secondary battery

Abstract

This application relates to secondary batteries. The secondary battery includes: an electrode assembly, a first terminal and a second terminal, a top cover sheet and a casing, the electrode assembly includes a first pole piece and a second pole piece, the first pole piece is electrically connected to the first terminal, and the second pole piece The sheet is electrically connected to the second terminal, and the secondary battery further includes: a sealing member, a contact sheet attached to the first terminal, and a conductive sheet electrically connected to the second terminal, and the top cover sheet is connected to the first terminal and the second terminal. At least one of them is insulated. When the internal pressure of the secondary battery exceeds the reference pressure, the contact sheet moves under the action of air pressure and contacts the conductive sheet, and the top cover sheet is closed with the casing to form the first chamber and the second chamber. The sealing member is sealed between the first chamber and the second chamber. The sealing member has a first sealing surface in sealing contact with the top cover sheet and a second sealing surface in sealing contact with the first terminal or the contact sheet. The first sealing surface It is arranged opposite to the second sealing surface along the extension direction of the top cover sheet.

Description

technical field [0001] The present application relates to the technical field of energy storage devices, in particular to a secondary battery. Background technique [0002] The secondary battery can be repeatedly charged and discharged. When the secondary battery is in an overcharged state, excessive heat will be generated inside and the electrolyte will decompose. This heat generation and decomposition of the electrolyte will increase the pressure inside the secondary battery. Large, may cause the secondary battery to catch fire and explode, reducing the safety of the secondary battery. [0003] In order to overcome the above defects, a contact sheet and a conductive sheet are usually provided in the secondary battery, and the air pressure inside the secondary battery is used to make the contact sheet move and make electrical contact with the conductive sheet, thereby short-circuiting the positive electrode sheet and the negative electrode sheet of the secondary battery. T...

AI Technical Summary

Problems solved by technology

[0002] The secondary battery can be repeatedly charged and discharged. When the secondary battery is in an overcharged state, excessive heat will be generated inside and the electrolyte will decompose. This heat generation and decomposition of the electrolyte will increase the pressure inside the secondary battery. Large, it may cause the secondary battery to catch fire and explode, reducing the safety of the secondary battery

[0005] Moreover, in order to ensure the sensitivity of the action of the contact piece, a sealing member needs to be provided so that a pressure difference is formed on both sides of the contact piece. When the sealing contact force applied by the sealing member to the extension portion acts along the height direction of the secondary battery, the extension portion is easy to Under this force, the deformation displacement towards the bottom of the secondary battery occurs, which makes the sealing effect poor, resulting in a decrease in the action sensitivity of the contact piece, and the contact piece cannot operate under the rated pressure, which reduces the safety of the secondary battery

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