Sulfide Solid-State Battery Anode Production Method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The expansion and contraction of silicon-based active materials in sulfide solid-state batteries cause ion paths to be easily cut off, and the use of sulfide solid electrolytes in the anode mixture layer leads to decomposition or reaction with the current collector during heat treatment, resulting in poor anode production and peel strength issues.
Innovation Solution
A method is developed where an anode mixture layer without sulfide solid electrolyte is first formed over a current collector, then heated to create a polyimide with voids, followed by the insertion of a sulfide solid electrolyte into these voids, and finally, an additional anode mixture layer with carbonaceous active material and binder is applied to secure ion paths and prevent decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a sulfide solid electrolyte is contained in an anode mixture layer and heat treatment is performed to imidize polyamic acid, then the anode mixture layer can be formed with binder and active material, but the sulfide solid electrolyte decomposes or reacts with the anode current collector
Solution Approach 1:
The anode is divided into two separate layers: a first anode mixture layer containing silicon-based active material, polyamic acid, and sulfide solid electrolyte; and a second anode mixture layer containing carbonaceous active material and binder. This segmentation allows the sulfide solid electrolyte to be protected from direct contact with the current collector during heat treatment, preventing decomposition and reaction while maintaining structural integrity.
Solution Approach 2:
The first anode mixture layer is formed and heat-treated to imidize the polyamic acid before the second layer is applied. This preliminary action creates a stable polyimide binder structure that secures ion paths before the sulfide solid electrolyte is exposed to conditions that would cause decomposition or reaction with the current collector.
2Quantity of substance
If silicon-based active material is used in the anode, then high capacity can be achieved, but the expanding and contracting volume causes ion paths to be cut off
Solution Approach 1:
The second anode mixture layer is applied specifically over the first layer to provide a protective matrix that maintains ion path continuity. This layer contains carbonaceous active material and binder that accommodate volume changes of the silicon-based active material in the first layer, preventing ion path cutoff while preserving the high capacity benefits of silicon.
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 method secures ion paths within the anode mixture layer, preventing them from being cut off during charge and discharge, and avoids decomposition or reaction with the current collector, thereby improving the production of sulfide solid-state batteries and enhancing their cycle characteristics.
Implementation Method 1
heating the anode mixture layer A1 to imidize the polyamic acid, to make an anode mixture layer A2 which contains a polyimide
Data Source
AI summary
A method for producing a sulfide solid-state battery in which, an anode mixture (a) is layered over a surface of an anode current collector, to form an anode mixture layer A1, the anode mixture (a) containing a polyamic acid, and silicon-based active material but not containing a sulfide solid electrolyte; the anode mixture layer A1 is heated to imidize the polyamic acid, to make an anode mixture layer A2; a sulfide solid electrolyte is layered over a surface of the anode mixture layer A2; to be pressed to insert the sulfide solid electrolyte into a void in the anode mixture layer A2, to make an anode mixture layer A3; and thereafter an anode mixture (b) is layered over a surface of the anode mixture layer A3, to form an anode mixture layer B, the anode mixture (b) containing carbonaceous active material and binder.