Prelithiated Electrode Strip Rinsing via Pressure Gradient

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Solution Overview

Problem

Existing methods for prelithiating electrode strips in lithium-ion battery production are inefficient in removing excess electrolyte, leading to slow diffusion and potential mechanical stress on the electrode strips during rinsing.

Innovation Solution

A method involving a porous prelithiated electrode strip being introduced into a rinsing bath with a pressure difference, allowing the rinsing liquid to flow through and remove excess electrolyte, utilizing a perforated element to reduce mechanical stress and facilitate faster rinsing, and applying the current conductor post-rinsing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the electrode strip is rinsed by immersing in a rinsing liquid, then the excess electrolyte is removed, but the rinsing process is slow due to diffusion and mechanical stress occurs on the electrode strip

Engineering Contradiction:
Improverinsing speedVSAvoidmechanical stress on electrode strip
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies hydraulic principles by using a pressure difference (first pressure on the first surface greater than second pressure on the second surface) to drive the rinsing liquid through the porous electrode strip. This forced flow through the porous structure accelerates electrolyte removal while distributing mechanical stress uniformly, preventing damage to the electrode strip.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The electrode strip is designed with porous structure that allows the rinsing liquid to flow through it under pressure difference. The porosity enables rapid electrolyte removal via through-flow rather than slow diffusion, while the porous network distributes mechanical stress uniformly throughout the structure, preventing localized damage.

Inventive Principle:
Principle #31Porous materials

2Productivity

If the rinsing liquid flows through the electrode strip under pressure difference, then the rinsing process is significantly accelerated, but the electrode strip must be porous and free of metallic current conductor

Engineering Contradiction:
Improverinsing speedVSAvoidelectrode strip structure requirements
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The electrode strip is prepared in advance with a porous structure and without metallic current conductor before the rinsing process. This preliminary configuration enables the subsequent pressure-driven rinsing to proceed rapidly, as the structure is already optimized for fluid flow through the electrode material.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The electrode strip utilizes a porous structure that inherently facilitates rapid fluid flow when pressure difference is applied. The porosity is built into the electrode design, allowing rinsing liquid to penetrate and flush through the electrode matrix efficiently, achieving fast rinsing without requiring additional complex flow control mechanisms.

Inventive Principle:
Principle #31Porous materials

3Ease of operation

If a metallic current conductor is present during rinsing, then the electrode structure is complete, but the rinsing liquid cannot flow through the electrode strip effectively

Engineering Contradiction:
Improverinsing effectivenessVSAvoidelectrode strip integrity
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The electrode manufacturing process is segmented into distinct stages: first forming the porous electrode strip without metallic current conductor for effective rinsing, then adding the current conductor after rinsing is complete. This segmentation allows each stage to optimize for its specific function - porous structure for fluid flow, metallic layer for electrical conductivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rinsing operation is performed preliminarily before applying the metallic current conductor. This sequence ensures that the electrode strip maintains its porous, conductor-free state during rinsing for optimal fluid flow, and only after successful rinsing is the current conductor added to complete the electrode structure.

Inventive Principle:
Principle #10Preliminary 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 method significantly accelerates the rinsing process, reduces mechanical stress on the electrode strips, and prevents damage by allowing the rinsing liquid to flow through the porous strip, resulting in an electrode film largely free of electrolyte.

Implementation Method 1

A pressure difference is generated in the rinsing bath such that a first pressure prevailing on the first surface of the electrode band is greater than a second pressure prevailing on at least part of a second surface of the electrode band opposite the first surface. The rinsing liquid flows through the electrode strip due to the pressure difference created in this way.

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP3615715B1Method of manufacturing an electrode film and electrode
Publication Date: 2021.03.17 ROBERT BOSCH GMBH
  • EP3615715B1 patent drawingFigure 1~2
  • EP3615715B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for producing an electrode film, wherein an electrode strip (20) of high tensile strength is provided, which electrode strip contains an electrochemical active material, wherein the electrode strip (20) is electrochemically prelithiated, wherein the prelithiated electrode strip (20) is rinsed in a rinse bath. The prelithiated electrode strip (20) is introduced into the rinse bath in such a way that at least one first surface (21) of the electrode strip (20) comes into contact with a rinse liquid which is contained in the rinse bath. A pressure difference is generated in the rinse bath in such a way that a first pressure (51), which prevails at the first surface (21) of the electrode strip (20), is greater than a second pressure (52) which prevails at at least one portion of a second surface (22) of the electrode strip (20), which second surface is situated opposite the first surface (21).