High-Nickel Cathode Polymer Coating via Spray Drying
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Solution Overview
Problem
The dry coating process for high-nickel ternary cathode materials in lithium-ion batteries lacks homogeneity, affecting interface stability and comprehensive performance, while the conventional wet coating process generates excessive wastewater, increasing manufacturing costs.
Innovation Solution
A method involving the preparation of a lignin-amine-modified polymer emulsion, followed by spray drying to form a continuous and homogeneous polymer coating on high-nickel ternary cathode materials, reducing wastewater and manufacturing costs, and enhancing mechanical and electrochemical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dry coating process is used, then manufacturing cost is reduced and process is simplified, but coating homogeneity and continuity cannot be ensured
Solution Approach 1:
The patent employs spray drying technology, which utilizes pneumatic principles to atomize the coating slurry into fine droplets that are uniformly distributed and deposited on the cathode material surface. This pneumatic delivery system ensures both coating homogeneity and process simplicity, resolving the contradiction between manufacturing ease and coating quality.
Solution Approach 2:
The patent optimizes key parameters including slurry viscosity (0.05-0.2 Pa·s), spray drying temperature (80-150°C), and nickel content (80-95 mol%) to achieve optimal coating homogeneity. By controlling these parameters, the process maintains both manufacturing simplicity and coating quality simultaneously.
2Manufacturing precision
If wet coating process is used, then coating homogeneity is improved, but large amount of wastewater is generated increasing manufacturing costs
Solution Approach 1:
The patent utilizes the phase transition from liquid slurry to solid coating through spray drying. The slurry is sprayed as liquid droplets and rapidly evaporated to form a solid, continuous coating layer. This phase transition approach achieves wet-coating-level homogeneity while eliminating the need for water-intensive washing steps, thus reducing wastewater generation.
Solution Approach 2:
The patent replaces the conventional wet coating mechanical system (dip coating, spin coating followed by washing) with a spray drying system. This substitution eliminates the wastewater generation step while maintaining coating homogeneity through controlled atomization and evaporation, resolving the contradiction between coating quality and environmental impact.
3Loss of substance
If cobalt content is reduced to lower cost, then manufacturing cost decreases, but material stability deteriorates
Solution Approach 1:
The patent creates a composite structure consisting of the high-nickel cathode material core (80-95 mol% Ni) coated with a protective polymer-lignin composite layer. This composite coating combines polymer matrix with lignin reinforcement, providing enhanced mechanical strength and chemical stability that compensates for the reduced cobalt content, thus maintaining material stability while reducing manufacturing cost.
Solution Approach 2:
The patent applies a thin film protective coating (5-20 μm) of polymer-lignin composite on the high-nickel cathode material surface. This flexible protective shell acts as a barrier that stabilizes the underlying low-cobalt material, preventing degradation while allowing the bulk composition to be cost-optimized with reduced cobalt content.
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 method significantly improves the cycling stability and mechanical properties of high-nickel positive electrode materials, providing a cost-effective and environmentally friendly solution for industrial production.
Implementation Method 1
spray drying for film formation
Data Source
AI summary
The present disclosure discloses a method for preparing a coating-modified high-nickel ternary cathode material, relating to the technical field of lithium-ion battery cathode materials. The method includes: reacting a diisocyanate with a dihydric alcohol, and adding lignin modified with an organic amine instead of an amine chain extender to prepare a modified polymer emulsion; and adding a high-nickel ternary cathode material to a lignin-amine-modified polymer emulsion, and carrying out spray drying for curing and film formation, thereby obtaining the coating-modified high-nickel ternary cathode material. The beneficial effects lie in that spray drying is used for curing and film formation, so a polymer coating layer is continuous and homogeneous, which provides the material with good mechanical properties. Thus, structural changes caused by a reduced cobalt content can be inhibited. A large amount of wastewater resulting from a wet coating process is reduced, and the manufacturing costs are reduced.