Multilayer Annular Pore NCA Precursor for Stable Li-Ion Cathodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing positive electrode materials for lithium-ion batteries, such as LiNiO2 and LiCoO2, face challenges including insufficient energy density, short cycle life, high cost, and limited structural stability, which hinder the widespread adoption of electric vehicles.
Innovation Solution
A multilayer annular pore nickel-cobalt-aluminum precursor is developed, characterized by a chemical formula NiMCONAl1-M-N(OH)2, with carefully controlled pH and aluminum solution concentration in each reaction stage to enhance the morphology and porosity of the precursor particles. This precursor is then sintered to produce a high-performance positive electrode material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If traditional LiNiO2 and LiCoO2 materials are used, then the battery can achieve basic energy density, but the cycle life is short and structural stability is insufficient
Solution Approach 1:
The patent develops a Ni-Co-Al layered precursor material that combines nickel, cobalt, and aluminum elements in specific ratios (Ni:Co:Al = 0.8-0.97:0.02-0.09:0.01-0.055). This composite material integrates the high capacity of LiNiO2 with the structural stability of LiCoO2 and the thermal stability enhancement from aluminum, achieving both extended cycle life and improved structural reliability simultaneously
Solution Approach 2:
The patent introduces a multilayer annular pore structure with controlled porosity (6-14%) within the precursor particles. This creates localized regions with different densities and diffusion characteristics, where the annular pores provide fast diffusion pathways while the surrounding dense regions maintain structural integrity, resolving the contradiction between cycle life and structural stability
2Use of energy by moving object
If high energy density materials are developed, then driving mileage improves, but cost increases significantly
Solution Approach 1:
The patent optimizes the chemical composition parameters by precisely controlling the molar ratios of Ni, Co, and Al elements, as well as the porosity parameter (6-14%). By adjusting these parameters, the material achieves high energy density while using cost-effective element combinations and a simplified single-step co-precipitation manufacturing process, making high-performance materials more affordable
3Shape
If the precursor has high sphericity without twin particles, then surface morphology improves, but the internal spatial structure and sintering benefits are not adequately addressed
Solution Approach 1:
The patent creates a nested hierarchical structure with secondary spherical particles (8-20 μm D50) containing multiple annular pores within them. Each secondary particle is composed of primary particles arranged in a nested configuration with 6-14% porosity. This nested structure maintains good surface morphology while providing complex internal spatial pathways for lithium ion diffusion and effective sintering, addressing both surface and internal structure requirements
4Strength
If the precursor has a dense internal structure, then mechanical strength improves, but lithium ion diffusion paths are limited and modified element inclusion is hindered
Solution Approach 1:
The patent deliberately introduces a controlled porous structure with 6-14% porosity in the form of multilayer annular pores within the precursor particles. This porous structure creates numerous internal channels that serve as fast diffusion pathways for lithium ions, significantly improving diffusion rate. The porous structure also facilitates the inclusion of modified elements during subsequent processing while maintaining adequate mechanical strength through the overall spherical particle morphology and controlled pore distribution
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 resulting positive electrode material exhibits improved energy density, longer cycle life, reduced internal resistance, and enhanced thermal stability, while maintaining a lower cost structure, thus addressing the limitations of traditional materials.
Implementation Method 1
perform a co-precipitation reaction in stages
Implementation Method 2
perform a co-precipitation reaction in stages
Implementation Method 3
sintered to produce a high-performance positive electrode material
Data Source
AI summary
The present disclosure discloses a multilayer annular pore nickel-cobalt-aluminum precursor and a preparation method and a positive electrode material thereof. The precursor D50 is 8 to 20 μm. It may be seen from a section diagram that there is a plurality of layers of annular pores in a secondary spherical particle structure, and a average porosity value of the section with a single particle or a plurality of particles is 6% to 14%. A co-precipitation reaction of nickel-cobalt mixed salt solution, alkali-aluminum solution, a complexing agent, and a precipitating agent is performed, a pH value and a concentration of aluminum solution at each stage are strictly controlled, and then working procedures of solid-liquid separating, washing, drying, mixing, sieving, and demagnetizing are performed to obtain the multilayer annular pore nickel-cobalt-aluminum precursor.