Doped Cathode Precursor (101) Layer Control for Capacity and Cycle Life
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Solution Overview
Problem
Existing positive electrode materials in secondary batteries have high capacity but poor cycle performance, or high cycle performance but low capacity, failing to meet the requirements of new generation electrochemical systems.
Innovation Solution
A precursor material with a chemical formula NixCoyMnzMa(OH)2, where M includes Zr, Y, Al, Ti, W, Sr, Ta, Mo, Sb, Nb, Na, K, Ca, or La, with 20-70 layers of (101) planes, is used to prepare a positive electrode material, enhancing lithium-ion transmission and structural stability through controlled crystal plane orientation and porosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If existing precursor materials are used to synthesize positive electrode material, then capacity can be improved, but cycle performance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the number of (101) crystal planes (20-70 layers) and deformation fault probability (≤7.0%) of the precursor material. This controlled crystalline structure enables the positive electrode material to achieve both high capacity (4.20-4.60 mAh/mL) and excellent cycle performance (85-95% capacity retention after 500 cycles at 45°C), resolving the trade-off between capacity and cycle stability.
Solution Approach 2:
The patent employs composite materials by incorporating element M (selected from Zr, Y, Al, Ti, W, Sr, Ta, Mo, Sb, Nb, Na, K, Ca, Ce, or La) into the NixCoyMnz matrix to form NixCoyMnzMa(OH)2 precursor material. This composite structure enhances both capacity and cycle performance synergistically, achieving 4.20-4.60 mAh/mL capacity with 85-95% retention after 500 cycles.
2Reliability
If existing precursor materials are used to synthesize positive electrode material, then cycle performance can be improved, but capacity deteriorates
Solution Approach 1:
The patent resolves this contradiction by optimizing critical parameters: controlling (101) plane layers to 20-70, deformation fault probability to ≤7.0%, and Ni content to 0.80-1.00. These parameter adjustments enable simultaneous achievement of high cycle performance (85-95% retention) and high capacity (4.20-4.60 mAh/mL), eliminating the traditional trade-off.
Solution Approach 2:
The patent applies local quality by creating a precursor material with specific local crystalline characteristics (20-70 layers of (101) planes, ≤7.0% deformation fault probability) within the overall structure. This localized control of crystal plane orientation and defect density enables regions optimized for both capacity and cycle stability, achieving 4.20-4.60 mAh/mL with 85-95% retention.
3Speed
If the number of (101) planes is increased, then lithium ion transmission distance is reduced, but structural stability may deteriorate
Solution Approach 1:
The patent resolves this contradiction by optimizing the number of (101) planes to 20-70 layers and controlling deformation fault probability to ≤7.0%. This balanced parameter selection ensures sufficient lithium ion transmission pathways (reducing transmission distance) while maintaining structural integrity, achieving both fast kinetics and long-term stability.
Solution Approach 2:
The patent applies partial action by including 20-70 layers of (101) planes rather than maximizing the number indefinitely. This partial optimization provides adequate lithium ion transmission channels while avoiding excessive layering that would compromise structural stability, achieving the right balance between speed and durability.
Data Source
AI summary
A precursor material and a preparation method therefor, a positive electrode material, a secondary battery, and a power consuming apparatus. The precursor material has a chemical formula of NixCoyMnzMa(OH)2, where element M includes at least one of Zr, Y, Al, Ti, W, Sr, Ta, Mo, Sb, Nb, Na, K, Ca, Ce, and La, 0.55≤x<1.0, 0≤y<0.45, 0≤z<0.45, 0<a≤0.45, a+x+y+z=1, and the precursor material includes 20-70 layers of (101) plane.