Electrode Drying with Induction Heating for Uniform Slurry Evaporation

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Solution Overview

Problem

The manufacturing of secondary battery electrodes faces challenges such as surface cracks and binder migration due to uneven drying, leading to performance issues like lithium plating and increased resistance, which affect the stability and productivity of high-capacity electrodes.

Innovation Solution

A method involving the application of slurry on a current collector, followed by drying using a combination of hot air and induction heating within a multi-zone drying apparatus, where the induction heating unit is strategically placed to ensure uniform drying, preventing defects and improving productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-capacity electrodes are manufactured with increased solvent content in slurry, then electrode capacity is improved, but drying defects such as cracks and binder migration occur

Engineering Contradiction:
Improveelectrode capacityVSAvoiddrying uniformity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The drying process is divided into multiple sequential drying zones with progressively increasing temperatures. The first drying zone uses a lower temperature to remove excess solvent without causing rapid evaporation, while subsequent zones gradually increase temperature to complete drying. This segmented approach prevents cracks and binder migration while enabling high-capacity electrodes with increased solvent content.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drying temperature parameter is changed progressively across different zones rather than using a single high temperature. The temperature increases step-by-step from the first drying zone to subsequent zones, allowing controlled solvent evaporation that prevents defects while maintaining high electrode capacity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If drying temperature is increased to improve productivity, then drying speed is improved, but cracks and binder migration occur on electrode surface

Engineering Contradiction:
Improvedrying speedVSAvoidsurface quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The drying apparatus is divided into multiple drying zones with different temperature levels. The first drying zone operates at a lower temperature to prevent defects, while subsequent zones operate at progressively higher temperatures to maintain high drying speed. This segmentation enables both high productivity and surface quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first drying zone performs preliminary drying at a lower temperature to remove excess solvent gradually before the slurry enters subsequent high-temperature zones. This preliminary action prevents cracks and binder migration from occurring in advance, allowing high-temperature drying in later zones without causing defects.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If uniform drying is achieved through extended drying time, then drying quality is improved, but manufacturing productivity decreases

Engineering Contradiction:
Improvedrying uniformityVSAvoidmanufacturing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The drying process is segmented into multiple zones with different temperature characteristics. This segmentation allows the system to achieve uniform drying quality through controlled temperature gradients while maintaining high manufacturing speed, as each zone contributes specifically to different aspects of the drying process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Temperature parameters are changed across different zones to optimize both drying uniformity and productivity. The progressive temperature increase ensures uniform solvent removal throughout the slurry while the overall process remains fast enough to maintain high manufacturing throughput.

Inventive Principle:
Principle #35Parameter changes

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

This approach enables stable and efficient drying of electrodes, reducing defects and maintaining electrode quality by ensuring uniform heat distribution, thereby enhancing the performance and manufacturing speed of secondary battery electrodes.

Implementation Method 1

drying the slurry using induction heating of an induction heating unit

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 2

supplying hot air to the slurry while the current collector passes through the inside of the drying apparatus

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP4239707A1Manufacturing method and drying apparatus of electrode
Publication Date: 2023.09.06 SK ON CO LTD
  • EP4239707A1 patent drawingFigure 1
  • EP4239707A1 patent drawingFigure 2
  • EP4239707A1 patent drawingFigure 3

AI summary

According to embodiments of the present disclosure, a method of manufacturing an electrode includes applying slurry comprising an active material and a solvent on a current collector, and when a degree of drying of the slurry reaches a reference value while the current collector passes through a drying apparatus, drying the slurry using induction heating of an induction heating unit.