Solid-State Battery Electrolyte Split for Oxidation-Resistant Charging

Solution Overview

Problem

Existing batteries suffer from reduced charge and discharge efficiency due to oxidative degradation of bromine-containing solid electrolytes when charged at potentials above 3.5 V versus Li electrode, leading to excessive electricity extraction during charging and insufficient reversible reduction during discharging.

Innovation Solution

A battery configuration with a positive electrode containing a first solid electrolyte and an electrolyte layer comprising a second solid electrolyte, where the molar ratio of bromine to anions in the first solid electrolyte is lower than that in the second, inhibiting oxidation of the electrolyte and enhancing ionic conductivity, thereby improving charge and discharge efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bromine-containing solid electrolyte is used in the battery, then ionic conductivity is improved, but oxidative degradation occurs when charged at potentials above 3.5 V versus Li electrode

Engineering Contradiction:

Improvecharge and discharge efficiencyVSAvoidoxidative degradation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The battery is divided into two distinct regions with different solid electrolytes: the positive electrode contains a first solid electrolyte with low Br/anion molar ratio to prevent oxidation, while the electrolyte layer contains a second solid electrolyte with high Br/anion molar ratio to provide high ionic conductivity. This segmentation allows each region to perform its specific function without the harmful effects of the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the battery are assigned different electrolyte compositions tailored to their specific functional requirements. The positive electrode region uses an electrolyte optimized for oxidation resistance, while the electrolyte layer uses an electrolyte optimized for ion transport, creating local quality variations that solve the overall system contradiction.

Inventive Principle:

Principle #3Local quality

2Speed

If the molar ratio of Br to anions in the solid electrolyte is increased, then ionic conductivity is enhanced, but the susceptibility to oxidation increases

Engineering Contradiction:

Improveionic conductivityVSAvoidoxidation resistance

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The battery is divided into two distinct regions with different solid electrolytes: the positive electrode contains a first solid electrolyte with low Br/anion molar ratio to prevent oxidation, while the electrolyte layer contains a second solid electrolyte with high Br/anion molar ratio to provide high ionic conductivity. This segmentation allows each region to perform its specific function without the harmful effects of the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the battery are assigned different electrolyte compositions tailored to their specific functional requirements. The positive electrode region uses an electrolyte optimized for oxidation resistance, while the electrolyte layer uses an electrolyte optimized for ion transport, creating local quality variations that solve the overall system contradiction.

Inventive Principle:

Principle #3Local quality

3Use of energy by moving object

If charging is performed at potentials above 3.5 V versus Li electrode, then energy density is improved, but excessive electricity extraction occurs due to electrolyte oxidation

Engineering Contradiction:

Improveenergy densityVSAvoidexcessive electricity extraction

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The positive electrode is pre-configured with a first solid electrolyte that has low susceptibility to oxidation before charging begins. This preliminary protective configuration prevents oxidation-related electricity extraction even when charging at high potentials above 3.5 V, allowing full utilization of the energy storage capacity without losses.

Inventive Principle:

Principle #10Preliminary action

4Productivity

If the solid electrolyte composition is optimized for high ionic conductivity, then charge and discharge rate is improved, but the electrolyte becomes more prone to oxidative degradation

Engineering Contradiction:

Improvecharge and discharge rateVSAvoidoxidative degradation

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The battery is divided into two distinct regions with different solid electrolytes: the positive electrode contains a first solid electrolyte with low Br/anion molar ratio to prevent oxidation, while the electrolyte layer contains a second solid electrolyte with high Br/anion molar ratio to provide high ionic conductivity. This segmentation allows each region to perform its specific function without the harmful effects of the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the battery are assigned different electrolyte compositions tailored to their specific functional requirements. The positive electrode region uses an electrolyte optimized for oxidation resistance, while the electrolyte layer uses an electrolyte optimized for ion transport, creating local quality variations that solve the overall system contradiction.

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

The proposed configuration reduces oxidative degradation, enhances ionic conductivity, and improves charge and discharge efficiency by preventing contact between bromine in the electrolyte and electron-conducting materials, allowing for higher energy and power densities.

Implementation Method 1

the first solid electrolyte contains lithium and two or more types of anions, the second solid electrolyte contains lithium and two or more types of anions

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

a molar ratio of Br to the two or more types of anions contained in the first solid electrolyte is smaller than a molar ratio of Br to the two or more types of anions contained in the second solid electrolyte

Methodology Applied

Scientific EffectOxidation prevention: Oxidation

Data Source

PatentUS12537223B2Battery

Publication Date: 2026.01.27 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A battery of the present disclosure includes a positive electrode, a negative electrode, and an electrolyte layer provided between the positive electrode and the negative electrode. The positive electrode contains a positive electrode active material and a first solid electrolyte. The electrolyte layer contains a second solid electrolyte. The first solid electrolyte contains lithium and two or more types of anions. The second solid electrolyte contains lithium and two or more types of anions. The molar ratio of Br to the two or more types of anions contained in the first solid electrolyte is smaller than the molar ratio of Br to the two or more types of anions contained in the second solid electrolyte.