CN111710898A - Lithium battery cell, preparation method of lithium battery cell and lithium battery - Google Patents

Abstract

The present application provides a lithium battery cell, a method for preparing a lithium battery cell, and a lithium battery, wherein the lithium battery cell includes a positive electrode sheet and a negative electrode sheet that are isolated from each other and have a preset pattern, and the lithium battery cell consists of the positive electrode sheet It is formed by winding a negative electrode sheet, wherein the first preset area of the positive electrode sheet is provided with a plurality of positive electrode tabs, and the second predetermined area of the negative electrode sheet is provided with a plurality of negative electrode tabs; the wound positive electrode tabs are stacked to form At least one positive terminal of the lithium battery cell, and a plurality of negative terminals are stacked to form at least one negative terminal of the lithium battery cell, and the stacked positive terminals are arranged in parallel, and the stacked negative terminals are arranged in parallel. The dislocation arrangement reduces the internal resistance value of the lithium battery cell, enhances the overcurrent capability of the lithium battery cell, and then can receive the large current (charging current) output by the external charging device, so as to realize the fast charging of the lithium battery cell. Charge.

Description

Lithium battery cell, preparation method of lithium battery cell and lithium battery

technical field

The present application relates to the technical field of batteries, and in particular, to a lithium battery cell, a method for preparing a lithium battery cell, and a lithium battery.

Background technique

With the development of science and technology, the types of batteries are becoming more and more abundant. In order to meet the needs of people's daily production and use, the requirements for battery life are also getting higher and higher. At present, in the mainstream graphite system lithium-ion batteries used in mobile terminals such as mobile phones, the energy density of the battery is generally 500-700Wh/L, and the charging rate is about 0.5-3C, but this gradually cannot meet the user's needs for the battery life of the entire mobile phone. Placing the largest battery in a limited space is also one of the ways for mobile terminals to achieve large capacity. Therefore, the popular application of special-shaped batteries has attracted more and more attention in the lithium battery industry.

The general lamination process can produce special-shaped batteries, such as punching to form a plurality of positive plates of the same shape and a plurality of negative plates of the same shape. Although the lamination method can meet the requirements of the special-shaped battery, it also has many disadvantages: the production of side material is low, the performance is low, the production efficiency is low, and the internal resistance of the generated special-shaped battery is large.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a lithium battery cell, a method for preparing a lithium battery cell, and a lithium battery, which can reduce the internal resistance of the lithium battery cell and enhance the overcurrent capability of the lithium battery cell.

A lithium battery cell includes a positive electrode sheet and a negative electrode sheet that are isolated from each other and are in a preset pattern, and the lithium battery cell is formed by winding the positive electrode sheet and the negative electrode sheet, wherein the first electrode of the positive electrode sheet is formed. A preset area is provided with a plurality of positive electrodes, and a second preset area of the negative electrode sheet is provided with a plurality of negative electrodes;

A plurality of coiled positive tabs are stacked to form at least one positive terminal of the lithium battery cell, a plurality of negative tabs are stacked to form at least one negative terminal of the lithium battery cell, and the stacked positive tabs are arranged in parallel, A plurality of stacked negative electrode tabs are arranged in parallel, wherein the positive electrode tab and the negative electrode tab are staggered.

A lithium battery includes the above-mentioned lithium battery cells.

The above-mentioned lithium battery cells can be formed by winding a positive electrode sheet and a negative electrode sheet with a preset pattern, so that the shapes of the lithium battery cells are diversified, the energy density of the lithium battery cells is improved, and the preparation efficiency is high. Because the stacked multiple positive tabs after winding constitute at least one positive terminal of the lithium battery cell, and the multiple stacked negative tabs constitute at least one negative terminal of the lithium battery cell, and the stacked multiple positive tabs are arranged in parallel, the stacked Multiple negative electrodes are arranged in parallel, which reduces the internal resistance value of the lithium battery cell, enhances the overcurrent capability of the lithium battery cell, and then can receive the large current (charging current) output by the external charging device, so as to realize the charging current of the lithium battery. Fast charging of the core.

A manufacturing method of a lithium battery cell, comprising:

Preparation of positive and negative electrode sheets isolated from each other;

cutting the positive electrode sheet and the negative electrode sheet isolated from each other according to a preset pattern;

A plurality of positive electrode tabs are welded in the first preset area of the positive electrode sheet, and a plurality of negative electrode tabs are welded in the second preset area of the negative electrode sheet, and the positive electrode tabs and the negative electrode tabs are staggered;

The positive electrode sheet and the negative electrode sheet, which are isolated and stacked from each other, are wound according to the preset pattern, and a plurality of stacked positive tabs after winding constitute at least one positive terminal of the lithium battery cell, and a plurality of stacked negative tabs At least one negative terminal of the lithium battery cell is formed, a plurality of stacked positive tabs are arranged in parallel, and a plurality of stacked negative tabs are arranged in parallel.

