Lithium-Rich Cathode Material Cooling for Capacity and Stability
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Solution Overview
Problem
Lithium-rich layered oxide positive electrode materials face challenges such as low initial Coulombic efficiency, structural instability, and the production of toxic HF molecules, hindering their commercialization and battery performance.
Innovation Solution
A method involving sol-gel preparation, primary and secondary sintering, and rapid cooling using liquid nitrogen is employed to control particle size and ionic states, enhancing the positive electrode active material's structure and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium-rich layered oxide is used as positive electrode material, then energy density and capacity are improved, but initial Coulombic efficiency deteriorates
Solution Approach 1:
The patent applies parameter changes by controlling the cooling temperature and cooling time of the precursor, as well as the sintering temperature, to optimize the material structure. This resolves the contradiction by adjusting processing parameters to achieve both high energy density and improved initial Coulombic efficiency
Solution Approach 2:
The patent uses composite materials by creating a specific microstructure through controlled cooling and sintering processes. The resulting material combines the high capacity characteristics of lithium-rich layered oxide with improved structural stability, achieving both high energy density and better Coulombic efficiency
2Quantity of substance
If lithium-rich layered oxide is used as positive electrode material, then capacity is improved, but structural stability deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the sintering temperature (750-850°C) and cooling conditions to stabilize the crystal structure. This allows the material to maintain high lithium ion capacity while preventing structural degradation during cycling
Solution Approach 2:
The patent applies preliminary action by performing controlled cooling and sintering treatments before the material is used in batteries. This pre-treatment stabilizes the crystal structure in advance, preventing the transformation from layered to spinel phase that would otherwise occur during battery cycling
3Loss of time
If rapid cooling method is used for NCA positive electrode materials, then production time is reduced, but interlayer distance and Ni3+ composition are adversely affected
Solution Approach 1:
The patent applies parameter changes by optimizing the cooling temperature and cooling time parameters. Instead of extreme rapid cooling, the patent uses controlled cooling at specific temperature ranges to achieve the desired interlayer distance and Ni3+ composition while maintaining reasonable production time
Solution Approach 2:
The patent applies dynamics by making the cooling process adjustable and controllable rather than fixed. The cooling rate and temperature profile can be dynamically adjusted to balance production efficiency with material quality, avoiding the adverse effects of excessive rapid cooling
4Reliability
If element doping, coating, and particle size control are used to address OLO drawbacks, then material performance is improved, but production complexity increases
Solution Approach 1:
The patent applies parameter changes by optimizing the sintering temperature (750-850°C) and cooling conditions to directly improve material performance without requiring additional doping or coating steps. This resolves the contradiction by achieving better battery life through process parameter optimization rather than complex multi-step modifications
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 improves the specific capacity and stability of the positive electrode active material, leading to enhanced performance and extended life of electrochemical devices.
Implementation Method 1
an OLO material has been prepared in a form involving a sol-gel method, which is advantageous in the formation of nanoparticles
Implementation Method 2
S30 of subjecting the thermally treated precursor for the positive electrode active material to primary sintering and secondary sintering
Implementation Method 3
S50 of rapidly cooling the sintered precursor for the positive electrode active material
Implementation Method 4
rapid cooling using liquid nitrogen is employed to control particle size and ionic states
Data Source
AI summary
Proposed are a positive electrode active material, a method of preparing the same, and an electrochemical device including the same. Specifically, proposed are a positive electrode active material capable of improving the specific capacity of an electrochemical device through control over the cooling temperature, cooling time, and sintering temperature of a precursor to prepare the positive electrode active material, a method of preparing the same, and an electrochemical device including the same.