Stacked Electrode Assembly With Welded Separators for Electrolyte Flow

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Solution Overview

Problem

Conventional power storage modules have a large space not contributing to charging and discharging due to the arrangement of separators, and misalignment of separators is not adequately addressed, leading to inefficiencies in electrolyte impregnation and potential misalignment of electrodes.

Innovation Solution

The separators are welded on at least one side surface across the length of the stacked electrode assembly, restricting their movement and reducing protrusions, while allowing electrolyte impregnation through non-welded portions, with the injection hole positioned to facilitate efficient electrolyte distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separators are extended from outer edges of electrodes toward separator joints, then misalignment of separators is prevented, but large space not contributing to charging and discharging has to be provided

Engineering Contradiction:

Improveseparator alignmentVSAvoidspace not contributing to charging and discharging

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The separator is divided into multiple sections: a first section extending from the electrode outer edge, a second section forming a protrusion, and a third section extending to the separator joint. This segmentation allows the separator to maintain alignment functionality while reducing the overall protrusion distance, thereby minimizing non-contributing space.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of extending the separator fully from the electrode outer edge to the separator joint, the invention uses partial extension with a controlled protrusion. The separator extends only to a necessary degree (partial action) to prevent misalignment, while avoiding excessive extension that would create large non-contributing spaces.

Inventive Principle:

Principle #16Partial or excessive action

2Reliability

If separators are welded on side surfaces across the length of stacked electrode assembly, then movement and misalignment of separators is restricted, but electrolyte impregnation may be hindered

Engineering Contradiction:

Improveseparator position stabilityVSAvoidelectrolyte impregnation

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The welding structure is designed with local quality variations: the separator is welded at specific locations (first and second locations) on the side surface, but not along the entire length. This allows electrolyte to penetrate through non-welded portions while maintaining position stability at welded areas, thus balancing both requirements.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If injection hole is formed in housing, then electrolyte solution can be injected into housing, but efficient electrolyte distribution into stacked electrode assembly must be ensured

Engineering Contradiction:

Improveelectrolyte injectionVSAvoidelectrolyte impregnation efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The separator structure acts as an intermediary for electrolyte distribution. The non-welded portions of the separator on the side surface serve as channels or pathways that guide and distribute electrolyte from the injection hole throughout the stacked electrode assembly, ensuring efficient impregnation while maintaining structural integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This configuration reduces the non-charging and discharging space, prevents separator misalignment, and enhances electrolyte impregnation efficiency by directing the electrolyte flow towards non-welded areas, ensuring effective electrode alignment and improved module performance.

Implementation Method 1

The separator is welded on at least one of the first side surface and the second side surface across a length of the stacked electrode assembly in the first direction

Methodology Applied

Scientific EffectWelding: Welding

Implementation Method 2

the electrolyte solution can be impregnated into the stacked electrode assembly through a portion of the second side surface where the separators are not welded

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentUS20250329881A1Stacked electrode assembly and power storage module

Publication Date: 2025.10.23 TOYOTA JIDOSHA KK

AI summary

A stacked electrode assembly includes a plurality of electrodes and a plurality of separators. The electrode and the separator are alternately stacked in a first direction. The stacked electrode assembly extends in a second direction perpendicular to the first direction. The stacked electrode assembly further includes a circumferential surface extending in the second direction. A length of the separator in a third direction perpendicular to the first and second directions is longer than a length of the electrode in the third direction. The circumferential surface has first and second primary surfaces in the first direction and first and second side surfaces in the third direction, the first and second side surfaces continuing to the first and second primary surfaces, respectively. The separator is welded on at least one of the first side surface and the second side surface across a length of the stacked electrode assembly in the first direction.