A lithium battery is prepared according to the above-mentioned manufacturing method of a lithium battery cell.

The manufacturing method of the above-mentioned lithium battery cell can first stack the positive electrode sheet and the negative electrode sheet, and then cut the positive electrode sheet and the negative electrode sheet that are isolated and stacked from each other according to a preset pattern, which can improve the cutting efficiency, and can also reduce the positive electrode sheet. , The probability of burr generation during the cutting process of the negative electrode sheet, thereby reducing the risk of short circuit inside the cell. Compared with the laminated battery, the lithium battery cell prepared by winding has a higher energy density than that of the laminated battery. At the same time, the morphology of the lithium battery cells prepared by the preparation method is diversified, and the energy density of the lithium battery cells is improved. Because the stacked multiple positive tabs after winding constitute at least one positive terminal of the lithium battery cell, and the multiple stacked negative tabs constitute at least one negative terminal of the lithium battery cell, and the stacked multiple positive tabs are arranged in parallel, the stacked Multiple negative electrodes are arranged in parallel, which reduces the internal resistance value of the lithium battery cell, enhances the overcurrent capability of the lithium battery cell, and then can receive the large current (charging current) output by the external charging device, so as to realize the charging current of the lithium battery. Fast charging of the core.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic diagram of stacking a positive electrode sheet and a negative electrode sheet according to an embodiment;

FIG. 2 is a schematic diagram of an exploded structure of a lithium battery cell before winding according to an embodiment;

FIG. 3 is one of the schematic diagrams of the lithium battery cell in FIG. 2 after winding;

FIG. 4 is a schematic diagram of stacking of cell units according to an embodiment;

FIG. 5 is a schematic view of stacking a plurality of cell units according to an embodiment;

FIG. 6 is the second schematic diagram of the lithium battery cell in FIG. 2 after winding;

FIG. 7 is the third schematic diagram of the lithium battery cell in FIG. 2 after winding;

8 is a schematic exploded schematic diagram of the structure of a lithium battery cell before winding according to another embodiment;

Fig. 9 is the structural schematic diagram after the winding of the lithium battery cell in Fig. 8;

FIG. 10 is a schematic exploded view of the structure of a lithium battery cell before winding according to another embodiment;

FIG. 11 is a schematic structural diagram of the lithium battery cell in FIG. 10 after winding;

12 is a flowchart of a method for manufacturing a lithium battery cell in one embodiment;

FIG. 13 is a flowchart of cutting a positive electrode sheet and a negative electrode sheet isolated from each other according to a preset pattern according to an embodiment.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, the first preset area may be referred to as the second preset area, and similarly, the second preset area may be referred to as the first preset area, without departing from the scope of the present application. Both the first preset area and the second preset area are preset areas, but they are not the same preset area.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless expressly and specifically defined otherwise. In the description of this application, "several" means at least one, such as one, two, etc., unless expressly and specifically defined otherwise.

Embodiments of the present application provide a lithium battery cell. In one embodiment, as shown in FIG. 1 , a lithium battery cell includes a positive electrode sheet 110 and a negative electrode sheet 120 that are isolated from each other and are stacked in a preset pattern, and the lithium battery cell is wound by the positive electrode sheet 110 and the negative electrode sheet 120 made.

The positive electrode sheet 110 is formed by uniformly stirring the positive electrode active material, the conductive agent, the binder and the solvent, and then coating the positive electrode metal layer (eg, aluminum foil) on the positive electrode metal layer (eg, aluminum foil). The positive active material may include one of lithium cobalt oxide, lithium nickel cobalt manganate, lithium iron phosphate, and lithium nickel cobalt aluminate. The negative electrode sheet 120 is formed by stirring the negative electrode active material, the conductive agent, the binder and the solvent (deionized water) evenly, then coating the negative electrode metal layer (for example, copper foil), drying and rolling by the roller press. Negative electrode sheet 120 . The negative active material may include one of artificial graphite, natural graphite, mesocarbon microspheres, hard carbon, graphene, and lithium titanate.

It should be noted that, in the embodiments of the present application, the composition and formation process of the positive electrode sheet 110 and the negative electrode sheet 120 are not further limited.

In one embodiment, the positive electrode sheet 110 and the negative electrode sheet 120 are isolated and stacked from each other, and the isolated and stacked positive electrode sheet 110 and the negative electrode sheet 120 can be cut into a positive electrode sheet 110 and a negative electrode with a preset pattern at the same time through a cutting process. Sheet 120, as shown in FIG. 2 . The shapes of the cut positive electrode sheet 110 and the negative electrode sheet 120 are the same, that is, the cut positive electrode sheet 110 and the negative electrode sheet 120 both have preset patterns. The preset graphics may be used to indicate the winding operation of the positive electrode sheet 110 and the negative electrode sheet 120 . That is, the lithium battery cell can be wound based on the positive electrode sheet 110 and the negative electrode sheet 120 having a preset pattern, and the wound lithium battery cell can be understood as a special-shaped lithium battery cell.

