Folded Contact Sheet Metal for Low-Resistance Battery Cells
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Solution Overview
Problem
Existing energy storage elements, particularly lithium-ion cells, face challenges in achieving high energy density while minimizing internal resistance and dead volume, especially in cylindrical forms used for high-energy applications like electric vehicles and tools.
Innovation Solution
A contact sheet metal part with specific geometrical features, including bending zones and recesses, is designed to minimize dead volume by allowing compact assembly and efficient electrical contact, reducing internal resistance and enhancing energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a contact plate part is used to electrically contact the electrode-separator assembly, then electrical conductivity is improved, but dead volume increases
Solution Approach 1:
The contact plate part is divided into multiple contacting sections (first contacting section, second contacting section, third contacting section) that can be independently positioned and folded. This segmentation allows the contact plate to make electrical contact at multiple points while reducing the overall volume occupied by the contact structure.
Solution Approach 2:
The contact plate part is inserted into a receiving space formed by the housing and the electrode-separator assembly. The contact plate nests within the existing structure, utilizing the receiving space rather than adding external volume, thereby minimizing dead volume while maintaining electrical conductivity.
2Volume of stationary object
If the contact sheet part is folded into bending zones to reduce volume, then dead volume is reduced, but manufacturing complexity increases
Solution Approach 1:
The bending zones are pre-formed in the contact plate part during manufacturing, creating predetermined fold lines along which the contact plate can be easily folded during assembly. This preliminary preparation reduces the complexity of the folding operation and ensures consistent results.
Solution Approach 2:
The bending zones introduce curved or folded geometries in the contact plate part, allowing it to adapt to the three-dimensional space within the housing. These curved transitions enable the contact plate to reduce its projected volume while maintaining structural integrity and electrical conductivity.
3Volume of stationary object
If the contact plate part is pressed into the receiving space to minimize volume, then dead volume is reduced, but internal resistance may increase
Solution Approach 1:
Different sections of the contact plate part have different properties: the contacting sections are designed to maintain good electrical contact with the electrode-separator assembly, while the bending zones are designed to be flexible and compact. This local differentiation ensures that electrical conductivity is maintained at contact points while allowing volume reduction in non-critical areas.
Solution Approach 2:
The contact plate part is designed to be dynamically adjustable during assembly. It can be folded along the bending zones and pressed into the receiving space, allowing it to adapt its shape and volume. This dynamic capability enables the contact plate to minimize dead volume while maintaining adequate electrical contact through the contacting sections.
Data Source
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AI summary
This document describes a contact plate part (200) for an energy storage element and an energy storage element (100) provided therewith. The contact plate part comprises a first contacting section (201) with a top (201a) and a bottom (201b), which is intended for contacting a first component of an energy storage element, and a second contacting section (202) with a top (202a) and a bottom (202b), which is intended for contacting a second component of an energy storage element.Between the first contact section (201) and the second contact section, the contact sheet part (200) comprises a connecting section (203) with a top (203a) and a bottom (203b), wherein the top (203a) of the connecting section (203) faces the bottom (201b) of the first contact section (201) and the bottom (203b) of the connecting section (203) faces the top (202a) of the second contact section (202). The first contact section (201) and the connecting section (203) are connected to each other via a first bending zone (204) in which the contact sheet part (202) is bent along at least one bend line. The second contact section (202) and the connecting section (203) are connected to each other via a second bending zone (205) in which the contact sheet part (200) is bent along at least one bend line (205a).The second contacting section (202) has a recess (206) or a perforation (207) which forms a receptacle for the first bending zone (204).