Secondary battery top cover and secondary battery

Abstract

The invention provides a secondary battery top cover, comprising: a top cover sheet and a first electrode unit, a second electrode unit and a flipping sheet arranged on the top cover sheet, the first electrode unit includes a first pole and a resistor arranged on the first pole, the first pole is electrically connected to the top cover sheet through the resistor, the second electrode unit includes a second pole and a conductive sheet electrically connected to the second pole, the second pole is connected to the second pole The top cover is insulated and assembled, the overturning piece is electrically connected to the top cover, the conductive piece is located above the overturning piece, and the resistor has conductive filler and adhesive. When an accident happens to the battery, the first electrode unit and the second electrode unit are electrically connected to form an external short circuit due to the action of the flipping sheet and the electrical connection of the resistance to the first electrode and the top cover sheet, because the conductive filler and adhesive are used. Resistance, the resistance of the resistance is stable, and the contact resistance is small, which can well control the magnitude of the current, thereby improving the safety performance of the battery.

Description

technical field [0001] The invention relates to the field of energy storage devices, in particular to a secondary battery top cover and the secondary battery. Background technique [0002] In modern society, more and more driving power sources of electric tools and new energy vehicles are developing in the direction of high capacity and high safety. Batteries are widely used in electric tools and new energy vehicles due to their excellent characteristics such as high capacity . In addition to high capacity, these batteries should also have good safety in order to meet the standard bricks used and meet people's needs. [0003] In order to ensure the safety of the secondary battery, some batteries in the prior art are equipped with a flip sheet on the top cover, and the first electrode and the top cover sheet are electrically connected by setting a resistor, so that the battery will not be damaged due to accidents such as overcharging or electrolyte reaction. When the air pr...

AI Technical Summary

Problems solved by technology

When a metal sheet is used, there is a common contact resistance between the metal sheet, the electrode pole, and the top cover sheet, the resistance value is unstable, the change is large, and the resistance value is difficult to control. To reduce the charge accumulated in the battery core so that it cannot play a protective role, or the external current generated may be too large to directly melt the top cover

When conductive plastic is used, the conductive plastic is used as a resistor to electrically connect the first electrode and the top cover. Because the high temperature resistance of the conductive plastic is not good, the conductive plastic will soften or even be melted in a high temperature environment and cannot work normally.

However, conductive ceramics are used to connect the first electrode and the resistance of the top cover sheet. Although this type of material is resistant to high temperature, its resistance changes greatly due to the influence of temperature, and the consistency is poor. Moreover, this type of material has poor toughness and bending resistance, and is easy to break. Unable to resolve security issues

Images