Orthogonal Z-Folded Electrode Separator for Battery Pressure Distribution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrochemical cell technologies face challenges in achieving homogeneous pressure and force distribution during charge and discharge cycles, leading to reduced performance, safety, and lifetime, particularly in wound cells, while stacked cells are expensive and require precise alignment.

Innovation Solution

The electrochemical cell design involves a first electrode layer and a separator layer that are orthogonally z-folded, with a second electrode plate placed between the folded sections, allowing for easy alignment and reduced manufacturing costs, while maintaining a homogeneous pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If wound cell structure is used to increase charge capacity, then manufacturing cost is reduced and charge capacity is improved, but inhomogeneous pressure distribution occurs during charge and discharge

Engineering Contradiction:
Improvecharge capacityVSAvoidpressure distribution
Core Design Contradiction:
Quantity of substanceVSStress or pressure

Solution Approach 1:

The cell structure is divided into multiple segments or layers that are stacked together. Each layer contains electrodes and separator arranged in a modular fashion, allowing independent compression and more uniform pressure distribution across the entire cell during charge and discharge cycles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a two-dimensional wound structure to a three-dimensional stacked configuration. This dimensional change allows for better pressure distribution by distributing mechanical stress across multiple layers and planes, rather than concentrating it in a single wound cylinder.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stress or pressure

If stacked cell structure is used to achieve homogeneous force distribution, then performance and safety are improved, but manufacturing cost and complexity increase

Engineering Contradiction:
Improveforce distributionVSAvoidmanufacturing cost
Core Design Contradiction:
Stress or pressureVSEase of manufacture

Solution Approach 1:

The patent combines the advantages of both wound and stacked structures by integrating continuous material processing with layered assembly. Multiple layers are formed from continuous rolls and then stacked, maintaining manufacturing efficiency while achieving homogeneous force distribution characteristic of stacked cells.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent optimizes parameters such as layer thickness, material composition, and stacking configuration to achieve homogeneous force distribution. By carefully controlling these parameters, the cell structure can distribute stress uniformly without requiring complex alignment procedures or expensive equipment.

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If stacked cell structure is used for homogeneous force distribution, then performance is improved, but manufacturing precision requirements increase due to precise alignment needs

Engineering Contradiction:
Improveforce distributionVSAvoidalignment precision
Core Design Contradiction:
Stress or pressureVSManufacturing precision

Solution Approach 1:

The patent designs universal interface features and standardized layer configurations that can be easily aligned and assembled. The modular structure includes built-in alignment guides and standardized connection points, allowing layers to be stacked with minimal precision requirements while still achieving homogeneous force distribution.

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

4Stress or pressure

If z-fold technique is used to improve pressure distribution, then homogeneous pressure distribution is achieved, but equipment complexity and manufacturing time increase

Engineering Contradiction:
Improvepressure distributionVSAvoidequipment complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The patent incorporates pressure distribution features directly into the cell structure during the forming process, rather than requiring additional equipment to adjust pressure afterward. The layered design and material selection inherently promote homogeneous pressure distribution, eliminating the need for complex pressure regulation equipment.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2973835B1Electrochemical cell having a folded electrode and separator, battery including the same, and method of forming same
Publication Date: 2019.10.30 ROBERT BOSCH GMBH
  • EP2973835B1 patent drawingFigure 1
  • EP2973835B1 patent drawingFigure 2
  • EP2973835B1 patent drawingFigure 3

AI summary

An electrochemical cell including a folded electrode layer and a folded separator, a battery including the electrochemical cell, and methods of forming the electrochemical cell and battery are disclosed. The electrode layer is folded in a first direction and the separator is folded in a second direction, such that the first direction and second direction are orthogonal each other.