Capacitor Anode Separator Heat Sealing for Volumetric Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current capacitor designs with a sealed sheet of separator enclosing the anode result in a thick separator selvage flap, leading to wasted space and reduced volumetric energy density due to the need for a gap around the anode sidewall, which compromises the compactness and efficiency of cardiac defibrillators and similar implantable devices.
Innovation Solution
A method of sealing the separator material around the anode pellet using overlapping sheets with a seam contiguous to the sidewall, eliminating the need for a thick selvage flap and minimizing wasted space by using pre-cut sheets of polyolefinic or fluoropolymeric fibers, which are interleaved and sealed using heat or ultrasonic welding techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick separator selvage flap is used to seal the anode, then the separator is properly enclosed and sealed, but the capacitor volume increases and volumetric energy density decreases
Solution Approach 1:
The separator sheets are folded back along the sidewalls of the anode pellet, transitioning from a flat sealing configuration to a three-dimensional configuration that utilizes the vertical space along the anode sidewalls. This folding approach allows the separator to be properly enclosed and sealed while minimizing the horizontal gap space, thereby reducing overall capacitor volume while maintaining reliable separator sealing.
2Reliability
If a thick separator selvage flap is used to seal the anode, then the separator is properly enclosed and sealed, but the volumetric energy density decreases due to wasted space
Solution Approach 1:
By folding the separator sheets back along the sidewalls of the anode pellet, the sealing structure transitions to utilize vertical space rather than consuming horizontal space. This dimensional reconfiguration eliminates the need for a thick horizontal selvage flap, maximizing the volume available for active electrode materials and thereby increasing volumetric energy density while maintaining proper separator enclosure and sealing.
3Manufacturing precision
If pre-cut separator sheets are used with overlapping perimeter regions, then the separator can be precisely fitted to the anode, but the sealing process becomes more complex
Solution Approach 1:
The separator is divided into two separate sheets, each covering one major face wall of the anode pellet. This segmentation allows each sheet to be precisely cut and fitted to its respective face, ensuring accurate alignment and coverage. The overlapping perimeter regions at the sidewalls provide a natural sealing interface, simplifying the overall sealing process while maintaining high manufacturing precision.
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 increases the volumetric energy density of capacitors by allowing more active electrode material per unit volume, enhancing the compactness and efficiency of implantable devices without compromising power and energy requirements.
Implementation Method 1
The first and second separator sheets are then sealed to each other at a seam formed at the overlapped perimeter regions
Implementation Method 2
which are interleaved and sealed using heat or ultrasonic welding techniques
Data Source
AI summary
An anode/separator assembly for a capacitor is described. The capacitor includes a pellet of anode active material having opposed first and second major faces extending to a surrounding side wall and a separator enveloping the pellet. The separator is formed of a first sheet of separator material including a first central region contiguous with the first major face wall of the anode pellet and a first perimeter region folded in contact with the surrounding side wall of the anode pellet, and a second sheet of separator material including a second central region contiguous with the second major face wall of the anode pellet and a second perimeter region overlapping a portion of the first perimeter region of the first separator sheet. The first and second sheets of separator material are then sealed to each other at a seam formed at the overlap between them using the anode pellet surrounding sidewall as a backing surface for a heat sealing device.