It should be noted that the shape of the special-shaped lithium battery cells can be irregular polygons, such as "L" shape and so on.

A plurality of positive electrode tabs 131 are provided in the first predetermined area of the positive electrode sheet 110 having a predetermined pattern after cutting. Specifically, an ultrasonic powder cleaner can be used to clean out the first preset area on the positive electrode sheet 110 with a preset pattern near the edge, and an ultrasonic spot welder can be used to weld the plurality of positive electrode tabs 131 to the first pre-set area of the positive electrode sheet 110 . on each preset position of the setting area. Wherein, the plurality of positive electrode tabs 131 welded to the first predetermined area are disposed protruding from the edge of the positive electrode sheet 110 .

A plurality of negative electrode tabs 141 are disposed in the second predetermined area of the negative electrode sheet 120 having the predetermined pattern after cutting. Correspondingly, an ultrasonic cleaner can be used to clean out a second preset area on the negative electrode sheet 120 with a preset pattern near the edge, and an ultrasonic spot welder can be used to weld the plurality of negative electrode tabs 141 on the second pre-set area of the negative electrode sheet 120 . on each preset position of the set area. Wherein, the plurality of negative electrode tabs 141 welded in the second preset area are disposed protruding from the edge of the negative electrode sheet 120 .

Wherein, the areas of the multiple positive tabs 131 in the first preset area and the multiple negative tabs 141 in the second preset area projected on the same horizontal plane do not overlap and are staggered. That is, the plurality of positive electrode tabs 131 provided on the positive electrode sheet 110 and the plurality of negative electrode tabs 141 provided on the negative electrode sheet 120 do not overlap and are arranged in a staggered manner. The horizontal plane can be understood as a plane disposed parallel to the positive electrode sheet 110 and the negative electrode sheet 120 .

The positive electrode sheet 110 provided with a plurality of positive electrode tabs 131 and the negative electrode sheet 120 provided with a plurality of negative electrode tabs 141 are wound to form a lithium battery cell. As shown in FIG. 3 , the wound positive electrode tabs 131 are stacked to form a lithium At least one positive terminal 130 of the battery cell and a plurality of negative tabs 141 are stacked to form at least one negative terminal 140 of the lithium battery cell, and the stacked positive tabs 131 are arranged in parallel, and the stacked negative tabs 141 are arranged in parallel. The positive terminal 130 of the lithium battery cell can be understood as a connection terminal for connecting with the positive terminal of an external power supply device or discharge device, and the positive terminal 130 of the lithium battery cell can be understood as a connection terminal used for connecting with the negative electrode of an external power supply device or discharge device connection terminal.

It should be noted that the settings of the first preset area and the second preset area can be set according to the required final positions of the positive terminal 130 and the negative terminal 140 of the lithium battery cells, and the special-shaped shape of the lithium battery cells. Certainly.

The above-mentioned lithium battery cell includes a positive electrode sheet 110 and a negative electrode sheet 120 that have a preset pattern and are arranged in isolation from each other. The first predetermined area of the positive electrode sheet 110 is provided with a plurality of positive electrode tabs 131, and the second predetermined area of the negative electrode sheet 120 is provided. A plurality of negative tabs 141 are arranged on the top. By winding the positive electrode sheet 110 and the negative electrode sheet 120, a special-shaped lithium battery cell can be formed, so that the shape of the lithium battery cell is diversified, the energy density of the lithium battery cell is improved, and the preparation efficiency is high. Since the wound positive tabs 131 are stacked to form at least one positive terminal 130 of the lithium battery cell, the plurality of negative tabs 141 are stacked to form at least one negative terminal 140 of the lithium battery cell, and the stacked positive tabs 131 Parallel arrangement, the stacked multiple negative electrodes 141 are arranged in parallel, which reduces the internal resistance value of the lithium battery cell, enhances the overcurrent capability of the lithium battery cell, and can receive the large current (charging current) output by the external charging device, In order to achieve fast charging of lithium battery cells.

As shown in FIG. 4 , in one embodiment, the lithium battery cell further includes a separator 150 disposed between the positive electrode sheet 110 and the negative electrode sheet 120 . The separator 150 may include an insulating material layer, and an electrolyte layer respectively disposed on both sides of the insulating material layer. The insulating material of the insulating material layer may include at least one of self-terminated polymer oligomers, polyimide films, high polymer films and polyethylene films. The positive electrode sheet 110 , the separator 150 and the negative electrode sheet 120 constitute the battery cell unit 10 . Wherein, the shape of each cell unit 10 is the same, and the shape of the cell unit 10 is the same as the pre-cut pattern of the positive electrode sheet 110 and the negative electrode sheet 120 .

