Square power lithium ion battery cell and manufacturing method thereof

Abstract

The invention discloses a square power lithium ion battery cell and a manufacturing method thereof, belonging to the field of lithium ion battery manufacturing. The square power lithium ion battery cell comprises a positive plate, a diaphragm, a negative plate, a positive lug and a negative lug; the square power lithium ion battery cell is formed by winding the positive plate, the diaphragm and the negative plate around a coiling needle; the upper side and the lower side of the coiling needle after coiled are both provided with the negative lug and the positive lug; the positive lug is positioned on one end of the battery cell body; the negative lug is positioned on the other end of the battery cell body; the positive lug and the negative lug are positioned on the same side of the battery cell body; and the negative lug and the positive lug are reserved by laser cutting. The method comprises: reserving a non-coated area for a pole piece coating coat; cutting the reserved lug by laser cutting according to the preset lug interval; and successively stacking and coiling the positive plate, the diaphragm and the negative plate into the battery cell. The square power lithium ion battery cell of the invention has tidy lug arrangement and can realize the large current discharging performance of the battery.

Description

technical field [0001] The invention relates to a power lithium ion battery, in particular to a square power lithium ion battery cell and a manufacturing method thereof. Background technique [0002] In today's rapidly developing society, traditional energy sources such as oil, coal, and natural gas are decreasing as people increasingly exploit them. Clean and efficient energy conversion and energy storage systems such as lithium-ion batteries and fuel cells have become the key to solving the environmental and energy problems faced by modern civilization. Useful ways. Among them, power lithium-ion batteries have been widely used in the fields of electric bicycles, electric and fuel motorcycles, electric and fuel vehicles, and other electric tools. [0003] In the prior art, power lithium-ion battery cells often adopt a multi-tab winding structure. There are mainly two tab manufacturing methods for cells with a multi-tab winding structure: one is to weld the positive and neg...

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Problems solved by technology

[0004] In the process of realizing the present invention, the inventors found that the prior art has at least the following problems: When producing large-capacity power battery cells, if the first method is used to make tabs, after the pole pieces are wound to form cells, It can only ensure that multiple tabs are distributed in a fan-shaped area. During production, it is easy to cause positive and negative tabs to overlap together, which will bring inconvenience to the connection operation between tabs and between tabs and polar terminals, and even easily lead to positive and negative tabs. Negative tabs are in contact with each other to produce a short circuit; if the second method is used to make the tabs, according to the tab spacing T of the pole piece A+1 =T A + (difference in the winding circumference of the upper and lower layers) to die-cut or cut to reserve a plurality of tabs, after winding into a cell, only one set of positive and negative tabs can be set in one cycle of winding, which affects the large capacity High current discharge performance of power battery

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