Multilayer Battery Lead Electrode Structure for High Density

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Solution Overview

Problem

Existing secondary battery stacking structures face challenges in high-density packaging due to thickness and weight increases from terminal tabs and insulating substrates, and require complex electrode configurations for efficient electrical connection, which limits capacity and manufacturing efficiency.

Innovation Solution

A lead electrode structure is introduced that connects battery cells in parallel by sandwiching smaller, strip-shaped or linear lead electrodes between electrodes, preventing overlap and reducing thickness, while ensuring low resistance and easy manufacturing, allowing for high-density stacking and mass production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If terminal tabs and insulating substrates are used to connect battery cells in parallel, then electrical connection is achieved, but thickness and weight increase

Engineering Contradiction:
Improveelectrical connectionVSAvoidbattery assembly weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent extracts and eliminates the insulating substrate from the battery cell connection structure. By directly contacting the electrode surfaces without requiring an insulating substrate, the connection structure achieves electrical connection while reducing weight and simplifying the assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The terminal tab serves multiple functions: it provides electrical connection between cells, acts as a structural support element, and eliminates the need for separate insulating substrates. This multi-functionality reduces the overall weight and complexity of the battery assembly.

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

2Reliability

If terminal tabs and insulating substrates are used to connect battery cells in parallel, then electrical connection is achieved, but thickness increases

Engineering Contradiction:
Improveelectrical connectionVSAvoidbattery assembly thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The insulating substrate is extracted and removed from the connection structure. The terminal tab directly contacts the electrode surfaces, eliminating the thickness contribution of the insulating substrate and reducing overall assembly thickness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The terminal tab is designed as a thin, flexible conductive element that can conform to the electrode surface without requiring thick insulating layers, thereby reducing the overall thickness of the connected battery assembly.

Inventive Principle:
Principle #30Flexible shells and thin films

3Productivity

If complex electrode configurations are used for efficient electrical connection, then connection efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveconnection efficiencyVSAvoidelectrode configuration complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The battery cell is segmented into functional regions with the terminal tab positioned at specific locations on the electrode. This segmentation allows for simplified connection configurations while maintaining efficient electrical connection between cells.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using complex insulating substrate patterns to achieve connection, the patent inverts the approach by using direct terminal tab contact with electrodes, simplifying the configuration while maintaining connection efficiency.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3131148B1Multilayer secondary battery
Publication Date: 2019.08.14 NIHON MICRONICS KK
  • EP3131148B1 patent drawingFigure 1
  • EP3131148B1 patent drawingFigure 2(A)~2(C)
  • EP3131148B1 patent drawingFigure 3(A)~3(B)

AI summary

There is provided a structure with suppressed thickness and high density when battery cells of a thin film solid secondary battery are stacked. Adjacent battery cells are stacked such that negative electrodes are in contact with each other and positive electrodes are in contact with each other, and arranged such that a taking-out lead electrode smaller than a negative electrode surface or a positive electrode surface is sandwiched between two negative electrodes in contact with each other or two positive electrodes in contact with each other, and the lead electrodes sandwiched between electrodes of different layers are arranged such that there is no region where all of the lead electrodes simultaneously overlap one another as viewed in a planar arrangement. As for the shape of the lead electrode, there are a strip-shaped lead electrode and a linear lead electrode. Further, a conductive sheet forming the electrode is extended to also serve as the taking-out electrode, thereby making it possible to reduce the number of lead electrodes.