As shown in FIG. 5 , in one embodiment, the number of the cell units 10 is multiple, and the multiple cell units 10 are stacked. Wherein, a diaphragm 150 is disposed between two adjacent cell units 10 .

The positive electrode tabs 131 and the negative electrode tabs 141 provided on each cell unit 10 do not overlap with each other, and are arranged in a staggered position. The positions of the positive electrode tabs 131 and the negative electrode tabs 141 provided on each layer of cell units 10 correspond to each other, that is, the plurality of positive electrode tabs 131 are located on the same axis in the stacking direction of the plurality of cell units 10, and the plurality of negative electrode tabs 141 The stacking direction of the plurality of cell units 10 is also located on the same axis. By arranging multiple cell units 10, the battery life of the lithium battery is improved.

It should be noted that the number of the battery cells 10 can be set according to the required thickness of the lithium battery cells. Here, the number of the cell units 10 is not further limited.

Referring to FIG. 2 , in one embodiment, the battery cell 10 includes a winding portion 111 and a special-shaped portion 113 , and the positive electrode sheet 110 of the winding portion 111 is wound to form a lithium battery cell in the special-shaped portion 113 , wherein , the shape of the special-shaped portion 113 is the same as the shape of the lithium battery cell formed after winding. Exemplarily, the special-shaped portion 113 may be a regular polygon, an irregular polygon, etc., for example, a trapezoid, a rectangle, and an “L” shape (as shown in FIG. 2 ).

In one embodiment, the winding portion 111 is provided with a slit 112 , and the extending direction of the slit 112 is the same as the winding direction of the winding portion 111 , wherein the winding direction is shown in the direction of the solid arrow in the figure. When the number of slits 112 is one, the slit 112 can split the winding part 111 into a first winding part 111 and a second winding part 111 , wherein the end of the first winding part 111 is connected with the special-shaped part 113 The end of the second winding part 111 is connected to the special-shaped part 113 . It should be noted that, the end of the first winding portion 111 and the end of the second winding portion 111 may be understood as winding ends.

Specifically, the width of the slit 112 is 0.1˜0.1 mm.

In one of the embodiments, the opening position of the slit 112 is associated with the shape of the special-shaped portion 113 . Exemplarily, when the shape of the special-shaped part 113 is an "L" shape, the boundary line between the special-shaped part 113 and the winding part 111 includes a first boundary line L1 and a second boundary line L2. The slit 112 may be opened at the connection between the first dividing line L1 and the second dividing line L2, and the extending direction of the slit 112 is perpendicular to the first dividing line L1.

Exemplarily, when the number of boundary lines between the special-shaped portion 113 and the winding portion 111 is three, the number of the slits 112 can be set to two correspondingly. It should be noted that, in the embodiment of the present application, the number of the slits 112 and the opening positions of the slits 112 are not further limited.

In the embodiment of the present application, by opening a slit 112 in the winding portion 111 , the winding effect can be improved, thereby improving the yield of lithium battery cells.

In one embodiment, the cell unit 10 includes a first side 115 and a second side 116 that are opposite to each other, and both the first predetermined area and the second predetermined area are arranged on the first side 115 . The first side 115 and the second side 116 of the cell unit 10 can also be understood as the first side 115 and the second side 116 of the positive electrode sheet 110 , and can also be understood as the first side side of the positive electrode sheet 120 115 and the second side 116.

In one embodiment, a plurality of wound positive tabs 131 are stacked to form a positive terminal of a lithium battery cell, and a plurality of negative tabs 141 are stacked to form a negative terminal of a lithium battery cell. Exemplarily, five positive electrode tabs 131 may be provided in the first preset area of the first side 115 of the positive electrode sheet 110 , and correspondingly, five negative electrodes may be provided in the second preset area of the first side 115 of the negative electrode sheet 120 . The lugs 141, wherein the positions of the five positive lugs 131 and the five negative lugs 141 before winding do not coincide with each other, and are arranged in a staggered manner. Referring to FIG. 3 , the stacked five positive tabs 131 after winding form one positive terminal 130 of the lithium battery cell, and the five negative tabs 141 are stacked to form one negative terminal 140 of the lithium battery cell. That is, the positive terminal 130 and the negative terminal 140 of the lithium battery cell formed after winding are both located on the same side of the lithium battery cell.

In one of the embodiments, as shown in FIG. 6 and FIG. 7 , a plurality of coiled positive tabs 131 are stacked to form the first positive terminal 130a of a lithium battery cell, and a plurality of coiled positive tabs 131 are stacked. The second positive terminal 130b of the lithium battery cell is formed; some of the wound negative tabs 141 are stacked to form the first negative terminal 140a of the lithium battery cell, and some of the wound negative tabs 141 are stacked to form the lithium battery cell. The second negative terminal 140b of the core.

