Ultrasonic Welded Current Collector Junctions for Implantable Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in constructing small-sized electrochemical cells is the difficulty in assembling and manufacturing intricate devices with durable and robust connections, particularly between the current collector and the lead or terminal pin, while minimizing component size and number, and ensuring resistance to thermal expansion and mechanical shock.
Innovation Solution
The use of ultrasonic welding to join the current collector to the lead or terminal pin, creating a solid-state bond that is mechanically robust and adaptable to various materials, including cost-effective ones like aluminum, and the folding and welding of multiple connection tabs to form a compact and redundant connection structure between electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional joining methods are used to connect current collector to lead or terminal pin, then connection strength may be adequate, but manufacturing complexity and cost increase, and component size increases
Solution Approach 1:
The patent combines the current collector and lead or terminal pin into a single integrated component structure. The lead or terminal pin is directly formed from or integrally connected to the current collector material, eliminating the need for separate joining operations and reducing manufacturing complexity while maintaining connection strength through the unified structure.
Solution Approach 2:
The current collector is designed to serve multiple functions simultaneously: it acts as both the electrical current collection component and the structural support for the lead or terminal pin. This multi-functionality reduces the number of separate components needed and simplifies the overall manufacturing process while ensuring reliable electrical and mechanical connections.
2Reliability
If multiple connection components are used to ensure robust connections, then connection reliability improves, but device size and component number increase
Solution Approach 1:
Multiple connection functions are merged into a single integrated structure. The current collector design incorporates the lead or terminal pin as an integral part, eliminating the need for separate connection components such as welds, adhesives, or mechanical fasteners, thereby reducing component number while maintaining connection durability through the unified design.
3Strength
If larger components are used to withstand mechanical shock and vibration, then connection robustness improves, but cell size increases
Solution Approach 1:
The current collector and lead or terminal pin are constructed from composite material structures that provide high strength-to-weight ratios. The integrated design utilizes materials and structural configurations that offer enhanced mechanical properties, allowing the components to withstand mechanical shock and vibration without increasing the overall cell size, as the composite structure provides superior strength in a compact form.
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 reduces manufacturing complexity and cost, enables smaller cell sizes, and provides durable connections that withstand mechanical shock, vibration, and thermal expansion, while being applicable to various electrochemical cell designs and chemistries.
Implementation Method 1
The present invention, therefore, provides various current collector embodiments that may utilize various configurations and weld connections. Specifically, embodiments which improve the connection between the current collector and a lead and/or a terminal pin are disclosed. In a preferred embodiment, the various current collector embodiments utilize an ultrasonic weld connection
Data Source
AI summary
An electrochemical cell comprising an electrode assembly having a plurality of cathodes in which the plurality of cathodes is electrically connected together at a connection tab junction is disclosed. The junction preferably comprises a plurality of cathode connection tabs that are folded over each other to construct a junction that is mechanically and electrically robust. The junction is comprised of a plurality of connection tabs that each extend from a cathode. Each of the respective tabs is folded over each other to form a compact electrode junction having redundant connections. An elongated lead extends from the junction to provide an electrical connection to the plurality of cathodes. The junction is welded together such as by a laser, resistance or ultrasonic weld joint. The cathode junction is suitable for either primary or secondary cells, particularly those powering implantable biomedical devices.