovation Solution

A power storage module design where both surfaces of the negative terminal electrode are bonded to the sealing body, creating surplus spaces that prevent humidity fluctuations and inhibit the alkaline creep phenomenon, along with additional surplus spaces and resin portions for enhanced sealing and stiffness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electrolytic solution contains an alkaline solution, then the power storage module can function as a bipolar battery, but the alkaline creep phenomenon causes the electrolytic solution to propagate on the metal plate surface and seep out of the module

Engineering Contradiction:

Improvebattery functionVSAvoidelectrolytic solution leakage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by bonding both surfaces of the metal plate to the sealing body before the alkaline creep phenomenon can cause leakage. This preventive bonding creates a sealed structure that stops the electrolytic solution propagation path at the metal plate surfaces, preventing the harmful effect before it occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sealing body acts as an intermediary element between the metal plate and the external environment. By bonding the sealing body to both surfaces of the metal plate, it creates a barrier that prevents the electrolytic solution from propagating on the metal plate surface and leaking outward.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the electrolytic solution propagates on the metal plate surface, then alkaline creep occurs, but bonding both surfaces to the sealing body creates a more complex sealing structure

Engineering Contradiction:

Improveprevention of electrolytic solution seepageVSAvoidsealing structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by bonding both surfaces of the metal plate to the sealing body before the alkaline creep phenomenon can cause leakage. This preventive bonding creates a sealed structure that stops the electrolytic solution propagation path at the metal plate surfaces, preventing the harmful effect before it occurs.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If the metal plate surfaces are left unbonded, then the structure is simpler, but humidity fluctuations from external moisture infiltration promote alkaline creep progression

Engineering Contradiction:

Improvesealing structureVSAvoidhumidity fluctuation

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The sealing body acts as an intermediary element between the metal plate and the external environment. By bonding the sealing body to both surfaces of the metal plate, it creates a barrier that prevents the electrolytic solution from propagating on the metal plate surface and leaking outward.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing structure creates a protected environment around the metal plate surfaces, isolating them from external moisture and humidity fluctuations. This inert environment prevents the conditions necessary for alkaline creep from developing.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

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 electrolytic solution leakage and corrosion by reducing the likelihood of alkaline creep, ensuring the integrity and safety of the power storage module.

Implementation Method 1

a so-called alkaline creep phenomenon causes the electrolytic solution that is housed in the internal space to propagate on the surface of the metal plate of the negative terminal electrode

Methodology Applied

Scientific EffectAlkaline creep phenomenon: Capillary Action

Data Source

PatentUS11757136B2Power storage module and manufacturing method of power storage module

Publication Date: 2023.09.12 TOYOTA INDUSTRIES CORP

AI summary

A power storage module includes an electrode laminate including a laminate of a plurality of bipolar electrodes and a negative terminal electrode disposed on one end side of the laminate in a laminating direction, a sealing body provided to surround a side surface of the electrode laminate and sealing an internal space formed between electrodes adjacent to each other, and an electrolytic solution containing an alkaline solution that is housed in the internal space, both surfaces of a metal plate of the negative terminal electrode are bonded to the sealing body, and a first surplus space surrounded by the sealing body and the metal plate of the negative terminal electrode is present.