Secondary battery, battery module, battery pack, and secondary battery manufacturing method

Abstract

The invention discloses a secondary battery, a battery module, a battery pack and a manufacturing method of the secondary battery, and belongs to the technical field of power batteries. The secondary battery comprises a shell, a top cover plate, a terminal polar plate and a roll core, the shell is provided with a containing space, the top cover plate covers a top opening of the containing space, a tab through hole communicated with the containing space is formed in the top cover plate, the terminal polar plate is arranged on the side, away from the shell, of the top cover plate and covers the tab through hole, and the roll core is arranged on the side, away from the shell, of the terminal polar plate. The inner wall surface of the tab through hole and the bottom surface of the terminal polar plate form a tab accommodating cavity, the roll core is arranged in the accommodating space, and at least part of the roll core tab of the roll core penetrates through the tab through hole and is welded with the bottom surface of the terminal polar plate. According to the secondary battery, an electric connecting sheet is omitted, and the roll core tab is arranged in the tab accommodating cavity in the bent state, so that the welding frequency is reduced, the safety is improved, the tab filling rate is improved, the overcurrent capability is enhanced, the manufacturing cost is reduced, and the heat dissipation capability is improved.

Description

technical field [0001] The invention relates to the technical field of power batteries, in particular to a secondary battery, a battery module, a battery pack and a manufacturing method for the secondary battery. Background technique [0002] Secondary batteries, also known as rechargeable batteries, refer to batteries that can be activated by charging the active material after the battery is discharged and continue to be used. Common secondary batteries on the market include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc. Batteries and lithium-ion batteries. [0003] The existing secondary battery includes a winding core, an electrical connecting piece and a terminal plate. The winding core tab on the winding core is electrically connected to the terminal plate through the electrical connecting piece, and the winding core tab and the electrical connecting piece are passed through The electrical connection is realized by welding, and the ...

AI Technical Summary

Problems solved by technology

[0003] The existing secondary battery includes a winding core, an electrical connecting piece and a terminal plate. The winding core tab on the winding core is electrically connected to the terminal plate through the electrical connecting piece, and the winding core tab and the electrical connecting piece are passed through The electrical connection is realized by welding, and the electrical connection piece and the terminal plate are also electrically connected by welding. The two times of welding increase the probability of welding slag generation, thereby increasing the risk of welding slag falling into the inside of the cell and causing an internal short circuit

Moreover, the existence of the electrical connection sheet takes up too much vertical space inside the secondary battery, thereby reducing the filling rate of the winding core and limiting the energy of the secondary battery.

In addition, the poor heat dissipation and temperature rise of the electrical connecting sheet limit the design of the fast charging capacity of the battery cell

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