Sulfide Solid Electrolyte Crystallization Temperature Control
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Solution Overview
Problem
When a sulfide solid electrolyte material, such as LiI—LiBr—Li3PS4, is heated with an oxide active material of a rock salt bed type, it can lead to a decrease in the capacity of the oxide active material, while improving Li ion conductance.
Innovation Solution
A method involving heating the oxide active material and amorphous sulfide solid electrolyte material in contact with each other at a temperature between the crystallization onset and peak temperatures of the sulfide solid electrolyte material, typically between 140°C and 160°C, to enhance Li ion conductance without reducing the oxide active material's capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sulfide solid electrolyte material is heated at high temperature to improve Li ion conductance, then the Li ion conductance is improved, but the capacity of the oxide active material decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the heating temperature within a specific range (crystallization onset temperature to crystallization peak temperature) to achieve the desired Li ion conductance improvement while preventing excessive temperature effects that would damage the active material capacity
Solution Approach 2:
The patent uses preliminary action by performing heating treatment at controlled temperatures before the oxide active material undergoes capacity degradation, thereby improving Li ion conductance in advance while preserving the active material's capacity
2Reliability
If the sulfide solid electrolyte material is heated to transition from amorphous to crystalline state, then the Li ion conductance is improved, but the oxide active material may undergo unwanted reactions
Solution Approach 1:
The patent changes the temperature parameter within a precisely defined range to induce crystallization of the sulfide solid electrolyte while maintaining the compositional stability of the oxide active material, avoiding unwanted reactions
Solution Approach 2:
The controlled heating process acts as an intermediary mechanism that facilitates the phase transition of the sulfide solid electrolyte from amorphous to crystalline state while serving as a protective buffer that prevents direct harmful interactions with the oxide active material
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 suppresses the capacity decrease of the oxide active material while improving the Li ion conductance of the sulfide solid electrolyte material, resulting in an electrode body with high Li ion conductance and large capacity.
Implementation Method 1
when a sulfide solid electrolyte material represented by LiI—LiBr—Li3PS4 is heated, crystallinity is improved and Li ion conductance is also improved
Implementation Method 2
a heating step of heating an oxide active material and an amorphous sulfide solid electrolyte material in a state where the oxide active material and the amorphous sulfide solid electrolyte material are in contact with each other
Data Source
AI summary
A method for producing an electrode body, suppressing a decrease in capacity of an oxide active material while improving the Li-ion conductance of a sulfide solid electrolyte material. The method producing an electrode body, including a heating step of heating an oxide active material and amorphous sulfide solid electrolyte material in state where the oxide active material and amorphous sulfide solid electrolyte material are in contact with each other, in which the oxide active material is a rock salt bed type active material, the sulfide solid electrolyte material contains a Li element, P element, and S element, and includes an ion conductor containing PS43—as main component of an anion structure, LiI, and LiBr, and heating temperature in the step is equal to or higher than the crystallization onset temperature of the sulfide solid electrolyte material and equal to or lower than the sulfide solid electrolyte material crystallization peak temperature.