Solid Polymer Electrolyte Battery Coating for High Voltage Stability

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Solution Overview

Problem

Conventional organic electrolyte batteries face challenges in achieving high energy density and cycle characteristics due to oxidative decomposition of the organic electrolyte and oxygen desorption from the positive electrode material, especially at high voltages, which limits their service life and efficiency.

Innovation Solution

A solid polymer electrolyte battery is designed with positive electrode active material particles coated by an ionically or electronically conductive attachment that prevents oxidative decomposition and oxygen desorption, allowing for indirect contact with the solid polymer electrolyte, thereby maintaining high voltage during discharge and enhancing cycle characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If high voltage (4.7V or higher) is used to increase energy density, then the voltage plateau and energy density improve, but oxidative decomposition of the electrolyte and oxygen desorption occur, degrading battery performance

Engineering Contradiction:

Improveenergy densityVSAvoidbattery performance stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

An inorganic solid electrolyte film is introduced as an intermediary layer between the positive electrode material and the organic electrolyte. This film acts as a mediator that prevents direct contact, thereby suppressing oxidative decomposition of the organic electrolyte and oxygen desorption from the positive electrode material, while still allowing ion transport to maintain high voltage operation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The battery employs a composite electrolyte system combining inorganic solid electrolyte film and organic electrolyte. This composite structure leverages the advantages of both materials: the inorganic film provides stability and protection against decomposition, while the organic electrolyte enables high voltage operation and energy density

Inventive Principle:

Principle #40Composite materials

2Reliability

If inorganic solid electrolyte film is formed between positive electrode material and organic electrolyte to suppress decomposition, then reliability improves, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvesuppression of oxidative decompositionVSAvoidbattery structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The inorganic solid electrolyte is formed as a thin film layer between the positive electrode material and organic electrolyte. This thin film approach provides the necessary protective function while minimizing the addition of structural complexity and maintaining a compact battery design

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of manufacture

If conventional organic electrolyte is used at high voltage, then ease of manufacture is maintained, but oxidative decomposition occurs leading to byproduct accumulation and performance degradation

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidoxidative decomposition and byproduct accumulation

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The inorganic solid electrolyte film is formed in advance before assembling the complete battery. This preliminary protective layer prevents oxidative decomposition from occurring in the first place, eliminating the harmful effects before they can manifest during battery operation

Inventive Principle:

Principle #9Preliminary anti-action

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 solution enables the solid polymer electrolyte battery to maintain high energy density and cycle stability by suppressing oxidative degradation, allowing for prolonged high-voltage discharge and improved battery performance.

Implementation Method 1

an inorganic solid electrolyte film is formed in advance between the positive electrode material and the organic electrolyte

Methodology Applied

Scientific EffectPhysical barrier (film formation):

Implementation Method 2

desorption of oxygen from the positive electrode material can also be suppressed

Methodology Applied

Scientific EffectPhysical barrier (film formation):

Implementation Method 3

a solid polymer electrolyte is interposed between a positive electrode material and a negative electrode material

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS8592090B2Solid polymer electrolyte battery and method for manufacturing positive electrode sheet used therein

Publication Date: 2013.11.26 CENTRAL RESEARCH INSTITUTE OF ELECTRIC POWER INDUSTRY

AI summary

An organic electrolyte battery (10) including positive electrode material (2) and negative electrode material (4) and, interposed therebetween, organic electrolyte (6), wherein positive electrode active material particles (8) as a constituent of the positive electrode have surfaces at least partially coated with attachment (12) with electronic conductance and ionic conductance not easily oxidized even when supplied with oxygen from the positive electrode active material. The above attachment (12) is composed of microparticles of inorganic solid electrolyte with ionic conductance (14) and microparticles of conductive material with electronic conductance (16).