Solid-State Battery Electrodes With Non-Tortuous Ion Conduction Paths
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Solution Overview
Problem
Existing solid-state batteries face challenges with high impedance and limited lithium ion transport due to random distribution of electrolyte and active particles, leading to restricted discharge rates and impractical battery construction methods, particularly with thick cathodes.
Innovation Solution
A non-homogenous mixture of large inorganic solid electrolyte particles and electrochemically active material is used, embedded within the electrode structure, with a low melting point electrolyte as a sintering aid and binder, allowing for low temperature sintering to create non-tortuous ion conduction paths and reduced impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a random distribution of electrolyte and active particles is used in solid-state batteries, then the manufacturing process is simple, but the lithium ion transport is limited and impedance is high
Solution Approach 1:
The electrode is segmented into distinct regions: a porous backbone structure providing mechanical support and ion transport pathways, and discrete active material particles embedded within. This segmentation allows the porous framework to facilitate lithium ion transport while the active particles provide electrochemical functionality, resolving the contradiction between manufacturing simplicity and ion transport efficiency.
Solution Approach 2:
A porous binder matrix acts as an intermediary between the active material particles and the electrolyte. This porous binder creates continuous ion transport pathways through the electrode while maintaining electrical contact between particles, enabling efficient lithium ion transport without requiring complex manufacturing processes.
2Quantity of substance
If thick cathodes are used in solid-state batteries, then the energy density is improved, but the discharge rate is restricted due to high impedance
Solution Approach 1:
The thick cathode is segmented into a porous backbone structure with embedded active particles. This segmentation creates multiple parallel ion transport pathways throughout the thickness of the cathode, reducing the distance lithium ions must travel and maintaining high discharge rates even with increased energy density.
Solution Approach 2:
The cathode employs a porous backbone structure that provides continuous ion transport pathways from the electrolyte interface to the current collector. This porous architecture enables efficient lithium ion diffusion through thick cathode layers, allowing high energy density without sacrificing discharge rate capability.
3Strength
If high temperature sintering is used to bond electrode materials, then the mechanical strength is improved, but the manufacturing cost and energy consumption increase
Solution Approach 1:
The sintering temperature parameter is changed from conventional high temperatures to lower temperatures (e.g., 400-600°C). This parameter change is enabled by using a porous binder matrix that provides mechanical strength at lower temperatures, reducing energy consumption while maintaining adequate mechanical strength for battery operation.
Solution Approach 2:
A porous binder material acts as an intermediary that provides mechanical strength and structural integrity at lower temperatures. This binder mediates between the active material particles, enabling electrode assembly and mechanical strength without requiring high energy input for sintering.
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 high 'C' rate capability and efficient lithium ion transport, reducing impedance and enhancing discharge rates in solid-state batteries, while maintaining a cost-effective manufacturing process.
Implementation Method 1
low temperature sintering to create non-tortuous ion conduction paths
Implementation Method 2
first low melting point solid inorganic electrolyte having a melting point of 300 to 850°C
Implementation Method 3
first inorganic solid particulate electrolyte having high conductivity
Data Source
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AI summary
Solid-state batteries, battery components, and related processes for their production are provided. The battery electrodes or separators contain sintered electrochemically active material, inorganic solid particulate electrolyte having large particle size, and low melting point solid inorganic electrolyte which acts as a binder and/or a sintering aid in the electrode.