Niobium Oxide Anode Particles for Fast-Charging Battery Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries using carbon-based negative electrodes face issues with rapid charge-and-discharge due to metal lithium dendrite precipitation, leading to heat generation and fires, while titanium oxide electrodes offer stable charge-and-discharge but have lower energy density and capacity due to their noble potential and limited lithium insertion sites.
Innovation Solution
The development of an active material with niobium-containing oxide particles having specific protruded and recessed parts, which enhance electrolyte retention and lithium ion diffusion, allowing for increased electrode density and improved energy density without compromising life performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If carbon-based negative electrode is used, then capacity per weight is high, but dendrite precipitation occurs during rapid charge-and-discharge
Solution Approach 1:
The invention changes the electrode material from carbon-based to titanium oxide-based, fundamentally altering the electrochemical parameters. Titanium oxide has a noble potential of about 1.5V vs Li/Li+, which prevents lithium dendrite formation during rapid charge-and-discharge while maintaining structural stability and safety
Solution Approach 2:
The invention accepts a trade-off where titanium oxide's lower capacity per weight (theoretical capacity of about 165 mAh/g for anatase TiO2) is compensated by other means, prioritizing safety and cycle life over maximum capacity density
2Duration of action of stationary object
If titanium oxide is used for negative electrode, then rapid charge-and-discharge performance is stable and life is extended, but energy density decreases
Solution Approach 1:
The invention uses composite oxide materials containing titanium and niobium in specific ratios. The composite structure combines the stability and safety benefits of titanium oxide with the higher capacity characteristics of niobium-containing materials, achieving both long cycle life and improved energy density
Solution Approach 2:
The invention optimizes the local composition by controlling the Ti:Nb ratio within specific ranges (0.4-1.6 and 0.6-2.0 in different embodiments). This local compositional control allows different regions of the electrode to contribute different properties, balancing stability and capacity
3Use of energy by moving object
If electrode density is increased to improve energy density, then capacity increases, but input/output performance deteriorates and charge-and-discharge life shortens
Solution Approach 1:
The invention optimizes multiple parameters simultaneously: particle size distribution (D10, D50, D90 values), porosity (30-70%), and composition ratios. These parameter optimizations work together to achieve high energy density while maintaining excellent input/output performance and long charge-and-discharge life
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-containing oxide particles enable a secondary battery with high energy density, excellent rapid charge-and-discharge performance, and long life by optimizing electrolyte retention and lithium ion migration, addressing the limitations of titanium oxide electrodes.
Implementation Method 1
The potential of the titanium oxide is due to a redox reaction between Ti3+ and Ti4+ when lithium is electrochemically inserted and extracted
Implementation Method 2
In order to enable rapid charge-and-discharge, it is necessary that electrons and lithium ions can rapidly migrate between a positive electrode and a negative electrode
Data Source
AI summary
In general, according to one embodiment, an active material including particles containing a niobium-containing oxide is provided. The particles containing the niobium-containing oxide contain single particles having protruded parts and recessed parts. Three or more of the recessed parts satisfy 0.1≤a/L≤0.5 (1). Where L is a length of a tangent line in contact with a first protruded part and a second protruded part, and a is a maximum length of a perpendicular line from the tangent line to a recessed part defined by the first protruded part and the second protruded part.