Secondary battery

Abstract

The invention relates to a secondary battery. The secondary battery comprises an electrode assembly, a top cover piece, a first terminal and a second terminal. The electrode assembly comprises a first pole piece and a second pole piece, the first pole piece is electrically connected with the first terminal, the second pole piece is electrically connected with the second terminal, and at least one of the first terminal and the second terminal is arranged on the top cover piece in an insulating mode. The secondary battery further comprises a conductive piece and a contact piece attached to the first terminal. The conductive piece comprises a first part and a second part which are connected. The first part is electrically connected with the second terminal. When the internal pressure of the secondary battery exceeds a standard pressure, the contact piece acts under the action of air pressure and makes contact with the second part so that an electric connection path passing through the first pole piece, the first terminal, the contact piece, the conductive piece, the second terminal and the second pole piece can be formed, and the second part is arranged to be fixed relative to the top cover piece. The secondary battery reduces the risk of displacement generated by the conductive piece under the action of contact force, and safety of the secondary battery is improved.

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] Electric vehicles and energy storage power stations generally need to use large-capacity secondary batteries as power sources. In addition to high capacity, these secondary batteries should also have good safety in order to meet the use standards and meet people's needs. [0003] 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. [0004] In the related art, there is a solution to the above-mentioned defects. For example, a contact piece an...

AI Technical Summary

Problems solved by technology

[0003] 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] However, when the above solution is adopted, there is a phenomenon that the contact force applied to the conductive sheet during the action of the contact sheet causes the conductive sheet to displace, thus making the electrical contact between the two unreliable, which in turn leads to an overcharged state of the secondary battery still going on

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