Niobium-Titanium Complex Oxide for Fast-Charging Battery Anodes
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Solution Overview
Problem
Nonaqueous electrolyte batteries using carbonaceous materials as negative electrodes have inferior rapid charge/discharge performance, while those using titanium complex oxides exhibit lower energy density due to higher potential and lower capacity per weight compared to carbonaceous materials.
Innovation Solution
Development of an active material comprising a complex oxide with a specific ratio of niobium to titanium (MNb/MTi) between 0.5 and 5, primarily having a monoclinic crystal structure, which enhances lithium ion insertion/release ability and electronic conductivity, thereby improving rapid charge/discharge performance and energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a complex oxide containing titanium is used as the negative electrode active material, then rapid charge/discharge performance is improved, but energy density deteriorates due to higher potential and lower capacity per weight compared to carbonaceous materials
Solution Approach 1:
The patent changes the chemical composition parameters of the complex oxide by incorporating niobium in a specific molar ratio (0.5 ≤ MNb/MTi ≤ 5) alongside titanium. This parameter modification transforms the material properties, achieving both high rapid charge/discharge performance and high energy density that neither pure titanium complex oxide nor carbonaceous materials can achieve alone.
Solution Approach 2:
The patent creates a composite complex oxide material combining niobium and titanium in a specific molar ratio. This composite material integrates the advantages of both elements: titanium provides structural stability and niobium enhances electronic conductivity and lithium ion insertion/release ability, resulting in a material that simultaneously achieves excellent rapid charge/discharge performance and high energy density.
2Productivity
If a complex oxide containing titanium is used as the negative electrode active material, then rapid charge/discharge performance is improved, but battery weight increases due to lower capacity per weight compared to carbonaceous materials
Solution Approach 1:
The patent optimizes the molar ratio of niobium to titanium (0.5 ≤ MNb/MTi ≤ 5) to achieve the best balance between capacity and weight. This parameter optimization ensures maximum lithium ion insertion/release capacity per unit weight, thereby improving rapid charge/discharge performance while minimizing battery weight increase.
Solution Approach 2:
The patent enhances the local electronic conductivity and lithium ion insertion/release ability at the atomic level by strategically incorporating niobium atoms within the complex oxide structure. This local quality improvement at the material level translates to superior overall battery performance with reduced weight penalty.
3Productivity
If conventional complex oxides are used as the negative electrode active material, then rapid charge/discharge performance is improved, but production cost increases due to the need for conductive agents and additives
Solution Approach 1:
The niobium-containing complex oxide material is self-sufficient in providing the necessary electronic conductivity and lithium ion insertion/release ability without requiring additional conductive agents or additives. The material's intrinsic properties satisfy all functional requirements, eliminating the need for extra components and simplifying the manufacturing process, thereby reducing production costs.
Solution Approach 2:
The patent extracts and eliminates the need for separate conductive agents and additives by incorporating the necessary functional properties directly into the complex oxide material itself through niobium incorporation. This extraction of unnecessary components simplifies the material composition and reduces production complexity and cost.
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 achieves high rapid charge/discharge performance and energy density, reducing the need for conductive agents, lowering battery weight, and decreasing production costs while maintaining capacity, thus enhancing the overall performance and efficiency of the battery.
Implementation Method 1
a complex oxide containing niobium and titanium... enhances lithium ion insertion/release ability
Implementation Method 2
enhances... electronic conductivity, thereby improving rapid charge/discharge performance
Data Source
AI summary
According to one embodiment, there is provided a active material for a battery including a complex oxide containing niobium and titanium. A ratio MNb/MTi of a mole of niobium MNb to a mole of titanium MTi in the active material satisfies either the following equation (I) or (II). 0.5≦̸MNb/MTi<2 (I) 2<MNb/MTi<5 (II)