Secondary Battery Collector Plate Joint Without Insulation Film Interference

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current secondary batteries suffer from poor connections and welding defects due to the first insulation film being inserted into the joining position between the first collector plate and the housing sidewall, leading to potential corrosion and electrical issues.

Innovation Solution

The first insulation film is designed to not extend beyond the negative electrode active substance layer region, preventing insertion into the joining position and reducing the occurrence of poor connections and welding defects by ensuring proper electrical connection and insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the first insulation film is extended to cover the entire outer periphery of the electrode assembly, then the insulation performance is improved, but the insulation film may be inserted into the joining position between the first collector plate and the housing sidewall causing poor connections

Engineering Contradiction:
Improveinsulation performanceVSAvoidpoor connection
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The first insulation film is designed with different extension lengths at different locations: it extends beyond the active substance layer region at some positions to provide insulation, but is controlled not to extend beyond the active substance layer region at the joining position between the first collector plate and the housing sidewall. This local differentiation ensures both insulation performance and connection reliability.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the first insulation film is wrapped tightly around the electrode assembly, then the structural stability is improved, but the insulation film may interfere with the joining position causing welding defects

Engineering Contradiction:
Improvestructural stabilityVSAvoidwelding quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The first insulation film is designed to have controlled extension at the joining position, not extending beyond the active substance layer region where the first collector plate connects to the housing sidewall. This local control prevents the insulation film from interfering with the welding process while maintaining structural stability in other areas.

Inventive Principle:
Principle #3Local quality

3Reliability

If the first insulation film extends beyond the active substance layer region, then the insulation coverage is improved, but the risk of insertion into joining position and causing corrosion increases

Engineering Contradiction:
Improveinsulation coverageVSAvoidcorrosion risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The first insulation film is designed with position-specific extension: it extends beyond the active substance layer region at locations where insulation is needed, but is controlled not to extend beyond the active substance layer region at the joining position between the first collector plate and the housing sidewall. This prevents the insulation film from being inserted into the joining position and causing corrosion while maintaining adequate insulation coverage elsewhere.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4708420A1Secondary battery, battery assembly, and electronic device
Publication Date: 2026.03.11 AESC JAPAN LTD
  • EP4708420A1 patent drawingFigure 1
  • EP4708420A1 patent drawingFigure 2
  • EP4708420A1 patent drawingFigure 3

AI summary

A secondary battery (300) including a housing (320) having an end wall and a sidewall, a positive electrode sheet, a first separator (210), a negative electrode sheet (220), a second separator (210), a first collector plate (310), and a first insulation film (230) is provided. An opening (330) is formed on one side of the sidewall facing away from the end wall. The positive electrode sheet, the first separator (210), the negative electrode sheet (220), and the second separator (210) are stacked and wound sequentially to form an electrode assembly (200) accommodated in the housing (320). The first collector plate (310) is disposed on one end of the electrode assembly (200) facing the opening (330), and the housing (320) is electrically connected to the negative electrode tab (221) through the first collector plate (310). The first insulation film (230) is wrapped around an outer periphery of the electrode assembly (200).