Dry Powder Electrode Coating via Electrostatic Deposition

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Solution Overview

Problem

Current methods for producing battery electrodes using powder pressing face challenges such as the need for solvents, high energy costs, limited mechanical stability, and increased contact resistance over time, along with difficulties in achieving homogeneous coatings and complex geometries.

Innovation Solution

A method involving a powder pressing device that compresses a powder mixture with an electrically conductive conductor directly, eliminating the need for solvents and allowing for the integration of the conductor without lamination, which enhances mechanical stability and enables complex geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If wet coating processes with solvents are used to produce battery electrodes, then homogeneous coatings can be achieved, but the process becomes time-consuming, expensive, and energy-intensive due to drying requirements

Engineering Contradiction:
Improvehomogeneity of coatingVSAvoiddrying time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention extracts and eliminates the solvent from the coating process entirely. Instead of using wet coatings that require drying, the patent applies dry powder mixtures directly to the current collector using electrostatic charging, thereby removing the time-consuming and energy-intensive drying step while still achieving homogeneous coverage

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the thermal drying process with an electrostatic field-based application method. By charging the powder particles electrostatically and using an electric field to deposit them onto the current collector, the process eliminates the need for thermal evaporation of solvents, significantly reducing energy consumption and processing time

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If organic solvents are used in coating processes, then binder solubility is achieved, but high levels of technical effort are required for explosion protection, fire protection, and solvent recovery

Engineering Contradiction:
Improvebinder solubilityVSAvoidsafety and recovery systems
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates organic solvents from the manufacturing process entirely. By using electrostatically charged dry powder mixtures instead of solvent-based coatings, the process removes the need for explosion protection, fire protection, and solvent recovery systems, significantly simplifying the manufacturing setup

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical state parameter of the coating material from liquid (solvent-based) to solid (dry powder). This parameter change fundamentally alters the process requirements, eliminating the need for hazardous solvent handling while maintaining effective binder functionality through direct powder deposition

Inventive Principle:
Principle #35Parameter changes

3Reliability

If press contacting is used to connect electrodes to battery housing, then electrical connection is achieved, but contact resistance increases over time due to cover layer formation, gas development, or corrosion

Engineering Contradiction:
Improveelectrical connectionVSAvoidcontact resistance stability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The invention merges the electrode structure with the current collector by directly integrating conductive material into the electrode body during the powder coating process. This integration eliminates the need for separate press-contacted connections, creating a unified structure that maintains stable electrical contact without the degradation issues of interface connections

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses electrostatically charged powder particles as an intermediary medium that inherently provides electrical conductivity. The conductive powder mixture serves as both the active material and the conductive pathway, eliminating the need for separate conductive adhesives or press contacts that are prone to degradation

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If powder mixtures are pressed into compacts without solvents, then mechanical stability is improved, but the contact surfaces remain small and battery capacity is limited

Engineering Contradiction:
Improvemechanical stabilityVSAvoidbattery capacity
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The invention transitions from three-dimensional compact pressing to two-dimensional surface coating on the current collector. By applying powder mixtures as a coating on the large surface area of the current collector, the method maximizes the quantity of active material that can be utilized while maintaining mechanical stability through the electrostatic bonding and subsequent curing process

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

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 eliminates the need for solvents, reduces energy costs, and provides high mechanical stability and complex geometry capabilities, while maintaining low binder content and efficient production.

Implementation Method 1

the powder mixture is compacted under pressure with the electrically conductive arrester

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP1796187B1Apparatus and procedure for the production of electrodes for batteries
Publication Date: 2010.09.15 BIOTRONIX CRM PATENT AG
  • EP1796187B1 patent drawingFigure 1a~1c
  • EP1796187B1 patent drawingFigure 2a~2c
  • EP1796187B1 patent drawingFigure 3a~3f

AI summary

The method involves pouring a quantity of powder mixture (6) into a cavity, before laying an electrically-conductive diverter onto the powder mixture. An additional quantity of powder mixture is poured into the cavity, before compressing the two quantities of powder mixture through use of a plunger (1). An independent claim is also included for a battery electrode manufacturing device.