Exemplarily, six positive tabs 131 may be provided in the first preset area of the first side 115 of the positive electrode sheet 110 , and correspondingly, six negative electrodes may be provided in the second preset area of the first side 115 of the negative electrode sheet 120 . The lugs 141, wherein the six positive lugs 131 and the six negative lugs 141 are not coincident with each other before being wound, and are arranged in a staggered manner. After winding, three positive tabs 131 are stacked to form the first positive terminal 130a of the lithium battery cell, and the other three positive tabs 131 are stacked to form the second positive terminal 130b of the lithium battery cell; three negative tabs 141 are stacked to form The first negative terminal 140a of the lithium battery cell and the other three negative electrodes 141 are stacked to form the second negative terminal 140b of the lithium battery cell. That is, the first positive terminal 130a, the second positive terminal 130b, the first negative terminal 140a and the second negative terminal 140b of the lithium battery cell formed after winding are all located on the same side of the lithium battery cell.

In one embodiment, the first preset area on the positive electrode sheet 110 for arranging the positive electrode tabs 131 and the second preset area on the negative electrode sheet 120 for arranging the negative electrode tabs 141 may also be both set on the cell unit 10 . on the second side 116 . The specific setting method is the same as the setting method on the first side 115 , and details are not repeated here.

As shown in FIG. 8 , in one embodiment, the cell unit 10 includes a first side 115 and a second side 116 arranged opposite to each other, and both the first predetermined area and the second predetermined area are arranged on the first side. on the side edge 115 and the second side edge 116 . That is, the plurality of positive electrode tabs 131 provided on the positive electrode sheet 110 may be correspondingly provided on the first side 115 and the second side 116, and the plurality of negative electrode tabs 141 provided on the negative electrode sheet 120 may also be correspondingly provided on the first side 115 and the second side 116. on one side 115 and the second side 116 . Based on this, as shown in FIG. 9 , after winding, the plurality of positive electrode tabs 131 on the first side 115 are stacked to form the first positive terminal 130 a of the lithium battery cell, and the plurality of negative electrodes on the first side 115 are stacked. The ears 141 are stacked to form the first negative terminal 140a of the lithium battery cell; correspondingly, the plurality of positive terminals 131 located on the second side 116 are stacked to form the second positive terminal 130b of the lithium battery cell, located on the second side 116 A plurality of negative electrode tabs 141 are stacked to form the second negative terminal 140b of the lithium battery cell. That is, the first positive terminal 130a and the first negative terminal 140a formed after winding are located on one side of the lithium battery cell, and the second positive terminal 130b and the second negative terminal 140b formed after winding are located on the side of the lithium battery cell. The other side.

As shown in FIG. 10 , in one embodiment, the plurality of positive electrode tabs 131 provided on the positive electrode sheet 110 can be correspondingly provided on the second side 116 , and the plurality of negative electrode tabs 141 provided on the negative electrode sheet 120 are correspondingly provided on the first side 115 . Based on this, after winding, a plurality of positive tabs 131 on the second side 116 are stacked to form a positive terminal 130 of a lithium battery cell, and a plurality of negative tabs 141 on the first side 115 are stacked to form a lithium battery cell One negative terminal 140 of the core. That is, the number of the positive terminal 130 and the negative terminal 140 formed after winding is only one, and they are respectively located on different sides of the lithium battery cell.

In one embodiment, the plurality of positive tabs 131 disposed on the positive electrode sheet 110 may be correspondingly disposed on the second side 116 , and the plurality of negative tabs 141 disposed on the negative electrode sheet 120 may be correspondingly disposed on the first side 115 superior. Based on this, as shown in FIG. 11 , after winding, some positive tabs 131 on the second side 116 are stacked to form the first positive terminal 130 a of the lithium battery cell, and some positive tabs 131 on the second side 116 are stacked. Stacked to form the second positive terminal 130b of the lithium battery cell; part of the negative electrode tabs 141 located on the first side 115 stacked to form the first negative terminal 140a of the lithium battery cell, and part of the negative tab 141 located on the first side 115 The stack constitutes the second negative terminal 140b of the lithium battery cell. That is, the number of positive and negative terminals formed after winding is two, and the first positive terminal 130a and the second positive terminal 130b are located on one side of the lithium battery cell, and the first negative terminal 140a and the second negative terminal The extreme 140b is located on the other side of the lithium battery cell.

In the embodiment of the present application, the preset shape of the cell unit 10 , and the first preset area for welding the positive electrode tab 131 and the first preset area for welding the negative electrode tab 141 can be set according to the required forming shape of the lithium battery cell. the second preset area.

