Li-Ion Cathode Composition for High Volumetric Energy Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face challenges with low volumetric energy density, high-percent capacity irreversibility in the first cycle, capacity degradation over cycling, and low rate capability due to conventional cathode active materials.
Innovation Solution
A cathode active material composition represented by xLi2MO3 • (1-x)LiCo y M' (1-y) O2, where 0.01 ≤ x < 0.3 and 0.8 ≤ y < 1.00, incorporating manganese, titanium, ruthenium, and zirconium, with metal cations like Li+, Ni2+, Cu+, and others, stabilized by a Li2MO3 domain, synthesized using a mixed-metal hydrated hydroxide precursor and solid-state reaction, enhancing reversible lithium extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional cathode active materials are used, then the battery structure is simple and easy to manufacture, but the volumetric energy density is low and capacity degradation occurs over cycling
Solution Approach 1:
The patent employs composite cathode materials comprising multiple metal cations (manganese, titanium, ruthenium, zirconium, and other transition metal cations) in specific ratios to achieve high volumetric energy density while maintaining structural stability during cycling, thereby resolving the contradiction between energy density improvement and material complexity
Solution Approach 2:
The patent optimizes specific compositional parameters including the ratios of different metal cations (0.05-0.20 for Mn, 0.05-0.15 for Ti, 0.01-0.05 for Ru, 0.01-0.05 for Zr) and the lithium content (x value between 0.01-0.3) to maximize volumetric energy density while preventing capacity degradation through parameter optimization
2Reliability
If conventional cathode materials are used, then the manufacturing process is simple, but capacity irreversibility is high in the first cycle
Solution Approach 1:
The patent applies preliminary surface treatment and coating to the cathode material before battery assembly to prevent capacity irreversibility during the first charge-discharge cycle, thereby improving capacity retention while managing manufacturing complexity through pre-processing
Solution Approach 2:
The patent introduces intermediary protective coatings and surface treatments on the cathode material to mediate between the electrode and electrolyte, reducing capacity irreversibility and improving reliability while maintaining reasonable ease of manufacture
3Productivity
If conventional cathode materials are used, then the battery design is simple, but rate capability is low
Solution Approach 1:
The patent segments the cathode material into fine particles with controlled size distribution (average particle size 5-20 micrometers) to enhance rate capability by reducing diffusion paths, thereby improving productivity while managing structural complexity through particle size control
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 provides improved volumetric energy density, extended cycle life, and high-rate discharging capability, with reversible lithium extraction exceeding 165mAh/g and potentially up to 200mAh/g, stabilizing the cathode structure during charging and discharging.
Implementation Method 1
the amount of lithium that can be reversibly extracted from the cathode active material is greater than 165mAh/g
Implementation Method 2
stabilized by a Li2MO3 domain, synthesizing a material that enables reversible lithium extraction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The disclosed embodiments provide a battery cell. The battery cell includes an anode containing an anode current collector and an anode active material disposed over the anode current collector. The battery cell also includes a cathode containing a cathode current collector and a cathode active material disposed over the cathode current collector. The cathode active material has a composition represented by xLi2MO3• (1-x)LiCoyM'(1-y)O2.