All-solid-state battery solid electrolyte particle size control
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Solution Overview
Problem
The penetration of solid electrolyte into the pores of the negative electrode active material layer in all-solid-state batteries increases irreversible capacity and reduces the battery's lifetime characteristics, particularly when a carbon-based material is used as the negative electrode active material.
Innovation Solution
The all-solid-state battery design includes a negative electrode active material layer with a porosity of 15 to 40% and pore diameter of 0.5 to 0.7 µm, and the solid electrolyte at the interface between the negative electrode active material layer and the solid electrolyte layer has an average particle size of 1 to 3 µm, achieved through specific manufacturing steps involving mixing, applying, and pressurizing compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a composition for forming a solid electrolyte layer is applied to the negative electrode active material layer, then the solid electrolyte layer can be formed with high process efficiency and thin thickness, but the solvent causes solid electrolyte particles to penetrate into the pores of the negative electrode active material layer
Solution Approach 1:
The invention changes the particle size parameter of the solid electrolyte from conventional small particles to specifically sized particles with D50 of 0.5 to 2.0 μm. This parameter change prevents penetration into the negative electrode pores while maintaining the benefits of the slurry application method, thus resolving the contradiction between high process efficiency and penetration control.
2Quantity of substance
If the negative electrode active material layer includes carbon-based material, then the battery capacity is improved, but the porosity of the layer causes solvent penetration and solid electrolyte migration into the pores
Solution Approach 1:
The invention changes the particle size parameter of the solid electrolyte to D50 of 0.5 to 2.0 μm, which is large enough to be blocked by the pore structure of the carbon-based negative electrode material. This prevents solid electrolyte migration into the pores, reducing irreversible capacity and improving battery lifetime while maintaining the high capacity benefits of carbon-based materials.
3Ease of manufacture
If solid electrolyte penetrates into the pores of the negative electrode active material layer, then the coating process is simplified, but the irreversible capacity increases and lifetime characteristics deteriorate
Solution Approach 1:
The invention changes the particle size parameter of the solid electrolyte to D50 of 0.5 to 2.0 μm, which is strategically selected to be larger than the pore size of the negative electrode material. This parameter change naturally prevents penetration during the coating process, maintaining process simplicity while eliminating the harmful effects of solid electrolyte migration and improving battery lifetime.
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
This configuration reduces the penetration of solid electrolyte into the negative electrode active material layer, thereby reducing irreversible capacity and improving the battery's lifetime characteristics.
Implementation Method 1
the solid electrolyte present at the interface between the negative electrode active material layer and the solid electrolyte layer has an average particle size of 1 to 3 μm
Data Source
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AI summary
The present invention relates to an all-solid-state battery, wherein the solid electrolyte present at the interface of the negative electrode active material layer and the solid electrolyte layer has an average particle size of 1 µm to 3 µm, and a method of manufacturing same.