High-Loading Electrode Layering for Binder Stability and Edge Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrode manufacturing methods result in thick electrode layers that hinder lithium ion transfer, cause binder separation, and lead to reduced battery lifespan and strength issues during the charge/discharge process, particularly in lithium secondary batteries for electric vehicles.
Innovation Solution
A method involving applying electrode slurry on a release film, punching and separating the film to create a high loading electrode with multiple layers on a current collector, which prevents binder lifting and edge damage, and maintains electrode strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the thickness of the electrode layer is increased to increase battery capacity, then the energy density is improved, but the lithium ion transfer path becomes long causing deterioration of cycle characteristics and reduction of battery lifetime
Solution Approach 1:
The electrode layer is divided into multiple thin layers (first electrode layer, second electrode layer, etc.) stacked on the current collector. Each thin layer maintains short lithium ion transfer paths while the stacked configuration achieves high capacity, resolving the contradiction between thickness and ion transfer efficiency.
2Quantity of substance
If the thickness of the electrode layer is increased to increase battery capacity, then the energy density is improved, but the binder separation occurs leading to reduction of battery lifetime
Solution Approach 1:
By segmenting the thick electrode layer into multiple thin layers, the binder remains uniformly distributed throughout the electrode structure. Each thin layer ensures adequate binder dispersion, preventing the floating and separation phenomena that occur in thick single-layer electrodes.
3Quantity of substance
If a large amount of slurry is placed on the current collector to increase electrode thickness, then the capacity is improved, but drying problems occur and electrode strength decreases
Solution Approach 1:
The electrode is constructed as multiple thin layers instead of one thick layer. Each thin layer dries uniformly without internal moisture retention, and the layered structure provides mechanical reinforcement that maintains electrode strength while achieving high loading capacity.
Solution Approach 2:
Instead of increasing thickness in one dimension (vertical), the patent achieves high capacity by stacking multiple layers in the horizontal plane. This dimensional approach allows adequate drying of each layer while maintaining high electrode loading through increased surface area utilization.
4Quantity of substance
If the electrode layer thickness is increased, then the capacity is improved, but the corners and edges of the electrode layer are damaged during punching
Solution Approach 1:
By dividing the electrode into multiple thin layers, each layer can be punched with better edge integrity. The thinner material is less prone to damage during the punching process, and the stacked configuration achieves the required loading without compromising corner and edge strength.
Data Source
Figure 1(a)~1(d)
Figure 2(a)~2(e)
Figure 3(a)~3(e)
AI summary
Provided is a method of manufacturing a high loading electrode, which prevents the phenomenon of the binder being lifted, does not cause drying of the electrode slurry, and does not cause damage of the electrode layer and reduction of the electrode strength at the corners in the punching. The method of manufacturing a high loading electrode includes: applying an electrode slurry on a release film to thereby produce an electrode layer having the release film attached thereto; punching the electrode layer having the release film attached thereto to a size of a unit electrode; and separating and removing the release film from the punched electrode layer and then rolling up the electrode layer to at least two layers on a current collector.