Niobium-Titanium Oxide Electrode for Fast Charging Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries using carbon-based negative electrodes face issues with dendrite deposition and low energy density due to rapid charging and discharging, leading to potential heat generation and internal short circuits, while titanium oxide electrodes offer stability but have limited capacity and high electrode potential.
Innovation Solution
A niobium-titanium oxide with a specific L*a*b* color space is synthesized to enhance electron conductivity and lithium ion mobility, incorporating elements like Fe, Cr, W, or Mo to narrow the band gap and improve charge-discharge capacity, reducing the generation of amorphous phases and maintaining high energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carbon-based negative electrode is used for rapid charging and discharging, then charging time is shortened and power performance is improved, but dendrite deposition occurs leading to heat generation and internal short circuits
Solution Approach 1:
The patent uses a composite oxide material (Li4Ti5O12 and TiO2) combining two different titanium oxide phases to achieve both rapid charge-discharge capability and high safety. The spinel Li4Ti5O12 provides fast ion transport while anatase TiO2 contributes to structural stability, creating a composite that avoids dendrite formation while maintaining high productivity
2Reliability
If titanium oxide is used for negative electrode to ensure stability and long life, then battery reliability is improved, but energy density is reduced due to high electrode potential and low capacity per weight
Solution Approach 1:
The patent changes the crystal structure parameters of titanium oxide by combining spinel Li4Ti5O12 with anatase TiO2, creating a composite with optimized electrochemical properties. This parameter change in crystal structure enables lower operating potential and higher capacity while maintaining the stability characteristics of titanium oxide
3Productivity
If niobium-titanium oxide is synthesized with specific L*a*b* color space to enhance electron conductivity, then charge-discharge capacity is improved, but manufacturing precision is required to control color and composition
Solution Approach 1:
The patent uses color (L*a*b* values) as an indicator of the niobium-titanium oxide composition and crystalline phase. By controlling and measuring the color properties, the patent ensures consistent electrochemical performance without requiring complex compositional analysis, simplifying quality control while maintaining high charge-discharge capacity
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 niobium-titanium oxide achieves high capacity and excellent rate characteristics by suppressing amorphous phase formation, improving electron conductivity, and maintaining energy density, thus addressing the limitations of carbon-based and titanium oxide electrodes.
Implementation Method 1
incorporating elements like Fe, Cr, W, or Mo to narrow the band gap and improve charge-discharge capacity
Implementation Method 2
The potential of the titanium oxide is electrochemically restricted because it is caused by an oxidation-reduction reaction between Ti3+ and Ti4+ at the time of electrochemically inserting and extracting lithium
Data Source
AI summary
In general, according to one embodiment, a niobium-titanium oxide is provided. The niobium-titanium oxide satisfies Formulae (1) to (3) below in an L*a*b* color space according to Japanese Industrial Standard JIS Z 8722:2009:95.0≤L*≤100 (1)−1.0≤a*≤1.0 (2)−1.0≤b*≤6.0 (3).