Spinning Apparatus for Battery Electrode Separator Formation

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Solution Overview

Problem

Existing spinning technologies face challenges in forming an organic fiber sheet integrally with electrodes while ensuring even film thickness and accurately removing organic fibers from areas where current collectors are joined, affecting the integrity and insulation of battery electrodes.

Innovation Solution

A spinning apparatus comprising a spinning head and a rotational brush, where the spinning head forms an organic fiber sheet on an electrode surface using electrospinning, and the rotational brush, with adjustable bristle diameter and length, strips the fibers from specific areas, ensuring uniformity and appropriate removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electrospinning method is used to form an organic fiber sheet on the entire electrode surface, then the separator is integrally formed with the electrode, but organic fiber remains on the current collecting tab area where active material is not supported

Engineering Contradiction:
Improveseparator formationVSAvoidfiber removal accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The electrode surface is divided into two functional zones: the active material support area where the organic fiber sheet is formed to create separator, and the current collecting tab area where no fiber sheet is formed to allow proper electrical connection. This spatial segmentation resolves the contradiction by enabling selective fiber formation only where needed for separator function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrospinning process parameters are controlled to create local quality differences in fiber sheet formation. By adjusting the electrospinning conditions and mask design, the organic fiber sheet is formed with appropriate thickness and density on the active material area while deliberately avoiding the current collecting tab area, thus achieving both separator formation and electrical connection integrity.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If control is applied to avoid forming organic fiber sheet in the current collector area without active material, then fiber removal is simplified, but the evenness of film thickness of the organic fiber sheet is affected

Engineering Contradiction:
Improvefiber removal processVSAvoidfilm thickness uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The current collecting tab area is prepared in advance by applying a mask or adjusting the electrospinning setup before the fiber sheet formation process begins. This preliminary action defines the boundary between the fiber formation zone and the tab area, allowing the electrospinning process to naturally avoid the tab region and maintain uniform film thickness in the active material area without requiring post-process fiber removal.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the organic fiber sheet is formed entirely on the electrode surface by electrospinning, then complete separator coverage is achieved, but additional processing steps are required to remove fiber from the current collecting tab area

Engineering Contradiction:
Improveseparator coverageVSAvoidprocessing steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The current collecting tab area is excluded from the fiber sheet formation process by using a mask or selective positioning of the electrospinning nozzle. This extraction of the tab area from the fiber formation zone eliminates the need for subsequent fiber removal steps, reducing process complexity while maintaining complete separator coverage on the active material areas.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The apparatus effectively forms a uniform organic fiber sheet on electrodes and accurately removes fibers from current collector tabs, enhancing the electrical insulation and structural integrity of battery electrodes without compromising film thickness uniformity.

Implementation Method 1

an organic fiber sheet is formed on a surface of an electrode (positive electrode or negative electrode), which is formed integrally with a separator, by an electrospinning method

Methodology Applied
Scientific EffectElectrospinning: Electrohydrodynamics

Implementation Method 2

The rotational brush includes a plurality of brush bristles and is rotated while the brush bristles are in contact with the sheet in the surface of the base. The rotational brush strips the organic fiber from a part of the sheet by the rotation.

Methodology Applied
Scientific EffectMechanical abrasion: Abrasion

Data Source

PatentEP3686324B1Spinning apparatus
Publication Date: 2023.02.22 KK TOSHIBA
  • EP3686324B1 patent drawingFigure 1
  • EP3686324B1 patent drawingFigure 2A~2B
  • EP3686324B1 patent drawingFigure 3

AI summary

According to one embodiment, a spinning apparatus includes a spinning head and a rotational brush. An organic material is filled up inside the spinning head, and the spinning head ejects the organic material on a surface of a base to form a sheet of the organic fiber on the surface of the base. The rotational brush includes a plurality of brush bristles and is rotated while the brush bristles are in contact with the sheet in the surface of the base. The rotational brush strips the organic fiber from a part of the sheet by the rotation.