Coated Active Material for Lower Solid-State Battery Interface Resistance
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Solution Overview
Problem
Solid-state batteries face issues with increased resistance at the interface between the positive electrode active material and the solid electrolyte, leading to degradation in battery characteristics, which current technologies have not adequately addressed.
Innovation Solution
An active material with a core portion and a surface coating containing elements like titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), or aluminum (Al), where the coating portion has two or more inflection points in its first-order derivative, reducing interfacial resistance and improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer is formed on the surface of the positive electrode active material to address interfacial resistance, then battery characteristics improve, but the manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the coating thickness to be 1 nm to 10 nm and specifying the atomic ratio of element A to lithium (0.1 to 2.0). This quantitative parameter control optimizes the coating layer to reduce interfacial resistance while maintaining manufacturability, resolving the contradiction between improved battery characteristics and manufacturing complexity.
Solution Approach 2:
The patent applies local quality by forming a coating layer with specific compositional characteristics (containing element A and lithium with controlled atomic ratios) only at the critical interface region between the positive electrode active material and solid electrolyte. This targeted local modification addresses the interfacial resistance problem without requiring complex overall structural changes.
2Reliability
If the coating layer thickness is increased to reduce interfacial resistance, then battery performance improves, but the energy density decreases
Solution Approach 1:
The patent resolves this contradiction by optimizing the coating thickness parameter to a specific range (1 nm to 10 nm) and controlling the atomic ratio of element A to lithium (0.1 to 2.0). This precise parameter control ensures sufficient resistance reduction while minimizing the volume occupied by the coating layer, thereby preserving energy density.
3Reliability
If a coating layer is formed to improve battery characteristics, then interfacial resistance decreases, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies concrete parameter ranges (coating thickness: 1 nm to 10 nm; atomic ratio of element A to lithium: 0.1 to 2.0) that provide clear manufacturing targets. These well-defined parameters enable manufacturers to achieve the desired interfacial resistance reduction through controlled processes without requiring excessive manufacturing precision.
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
The active material effectively suppresses the formation of high-resistance layers, resulting in reduced interfacial resistance and enhanced battery rate characteristics and overall performance.
Implementation Method 1
a first-order derivative obtained with respect to a peak attributed to the element A, the first-order derivative being obtained based on a constituent element average intensity profile measured for the coating portion with use of an energy dispersive X-ray spectrometer
Data Source
AI summary
An active material has: a core portion made of an active material base material; and a coating portion located on a surface of the core portion. The coating portion contains an element A comprising at least one selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), and aluminum (Al). The active material has two or more inflection point in a first-order derivative obtained with respect to a peak attributed to the element A, the first-order derivative being obtained based on a constituent element average intensity profile measured for the coating portion with use of an energy dispersive X-ray spectrometer.