Lithium Titanium Oxide Negative Electrode for High-Rate Hybrid Battery Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium titanium oxide materials used in negative electrodes of lithium secondary batteries fail to meet the high output requirements for hybrid vehicles, particularly in terms of capacity maintenance and initial capacity at high rates.
Innovation Solution
A negative electrode active material comprising lithium titanium oxide particles with controlled average particle diameter (D50), specific surface area, and pellet density, combined with primary and secondary particles, and optionally including additional active materials, to enhance high-rate charge/discharge characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium titanium oxide is used as negative electrode material to achieve high operating voltage and prevent surface film formation, then initial charge/discharge cycle efficiency reaches approximately 100%, but the material cannot satisfy high output requirements of 20 C or more charge/discharge rates
Solution Approach 1:
The patent changes physical parameters of lithium titanium oxide particles, specifically controlling average particle diameter to 3 μm or less and specific surface area to 5 m²/g or more, to simultaneously achieve high initial efficiency and high-rate output characteristics
Solution Approach 2:
The patent creates a composite structure where small primary particles (3 μm or less) form aggregates of secondary particles, combining the advantages of small particle size (high surface area for fast reaction) with larger aggregate structure (good packing and electrical contact)
2Productivity
If particle size of lithium titanium oxide is reduced to increase specific surface area for high rate performance, then charge/discharge rate capability improves, but manufacturing complexity and control difficulty increase
Solution Approach 1:
The patent performs preliminary size reduction and classification during manufacturing to produce primary particles of 3 μm or less before electrode assembly, ensuring consistent high-rate performance while simplifying downstream processing by establishing particle size control early in the manufacturing sequence
Data Source
AI summary
Disclosed are a negative electrode active material including lithium titanium oxide particles, wherein the lithium titanium oxide particles have an average particle diameter (D50) of 0.5-9 μm, a specific surface area of 3-7 m2/g, and a pellet density of 1.7 g/cc or more under a pressure of 64 MPa, and a lithium secondary battery including the same.