Composite Battery Substrate With Buried Tabs for Low Contact Resistance

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Solution Overview

Problem

Rechargeable lithium batteries face challenges in achieving high energy density and capacity, particularly in ensuring adequate adhesive force and contact resistance between the tab and the composite substrate, which affects the overall performance and efficiency of the battery.

Innovation Solution

A composite substrate is designed with a support layer sandwiched between two metal layers, incorporating buried and exposed tabs to enhance the adhesive force and contact resistance, thereby improving the electrical connection and stability of the battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the tab is buried between the support layer and metal layer, then adhesive force is improved, but contact resistance increases

Engineering Contradiction:
Improveadhesive forceVSAvoidcontact resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The tab is divided into two distinct portions: a buried portion embedded between the support layer and metal layer to provide adhesive force, and an exposed portion extending outward to ensure low contact resistance for electrical connection. This segmentation allows each portion to fulfill its specific function optimally.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the tab are designed with different characteristics: the buried portion is optimized for adhesion to the support layer and metal layer, while the exposed portion is optimized for electrical contact. This local differentiation of properties resolves the contradiction between adhesive force and contact resistance.

Inventive Principle:
Principle #3Local quality

2Reliability

If the tab is exposed on the metal layer surface, then contact resistance is reduced, but adhesive force decreases

Engineering Contradiction:
Improvecontact resistanceVSAvoidadhesive force
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The tab structure is segmented into buried and exposed portions, allowing the exposed portion to provide low contact resistance while the buried portion maintains adhesive force through embedding in the support layer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tab extends in multiple dimensions: vertically embedded in the support layer for adhesion, and horizontally exposed on the surface for electrical contact. This multi-dimensional configuration resolves the trade-off between adhesive force and contact resistance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4648141A1Composite substrate for rechargeable lithium battery, and rechargeable lithium battery including the same
Publication Date: 2025.11.12 SAMSUNG SDI CO LTD
  • EP4648141A1 patent drawingFigure 1
  • EP4648141A1 patent drawingFigure 2
  • EP4648141A1 patent drawingFigure 3

AI summary

Disclosed are composite substrates and rechargeable lithium batteries. The composite substrate includes a support layer, a first metal layer on a top surface of the support layer, a second metal layer on a bottom surface of the support layer, and at least one tab that is buried between the support layer and at least one of the first and second metal layers. The tab includes a buried portion and an exposed portion.