Microwave Drying of Lithium-Ion Battery Electrode Materials

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Solution Overview

Problem

The existing methods for desiccating electrode materials in lithium-ion batteries, such as vacuum treatment, are costly and time-consuming, and are not easily applicable to continuous processing like roll-to-roll methods, which affects the performance and longevity of the batteries due to moisture exclusion.

Innovation Solution

The use of microwave radiation with varying frequencies to desiccate electrode materials, which includes depositing the materials on a substrate, irradiating them with microwave radiation, and then sealing them in an air-tight enclosure with a non-aqueous electrolyte solution, preventing nodal planes formation that can cause non-uniform heating and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vacuum treatment is used to desiccate electrode materials, then moisture exclusion is improved, but processing time and cost increase

Engineering Contradiction:

Improvemoisture exclusionVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical vacuum treatment system with an electromagnetic field-based microwave heating system. The microwave emitter irradiates the electrode material with microwave radiation, causing internal heating that evaporates moisture without requiring vacuum conditions. This substitution of heating mechanism eliminates the need for vacuum equipment and significantly reduces processing time while maintaining effective moisture removal.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the phase transition of water from liquid to vapor through microwave-induced heating. The microwave radiation directly heats the water molecules in the electrode material, causing rapid evaporation and phase change to steam, which then escapes from the material. This phase transition mechanism enables efficient moisture removal without requiring vacuum conditions, resolving the contradiction between moisture exclusion and processing time.

Inventive Principle:

Principle #36Phase transitions

2Reliability

If vacuum treatment is used to desiccate electrode materials, then moisture exclusion is improved, but device complexity and cost increase

Engineering Contradiction:

Improvemoisture exclusionVSAvoidprocessing equipment

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If fixed frequency microwave radiation is used, then processing is simplified, but non-uniform heating and damage occur due to nodal planes

Engineering Contradiction:

Improveprocessing simplicityVSAvoidheating uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements dynamic frequency modulation of the microwave radiation, transitioning from fixed frequency to variable frequency operation. The system continuously varies the microwave frequency to prevent the formation of stationary nodal planes that cause non-uniform heating. This dynamic adjustment ensures that different regions of the electrode material receive uniform energy distribution, eliminating hot spots and cold zones while maintaining processing simplicity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the frequency parameter of the microwave radiation from a constant value to a dynamically varying value. By modulating the frequency parameter, the system prevents the formation of stable standing wave patterns and nodal planes that cause non-uniform heating. This parameter change enables uniform heating throughout the electrode material while keeping the processing method simple and efficient.

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 method effectively removes moisture and volatile components from electrode materials, ensuring uniform heating and preventing damage, thus enhancing the performance and longevity of lithium-ion batteries while enabling continuous processing.

Implementation Method 1

irradiating the deposited electrode material with microwave radiation of varying frequency

Methodology Applied

Scientific EffectMicrowave radiation: Microwave Radiation

Implementation Method 2

The desiccation stage includes a microwave emitter configured to irradiate the deposited electrode material with microwave radiation

Methodology Applied

Scientific EffectDielectric heating: Dielectric Heating

Data Source

PatentUS10181599B2Microwave drying of lithium-ion battery materials

Publication Date: 2019.01.15 A123 SYSTEMS LLC

AI summary

A method for making a lithium-ion cell includes depositing an electrode material as a coating on a substrate of the lithium-ion cell, irradiating the deposited electrode material with microwave radiation of varying frequency, wetting the irradiated electrode material with a non-aqueous electrolyte solution, and sealing the wetted electrode material in an air-tight enclosure.