High-Ni Cathode Precursor Crystal Control for Stable Li Reactivity
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Solution Overview
Problem
High-Ni cathode active materials face challenges with structural instability and low reactivity during the firing process, affecting their electrochemical performance and cycle characteristics in secondary batteries.
Innovation Solution
A composite transition metal precursor with a Ni content of 60% or more, optimized through co-precipitation with specific ratios of intensity peaks in XRD analysis, is used to enhance structural stability and reactivity, ensuring efficient Li intercalation and deintercalation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-Ni cathode active materials are used to reduce cost and improve capacity, then price competitiveness and discharge capacity are improved, but structural stability and reactivity with Li deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the intensity ratio I(101)/I(001) within 0.7-1.1 and Ni content at 60 mol% or more. This optimization of crystallographic parameters ensures the precursor has both high reactivity with Li sources and structural stability during firing, resolving the contradiction between high-Ni content requirements and structural stability
Solution Approach 2:
The patent uses composite transition metal precursors containing Ni and at least one other transition metal in specific ratios. This composite structure combines the high capacity benefits of Ni with the structural stability provided by other transition metals, while the controlled I(101)/I(001) ratio ensures optimal reactivity and phase formation during firing
2Quantity of substance
If high-Ni cathode active materials are used to improve price competitiveness, then cost is reduced, but reactivity with Li and firing process efficiency deteriorate
Solution Approach 1:
The patent applies preliminary action by pre-forming the precursor with optimized crystal structure (I(101)/I(001) ratio of 0.7-1.1) before the firing process. This preliminary structural optimization ensures high reactivity with Li sources during subsequent processing, eliminating the need for complex firing conditions like LiOH addition or oxygen injection, thereby improving both ease of manufacture and reactivity
3Device complexity
If conventional firing processes are used for high-Ni materials, then processing is simplified, but structural stability and electrochemical performance deteriorate
Solution Approach 1:
The patent changes the critical parameter of precursor crystal structure (I(101)/I(001) ratio to 0.7-1.1) which enables conventional firing processes to produce high-quality cathode materials. This parameter optimization ensures structural stability and excellent cycle characteristics without requiring complex firing modifications, thus resolving the contradiction between process simplicity and product reliability
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 results in a cathode active material with improved initial capacity, electrochemical performance, and structural stability, reducing the cost and complexity of the firing process while maintaining high particle strength and lifespan.
Implementation Method 1
high-Ni cathode active materials have problems of difficulty in a firing process such as long firing time, use of LiOH, and oxygen injection due to low reactivity with Li
Implementation Method 2
a ratio (I101/I001) of an intensity of the (101) plane to an intensity of the (001) plane ranges from 0.7 to 1.1 in an XRD analysis
Data Source
AI summary
Disclosed is a composite transition metal precursor for a cathode active material containing Ni and at least one transition metal, wherein a molar amount of Ni is 60% or more based on a total amount of transition metal and a ratio (I101/I001) of an intensity of a (101) plane to an intensity of a (001) plane ranges from 0.7 to 1.1 in XRD analysis.