Cathode Active Material Composition for Crack-Resistant Li-Ion Cycling
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Solution Overview
Problem
Existing lithium-ion batteries face issues with the cracking of cathode active material particles, which leads to deterioration and reduced battery performance.
Innovation Solution
A cathode active material is developed using a lithium metal-containing composite oxide with a specific formula (LiaNixCoyMnzMbO2) that includes a lanthanide or transition element (M) with four or less electrons in the d orbital, which helps in suppressing expansion and contraction during charge and discharge cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a specific element is added to increase battery capacity, then battery capacity is improved, but particle cracking occurs leading to material deterioration
Solution Approach 1:
The patent employs a composite oxide material with a specific multi-element composition (Li-Ni-Co-Mn-M) where different elements work synergistically. The composite structure combines the high capacity contribution from Ni and Co with the structural stability provided by Mn and the specific M element, creating a material that achieves both high capacity and resistance to particle cracking during cycling.
Solution Approach 2:
The patent optimizes the compositional parameters of the cathode material by precisely controlling the ratios of different elements in the formula LiaNixCoyMnzMbO2. By adjusting these compositional parameters within specific ranges, the material achieves optimal balance between capacity and structural stability, preventing particle cracking while maintaining high battery capacity.
2Quantity of substance
If high capacity cathode material is used, then battery capacity increases, but expansion and contraction during charging causes particle cracking
Solution Approach 1:
The patent introduces local quality variations through the specific M element composition and its distribution within the cathode material structure. The M element (selected from rare earth metals or transition metals with specific d-orbital electron configurations) provides localized structural reinforcement at critical sites, enhancing particle strength and resistance to cracking while maintaining overall high capacity.
Solution Approach 2:
The patent modifies the crystallographic and compositional parameters of the cathode material by incorporating the M element with specific electronic configurations. This changes the local structural parameters and bonding characteristics, resulting in enhanced particle strength that can withstand the mechanical stresses of expansion and contraction during charging cycles.
Data Source
AI summary
A cathode active material comprising a lithium metal-containing composite oxide, wherein the lithium metal-containing composite oxide is represented by the following formula (1):LiaNixCoyMnzMcO2 (1),wherein x, y, z, a and b are x+y+z+b=1, 0≤x≤1,0≤y≤1, 0≤z≤1, 0<a≤1, 0<b≤0.15, M is a transition element the number of electrons of the lanthanide or d orbital is 4 or less.