Cylindrical Battery Cell Tab Isolation to Prevent Shell Shorting
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Solution Overview
Problem
The issue of short circuits in battery cells, particularly due to the deformation of electrode assembly tabs that accumulate elastic restoring force and overlap with the shell, leading to potential contact and circuit failure.
Innovation Solution
The design of a cylindrical battery cell with a tab structure where the first portion extends beyond the separator and is isolated by a second portion, surrounded by a separator to prevent contact with the shell, and further protected by insulating members to block conductive impurities and deformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tab is designed to extend toward the opening for electrical connection, then the electrical connectivity is improved, but the tab may deform and contact the shell causing short circuit
Solution Approach 1:
The patent introduces an insulating member as an intermediary element positioned between the tab and the shell. This insulating member prevents direct contact between the conductive tab and the shell, thereby eliminating the short circuit risk while maintaining the tab's electrical connectivity function. The insulating member acts as a mediator that allows the tab to extend toward the opening without creating harmful contact with the shell.
Solution Approach 2:
The patent applies preliminary anti-action by pre-positioning the insulating member to counteract the potential deformation of the tab before it can cause a short circuit. The insulating member is installed in advance to block the path between the tab and the shell, preventing the harmful effect from occurring even if the tab deforms during operation.
2Reliability
If the separator wraps the second portion to isolate it from the shell, then the short circuit prevention is improved, but the structural complexity increases
Solution Approach 1:
The separator in the patent serves multiple functions: it isolates the first and second portions of the tab from each other, wraps around the second portion to prevent contact with the shell, and maintains the structural integrity of the electrode assembly. By making the separator multi-functional, the patent achieves improved short circuit prevention without adding separate components, thus avoiding increased structural complexity.
3Reliability
If the first portion extends beyond the separator for electrical contact, then the electrical connectivity is improved, but the exposure to conductive impurities increases
Solution Approach 1:
The insulating member acts as an intermediary barrier that protects the first portion of the tab from conductive impurities while allowing electrical connectivity to be maintained. The insulating member is positioned to block external conductive impurities from reaching the tab, thereby reducing the harmful effects of impurity exposure without compromising the electrical function.
Data Source
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AI summary
Embodiments of the present application relate to a cylindrical battery cell, a battery, an electric device, a manufacturing method, and a manufacturing system. The cylindrical battery cell comprises: a housing having openings; and electrode assemblies provided in the housing. Each electrode assembly comprises a diaphragm and a tab; in the axial direction of the electrode assembly, the tab is located at one end of the electrode assembly and extends towards the opening; the tab comprises a first portion and a second portion; the second portion surrounds the periphery of the first portion; the diaphragm wraps the second portion to isolate the second portion from the housing, wherein in the axial direction, the first portion exceeds the second portion and the diaphragm, and the second portion does not exceed the diaphragm. The battery cell of the present application aims at solving the technical problem of short circuit of the battery cell.