Niobium Oxide Powder Surface Doping for Low-Resistance Solid Electrodes
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Solution Overview
Problem
Existing power storage devices using niobium titanate as a negative electrode material face reduced initial capacity and charge rate characteristics due to high interface resistance with solid electrolytes, and carbon fiber coatings do not contribute to battery capacity, limiting energy density and cycle performance.
Innovation Solution
A niobium-containing oxide powder with specific metal elements like Mo and Ce localized on its surface is used to reduce interface resistance with solid electrolytes, enhancing initial discharge capacity, efficiency, and charge rate characteristics without the need for carbon fiber coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If niobium titanate is used as negative electrode material to increase energy density, then energy density is improved, but interface resistance with solid electrolyte increases
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the niobium titanate core provides high energy density while the lithium titanate shell provides low interface resistance. Different regions of the composite particle have different functional properties: the inner core maximizes capacity while the outer shell ensures good electrolyte interface characteristics.
Solution Approach 2:
The patent uses composite materials by combining niobium titanate and lithium titanate in a core-shell configuration. This composite structure allows the electrode material to simultaneously exhibit the high energy density of niobium titanate and the low interface resistance of lithium titanate, resolving the contradiction between these two properties.
2Productivity
If carbon fiber coating is applied to improve discharge performance, then discharge rate characteristics are improved, but battery capacity is reduced
Solution Approach 1:
The patent extracts the essential function of carbon fiber coating (improving discharge rate characteristics) and replaces it with lithium titanate, which provides both the desired discharge rate improvement and maintains battery capacity. The lithium titanate shell inherently provides good electronic conductivity and ion transport without the capacity penalty of carbon coatings.
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 approach significantly improves initial discharge capacity, efficiency, and charge rate characteristics of all-solid-state secondary batteries by reducing interface resistance, while maintaining low resistance after cycles, thus enhancing overall battery performance.
Implementation Method 1
at least one metal element selected from the group consisting of Mo and Ce is localized on surfaces of niobium-containing oxide particles which constitute the niobium-containing oxide powder
Data Source
AI summary
A niobium-containing oxide powder represented by General Formula Ti1-x/2Nb2O7-x (where X=0 to 2), wherein at least one metal element selected from the group consisting of Mo and Ce is localized on surfaces of niobium-containing oxide particles which constitute the niobium-containing oxide powder.