Battery Tab Welding Structure for Low-Resistance Thermal Disconnection
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Solution Overview
Problem
Conventional secondary batteries face issues with welding resistance and safety due to the use of electrode leads, which can lead to thermal and electrical conductivity problems, especially in pouch-type batteries that lack thermal stability.
Innovation Solution
A secondary battery design that eliminates the need for electrode leads by welding the electrode tabs in a specific configuration, where the length of the tab welding portion is adjusted to ensure mechanical rigidity and ease of disconnection at high temperatures, forming a disconnection portion to enhance safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrode leads are welded to electrode tabs, then electrical connection is established, but welding resistance increases and thermal stability deteriorates
Solution Approach 1:
The patent removes the electrode lead component entirely from the battery structure. Instead of welding separate leads to tabs, the tabs themselves are extended and configured to serve as the external electrical connection points, eliminating the welding interface and its associated resistance problems
Solution Approach 2:
The patent combines the functions of the electrode tab and electrode lead into a single integrated structure. The tab is extended outward to simultaneously provide internal electrical connection to the electrode plate and external connection capability, merging two previously separate components
2Power
If electrode leads are used, then current path is established, but thermal conductivity and safety worsen
Solution Approach 1:
The harmful electrode lead component is extracted and removed from the system. The remaining tab structure is optimized to provide current path functionality without the thermal instability inherent in welded lead connections
Solution Approach 2:
The patent changes the physical parameters of the tab structure by extending its length and configuring its geometry to optimize both electrical conductivity and thermal stability, replacing the lead-tab welding assembly with a purely tab-based solution
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 design improves safety by reducing welding resistance and allowing for easy disconnection of the electrode tabs at high temperatures, providing thermal stability even in pouch-type batteries, which otherwise lack it.
Implementation Method 1
a tab welding portion in which a plurality of positive electrode tabs and a plurality of negative electrode tabs which are overlapped in a thickness direction of the electrode assembly are welded is provided
Data Source
AI summary
The present disclosure relates to a secondary battery. The secondary battery may include an electrode assembly including a plurality of positive electrode plates with each plate having a positive electrode tab, a plurality of negative electrode plates with each plate having a negative electrode tab, and a plurality of separators with each separator interposed between a positive electrode plate and a negative electrode plate, a case accommodating the electrode assembly, and a tab welding portion comprising welded overlapping positive electrode tabs and welded overlapping negative electrode tabs. A length of the tab welding portion in an extension direction of the positive electrode tab or the negative electrode tab may be constant or different across a thickness direction of the positive electrode tab or the negative electrode tab.