It should be noted that, the extending direction of the first side edge 115 and the second side edge 116 disposed opposite to each other is the same as the winding direction of the lithium battery cell during forming.

The lithium battery cell with two positive terminals 130 and two negative terminals 140 provided in the embodiment of the present application has stronger discharge capacity, and provides more charging and discharging connection terminals for external discharge equipment and charging equipment.

In one of the embodiments, the present application further provides a lithium battery, and the lithium battery may include the lithium battery cells in any of the above embodiments. Further, the lithium battery may further include a casing for accommodating the cells of the lithium battery, and a connection plate disposed on the casing. Wherein, the connecting plate is correspondingly provided with a positive connecting terminal and a negative connecting terminal. The positive connection terminal is correspondingly connected to the positive terminal of the lithium battery cell, and the negative connection terminal is correspondingly connected to the negative terminal of the lithium battery cell.

Wherein, the shape of the casing can be similar to the shape of the lithium battery cell, and is used to encapsulate and protect the lithium battery cell.

In one of the embodiments, the number of connection plates can be set according to the positions of the positive terminal and the negative terminal of the lithium battery cells. If the positive terminal and the negative terminal of the lithium battery cell are located on the same side of the lithium battery cell, the number of connecting plates can be one, and the number of positive connecting terminals and negative connecting terminals on the connecting plate can be the same as the number of the lithium battery cells. The positive and negative extremes are set in one-to-one correspondence. If the positive and negative terminals of the lithium battery cells are located on different sides of the lithium battery cells, the number of connecting plates can be two, and the number of positive connecting terminals and/or negative connecting terminals on each connecting plate It can be set in one-to-one correspondence with the positive terminal and/or the negative terminal of the lithium battery cell.

The lithium battery provided in the embodiment of the present application includes the lithium battery cell in any of the above embodiments, which can diversify the shape of the lithium battery and improve the energy density of the lithium battery. The stack of ears constitutes at least one positive terminal of the lithium battery cell, and the stack of multiple negative ears constitutes at least one negative terminal of the lithium battery cell, and the stacked multiple positive electrodes are arranged in parallel, and the stacked multiple negative ears are arranged in parallel, which reduces the The internal resistance value of the lithium battery cell enhances the overcurrent capability of the lithium battery cell, which in turn can receive a large current (charging current) output by an external charging device to achieve fast charging of the lithium battery cell.

FIG. 12 is a flowchart of a method for manufacturing a lithium battery cell in one embodiment. As shown in FIG. 12 , the manufacturing method of a lithium battery cell includes steps 1202 to 1208 .

Step 1202, preparing a positive electrode sheet and a negative electrode sheet that are isolated from each other.

In one embodiment, the positive electrode active material, the conductive agent, the binder and the solvent can be uniformly stirred and then coated on the positive electrode metal layer (for example, aluminum foil), dried and rolled by a roller press to form the positive electrode Sheet 110. The positive active material may include one of lithium cobalt oxide, lithium nickel cobalt manganate, lithium iron phosphate, and lithium nickel cobalt aluminate. Correspondingly, the negative electrode active material, conductive agent, binder and solvent (deionized water) can be uniformly stirred and then coated on the negative electrode metal layer (for example, copper foil), dried and then rolled by a roller press to form. The negative electrode sheet 120. The negative active material may include one of artificial graphite, natural graphite, mesocarbon microspheres, hard carbon, graphene, and lithium titanate.

It should be noted that, in the embodiments of the present application, the composition and formation process of the positive electrode sheet 110 and the negative electrode sheet 120 are not further limited.

Step 1204: Cut the positive electrode sheet and the negative electrode sheet that are isolated and stacked from each other according to a preset pattern.

In one embodiment, the positive electrode sheet 110 and the negative electrode sheet 120 are isolated and stacked from each other, and the isolated and stacked positive electrode sheet 110 and the negative electrode sheet 120 can be separated and stacked by a cutting process (for example, punching with a customized special type of die). Cut the positive electrode sheet 110 and the negative electrode sheet 120 with preset patterns, as shown in FIG. 2 . The shapes of the cut positive electrode sheet 110 and the negative electrode sheet 120 are the same, that is, the cut positive electrode sheet 110 and the negative electrode sheet 120 both have preset patterns. The preset graphics may be used to indicate the winding operation of the positive electrode sheet 110 and the negative electrode sheet 120 .

Step 1206 , welding a plurality of positive electrode tabs in the first predetermined area of the positive electrode sheet, and welding a plurality of negative electrode tabs in the second predetermined area of the negative electrode sheet.

