Lithium Electrode Particle Size Distribution for Energy Density

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Solution Overview

Problem

Current solid polymer electrolyte lithium batteries face challenges in achieving high active material loading and optimal spatial arrangement of electrode material particles, which affects energy density and porosity.

Innovation Solution

The development of an electrode material with a specific particle size distribution, characterized by a median size between 1.5µm and 3µm, a standard deviation ratio of 0.5 or greater, and a calculated ratio of (D90 / D10) / D50 ≥ 3.0, ensuring a broad distribution that allows for higher active material loading and reduced porosity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the ratio of active material to binder is increased to achieve higher active material loading, then the energy density is improved, but air or gas is trapped in the spacing between contacting electrode material particles, increasing porosity

Engineering Contradiction:
Improveactive material loadingVSAvoidtrapped air or gas
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by optimizing the particle size distribution of electrode materials with specific metrics (D10, D50, D90 values and their ratios) to improve packing density. This controlled parameter adjustment allows higher active material loading while minimizing trapped air through scientifically defined particle characteristics

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If cathode thickness is increased to achieve higher energy content, then the energy density is improved, but the high rate performance is deteriorated

Engineering Contradiction:
Improveenergy contentVSAvoidhigh rate performance
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The patent resolves this contradiction by changing the particle size distribution parameters of the electrode material. The optimized particle size range and distribution allow thicker electrodes to maintain both high energy content and good rate performance by improving electrolyte penetration and lithium ion diffusion pathways

Inventive Principle:
Principle #35Parameter changes

3Reliability

If electrode porosity is increased to accommodate sufficient electrolyte penetration, then the ionic conduction is improved, but the active material loading is reduced

Engineering Contradiction:
Improveionic conductionVSAvoidactive material loading
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by defining specific particle size distribution characteristics (D10 ≥ 0.5μm, D50 ranging from 1.5μm to 3μm, D90 ≤ 10.0 μm, and (D90/D10)/D50 ≥ 3.0 μm-1). These parameter optimizations enable reduced porosity while maintaining sufficient ionic conduction through improved particle packing and electrolyte distribution

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2430685B1Electrodes and electrode material for lithium electrochemical cells
Publication Date: 2017.07.26 BATHIUM CANADA
  • EP2430685B1 patent drawingFigure 1
  • EP2430685B1 patent drawingFigure 2
  • EP2430685B1 patent drawingFigure 3

AI summary

An electrode and an electrode material for lithium electrochemical cells are disclosed. The electrode material is in powder form and has a particle size distribution wherein the measured particle size distribution of the electrode material has a median size D5o ranging from 1.5µm and 3µm, a D10 = 0.5µm, a D90 =10.0 µm, and a calculated ratio (D90 / D 10) / D50 = 3.0 which is indicative of a peak of the measured particle size distribution on the left of the median D50 which improves the loading and energy density of the electrode produced with this electrode material powder.