Doped Halide Solid Electrolyte for Higher Ionic Conductivity

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Solution Overview

Problem

Halide solid electrolytes in lithium ion batteries have room for improvement in ionic conductivity.

Innovation Solution

An ion conductive substance containing an alkali metal element, a metal element M (Ta or Nb), a halogen element, and a dopant element X (Ga, In, Sb, Bi, Mg, Ca, or Ba) with specific atomic percentages and a half-value width of diffraction peaks in X-ray diffraction charts, enhancing ionic conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If halide solid electrolytes are used in lithium ion batteries, then safety is improved and high-temperature resistance is enhanced, but ionic conductivity is insufficient

Engineering Contradiction:
ImprovesafetyVSAvoidionic conductivity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the compositional parameters of the halide solid electrolyte by introducing specific dopant elements (Ga, In, Sb, Bi, Mg, Ca, Sr, or Ba) at controlled concentrations (0.01-5.0 mol%). This doping strategy modifies the crystal structure and electronic properties of the base material (Li-M-X-O, where M is Ta or Nb), thereby enhancing ionic conductivity while preserving the inherent safety advantages of halide-based electrolytes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite electrolyte system by combining multiple elements within a unified crystal structure. The base composition (Li, M, X, O) is integrated with dopant elements to form a multi-component solid electrolyte with improved properties. This composite approach allows the material to benefit from both the high safety of halide structures and the enhanced ionic conductivity provided by the dopants.

Inventive Principle:
Principle #40Composite materials

2Reliability

If halide solid electrolytes are used in lithium ion batteries, then high voltage resistance is improved, but ionic conductivity is insufficient

Engineering Contradiction:
Improvehigh voltage resistanceVSAvoidionic conductivity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent modifies the electrical and structural parameters of the halide solid electrolyte through controlled doping with elements having different valence states. The dopants (particularly trivalent elements like Ga, In, Sb, Bi and divalent elements like Mg, Ca, Sr, Ba) create charge carriers and modify the band structure, enabling the material to maintain high voltage resistance while achieving improved ionic conductivity through parameter optimization.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If conventional solid electrolytes are used, then high-temperature resistance is improved, but ionic conductivity and safety are insufficient

Engineering Contradiction:
Improvehigh-temperature resistanceVSAvoidionic conductivity
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent develops a composite halide-based solid electrolyte that combines the thermal stability of conventional high-temperature resistant materials with the high ionic conductivity potential of doped halide structures. The multi-element composition (Li-M-X-O with dopants) creates a material that maintains structural integrity at elevated temperatures while providing adequate ionic conductivity for practical battery applications.

Inventive Principle:
Principle #40Composite materials

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 substance achieves improved ionic conductivity, leading to better battery performance and stability, especially at high temperatures.

Implementation Method 1

an ion conductive substance containing an alkali metal element, a metal element M, a halogen element, a dopant element X, and an oxygen element

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

at least one diffraction peak having a half-value width of 1.5° to 10° is present within a range in which a 2θ angle is 10° to 20° in an X-ray diffraction chart measured using a CuKα ray at 25°C

Methodology Applied
Scientific EffectX-ray diffraction: Bragg Diffraction

Data Source

PatentEP4600971A1Ion conductive substance, electrolyte, and battery
Publication Date: 2025.08.13 SUMITOMO CHEM CO LTD
  • EP4600971A1 patent drawingFigure 1
  • EP4600971A1 patent drawingFigure 2
  • EP4600971A1 patent drawingFigure 3

AI summary

An ion conductive substance contains an alkali metal element, a metal element M, a halogen element, a dopant element X, and an oxygen element, in which the metal element M is at least one of Ta and Nb, and the dopant element X is at least one element selected from the group consisting of Ga, In, Sb, Bi, Mg, Ca, Sr, and Ba.