Folded Foil Battery Assembly Without Welded Interconnects
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Solution Overview
Problem
The existing methods for assembling batteries in implantable medical devices (IMDs) face challenges such as undesirable heat generation and potential damage to neighboring components due to welding processes, along with susceptibility to weld failure and increased manufacturing costs.
Innovation Solution
The use of a foil package that encloses electrodes and electrolytes, featuring conductive tabs and current collectors formed from thin metal sheets, which eliminates the need for interconnect welding by integrating the tabs with the current collectors and employing a folded configuration of multiple cathode plates connected via connectors to reduce in-plane expansion and stress on the foil pack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding processes are used to connect battery components, then electrical connectivity is achieved, but heat generation increases and risk of damage to neighboring components occurs
Solution Approach 1:
The patent replaces the welding process (thermal/mechanical system) with a mechanical compression system. The battery components are connected through direct physical contact and compression forces rather than thermal welding, thereby eliminating heat generation while maintaining electrical connectivity. The compression mechanism applies sustained mechanical force to ensure reliable electrical contact between components.
2Quantity of substance
If multiple cathode plates are used to increase battery capacity, then energy storage increases, but in-plane expansion and stress on foil pack increase
Solution Approach 1:
The patent addresses the in-plane expansion problem by transitioning from a two-dimensional planar arrangement to a three-dimensional stacked configuration. Multiple cathode plates are arranged in vertical layers rather than spreading out in-plane, thereby increasing battery capacity through the third dimension (height/thickness) while minimizing in-plane expansion and reducing stress on the foil pack structure.
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 solution reduces manufacturing costs, minimizes heat generation, enhances reliability by avoiding weld failures, and provides a more efficient power source with increased battery capacity while maintaining a hermetic seal.
Implementation Method 1
heat sealing a foil package over the first conductive tab and the second conductive tab to partially enclose the first electrode and second electrode
Data Source
AI summary
In some examples, an assembly for a medical device. The assembly includes a first electrode comprising a first conductive tab, and a first current collector; a second electrode including a second conductive tab, a second current collector, a third current collector, and at least one connector connecting the second current collector to the third current collector, wherein the second current collector and the third current collector are folded over each other about the at least one connector, wherein the second conductive tab is coupled to the second current collector, and wherein the third current collector is electrically coupled to second conductive tab via the at least one connector and the second current collector; and a foil package being sealed over the first conductive tab and the second conductive tab to partially enclose the first electrode and second electrode.