Garnet Separator for Aqueous Battery Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional batteries with aqueous electrolytes face issues of reductive decomposition and unstable performance due to contact with the anode, leading to poor cycle characteristics and ion conductivity.
Innovation Solution
A battery design incorporating a cathode, anode, and a separator with a garnet-type ion-conducting oxide electrolyte sintered body, where the separator has grain boundaries and a resin, preventing aqueous electrolyte contact with the anode and maintaining ion conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If an aqueous electrolyte is used in the battery, then stability during working and storage is improved, but reductive decomposition occurs at the anode interface leading to poor cycle characteristics
Solution Approach 1:
A solid electrolyte layer is introduced as an intermediary between the aqueous electrolyte and the anode. This solid electrolyte layer acts as a mediator that allows ion transport while preventing direct contact between the aqueous electrolyte and anode, thereby eliminating reductive decomposition and improving cycle characteristics while maintaining the stability benefits of aqueous electrolytes.
2Power
If the anode is in direct contact with the aqueous electrolyte, then ion conductivity is improved, but reductive decomposition of water occurs resulting in unstable battery performance
Solution Approach 1:
A solid electrolyte layer is introduced as an intermediary between the aqueous electrolyte and the anode. This solid electrolyte layer acts as a mediator that allows ion transport while preventing direct contact between the aqueous electrolyte and anode, thereby eliminating reductive decomposition and improving cycle characteristics while maintaining the stability benefits of aqueous electrolytes.
3Reliability
If a separator is introduced to prevent aqueous electrolyte contact with the anode, then reductive decomposition is prevented, but ion conductivity between cathode and anode is reduced
Solution Approach 1:
The solid electrolyte layer used as separator undergoes parameter optimization including controlled thickness (5-50 μm), specific porosity (30-70%), and controlled grain boundary characteristics. These parameter changes allow the separator to provide effective protection against reductive decomposition while maintaining sufficient ion conductivity for high-performance battery operation.
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 enhances battery stability and output characteristics by preventing reductive decomposition and extending the potential window of the aqueous electrolyte, while maintaining high ion conductivity between the cathode and anode.
Implementation Method 1
the separator comprises a first oxide electrolyte sintered body and a resin; wherein the first oxide electrolyte sintered body has grain boundaries between crystal particles of a garnet-type ion-conducting oxide
Implementation Method 2
a first oxide electrolyte sintered body
Implementation Method 3
the separator comprises a first oxide electrolyte sintered body and a resin... preventing aqueous electrolyte contact with the anode
Data Source
AI summary
A battery with excellent output characteristics and stability. The battery comprising a cathode, an anode and a separator disposed between the cathode and the anode, wherein the cathode comprises an aqueous electrolyte and a cathode active material; wherein the anode comprises an anode active material; wherein the separator comprises a first oxide electrolyte sintered body and a resin; wherein the first oxide electrolyte sintered body has grain boundaries between crystal particles of a garnet-type ion-conducting oxide represented by a general formula (A); wherein a number average particle diameter of the crystal particles is 3 μm or less; and wherein the first oxide electrolyte sintered body satisfies the following formula 1: Rgb/(Rb+Rgb)≤0.6 where Rb is an intragranular resistance value that is an ion conductivity resistance inside the crystal particles, and Rgb is a grain boundary resistance value that is an ion conductivity resistance of the grain boundaries between the crystal particles.