Niobium-Titanium Composite Electrode for High-Capacity Battery
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Solution Overview
Problem
Lithium ion nonaqueous electrolyte batteries used in electric automobiles require high energy density, efficient charge and discharge capabilities, especially for instant current input and output, and existing materials like carbon and spinel lithium titanate have limitations in energy density and safety.
Innovation Solution
The use of niobium-titanium composite oxides, such as Nb2TiO7, with specific structural arrangements of active material particles in electrodes to enhance capacity and rate characteristics, including a monoclinic niobium-titanium composite oxide with a theoretical capacity twice that of spinel-type lithium titanate, providing stable and rapid charge-and-discharge performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If carbon material is used as negative electrode active material, then energy density is improved, but safety deteriorates due to lithium dendrite generation and thermal runaway risk
Solution Approach 1:
The patent uses spinel-type lithium titanate (Li4Ti5O12) as a composite negative electrode material that combines the advantages of high safety (ceramic material, no lithium dendrite generation) with improved energy density compared to conventional carbon materials. The spinel structure provides both safety and enhanced performance.
2Object-affected harmful factors
If spinel type lithium titanate is used as negative electrode active material, then safety is improved, but energy density deteriorates
Solution Approach 1:
The patent merges spinel-type lithium titanate particles with carbon material particles to form composite negative electrode particles. This combination allows the electrode to achieve both the high safety of lithium titanate (no dendrite formation) and the high energy density of carbon materials, resolving the contradiction between safety and energy density.
3Productivity
If large current is instantly input for regenerative braking, then charge efficiency is improved, but battery durability deteriorates
Solution Approach 1:
The patent changes the electrochemical parameters of the negative electrode by using spinel-type lithium titanate with its unique crystal structure and electrochemical properties. The material's ability to rapidly insert and extract lithium ions without significant volume change enables efficient regenerative braking charge acceptance while maintaining battery durability through reduced mechanical stress and no dendrite formation.
4Quantity of substance
If carbon material is used for high capacity, then energy density is improved, but rate characteristics deteriorate due to slow charge-discharge performance
Solution Approach 1:
The patent creates composite negative electrode particles combining spinel-type lithium titanate and carbon material, where the lithium titanate provides rapid lithium ion insertion/extraction kinetics for excellent rate characteristics, while the carbon material contributes to high capacity. The composite structure enables both high capacity and fast charge-discharge performance.
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 composite oxide electrodes achieve high capacity and rate characteristics, enabling batteries with improved energy density and safety by optimizing lithium ion insertion and extraction, and providing excellent performance under varying load conditions.
Implementation Method 1
the spinel type lithium titanate has a high safety, because a possibility of generation of lithium dendrite is lower compared to a case where the carbon material is used, and has a great merit in which it is difficult to cause thermal runaway because it is a ceramic
Data Source
AI summary
According to one embodiment, an electrode is provided. The electrode includes active material particles containing a niobium-titanium composite oxide. The active material particles include a first active material particle, and a second active material particle located with a space between the first active material particle and the second active material particle.