Low-Temperature Ion-Conductive Oxide for High-Conductivity Solid Batteries

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional oxide-based solid electrolytes in all-solid-state batteries require high-temperature heat treatment, leading to potential reactions with electrode active materials, which can form high-resistance phases and decrease ionic conductivity, thus affecting battery output.

Innovation Solution

An ion conductive solid represented by the formula Li6+x−y−zY1−x−y−zMgxZryCezB3O9, where x, y, and z are real numbers within specific ranges, is produced through low-temperature heat treatment, enhancing ionic conductivity and allowing for a monoclinic crystalline structure with controlled lattice volume and diffraction peak positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-temperature heat treatment (900°C or more) is performed to reduce contact resistance between particles of oxide-based solid electrolyte, then ionic conductivity is improved, but the solid electrolyte and electrode active material react to form high-resistance phases, decreasing ionic conductivity and battery output

Engineering Contradiction:
Improveionic conductivityVSAvoidformation of high-resistance phase
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the heat treatment temperature parameter from conventional high temperature (900°C or more) to a lower temperature range (500-800°C). This parameter change resolves the contradiction by achieving sufficient ionic conductivity without causing harmful reactions between the solid electrolyte and electrode active material that form high-resistance phases

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite oxide-based solid electrolyte containing multiple cations (Li, Na, K, Ca, Sr, Ba, Mg, Al, Ga, In, Ti, Zr, Hf, Nb, Ta, W) in specific concentration ranges. This composite material approach enables the electrolyte to achieve high ionic conductivity at lower heat treatment temperatures while maintaining stability and preventing harmful reactions with electrode materials

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If heat treatment temperature is reduced to less than 900°C to prevent reaction with electrode active material, then formation of high-resistance phase is prevented, but contact resistance between particles may increase, affecting ionic conductivity

Engineering Contradiction:
Improvereaction with electrode active materialVSAvoidionic conductivity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The composite oxide-based solid electrolyte with multiple cations in optimized ratios provides intrinsic high ionic conductivity that compensates for potentially higher contact resistance at lower heat treatment temperatures. The synergistic effect of multiple cations enables achieving both low contact resistance and prevention of harmful reactions

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes multiple parameters including heat treatment temperature (500-800°C), time (1-24 hours), and atmospheric conditions to achieve the desired balance between reducing contact resistance and preventing harmful reactions, thereby resolving the contradiction

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

The ion conductive solid achieves high ionic conductivity and prevents the formation of high-resistant phases, resulting in improved output characteristics for all-solid-state batteries without the need for high-temperature processing.

Implementation Method 1

an electrolyte that is placed between the positive electrode and the negative electrode, and includes an ion conductive solid

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

heat treatment is performed to reduce the contact resistance between the particles of an oxide-based material included in the solid electrolyte

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentUS20230420730A1Ion-conductive solid and all-solid-state battery
Publication Date: 2023.12.28 CANON OPTRON INC

AI summary

An ion conductive solid that can be produced by heat treatment at low temperature and has a high ion conductivity; and an all-solid-state battery comprising the ion conductive solid, and the ion conductive solid comprising an oxide represented by Formula Li6+x−y−zY1−x−y−zMgxZryCezB3O9, in formula, x is a real number satisfying 0.005≤x≤0.800, y is a real number satisfying 0.000≤y≤0.400, z is a real number satisfying 0.000≤z≤0.400, and x, y, z are real numbers satisfying 0.005≤x+y+z<1.000.