In one embodiment, an ultrasonic cleaning machine can be used to clean out a first preset area on the positive electrode sheet 110 with a preset pattern near the edge, and an ultrasonic spot welding machine can be used to weld a plurality of positive electrode tabs 131 to the positive electrode sheet 110 on each preset position of the first preset area. Wherein, the plurality of positive electrode tabs 131 welded to the first predetermined area are disposed protruding from the edge of the positive electrode sheet 110 . Correspondingly, an ultrasonic cleaner can be used to clean out a second preset area on the negative electrode sheet 120 with a preset pattern near the edge, and an ultrasonic spot welder can be used to weld the plurality of negative electrode tabs 141 on the second pre-set area of the negative electrode sheet 120 . on each preset position of the set area. Wherein, the plurality of negative electrode tabs 141 welded in the second preset area are disposed protruding from the edge of the negative electrode sheet 120 .

In step 1208, the positive electrode sheet and the negative electrode sheet that are isolated from each other are wound according to the preset pattern, and a plurality of rolled positive electrode tabs are stacked to form at least one positive terminal of a lithium battery cell, and a plurality of negative electrode tabs are stacked to form a lithium battery cell. At least one negative terminal of the core, a plurality of stacked positive tabs are arranged in parallel, and a plurality of stacked negative tabs are arranged in parallel.

The positive terminal 130 of the lithium battery cell can be understood as a connection terminal for connecting with the positive terminal of an external power supply device or discharge device, and the positive terminal 130 of the lithium battery cell can be understood as a connection terminal used for connecting with the negative electrode of an external power supply device or discharge device connection terminal.

The above-mentioned manufacturing method of the lithium battery cell first stacks the positive electrode sheet and the negative electrode sheet, and then cuts the positive electrode sheet and the negative electrode sheet that are isolated and stacked from each other according to a preset pattern, which can improve the cutting efficiency, and can also reduce the positive and negative electrode, The probability of burr generation during the cutting of the negative electrode sheet reduces the risk of short circuit inside the cell. Compared with the laminated battery, the lithium battery cell prepared by winding has a higher energy density than that of the laminated battery. At the same time, the morphology of the lithium battery cells prepared by the preparation method is diversified, and the energy density of the lithium battery cells is improved. Because the stacked multiple positive tabs after winding constitute at least one positive terminal of the lithium battery cell, and the multiple stacked negative tabs constitute at least one negative terminal of the lithium battery cell, and the stacked multiple positive tabs are arranged in parallel, the stacked Multiple negative electrodes are arranged in parallel, which reduces the internal resistance value of the lithium battery cell, enhances the overcurrent capability of the lithium battery cell, and then can receive the large current (charging current) output by the external charging device, so as to realize the charging current of the lithium battery. Fast charging of the core.

In one embodiment, the method for manufacturing a lithium battery cell further includes: preparing a cell unit, where the cell unit includes a positive electrode sheet, a separator, and a negative electrode sheet that are stacked in sequence. As shown in FIG. 4 , in one embodiment, the separator 150 may be formed by forming an electrolyte layer on both sides of the insulating material layer. The insulating material of the insulating material layer may include at least one of self-terminated polymer oligomers, polyimide films, high polymer films and polyethylene films.

The cell unit 10 can be formed by stacking the prepared negative electrode sheet 120 , the separator 150 , and the positive electrode sheet 110 along the stacking direction. Wherein, the shape of each cell unit 10 is the same, and the shape of the cell unit 10 is the same as the pre-cut pattern of the positive electrode sheet 110 and the negative electrode sheet 120 .

As shown in Figure 13, in one embodiment, the positive electrode sheet and the negative electrode sheet isolated from each other are cut according to a preset pattern, including:

Step 1302: Divide the cell unit into a winding part and a special-shaped part according to a preset pattern.

Step 1304: Cut the cell unit according to the divided winding portion and the special-shaped portion, and open a slit at a preset position of the winding portion, and the extending direction of the slit is the same as the winding direction of the winding portion.

Referring to FIG. 2 , the winding portion 111 is provided with a slit 112 , and the extending direction of the slit 112 is the same as the winding direction of the winding portion 111 , wherein the winding direction is shown in the direction of the solid arrow in the figure. When the number of slits 112 is one, the slit 112 can split the winding part 111 into a first winding part 111 and a second winding part 111 , wherein the end of the first winding part 111 is connected with the special-shaped part 113 The end of the second winding part 111 is connected to the special-shaped part 113 . It should be noted that, the end of the first winding portion 111 and the end of the second winding portion 111 may be understood as winding ends. Specifically, the width of the slit 112 is 0.1˜0.1 mm.

In the embodiment of the present application, by opening a slit 112 in the winding portion 111 , the winding effect can be improved, thereby improving the yield of lithium battery cells.

