Integrated Electrode Tab Forming for Li-Ion Cell Energy Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium ion battery cell production is costly due to separate electrode tabs, which increase cell thickness and reduce energy density, and are prone to cracking during welding.
Innovation Solution
An electrode piece with a current collector featuring a groove and diaphragm, where connecting portions are cut and bent from the blank current collector to form an electrode tab, eliminating thickness superposition and enhancing connection strength without the need for separate tabs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If separate electrode tabs are welded to the current collector, then the electrode piece can be assembled, but the production cost increases and the cell thickness increases
Solution Approach 1:
The patent merges the electrode tab function with the current collector by forming connecting portions directly on the current collector surface. This eliminates the need for separate electrode tabs and their welding operations, thereby reducing production cost and simplifying the cell structure while maintaining electrical connectivity functionality.
Solution Approach 2:
The current collector is given multiple functions: it serves as both the electrical conductor and the structural support, while its surface-formed connecting portions perform the tab function. This multi-functionality reduces the number of components needed and simplifies the overall cell construction.
2Ease of manufacture
If separate electrode tabs are used, then the electrode piece can be assembled, but the energy density of the cell decreases
Solution Approach 1:
By combining the current collector and electrode tab into a single integrated structure, the patent eliminates the thickness superposition that would occur with separate tabs. This reduces the overall cell thickness and increases the volume available for active materials, thereby improving energy density.
3Ease of manufacture
If multiple layers of electrode tabs are welded, then the electrode piece can be assembled, but the connection region becomes the maximum thickness region and space is wasted
Solution Approach 1:
The patent eliminates the need for multi-layer tab stacking by forming connecting portions directly on the current collector surface. This single-layer integration removes the thickness superposition problem and maximizes the usable volume within the cell.
4Ease of manufacture
If separate electrode tabs are welded to the current collector, then the electrode piece can be assembled, but the connection strength decreases and cracking or breaking occurs
Solution Approach 1:
By forming the connecting portions as an integral part of the current collector through surface formation processes, the patent eliminates the welding interface that is prone to cracking. The integrated structure ensures continuous material continuity and superior mechanical strength at the connection points.
Data Source
AI summary
The invention provides an electrode piece, a cell and an energy storage device. The electrode piece is used to form the cell, comprising: a current collector; a diaphragm; and a groove. Among them, the current collector exposed at the bottom of the groove is a blank current collector, and the blank current collector is formed with a connecting portion; the connecting portion is cut out from the blank current collector as a part of the blank current collector and bent on the blank current collector along the width direction; and at least a portion of the connecting portion extends beyond the outer edge of the current collector in the width direction. The electrode piece of the invention can increase the energy density of the cell and the connection strength of the blank current collector of the electrode tab and the electrode piece, and reduce the production cost.