Li-Ion Anode Slurry Coating for High Areal Loading
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Solution Overview
Problem
Current battery technologies for electric vehicles face challenges in achieving high energy density and reliable electrode coatings for lithium-ion batteries, leading to issues with agglomeration, delamination, and cracking in anode slurry formation.
Innovation Solution
A method involving the formation of a powder mix with carbonaceous material and conductive additives, iteratively added to a CMC solution, followed by mixing with a binder and deposition onto a conductive film, then calendering to achieve high areal loading and density coatings, reducing agglomeration and improving adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high active material percentage is used in anode to improve energy density, then energy density is improved, but agglomeration and delamination occur
Solution Approach 1:
The anode is segmented into multiple thin layers rather than a single thick layer. Each layer is applied separately and dried to form a distinct stratum, preventing agglomeration and delamination while achieving high overall active material content. This layered approach allows better control of slurry distribution and reduces internal stress that causes coating failure.
Solution Approach 2:
The patent employs a dynamic, iterative application process where slurry is applied in multiple passes with drying intervals. The coating thickness and active material percentage are adjusted dynamically across different layers, allowing optimization of both energy density and coating stability rather than using a static single-layer approach.
2Manufacturing precision
If predetermined thickness is used in anode formation, then manufacturing precision is improved, but slurry uniformity and adhesion deteriorate
Solution Approach 1:
The anode coating is divided into multiple thin layers applied in sequence. Each layer is thin enough to maintain slurry uniformity and proper adhesion, while the cumulative thickness of all layers achieves the predetermined target thickness. This segmentation allows each layer to be uniformly applied without the defects that occur in single thick coatings.
Solution Approach 2:
Each subsequent layer is applied only after the previous layer is fully dried and stabilized. This preliminary drying action ensures that each layer has proper adhesion to the substrate before the next layer is added, preventing delamination while building up the required thickness with uniform composition.
3Ease of manufacture
If conventional slurry formation is used, then process simplicity is maintained, but electrode coating quality deteriorates
Solution Approach 1:
The coating process is segmented into multiple application and drying cycles rather than a single conventional step. This segmentation improves coating quality by preventing agglomeration and ensuring uniform adhesion, while the overall process remains relatively simple and can be implemented with standard equipment.
Solution Approach 2:
The iterative process of applying slurry and drying continues until the desired thickness and quality are achieved. This continuous cycle of deposition and drying ensures consistent coating quality throughout the anode, maintaining high manufacturing precision while keeping the process straightforward and scalable.
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 solution enhances electrical characteristics by achieving high areal loading, active material percentage, and density electrode coatings, reducing agglomeration and delamination, and improving the mechanical flexibility of anodes, thus enhancing the performance and reliability of lithium-ion battery cells.
Implementation Method 1
forming a powder mix comprising a carbonaceous material and a conductive additive... generating a slurry by iteratively adding the portions to a solution... adding the powder portions iteratively to a carboxymethyl cellulose (CMC) solution
Implementation Method 2
The anode slurry and foil can be heated, during a first phase, at between 55° C. and 65° C. for between 3 minutes and 9 minutes. The anode slurry and the foil can be heated, during a second phase, at between 75° C. and 85° C. for between 2 minutes and 6 minutes.
Implementation Method 3
The anode slurry and foil can be heated, during a first phase, at between 55° C. and 65° C. for between 3 minutes and 9 minutes. The anode slurry and the foil can be heated, during a second phase, at between 75° C. and 85° C. for between 2 minutes and 6 minutes. An anode can be formed from at least a portion of the anode slurry on the face of the foil.
Data Source
AI summary
Described is a method to form an anode for a battery pack to power an electric vehicle. The method can include forming a powder mix of a carbonaceous material and a conductive additive. The powder mix can be divided into portions and iteratively added to a carboxymethyl cellulose solution to generate a slurry. The slurry can be dispensed onto a face of a conductive film. Also described is a battery cell for a battery pack to power an electric vehicle. The battery cell can have a housing and at least one anode coupled with the housing. Each anode can have a conductive film forming the anode surface. Each anode can have a coating disposed on the conductive film. The coating can have an area loading of between 12 mg/cm2 and 18 mg/cm2 and can be between 95% and 99% by weight of a carbonaceous material and a conductive additive.