Oxyhalide Solid Electrolyte Particles for Active-Material Contact
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Solution Overview
Problem
Existing solid electrolyte materials for batteries face challenges in achieving high ion conductivity and accessibility to active materials, leading to suboptimal charge and discharge characteristics, particularly in all-solid-state batteries where flat surfaces and large particle diameters hinder effective contact with active materials.
Innovation Solution
A solid electrolyte material comprising Li, M (Nb or Ta), and X (F, Cl, Br, or I) with a specific surface area greater than 7.5 m2/g, manufactured using a wet-pulverization method, which enhances ion conductivity and accessibility by having a smaller particle diameter and uneven surface, thereby improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solid electrolyte material has flat surface and large particle diameter, then manufacturing is easier, but accessibility to active material deteriorates
Solution Approach 1:
The patent changes the physical parameters of the solid electrolyte material by controlling particle diameter to 1 μm or less and specific surface area to 7.5 m²/g or more, transforming it from large flat particles to fine particles with high surface area, thereby improving accessibility to active material while maintaining ease of manufacture through the wet-pulverization method
2Ease of operation
If solid electrolyte material has fine particles with high specific surface area, then accessibility to active material improves, but ion conductivity may deteriorate
Solution Approach 1:
The patent optimizes compositional parameters by controlling the molar ratio of Li to M (0.60 ≤ Li/M ≤ 3.00) and selecting specific halogen elements (F, Cl, Br, or I), which enables fine particles to maintain both high accessibility and practical ion conductivity of 1×10⁻⁴ S/cm or more
Solution Approach 2:
The patent creates a composite solid electrolyte material combining Li, M (Nb or Ta), O, and X (halogen), where the specific composition and structure enable simultaneous achievement of fine particle morphology and high ion conductivity
3Reliability
If solid electrolyte material contains sulfur, then ion conductivity improves, but safety deteriorates
Solution Approach 1:
The patent extracts sulfur from the solid electrolyte material composition entirely, replacing it with halogen elements (F, Cl, Br, or I) to eliminate safety hazards while maintaining ion conductivity through alternative compositional design
Solution Approach 2:
The patent changes the compositional parameter by eliminating sulfur and controlling the halogen content ratio, achieving safety improvement while maintaining ion conductivity of 1×10⁻⁴ S/cm or more through the Li-M-O-X system
Data Source
AI summary
The solid electrolyte material of the present disclosure is a solid electrolyte material including Li, M, O, and X. Here, M is at least one selected from the group consisting of Nb and Ta, X is at least one selected from the group consisting of F, Cl, Br, and I, and the solid electrolyte material has a specific surface area of greater than 7.5 m2/g. The battery of the present disclosure includes a positive electrode, a negative electrode, and an electrolyte layer arranged between the positive electrode and the negative electrode. At least one of the positive electrode, the negative electrode, and the electrolyte layer contains the solid electrolyte material of the present disclosure.