Aqueous LTO Negative Electrode Slurry With High Solid Content
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Solution Overview
Problem
Aqueous negative electrode slurries for lithium secondary batteries containing lithium titanium oxide (LTO) face challenges with increased viscosity, which necessitates reducing solid content, leading to reduced battery capacity and manufacturing issues, especially when using aqueous solvents.
Innovation Solution
A negative electrode slurry with a high solid content is achieved by using lithium titanium oxide in the form of secondary particles and a carboxylic acid-containing polymer dispersant, which effectively disperses the LTO in an aqueous solvent, maintaining appropriate viscosity and preventing particle agglomeration, thereby enhancing battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the particle size of lithium titanium oxide is decreased to obtain high output, then the Li-ion diffusion rate improves, but the viscosity of the negative electrode slurry increases
Solution Approach 1:
The patent changes the particle size parameter of lithium titanium oxide to a specific range (D50: 0.5-1.5 μm) to optimize the balance between Li-ion diffusion rate and slurry viscosity, achieving high output without excessive viscosity increase
Solution Approach 2:
The patent introduces a dispersant as an intermediary substance to reduce slurry viscosity caused by fine lithium titanium oxide particles, enabling better processability while maintaining high Li-ion diffusion rates
2Object-generated harmful factors
If the solid content of the negative electrode slurry is reduced to address viscosity problems, then the slurry viscosity decreases, but the battery capacity is reduced
Solution Approach 1:
The patent optimizes the solid content parameter to a specific range (30-60 wt%) to simultaneously achieve acceptable slurry viscosity and high battery capacity, resolving the trade-off between processability and performance
3Ease of manufacture
If aqueous solvent is used in the negative electrode slurry to protect the environment and reduce manufacturing costs, then environmental friendliness and cost improve, but the slurry viscosity increases compared to non-aqueous solvents
Solution Approach 1:
The patent introduces a dispersant as an intermediary to mitigate the viscosity increase caused by using aqueous solvents, enabling environmental-friendly and cost-effective manufacturing while maintaining processability
Solution Approach 2:
The patent optimizes the particle size parameter of lithium titanium oxide to control slurry viscosity, enabling the use of aqueous solvents without excessive viscosity problems
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 solution allows for a high solid content in the negative electrode slurry, increasing battery capacity and reducing viscosity, leading to improved manufacturing processability and enhanced lithium ion diffusion rates, resulting in better charge/discharge characteristics and stability.
Implementation Method 1
a carboxylic acid-containing polymer dispersant, which effectively disperses the LTO in an aqueous solvent
Implementation Method 2
lithium titanium oxides having a high Li intercalation/deintercalation potential... excellent rapid charging... Li metal is not deposited at a Li intercalation/deintercalation potential
Data Source
AI summary
The present invention relates to a negative electrode slurry and a method of preparing the same. The negative electrode slurry includes lithium titanium oxide (LTO), a carboxylic acid-containing polymer dispersant, a binder, and an aqueous solvent, wherein the carboxylic acid-containing polymer dispersant has a weight average molecular weight (Mw) of 2,500 g/mol to 500,000 g/mol and is included in an amount of 1.5 parts by weight to 20 parts by weight with respect to 100 parts by weight of the lithium titanium oxide.