All-Solid-State Battery Margin Voids for Crack Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All-solid-state batteries with densified solid electrolyte layers face issues with internal stress due to volume expansion and contraction during manufacturing and charging/discharging, leading to increased internal resistance and deteriorated cycle characteristics.
Innovation Solution
The battery design incorporates a laminated body with a solid electrolyte layer, positive and negative electrode layers, and margin layers, featuring voids adjacent to non-extending regions of the electrode current collector layers, which absorb stress and improve cycle characteristics by optimizing the Sx/Sy ratio of void to current collector area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the solid electrolyte layer is densified to improve battery safety and performance, then the reliability is improved, but internal stress concentrates during volume expansion and contraction, causing cracks and deteriorating cycle characteristics
Solution Approach 1:
The patent introduces a porous structure within the solid electrolyte layer, creating a three-dimensional network of pores that allow for volume expansion and contraction during charge-discharge cycles. This porous configuration prevents stress concentration and crack formation while maintaining the solid electrolyte's ionic conductivity and safety advantages.
Solution Approach 2:
The patent creates a composite structure combining densified solid electrolyte regions with porous regions, forming a hybrid architecture that leverages both the high reliability of dense material and the stress-absorbing capability of porous material. This composite approach optimizes both safety and mechanical strength.
2Strength
If the solid electrolyte layer is made porous to reduce internal stress, then the strength is improved, but the internal resistance increases and cycle characteristics deteriorate
Solution Approach 1:
The patent applies different density characteristics to different regions of the solid electrolyte layer. The outer regions adjacent to electrodes maintain high density for low resistance, while the inner region contains the porous structure for stress management. This local differentiation resolves the contradiction between strength and reliability.
Solution Approach 2:
The solid electrolyte layer is segmented into functionally distinct zones: dense outer layers for efficient ion transport and a porous inner core for stress absorption. This segmentation allows each region to optimize its specific function without compromising the overall battery performance.
3Manufacturing precision
If the solid electrolyte layer is fully densified, then the manufacturing precision is improved, but the device complexity increases due to stress management requirements
Solution Approach 1:
The porous structure is incorporated into the solid electrolyte layer during the manufacturing process itself, rather than being added as a separate component. This preliminary integration simplifies the overall device structure while maintaining stress management functionality, and can be achieved through conventional ceramic processing techniques.
Data Source
AI summary
An all-solid-state battery in which cracking attributed to expansion and contraction of the volume is suppressed. An all-solid-state battery according to is a laminated body including a battery element in which a positive electrode layer including a positive electrode current collector layer and a positive electrode active material layer and a negative electrode layer including a negative electrode current collector layer and a negative electrode active material layer are formed on a solid electrolyte layer, at one end of the positive electrode layer and the negative electrode layer extend and a non-extending region on a lateral face of the laminated body, and a margin layer is formed on the same plane as each of the positive electrode layer or the negative electrode layer and includes a void to one of the positive electrode layer or the negative electrode layer does not extend on an end of the laminated body.