Secondary Battery Cap Plate Structure for Low-Resistance Embedded Terminals
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Solution Overview
Problem
Existing secondary battery designs face challenges in optimizing the structure of the cap assembly, leading to increased resistance and reduced capacity due to protruding terminals that occupy valuable space within the battery case.
Innovation Solution
The cap assembly incorporates an insulating member and a conductive member to space the terminals from the cap plate, embedding them within the cap plate structure, thereby reducing the current path resistance and increasing the available space for electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If terminals are allowed to protrude from the cap plate, then ease of connection is improved, but the available space for electrodes is reduced
Solution Approach 1:
The terminal is nested within the cap plate structure by forming a recess in the cap plate that receives the terminal. The terminal is positioned within this recess so that it does not protrude from the outer surface of the cap plate, thereby saving space while maintaining connection functionality through the recess opening.
Solution Approach 2:
Instead of allowing terminal protrusion in the vertical dimension (outside the cap plate), the invention moves the terminal into the horizontal dimension by creating a recess within the cap plate thickness. This dimensional reorganization allows the terminal to be accessible for connection while occupying space within the cap plate rather than extending beyond it.
2Volume of moving object
If terminals are embedded within the cap plate, then electrode space is increased, but resistance increases due to longer current path
Solution Approach 1:
The cap plate is segmented into different functional zones: a recess region that receives the terminal and allows direct electrical connection, and a sealing region that provides isolation. The recess creates a localized pathway for current that minimizes resistance while the rest of the cap plate maintains its sealing function.
Solution Approach 2:
The recess in the cap plate acts as an intermediary structure that facilitates direct electrical contact between the terminal and the external connection point. This intermediary feature allows current to flow through a shortened path by providing a direct pathway through the recess rather than requiring current to travel through longer external connections.
3Reliability
If insulating members are added to space terminals from cap plate, then electrical insulation is improved, but device complexity increases
Solution Approach 1:
The insulating function is merged with the structural cap plate by forming an integrated recess structure. The cap plate itself provides both the structural support and the insulating barrier, while the recess provides the terminal accommodation. This merging eliminates the need for separate insulating components while maintaining electrical insulation and structural integrity.
Solution Approach 2:
The cap plate is designed to perform multiple functions simultaneously: it provides structural support, electrical insulation, sealing, and terminal accommodation through the recess. By making the cap plate multi-functional, the invention eliminates the need for separate dedicated insulating members, thereby reducing overall device complexity while maintaining all necessary functions.
Data Source
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AI summary
A cap assembly including: a cap plate coupled to a case having an open top portion, the cap plate having a first terminal through-hole and a second terminal through-hole; a first terminal and a second terminal located in the first terminal through-hole and the second terminal through-hole, respectively, and electrically connected to an electrode assembly accommodated in the case; and at least one insulating member electrically insulating the cap plate from at least one of the first terminal or the second terminal.