Resin-Insulated Current Collector Structure for Higher Battery Energy Density

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Solution Overview

Problem

Existing current collectors in batteries do not adequately enhance energy density, necessitating improvements in their structural design.

Innovation Solution

A current collector with a support portion made of an electrically insulating resin composition, featuring a support layer and an extension portion that extends orthogonally and is bent, along with a first and second conductive layer, to improve electrical insulation and reduce the need for additional insulating members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional current collectors are used, then structural simplicity is maintained, but energy density of the battery cannot be improved

Engineering Contradiction:
Improveenergy densityVSAvoidcurrent collector structure
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The current collector is divided into a support layer and an extension portion, with the support layer further containing a resin layer and a conductive layer. This segmentation allows each part to perform its specific function optimally while contributing to overall energy density improvement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The current collector uses a composite structure combining resin material (electrically insulating) and conductive material (such as aluminum foil). This composite approach reduces the overall material volume while maintaining electrical functionality, thereby improving energy density.

Inventive Principle:
Principle #40Composite materials

2Reliability

If additional insulating members are used to ensure insulation, then insulation reliability is improved, but device complexity and volume increase

Engineering Contradiction:
Improveelectrical insulationVSAvoidnumber of insulating members
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulating function is merged into the support layer itself by using an electrically insulating resin material. This eliminates the need for separate insulating members between the current collector and the battery case, reducing device complexity while maintaining insulation reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support layer serves multiple functions: it provides structural support, ensures electrical insulation, and acts as a base for the conductive layer. This multi-functionality reduces the need for additional components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the support layer is made thicker to improve insulation, then insulation performance is improved, but volume of electrode material decreases

Engineering Contradiction:
Improveelectrical insulationVSAvoidvolume ratio of electrode material
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The support layer uses an electrically insulating resin material that provides adequate insulation performance with minimal thickness. This allows maximization of the volume available for electrode material while maintaining necessary insulation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The insulating function is combined into the thin support layer, eliminating the need for additional thick insulating structures. This enables higher volume allocation to electrode material.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4712182A1Current collector and battery
Publication Date: 2026.03.18 TOYOTA JIDOSHA KK
  • EP4712182A1 patent drawingFigure 1
  • EP4712182A1 patent drawingFigure 2
  • EP4712182A1 patent drawingFigure 3

AI summary

A current collector (100A) includes a support portion (110), a first conductive layer (120), and a second conductive layer (130). The support portion (110) includes an electrically insulating resin composition. The support portion (110) includes a support layer (111) and an extension portion (112). The first conductive layer (120) is in contact with the support layer (111) on a first side in a thickness direction (DT) of the support layer (111). The second conductive layer (130) is in contact with the support layer (111) on a second side in the thickness direction (DT). The extension portion (112) extends from the support layer (111) in an orthogonal direction (DO) orthogonal to the thickness direction (DT).