Electrode Assembly Stepped Stacking Thickness Control

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Solution Overview

Problem

Existing electrode assemblies with stepped portions have limited design freedom in thickness and often suffer from low capacitance and short lifespan due to uncontrollable swelling at interfaces, restricting their practical application.

Innovation Solution

An electrode assembly with stacked electrode units of varying areas, where positive and negative electrodes face each other at interfaces, maintaining a balanced ratio of reversible capacitance and thickness to ensure high electrical capacity and durability, allowing for flexible design in both area and thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If electrode units of different sizes are stacked to form stepped portions, then design freedom in shape is improved, but thickness control is limited to multiples of unit cell thickness

Engineering Contradiction:

Improvedesign freedomVSAvoidthickness control limitation

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The electrode assembly is divided into multiple electrode units with different areas, where each unit can be independently sized. This segmentation allows the battery to achieve various thickness profiles by selectively stacking units of different dimensions, overcoming the limitation of fixed thickness multiples while maintaining design flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from uniform two-dimensional electrode stacking to three-dimensional stepped stacking with varying areas. By introducing area variation as an additional design dimension, the battery can achieve complex thickness profiles and shapes that were previously impossible with conventional uniform stacking methods.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If electrode units of different sizes are stacked to form stepped portions, then various battery shapes can be realized, but severe swelling occurs at interfaces between stepped portions

Engineering Contradiction:

Improvebattery shape varietyVSAvoidswelling at interface

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A buffer layer is pre-installed at the stepped portions where electrode units of different areas meet. This buffer layer anticipates and compensates for the swelling that occurs during battery operation, absorbing expansion forces before they can cause damage to the electrode structure or reduce battery reliability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The buffer layer acts as an intermediary element between electrode units of different sizes at the stepped portions. It mediates the mechanical stress and swelling forces that arise at the interface, distributing these forces evenly and preventing the severe localized swelling that would otherwise occur at the sharp transitions between different electrode areas.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If electrode units of different sizes are stacked to form stepped portions, then design flexibility is increased, but battery capacitance is remarkably low compared to batteries of same volume

Engineering Contradiction:

Improvedesign flexibilityVSAvoidbattery capacitance

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention systematically varies the area parameters of electrode units in the stepped structure to optimize both design flexibility and capacitance. By carefully controlling the area reduction ratio between successive electrode units and their stacking arrangement, the design maximizes the volume utilization of active materials while maintaining the desired stepped shape, thereby achieving high capacitance despite the non-uniform structure.

Inventive Principle:

Principle #35Parameter changes

4Adaptability or versatility

If electrodes are cut to desired sizes to form unit cells of different areas, then design variety is achieved, but manufacturing complexity increases

Engineering Contradiction:

Improvedesign varietyVSAvoidmanufacturing complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The manufacturing process is segmented into standardized steps: cutting electrodes to predetermined sizes, forming unit cells with specific area ratios, and stacking them in defined sequences. This segmentation transforms the complex task of creating varied battery shapes into a series of simple, repeatable operations, reducing manufacturing complexity while maintaining design variety.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP2840638B1Electrode assembly, and battery cell and device comprising same

Publication Date: 2017.07.26 LG CHEM LTD

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AI summary

There are provided an electrode assembly, and a battery cell, a battery pack, and a device. The electrode assembly includes a combination of two or more types of electrode units having different areas, wherein the electrode units are stacked such that steps are formed, and electrode units are formed such that a positive electrode and a negative electrode face one another at an interface between the electrode units.