Battery Electrode Assembly with Stepped Units

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Solution Overview

Problem

Conventional battery electrode assemblies with stepped portions have limited design flexibility and electrical capacity due to uniform unit cell sizes, leading to operational errors and reduced lifespan, especially with repeated charging and discharging cycles.

Innovation Solution

A battery electrode assembly comprising multiple units with the same width but varying lengths, where electrodes of different polarities face each other at interfaces, allowing for balanced reversible capacity ratios and thickness adjustments to maintain high electrical capacity and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If electrode units of the same size are stacked to form an electrode assembly, then the manufacturing process is simple, but the design freedom is limited and the spatial efficiency is low

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddesign freedom
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The electrode assembly is segmented into multiple electrode units with different lengths, where each unit can be independently designed and stacked. This segmentation allows the battery to achieve complex stepped shapes while maintaining manageable manufacturing processes for each individual unit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrode units with asymmetric lengths are employed, where the first electrode unit has a different length than the second electrode unit. This asymmetry enables the battery to achieve varied external shapes and optimize spatial utilization while accommodating different device form factors.

Inventive Principle:
Principle #4Asymmetry

2Adaptability or versatility

If electrode units of different sizes are stacked to increase design freedom, then the design flexibility improves, but the thickness control becomes difficult and operational errors increase

Engineering Contradiction:
Improvedesign flexibilityVSAvoidthickness control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Different regions of the electrode assembly have different thickness characteristics. The first and second electrode units have different lengths creating a stepped structure, allowing each local region to be optimized for its specific function while maintaining overall thickness control within 15% variation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The length parameter of electrode units is varied to create different thickness profiles. By controlling the length ratio and stacking arrangement of electrode units with different lengths, the overall thickness can be precisely controlled while achieving desired design flexibility.

Inventive Principle:
Principle #35Parameter changes

3Shape

If unit cells are cut into different sizes to form stepped portions, then the shape variety increases, but the electrical capacity decreases and lifespan is reduced

Engineering Contradiction:
Improveshape varietyVSAvoidlifespan
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

Electrodes of different polarities are pre-positioned to face each other at the interfaces between electrode units of different lengths. This preliminary arrangement ensures balanced reversible capacity ratios from the outset, preventing operational errors and extending battery lifespan while maintaining shape variety.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The design incorporates feedback mechanisms by carefully calculating and balancing the reversible capacity ratios of electrodes at interfaces. This ensures that the stepped structure does not compromise electrical performance, maintaining high capacity retention after 500 cycles.

Inventive Principle:
Principle #23Feedback

4Adaptability or versatility

If electrodes are stacked with varying thicknesses to improve design freedom, then the spatial efficiency improves, but the thickness variation exceeds acceptable limits and durability decreases

Engineering Contradiction:
Improvespatial efficiencyVSAvoidthickness stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The electrode assembly employs a dynamic stepped structure where thickness varies in a controlled manner. The first and second electrode units have different lengths creating intentional thickness variations that optimize spatial efficiency while maintaining overall thickness stability within 15% variation through careful design of the stepped portions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3168919B1Electrode assembly including electrode units having the same width and different lengths, and battery cell and device including the electrode assembly
Publication Date: 2018.10.31 LG CHEM LTD
  • EP3168919B1 patent drawingFigure 1~2
  • EP3168919B1 patent drawingFigure 3~4
  • EP3168919B1 patent drawingFigure 5~6

AI summary

An electrode assembly comprising a combination of two or more electrode units having the same width and different lengths, wherein the electrode units are stacked so that a stepped portion is formed between the electrode units, a positive electrode and a negative electrode face each other at an interface between the electrode units, and the electrode assembly satisfies Formula 4: dNn/dPn≤dNn/dPn+1 where n denotes an integer equal to or greater than 1, dNn denotes a thickness of the negative electrode of the nth longest electrode unit, dPn denotes a thickness of the positive electrode of the nth longest electrode unit, and dPn+1 denotes a thickness of the positive electrode of the (n+1)th longest electrode unit.