Electrode Assembly Void Filling for Battery Contact Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Lithium batteries using ceramic electrolytes face challenges such as insufficient boundary contact between ceramic electrolyte powder and electrode active materials, unstable contact due to volume changes during charge-discharge cycles, and difficulties in achieving sufficient capacity and electrical characteristics.

Innovation Solution

A manufacturing method involving the formation of an active material compact with voids, impregnation of a precursor solution for a second amorphous solid electrolyte, and heat treatment to create a second solid electrolyte within the voids, using lithium double oxides and specific electrolyte materials like Li2SiO3 and Li6SiO5, to enhance ion conductivity and battery performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If ceramic electrolyte powder is used to improve safety, then ignition or explosion risk is reduced, but boundary contact between electrolyte and electrode active material becomes insufficient

Engineering Contradiction:
Improveignition or explosion riskVSAvoidboundary contact quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent uses porous ceramic electrolyte particles that can penetrate into the active material particles during pressing, creating extensive boundary contact areas. The porous structure allows the electrolyte to infiltrate the active material matrix, ensuring sufficient contact interfaces for ion transport while maintaining the inherent safety advantages of ceramic electrolytes

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent changes the particle size parameters of the ceramic electrolyte, using fine particles with specific size ranges (e.g., 0.1-10 μm) to improve packing density and contact area. By controlling particle size distribution and pressing conditions, the patent achieves optimal boundary contact while maintaining safety

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If ceramic electrolyte powder is used to improve safety, then side reactions are reduced, but contact stability during charge-discharge cycles deteriorates

Engineering Contradiction:
Improveside reaction occurrenceVSAvoidcontact stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent creates a composite structure where ceramic electrolyte particles are intimately mixed with active material particles at the micro-scale. This composite approach ensures stable mechanical contact during volume changes while the ceramic electrolyte layer protects against side reactions. The composite structure accommodates expansion/contraction without losing contact

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If active material thickness is increased to achieve sufficient capacity, then battery capacity is improved, but manufacturing difficulty increases

Engineering Contradiction:
Improvebattery capacityVSAvoidmanufacturing difficulty
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent creates local high-concentration regions of active material within the electrode assembly, rather than uniformly increasing thickness throughout. By optimizing the local distribution and packing of active material particles with ceramic electrolyte, the patent achieves high capacity in a compact form factor, avoiding the manufacturing difficulties of thick uniform structures

Inventive Principle:
Principle #3Local quality

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 enables the production of lithium batteries with improved safety, sufficient output, and large capacity, while minimizing the risk of ignition or explosion, and maintaining stability over charge-discharge cycles.

Implementation Method 1

impregnating a precursor solution of a second amorphous solid electrolyte conducting lithium ions with an active material compact

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

performing heat treatment of the active material compact where the precursor solution is impregnated and forming a second solid electrolyte

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

performing heat treatment of the active material compact where the precursor solution is impregnated and forming a second solid electrolyte in the plurality of voids

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 4

a second amorphous solid electrolyte conducting lithium ions

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentEP3079188B1Electrode assembly, and battery
Publication Date: 2019.08.28 SEIKO EPSON CORP
  • EP3079188B1 patent drawingFigure 1
  • EP3079188B1 patent drawingFigure 2~3
  • EP3079188B1 patent drawingFigure 4A~4B

AI summary

A manufacturing method of an electrode assembly includes: forming an active material compact containing a lithium double oxide and having a plurality of voids; forming a first solid electrolyte in the plurality of voids; impregnating a precursor solution of a second amorphous solid electrolyte conducting lithium ions with an active material compact in which the first solid electrolyte is formed; and performing heat treatment of the active material compact with which the precursor solution is impregnated and forming a second solid electrolyte in the plurality of voids.