Negative Electrode Magnetic Alignment for Fast-Charging Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The orientation of negative electrode active materials in secondary batteries, typically oriented horizontally, leads to longer lithium ion travel paths, increasing internal resistance and reducing battery performance, especially at high charging rates, which can result in lithium-plating and safety issues.
Innovation Solution
A manufacturing apparatus using a pair of magnet plates with specific magnet arrangements applies a magnetic field to orient the negative electrode active material vertically relative to the current collector, ensuring uniform orientation through a combination of vertical and horizontal unit magnets with alternating magnetic directions, enhancing the magnetic force distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If negative electrode active material is oriented horizontally parallel to current collector, then manufacturing process is simple, but lithium ion travel path becomes long and internal resistance increases
Solution Approach 1:
The patent changes the orientation parameter of negative electrode active material from horizontal to vertical by applying a magnetic field during the slurry coating process. This parameter change shortens the lithium ion travel path perpendicular to the current collector, reducing internal resistance and improving battery performance while maintaining manufacturing feasibility through magnetic field application.
2Quantity of substance
If loading amount of negative electrode is increased to increase capacity, then battery capacity increases, but lithium ion diffusion path becomes longer and charging rate decreases
Solution Approach 1:
The patent changes the orientation parameter of negative electrode active material to vertical, which shortens the lithium ion diffusion path from the surface to the interior of the electrode. This allows increased loading amount without proportionally increasing diffusion distance, thereby maintaining high charging rates even at higher capacities.
3Reliability
If magnetic field is applied to orient active material vertically, then lithium ion diffusion improves, but device complexity increases
Solution Approach 1:
The patent replaces mechanical mixing or physical alignment methods with a magnetic field application system to orient the negative electrode active material. This substitution enables vertical orientation without complex mechanical structures, as the magnetic field can be applied during the coating process to align paramagnetic or diamagnetic carbon materials vertically.
4Reliability
If vertical orientation of active material is achieved, then internal resistance decreases, but manufacturing process becomes more complex
Solution Approach 1:
The patent applies the magnetic field during the slurry coating process, before drying and consolidation. This preliminary action orients the active material particles in the slurry state when they are still mobile and responsive to magnetic fields, achieving vertical orientation without requiring additional post-processing steps.
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
This approach improves lithium ion diffusion rates, reduces internal resistance, and enhances fast-charging performance by aligning the active material perpendicular to the current collector, thereby increasing battery capacity and safety.
Implementation Method 1
A manufacturing apparatus using a pair of magnet plates with specific magnet arrangements applies a magnetic field to orient the negative electrode active material vertically relative to the current collector
Data Source
Figure 1~2
Figure 3A~3B
Figure 4
AI summary
Apparatuses and methods for manufacturing negative electrodes are disclosed. in an embodiment, an apparatus for manufacturing a negative electrode includes upper and lower magnet plates, each having (N+1) magnet modules with unit magnets arranged and offset in the Y-axis by N×d based on magnetic force direction patterns to control electrode alignment.