All-Solid-State Battery Electrode Layout Against Edge Dendrites
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Solution Overview
Problem
All-solid-state secondary batteries face durability issues due to the inward shifting of active material layers, leading to lithium dendrite formation and potential internal short circuits, caused by the surface tension of the active material slurry during the transfer process.
Innovation Solution
The battery design includes a positive electrode collector layer with an insulating layer around the perimeter edges of the positive electrode active material layer, where the outer edges of the positive electrode collector layer are further inward than the active material layer on the solid electrolyte side, reducing lithium ion concentration and inhibiting dendrite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the active material layer is formed by coating and drying slurry onto the transfer substrate and then transferred onto the solid electrolyte layer, then the active material layer can be successfully formed, but the outer edges of the active material layer on the solid electrolyte layer side are shifted inward from the outer edges on the current collector layer side due to surface tension
Solution Approach 1:
The patent applies preliminary anti-action by designing the positive electrode collector layer with its outer edges positioned further inward than the outer edges of the positive electrode active material layer on the positive electrode collector layer side. This pre-positioning compensates for the inward shifting that occurs during transfer, preventing the harmful exposure of the solid electrolyte layer at the outer edges and thus maintaining battery durability while accepting the edge alignment characteristics of the transfer method
2Ease of manufacture
If the outer edges of the positive electrode active material layer on the solid electrolyte layer side are shifted inward, then the transfer process becomes simpler, but lithium dendrites form at the exposed solid electrolyte layer edges leading to internal short circuits
Solution Approach 1:
The patent extracts the problematic region by positioning the positive electrode collector layer edges inward, effectively removing the solid electrolyte layer from exposure at the outer edges where lithium dendrites would form. This isolates the harmful factor (exposed solid electrolyte at edges) from the system, allowing the transfer process to remain simple while preventing dendrite formation and internal short circuits
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 design enhances the durability of the battery by preventing lithium dendrite growth and internal short circuits, maintaining high charge and discharge capacity over repeated cycles.
Implementation Method 1
a positive electrode layer, wherein the positive electrode layer has a positive electrode active material layer and an insulating layer disposed around a perimeter edges of the positive electrode active material layer
Implementation Method 2
The active material layer formed by this method is rounded at the outer edges due to surface tension of the slurry
Data Source
AI summary
The all-solid-state secondary battery of the disclosure comprises a positive electrode collector layer, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode collector layer stacked in that order, wherein the positive electrode layer has a positive electrode active material layer and an insulating layer disposed around the perimeter edges of the positive electrode active material layer, and when the all-solid-state secondary battery is viewed from the stacking direction, the outer edges of the positive electrode active material layer on the solid electrolyte layer side are further inward than the outer edges of the positive electrode active material layer on the positive electrode collector layer side, and the outer edges of the positive electrode collector layer are further inward than the outer edges of the positive electrode active material layer on the positive electrode collector layer side.