High-Nickel Cathode Active Material With XRD-Controlled Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reliability of cathode active materials in lithium secondary batteries is compromised due to high nickel content, leading to structural instability, increased reactivity, and reduced durability under high temperature and voltage conditions.
Innovation Solution
A lithium composite oxide particle with a specific XRD peak ratio and single particle structure, containing an excess amount of nickel, is developed, enhancing crystallinity and mechanical stability, thereby improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the content of nickel is increased to achieve sufficient capacity and power, then the power and capacity of the battery are improved, but the reliability of the cathode active material deteriorates due to mismatch and side reaction with lithium
Solution Approach 1:
The invention changes the crystal structure parameters of the cathode active material by controlling the XRD peak area ratio A(003)/A(104) to be within 1.05 to 1.30. This parameter control optimizes the crystal structure to accommodate high nickel content (molar ratio 0.65-0.95) while maintaining structural stability and reliability, resolving the contradiction between power improvement and reliability deterioration
Solution Approach 2:
The invention uses composite metal oxide materials with specific crystal structures that combine multiple elements to create a stable framework. The composite structure allows high nickel content for power while the overall composite maintains reliability through controlled crystallographic parameters and structural stability
2Quantity of substance
If the content of nickel is increased to achieve sufficient capacity, then the capacity of the battery is improved, but the stability of the cathode active material deteriorates due to structural instability
Solution Approach 1:
The invention controls the crystal structure parameters by maintaining the XRD peak area ratio A(003)/A(104) within 1.05 to 1.30, which optimizes the crystal structure to stabilize the cathode active material while accommodating high nickel content for improved capacity
Solution Approach 2:
The invention creates local structural optimization within the crystal lattice by controlling specific plane orientations (003 and 104 planes) to have appropriate area ratios. This local structural quality control ensures stability at critical interfaces while maintaining high nickel content throughout the material for improved capacity
3Power
If the content of nickel is increased, then the power and capacity are improved, but the durability under high temperature and voltage conditions is reduced
Solution Approach 1:
The invention optimizes the crystal structure parameters by controlling the XRD peak area ratio A(003)/A(104) to be within 1.05 to 1.30, which enhances the structural stability and durability of the cathode active material under high temperature and voltage conditions while maintaining high nickel content for improved power
Data Source
AI summary
A cathode active material for a lithium secondary battery according to an embodiment of the present invention includes a lithium composite oxide particle that contains lithium and transition metals including an excess amount of nickel. The lithium composite oxide particle satisfies a predetermined XRD peak area relation. A lithium secondary battery using the cathode active material and providing improved stability and durability is provided.