All-Solid Battery Electrode Layout to Prevent External Electrode Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All-solid-state batteries face challenges with cycle characteristics due to peeling off of external electrodes from positive and negative electrode layers caused by volume expansion during charge-discharge reactions, and the use of sulfide solid electrolytes limits safety and production environment.
Innovation Solution
The battery design includes positive and negative electrode auxiliary portions that protrude from the main electrode portions, increasing the contact area with external electrodes, which helps prevent peeling and enhances cycle characteristics by optimizing the lengths of these auxiliary portions relative to the electrode surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external electrodes are connected to electrode layers, then electrical connection is achieved, but peeling occurs due to volume expansion during charge-discharge reactions
Solution Approach 1:
The electrode auxiliary portions extend the electrode layers in the planar direction beyond the main portions, creating an overlapping region with external electrodes. This dimensional extension increases the bonding area from a simple end-surface contact to a multi-surface overlap configuration, preventing peeling during volume expansion.
2Strength
If electrode auxiliary portions are added to increase contact area, then bond strength improves, but device complexity increases
Solution Approach 1:
The electrode structure is segmented into a positive electrode main portion, positive electrode auxiliary portion, negative electrode main portion, and negative electrode auxiliary portion. This segmentation allows the auxiliary portions to specifically fulfill the bonding function with external electrodes, while the main portions handle the electrochemical function, separating concerns and simplifying the overall design.
Data Source
AI summary
This all-solid-state battery includes: a laminate; a positive electrode-side external electrode; and a negative electrode-side external electrode, in which the laminate includes a positive electrode layer and a negative electrode layer, in a plan view from a lamination direction of the laminate, the positive electrode layer includes a positive electrode main portion and a positive electrode auxiliary portion which protrudes from the positive electrode main portion and reaches a side surface, the negative electrode layer includes a negative electrode main portion and a negative electrode auxiliary portion which protrudes from the negative electrode main portion and reaches the side surface, and a length L1 of the positive electrode auxiliary portion on the side surface, a length L2 of the negative electrode auxiliary portion on the side surface, and a length L3 on the side surface satisfy a relation of 20 μm≤(L1+L2)<L3 (1).