Dry-Process Electrode Sheet Stacking for Flatness and Burr Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The dry-process electrode film, when directly bonded to a current collector, results in uneven thickness and deformation, leading to potential defects such as burrs during slitting and stacking, which compromises the safety performance of lithium-ion batteries.
Innovation Solution
A method and apparatus for preparing an electrode sheet by alternately stacking layers of dry-process electrode films with respect to the current collector, ensuring front and back sides of the layers alternate, reducing uneven thickness and burr formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dry-process electrode film is directly bonded to the current collector by rolling, then the manufacturing process is simple and efficient, but the electrode sheet exhibits uneven thickness and deformation
Solution Approach 1:
The electrode films are pre-cut to sizes larger than the current collector before stacking, ensuring that the edges extend beyond the current collector boundaries. This preliminary preparation allows the electrode films to wrap around the current collector edges during pressing, preventing burr formation and improving thickness uniformity without compromising manufacturing efficiency
2Ease of manufacture
If the electrode film is directly bonded to the current collector, then the manufacturing process is straightforward, but burrs appear on the aluminum foil or copper foil during slitting
Solution Approach 1:
The electrode films are pre-cut to extend beyond the current collector edges, creating an overhang that will wrap around during pressing. This preliminary action prevents burr formation by ensuring the electrode material covers the current collector edges, eliminating the need for complex post-processing while maintaining process simplicity
Solution Approach 2:
By extending the electrode film edges beyond the current collector before stacking, the invention creates a preliminary counteraction against the potential burr formation. The excess electrode material acts as a protective layer that prevents the current collector edges from exposing during slitting, thereby eliminating the harmful burr effect
3Device complexity
If multiple layers of electrode films are stacked with uniform orientation, then the stacking process is simple, but the electrode sheet exhibits obvious depression and bulging deformations
Solution Approach 1:
The invention employs asymmetric stacking where odd-numbered electrode films are oriented with their front sides facing upward, while even-numbered films are oriented with their back sides facing upward. This alternating asymmetric arrangement compensates for thickness variations and prevents depression and bulging deformations, improving flatness without significantly increasing stacking process complexity
Data Source
AI summary
Provided are a method for preparing an electrode sheet, an apparatus for preparing an electrode sheet, an electrode sheet, and a battery cell. The method for preparing the electrode sheet includes: cutting a dry-process electrode film material to form a dry-process electrode film; cutting a current collector material to form a current collector, a size of the current collector being smaller than or equal to that of the dry-process electrode film; and sequentially stacking and pressing a plurality of layers of dry-process electrode films, the current collector, and a plurality of layers of dry-process electrode films to form the electrode sheet, the plurality of layers of dry-process electrode films on a same side of the current collector are arranged in a manner that front and back sides of the plurality of layers of dry-process electrode films alternate with respect to the current collector.