Battery Electrode Sealing Structure for Low-Profile Stacked Cells

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Solution Overview

Problem

The existing methods for manufacturing stacked all-solid-state batteries result in increased battery thickness due to insulating resin jutting out in the laminating direction, which reduces structural efficiency.

Innovation Solution

An electrode design featuring a laminate with an active material layer and current collector, where the sealing portion is composed of a first and second sealing portion, with the second sealing portion being recessed into asperities on the adjacent face, preventing jutting out and ensuring firm adhesion and insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulator coating solution is coated on end portion of laminate to seal it, then insulation is improved, but battery thickness increases due to insulating resin jutting out

Engineering Contradiction:
ImproveinsulationVSAvoidbattery thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent applies local quality by creating asperities (surface irregularities) only at specific locations on the adjacent face where the sealing portion contacts the electrode. This localized surface treatment allows the sealing portion to conform to the asperities and be pressed into recessed portions, preventing jutting out while maintaining insulation. The asperities are formed only in the region where the sealing portion contacts the electrode, not across the entire surface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies preliminary action by forming asperities on the adjacent face before applying the insulator coating solution. This pre-formed surface structure guides the sealing portion material to flow into the asperities during the pressing process, ensuring that the sealing portion conforms to the asperity pattern and does not jut out. The asperities are created in advance to control the final shape and position of the sealing portion.

Inventive Principle:
Principle #10Preliminary action

2Length of stationary object

If sealing portion is pressed into recessed portions of asperities, then battery thickness is reduced, but adhesion and insulation may be compromised

Engineering Contradiction:
Improvebattery thicknessVSAvoidadhesion and insulation
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The patent applies the porous materials principle by utilizing the asperities as micro-cavities or recessed portions that the sealing portion material can penetrate and conform to. The asperities create a textured surface with increased surface area and mechanical interlocking features, allowing the sealing portion to adhere firmly while maintaining insulation. The recessed portions of the asperities act like a porous structure that the sealing material fills, enhancing both adhesion and insulation properties.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent applies composite materials by combining the sealing portion material with the asperity structure to create a composite interface. The sealing portion, when pressed into the asperities, forms a composite structure where the sealing material and the asperity surface work together to provide both mechanical adhesion and electrical insulation. This composite approach ensures that the sealing portion maintains strong adhesion and effective insulation while conforming to the asperity pattern.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4328990A1Electrode for battery, battery, and manufacturing method of electrode
Publication Date: 2024.02.28 TOYOTA JIDOSHA KK
  • EP4328990A1 patent drawingFigure 1
  • EP4328990A1 patent drawingFigure 2A~2C
  • EP4328990A1 patent drawingFigure 3

AI summary

An electrode (1) for a battery includes a laminate including an active material layer (13a, 13b) and a current collector (11), and a sealing portion covering an end portion surface of the laminate. The laminate includes two principal faces facing each other, and an end face (1a). The end portion surface includes the end face (1a), and an adjacent face (1b) on each of the two principal faces. The adjacent face (1b) includes one or more asperities. The sealing portion includes a first sealing portion (Sa) covering the end face (1a), and a second sealing portion (5b) covering at least part of the adjacent face (1b). The second sealing portion (5b) is present in one or more recessed portions of the one or more asperities of the adjacent face (1b) and does not include a portion higher than a height position (H) of the one or more asperities that is highest. The first sealing portion (5a) and the second sealing portion (5b) are connected.