Solid-State Battery Lamination to Prevent Pressing Short Circuits
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Solution Overview
Problem
Existing all-solid-state batteries face issues with internal short circuits due to deformation and contact between cathode and anode active material layers during press-molding, particularly when they have different sizes, leading to reduced effective area and increased risk of short circuits.
Innovation Solution
The method involves forming a solid electrolyte layer on the upper and side surfaces of a smaller cathode active material layer, preliminary pressing at a lower pressure, and final pressing with a symmetrical electrode structure to prevent short circuits by covering the cathode's outer periphery with the electrolyte layer and using elastic bodies in the press die to manage deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cathode active material layer is made smaller than the anode active material layer to prevent short circuits, then the risk of short circuit is reduced, but the effective area of the cathode is reduced leading to insufficient battery performance
Solution Approach 1:
The invention applies different properties to different parts of the electrode structure. Specifically, the cathode active material layer is made thicker at its outer periphery compared to its central portion. This local variation in thickness allows the cathode to maintain adequate size for performance while the thicker peripheral region prevents deformation and short circuits during pressing, thus resolving the contradiction between reliability and effective area.
2Area of moving object
If the outer periphery of the cathode active material layer is made thicker to prevent collapse during pressing, then the effective area is maintained, but the outer periphery expands more easily increasing the risk of short circuit near the end of the anode
Solution Approach 1:
The invention creates an asymmetric structure where the cathode active material layer has non-uniform thickness - thicker at the periphery and thinner at the center. This asymmetric thickness distribution serves dual purposes: the thicker peripheral region prevents collapse and maintains effective area, while the overall cathode size is controlled to be smaller than the anode, preventing the thicker periphery from expanding into the anode and causing short circuits.
3Quantity of substance
If the cathode active material layer is pressed at high pressure to form a laminated structure, then the battery density is improved, but the outer periphery deforms and the electrode layer collapses reducing effective area
Solution Approach 1:
The invention performs preliminary action by forming the cathode active material layer with a predetermined non-uniform thickness distribution (thicker at periphery, thinner at center) before the pressing process. This pre-configured structure is specifically designed to resist deformation during subsequent high-pressure pressing, allowing the battery to achieve high density while maintaining the effective area of the electrode layer.
4Reliability
If the cathode active material layer is made smaller than the anode active material layer to prevent erosion into the anode, then short circuit risk is reduced, but the effective area decreases leading to insufficient performance
Solution Approach 1:
The invention applies local quality by creating a cathode active material layer with non-uniform thickness - thicker at the periphery and thinner at the center. This allows the cathode to have a smaller overall size than the anode (preventing erosion and short circuits) while the thicker peripheral region maintains adequate effective area for performance, thus resolving the contradiction between reliability and effective area.
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 approach effectively prevents short circuits and ensures uniform pressure distribution, maintaining the battery's performance by minimizing deformation and erosion of the cathode active material layer into the anode, while suppressing warping and ensuring planar contact surfaces.
Implementation Method 1
forming a solid electrolyte layer on the upper and side surfaces of a cathode active material layer... effectively prevents short circuits... by covering the cathode's outer periphery with the electrolyte layer
Implementation Method 2
press-molding the resulting laminate at a high pressure to form a laminated structure... final pressing with a symmetrical electrode structure
Implementation Method 3
using elastic bodies in the press die to manage deformation... ensures uniform pressure distribution, maintaining the battery's performance by minimizing deformation
Data Source
AI summary
A method of manufacturing an all-solid-state battery includes forming an anode active material layer on surfaces of an anode current collector, forming a first solid electrolyte layer covering exposed surfaces of the anode active material layer to form a symmetrical electrode structure, pressing the structure at a preliminary pressing pressure lower to form an anode, forming a cathode active material layer on a surface of cathode current collectors, the cathode active material layer being smaller than the cathode current collectors, forming a second solid electrolyte layer covering the cathode active material layers and the cathode current collectors to form first and second cathodes, forming a laminate by laminating the cathodes on opposite surfaces of the anode, the second solid electrolyte layers of the cathodes facing the anode, and pressing the laminate at the final pressing pressure.