Multi-thickness Current Collector for Robust Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrochemical cells face challenges in maximizing active electrode material volume while maintaining a robust mechanical connection to terminal leads, as uniform current collectors occupy unnecessary space and may not withstand mechanical stresses.
Innovation Solution
A conductive substrate current collector with a thin active electrode material contact area and a thicker tab portion is designed, allowing for increased active electrode material volume and a robust mechanical connection through optimized thickness profiles, enabling efficient volumetric use and flexible motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current collector is constructed with uniform thickness, then the mechanical connection to terminal lead is robust, but the volume occupied by inactive components increases
Solution Approach 1:
The current collector is designed with non-uniform thickness, featuring a thicker tab portion for robust welding and a thinner body portion for reduced volume. This local variation in thickness allows each region to be optimized for its specific function: the tab provides mechanical strength for connection to terminal leads, while the thinner body minimizes space occupation to maximize active electrode material volume.
2Volume of stationary object
If the current collector thickness is reduced, then the volume for active electrode material increases, but the mechanical connection capability deteriorates
Solution Approach 1:
The current collector features localized thickness variation with a thicker tab portion specifically designed for welding operations. This thicker region provides sufficient material to withstand welding heat without burning through and creates a robust mechanical connection, while the rest of the collector body maintains reduced thickness to maximize active material volume.
3Reliability
If the tab portion thickness is increased, then the weld connection becomes more robust, but the overall current collector volume increases
Solution Approach 1:
The current collector is segmented into distinct thickness zones: a thicker tab portion for welding and a thinner body portion for active material accommodation. This segmentation allows the tab to be optimized independently for weld connection reliability while the body is optimized for minimizing volume, achieving both goals without compromise.
Solution Approach 2:
The tab portion is locally thickened only where needed for welding operations, rather than increasing the thickness of the entire current collector. This localized thickness enhancement provides robust weld connections while minimizing the overall volume increase, as only the tab region requires additional thickness for mechanical connection purposes.
Data Source
AI summary
A current collector in the form of a conductive substrate subjected to a special chemical etch to provide the current collector having a multi-thickness structure, is described. The multiple-thickness current collector structure provides an electrochemical cell with increased charge capacity per volume while enabling a robust weld connection thereto. The current collector has a frame and comprises within an inner perimeter of the frame, first strand structures that intersect second strand structures to provide a plurality of openings or interstices bordered by the strands. At least one tab portion having a thicker distal portion spaced from a thinner proximal tab portion that extends from an outer perimeter of the frame.