Spiral-line multi-pole lug lithium ion battery and method for manufacturing same

Abstract

The invention provides a spiral-line multi-pole lug lithium ion battery and a method for manufacturing the same, and belongs to the field of batteries. The spiral-line multi-pole lug lithium ion battery comprises an anode sheet, a cathode sheet and a membrane arranged between the anode sheet and the cathode sheet, wherein mixed paste made of an active substance is coated on a current collector; a blank position is reserved on a front side of one edge in a length direction of the anode sheet, and a blank position is reserved on a back side of one edge in the length direction of the anode sheet; the rest parts are coated with the paste; the mixed paste made of the active substance is coated on the current collector; a blank position is reserved on the front side of one edge in the length direction of the cathode sheet, and a blank position is reserved on the back side of one edge in the length direction of the cathode sheet; and the rest parts are coated with the paste. The spiral-line multi-pole lug lithium ion battery is characterized in that: pole lugs are arranged at intervals on the reserved blank position of the anode sheet; and the pole lugs are arranged at intervals on the reserved blank position of the cathode sheet. The distance between a pole sheet and an electrode terminal, the internal resistance, and heat generation while discharging are reduced; the safety and the rate of finished products are improved; and the problem that a small battery is not suitable for lamination is solved.

Description

technical field [0001] The invention discloses a helical wire multi-tab lithium ion battery and a manufacturing method thereof, which belong to the field of batteries, and in particular relate to the manufacture of a rechargeable and dischargeable secondary lithium ion battery with high-rate discharge performance. Background technique [0002] Since the advent of lithium-ion batteries, the assembly of batteries has always been the bottleneck of mass production of batteries, and it also plays a key role in the impact on electrical performance. At present, the cell forming of lithium-ion batteries is mainly divided into two types: winding type and laminated type. These two assembly methods have their own advantages and disadvantages in production and battery performance: the advantage of winding type is that the structure is simple 1 piece of positive electrode and 1 piece of negative electrode, the specific energy of the battery is large, the disadvantage is that the pole pie...

AI Technical Summary

Problems solved by technology

At present, the cell forming of lithium-ion batteries is mainly divided into two types: winding type and laminated type. These two assembly methods have their own advantages and disadvantages in production and battery performance: the advantage of winding type is that the structure is simple 1 piece of positive electrode and 1 piece of negative electrode, the specific energy of the battery is large, the disadvantage is that the pole piece is long, the internal resistance of the battery is large, it is not conducive to high current charging and discharging, and the specific power is small; the advantage of the laminated type is that the pole piece is short, the internal resistance of the battery It is relatively small, which is conducive to high-current charging and discharging. The disadvantage is that there are many battery pole pieces and many trimming edges, which is not conducive to the control of pole piece cutting edge burrs, and there are many side materials. The lamination process needs to be stacked one by one. The production efficiency is extremely low, only 1 / 10 of that of the winding battery. In addition, it is difficult to weld the multi-layer pole pieces, especially the multi-layer negative electrode, which uses copper foil, which has good conductivity and is not conducive to resistance welding. Copper foil has a high melting point, which is not conducive to ultrasonic welding. It may be weakly welded, weakly welded, or over-welded. The battery is low in capacity, and what is more serious is that the positive electrode works but the negative electrode does not work, which will cause lithium precipitation during use and cause safety accidents

The existing winding and laminated lithium batteries have their own shortcomings, which are not conducive to fast charging and high current discharging

Even if the positive and negative electrodes are coated evenly, unreasonable electrode structure and cell design will show uneven distribution of current density during high-current charging and discharging, which will affect the safety performance, fast charging performance and high-current charging and discharging of the battery. cycle life

[0003] The existing multi-tab batteries are made by punching the excess foil after winding the pole pieces to obtain multi-tabs protruding from both ends of the battery cell. This method is only suitable for square batteries with tabs at both ends. , it is impossible to realize the production of cylindrical multi-tab lithium-ion batteries and multi-tab lithium-ion batteries with tabs from the same head, and it is difficult to ensure the integrity of the pole pieces by punching multi-layer foils

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