Lithium-Titanium Composite Oxide Doping for Capacity and Phase Stability
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Solution Overview
Problem
Lithium-titanium composite oxides, particularly spinel-type, face limitations in high capacity due to theoretical capacity constraints and phase separation issues during manufacturing, leading to deteriorated effective capacity and reaction speed.
Innovation Solution
A manufacturing method involving solid-phase mixing of lithium, titanium, sodium, and zirconium compounds, followed by wet-pulverization, spray-drying, and firing to control particle sizes and suppress anatase and rutile-type titanium dioxide formation, resulting in a lithium-titanium composite oxide with improved initial capacity and rate capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spinel-type lithium titanate is used as electrode material, then long cycle-life and excellent reversibility are achieved, but theoretical capacity is limited to 175 mAh/g
Solution Approach 1:
The patent changes the compositional parameters by introducing doping elements (magnesium, aluminum, sodium, zirconium) at controlled concentrations (0.01-0.10 mol ratio relative to Li) to modify the spinel structure, thereby increasing theoretical capacity while maintaining cycle-life through structural stabilization
Solution Approach 2:
The patent creates composite doped spinel structures by incorporating multiple metal elements (Mg, Al, Na, Zr) into the Li4Ti5O12 matrix, forming a composite material system that combines the structural stability of spinel with enhanced capacity from dopant elements
2Ease of manufacture
If lithium-titanium composite oxide is manufactured conventionally, then production is simplified, but phase separation into rutile-type TiO2 occurs during manufacturing
Solution Approach 1:
The patent applies preliminary doping action before final sintering by incorporating dopant compounds into the raw mixture, which pre-establishes structural stability that prevents phase separation during the subsequent manufacturing process
Solution Approach 2:
The patent modifies the chemical composition parameters by adding specific dopants that lower the free energy of the spinel phase, making it thermodynamically more stable and resistant to phase separation at manufacturing temperatures
3Shape
If rutile-type TiO2 is formed in lithium-titanium composite oxide, then rock salt structure is achieved, but effective capacity deteriorates due to low reaction speed and small capacity
Solution Approach 1:
The patent converts the potentially harmful phase separation into a beneficial outcome by using controlled doping to stabilize the desired spinel structure, preventing the formation of low-capacity rutile phase while maintaining structural integrity
Solution Approach 2:
The patent changes the compositional parameters by introducing dopants that preferentially stabilize the spinel phase through lattice substitution and defect formation, thereby suppressing the thermodynamic driving force for rutile phase formation
4Quantity of substance
If doping with multiple metals is performed, then initial capacity and rate capability are improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple doping elements into a single manufacturing process by incorporating all dopant compounds (MgO, Al2O3, Na2CO3, ZrO2) into one mixed powder formulation, which is then processed through a unified sintering procedure rather than sequential doping steps
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 method enhances the initial capacity and rate capability of lithium-titanium composite oxides by controlling impurity content and particle sizes, leading to improved battery performance with a spinel structure and reduced impurity peaks, thus increasing battery efficiency.
Implementation Method 1
A non-aqueous electrolyte battery charged and discharged by lithium ions moving between negative and positive electrodes
Implementation Method 2
a lithium-titanium composite oxide having a high Li intercalation/deintercalation potential has drawn attention
Implementation Method 3
spray-drying the same to adjust contents of impurities
Implementation Method 4
firing the spray-dried particles to manufacture a lithium-titanium composite oxide
Implementation Method 5
firing the spray-dried particles to manufacture a lithium-titanium composite oxide doped with different metals
Data Source
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AI summary
The present invention relates to a manufacturing method of a lithium-titanium composite oxide doped with two kinds of different metals and a lithium-titanium composite oxide doped with two kinds of different metals. More particularly, the present invention relates to a manufacturing method of a lithium-titanium composite oxide doped with different metals, solid-phase mixing after adjusting a mixing ratio of two kinds of different metals and pulverizing the same, and spray drying the same to adjust contents of impurities, and a lithium-titanium composite oxide doped with different metals manufactured therefrom. By doping two kinds of different metals on the surface of the lithium-titanium composite oxide of the present invention after adjusting the ratio of the two different metals to be a desirable ratio, the present invention reduces the contents of rutile-type titanium dioxide, anatase-type titanium dioxide and Li2TiO3 which have been included as impurities in the prior arts, thereby manufacturing titanium dioxide having excellent capacity characteristics and structural characteristics, and a battery including the titanium dioxide having excellent battery characteristics of high initial charge and discharge efficiency and rate capability.