Electrode Coating Drying Profile to Prevent Edge Peeling

Solution Overview

Problem

The film thickness of the end portion of the coating film on the current collector foil is thinner due to dripping, leading to easier drying and subsequent peeling off from the foil, which can deteriorate battery performance.

Innovation Solution

The electrode manufacturing method involves applying slurry to a current collector foil and drying the coating film in a drying furnace, where the coating film is divided into three regions: center and end portions. The method uses a high energy density heat source for the center portion and a low energy density heat source for the end portions to ensure uniform drying time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If uniform drying is applied to the entire coating film, then the center portion dries adequately, but the end portions dry too quickly and peel off

Engineering Contradiction:

Improvedrying uniformityVSAvoidelectrode adhesion

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies different drying conditions to different regions of the coating film. Specifically, the end portions are dried with lower energy density heat sources while the center portion uses higher energy density heat sources, matching the local drying requirements of each region to prevent peeling while ensuring adequate drying.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The coating film is divided into three distinct regions (left end portion, center portion, right end portion) for differential drying treatment. This segmentation allows independent control of drying parameters for each region, enabling precise management of drying uniformity and adhesion.

Inventive Principle:

Principle #1Segmentation

2Productivity

If high energy density heat source is used for the entire coating film, then drying speed increases, but the end portions peel off due to excessive drying

Engineering Contradiction:

Improvedrying speedVSAvoidelectrode adhesion

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies different drying conditions to different regions of the coating film. Specifically, the end portions are dried with lower energy density heat sources while the center portion uses higher energy density heat sources, matching the local drying requirements of each region to prevent peeling while ensuring adequate drying.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial drying action by using high energy density heat sources only for the center portion and low energy density heat sources for the end portions. This partial application of high energy density prevents excessive drying at the vulnerable end portions while maintaining high productivity for the majority of the coating film.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If low energy density heat source is used for the entire coating film, then peeling is suppressed, but drying time increases significantly

Engineering Contradiction:

Improveelectrode adhesionVSAvoiddrying time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies different drying conditions to different regions of the coating film. Specifically, the end portions are dried with lower energy density heat sources while the center portion uses higher energy density heat sources, matching the local drying requirements of each region to prevent peeling while ensuring adequate drying.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial drying action by using high energy density heat sources only for the center portion and low energy density heat sources for the end portions. This partial application of high energy density prevents excessive drying at the vulnerable end portions while maintaining high productivity for the majority of the coating film.

Inventive Principle:

Principle #16Partial or excessive action

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 effectively suppresses peeling of the electrode from the current collector foil, thereby maintaining battery performance by ensuring uniform drying and adhesion of the electrode.

Implementation Method 1

a drying step of drying the coating film while transporting the current collector foil on which the coating film has been formed in a drying furnace

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

the drying step includes drying each of the end portions of the coating film using a heat source having a low energy density, and drying the center portion of the coating film using a heat source having a high energy density

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS20250079431A1Electrode manufacturing method

Publication Date: 2025.03.06 TOYOTA JIDOSHA KK

AI summary

A coating step of coating a slurry obtained by dispersing an electrode material on a current collector foil in a solvent to obtain a coating film, and a drying step of drying the coating film while transporting the current collector foil on which the coating film is formed in a drying furnace, the coating film, three regions divided along the transport direction, a central portion disposed in the center of the width direction, and an end portion disposed on both sides of the central portion, respectively, a drying step drying each end portion of the coating film by a heat source of low energy density, drying the central portion of the coating film by a high energy density heat source, an electrode manufacturing method.