Electrode Assembly Insulating Tape Layout for Battery Gas Venting
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Solution Overview
Problem
Existing insulating tapes in lithium secondary batteries can fuse and block gas discharge paths during thermal events, leading to increased internal pressure and potential explosion.
Innovation Solution
The electrode assembly incorporates insulating tapes with cut-out portions to maintain a gas discharge passage, preventing fusion and allowing smooth gas release, thereby reducing the risk of thermal runaway and explosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating tape is attached to the V-forming portion to prevent contact with the conductive metal layer, then internal short circuit is prevented, but gas discharge path is blocked due to fusion of the insulating tape
Solution Approach 1:
The insulating tape is segmented into multiple sections along its length, creating gaps between adjacent segments. These gaps form channels that allow gas to discharge from the battery cell during thermal events, while the tape segments remain in place to provide continuous electrical insulation between the V-forming portion and the conductive metal layer.
Solution Approach 2:
The insulating tape has non-uniform properties along its length, with segmented sections having different characteristics. The gaps between segments provide localized gas discharge pathways, while the tape segments themselves maintain localized electrical insulation functions. This spatial variation in properties allows simultaneous achievement of both safety functions.
2Reliability
If insulating tape is attached to prevent contact between V-forming portion and conductive metal layer, then electrical insulation is improved, but thermal runaway safety deteriorates due to gas trapping
Solution Approach 1:
The insulating tape is divided into multiple segments along its longitudinal direction, creating intentional gaps. These gaps serve as thermal relief channels that allow pressure equalization and gas escape during thermal runaway events, preventing the tape from fusing into a solid barrier that would trap gases and exacerbate thermal runaway conditions.
Solution Approach 2:
The segmented structure of the insulating tape acts as an intermediary between the requirement for continuous electrical insulation and the need for gas discharge pathways. The tape segments provide insulation while the gaps between them mediate gas flow, allowing both functions to coexist without direct conflict.
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3(a)~3(c)
AI summary
Disclosed are an electrode assembly having an insulating tape attached thereto, the electrode assembly including an electrode stack constituted by a plurality of positive electrodes and a plurality of negative electrodes stacked alternately with a separator disposed therebetween, a positive electrode lead coupled to a positive electrode tab bundle constituted by positive electrode tabs protruding respectively from outer peripheries of the plurality of positive electrodes and overlapping each other, a negative electrode lead coupled to a negative electrode tab bundle constituted by negative electrode tabs protruding respectively from outer peripheries of the plurality of negative electrodes and overlapping each other, a first insulating tape attached to at least a part of an upper surface of the electrode stack, to an upper surface of a positive electrode coupling portion where the positive electrode tab bundle and the positive electrode lead are coupled to each other, and to an upper surface of a negative electrode coupling portion where the negative electrode tab bundle and the negative electrode lead are coupled to each other, and a second insulating tape attached to at least a part of a lower surface of the electrode stack, to a lower surface of the positive electrode coupling portion where the positive electrode tab bundle and the positive electrode lead are coupled to each other, and to a lower surface of the negative electrode coupling portion where the negative electrode tab bundle and the negative electrode lead are coupled to each other, wherein the positive electrode tab bundle and the negative electrode tab bundle are formed at the same outer periphery so as to be spaced apart from each other, and at least one of the first insulating tape and the second insulating tape includes a cut-out portion formed such that at least a part between a positive electrode portion attached to the positive electrode coupling portion and a negative electrode portion attached to the negative electrode coupling portion is removed, and a lithium secondary battery including the same.