Composite Battery Terminal Structure for Reliable Collector Welding

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Solution Overview

Problem

The use of single metal poles in battery cells, such as copper and aluminum, leads to welding difficulties due to differing melting points, resulting in cracking and increased costs.

Innovation Solution

A conductive structure with a first-metal post and a second-metal layer, where the second-metal layer wraps the first end and extends toward the second end, featuring a second step portion for welding to a current collector, with optimized dimensions and bonding interfaces to reduce size and thickness while maintaining bonding strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a composite pole with thick second-metal layer and large diameter is used to ensure welding effect and bonding force, then welding reliability and bonding strength are improved, but manufacturing costs increase

Engineering Contradiction:
Improvewelding reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by creating a step portion structure where the second-metal layer has different thicknesses in different regions. The first region has a greater thickness to ensure welding reliability, while the second region has a reduced thickness to lower manufacturing costs. This localized variation in thickness optimizes both welding performance and cost efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the second-metal layer into distinct regions with different thicknesses. The step portion divides the structure into a first region (thicker) for welding and a second region (thinner) for cost reduction. This segmentation allows each region to fulfill its specific function optimally.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the second-metal layer thickness is reduced to lower costs, then manufacturing cost decreases, but bonding force between metal layers weakens

Engineering Contradiction:
Improvemanufacturing costVSAvoidbonding force
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent uses local quality by making the second-metal layer thickness position-dependent. The first region maintains greater thickness to ensure sufficient bonding force, while the second region reduces thickness to lower manufacturing costs. The step portion structure ensures that bonding strength is maintained where needed.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the pole diameter is reduced to lower costs, then manufacturing cost decreases, but bonding force between aluminum layer and copper layer weakens

Engineering Contradiction:
Improvemanufacturing costVSAvoidbonding force
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies local quality by creating a step portion structure where the pole has different diameters in different regions. The first region maintains a larger diameter to ensure sufficient bonding force between metal layers, while the second region has a reduced diameter to lower manufacturing costs.

Inventive Principle:
Principle #3Local quality

4Ease of manufacture

If single metal material is used for poles, then manufacturing cost decreases and structure is simplified, but welding reliability deteriorates due to different melting points

Engineering Contradiction:
Improvemanufacturing costVSAvoidwelding reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses composite materials by combining different metal materials in the pole structure. The pole includes a first-metal post and a second-metal layer, creating a composite structure that leverages the advantages of different materials to achieve both cost effectiveness and welding reliability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by assigning different metal materials to different regions of the pole. The first-metal post and second-metal layer use different materials optimized for their specific functions, with the second-metal layer's step portion structure further optimizing material distribution for welding performance.

Inventive Principle:
Principle #3Local quality

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 design allows for a smaller diameter and thinner second-metal layer, reducing costs and improving welding reliability while maintaining bonding strength and overcurrent capability.

Implementation Method 1

Different second-metal layers are bonded together by friction welding or stamping

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Data Source

PatentEP4708481A1Conductive structure, cover plate assembly, and battery cell
Publication Date: 2026.03.11 HUIZHOU EVE POWER CO LTD
  • EP4708481A1 patent drawingFigure 1~2
  • EP4708481A1 patent drawingFigure 3~4
  • EP4708481A1 patent drawingFigure 5~6

AI summary

The present disclosure provides a conductive structure (10), a cover plate assembly (100), and a battery cell (1000). The conductive structure (10) includes a first-metal post (1) and a second-metal layer (2). The first-metal post (1) includes a first end (11) and a second end (12) opposite to each other. The first end (11) is formed with a first step portion (11a). The second-metal layer (2) is bonded to a surface of the first-metal post (1). The second-metal layer (2) wraps the first end (11) and extends toward the second end (12). The second-metal layer (2) is formed with a second step portion (26) matching the first step portion (11a). The second step portion (26) is configured to be welded to a current collector (120).