In one embodiment, the method further includes the step of packaging the wound lithium battery cells to form a lithium battery. Specifically, the aluminum-plastic film casing corresponding to the special-shaped cavity can be punched according to the special-shaped shape of the lithium battery cell, and the lower part of the special-shaped aluminum-plastic film casing cavity can be turned over to wrap the lithium battery cell and then bake it after one packaging. Pre-packaged after baking and infusion. Further, after the semi-finished battery is aged for 24 hours at room temperature, high-temperature pressure pre-aging and fixture secondary high-temperature aging can be performed, air extraction and secondary packaging are performed, and the excess aluminum-plastic film casing is subtracted to obtain a special-shaped lithium battery.

It should be understood that although the various steps in the flowcharts of FIGS. 12-13 are shown in sequence according to the arrows, these steps are not necessarily executed in the sequence shown by the arrows. Unless explicitly stated herein, the execution of these steps is not strictly limited to the order, and these steps may be performed in other orders. Moreover, at least a part of the steps in FIGS. 12-13 may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed and completed at the same time, but may be executed at different times. These sub-steps or stages are not necessarily completed at the same time. The order of execution of the steps is not necessarily sequential, but may be performed alternately or alternately with other steps or at least a part of sub-steps or stages of other steps.

In one of the embodiments, the present application further provides a lithium battery, which can be prepared according to the method for manufacturing a lithium battery cell in any of the above embodiments. The lithium battery prepared based on the above-mentioned method for manufacturing a lithium battery cell can reduce the risk of short circuit inside the cell. Compared with the laminated battery, the lithium battery cell prepared by winding has a higher energy density than that of the laminated battery. At the same time, the morphology of the lithium battery cells prepared by the preparation method is diversified, and the energy density of the lithium battery cells is improved. Because the stacked multiple positive tabs after winding constitute at least one positive terminal of the lithium battery cell, and the multiple stacked negative tabs constitute at least one negative terminal of the lithium battery cell, and the stacked multiple positive tabs are arranged in parallel, the stacked Multiple negative electrodes are arranged in parallel, which reduces the internal resistance value of the lithium battery cell, enhances the overcurrent capability of the lithium battery cell, and then can receive the large current (charging current) output by the external charging device, so as to realize the charging current of the lithium battery. Fast charging of the core.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the patent of the present application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (13)

1. A lithium battery cell is characterized by comprising a positive plate and a negative plate which are mutually isolated and are in preset patterns, wherein the lithium battery cell is formed by winding the positive plate and the negative plate, a first preset area of the positive plate is provided with a plurality of positive lugs, and a second preset area of the negative plate is provided with a plurality of negative lugs;

a plurality of positive lugs after coiling pile up and constitute at least a positive terminal of lithium battery electricity core, a plurality of negative pole ears pile up and constitute at least a negative pole end of lithium battery electricity core, and a plurality of positive lugs that pile up set up in parallel, and a plurality of negative pole ears that pile up set up in parallel, wherein, positive lug with negative pole ear dislocation is arranged.

2. The lithium battery cell of claim 1, further comprising a separator disposed between the positive plate and the negative plate, wherein the positive plate, the separator, and the negative plate form a cell unit, the cell unit comprises a winding portion and a special-shaped portion, and the positive plate and the negative plate of the winding portion are wound to form the lithium battery cell at the special-shaped portion; the preset pattern is the same as the battery cell unit in shape, and the special-shaped portion is the same as the lithium battery cell in shape.

3. The lithium battery cell of claim 2, wherein the cell unit comprises a first side and a second side that are opposite to each other, and the first preset region and the second preset region are both disposed on the first side and/or the second side.

4. The lithium battery cell of claim 3, wherein the wound plurality of positive tabs are stacked to form a positive terminal of the lithium battery cell and the plurality of negative tabs are stacked to form a negative terminal of the lithium battery cell.

5. The lithium battery cell of claim 3, wherein the wound portion of the positive electrode tab stack forms a first positive terminal of the lithium battery cell and the wound portion of the positive electrode tab stack forms a second positive terminal of the lithium battery cell; and the coiled part of the negative electrode tabs are stacked to form a first negative electrode end of the lithium battery cell, and the coiled part of the negative electrode tabs are stacked to form a second negative electrode end of the lithium battery cell.

6. The lithium battery cell of claim 2, wherein the winding portion is slotted, and the slot extends in the same direction as the winding direction of the winding portion.

7. The lithium battery cell of claim 2, wherein the profiled portion is L-shaped in shape.

8. The lithium battery cell of any one of claims 2 to 7, wherein the number of the cell units is multiple, and the multiple cell units are stacked and isolated, and the lithium battery cell is formed by winding the multiple cell units which are stacked and isolated.

9. A manufacturing method of a lithium battery cell is characterized by comprising the following steps:

preparing a positive plate and a negative plate which are isolated from each other;

cutting the positive plate and the negative plate which are isolated from each other according to a preset pattern;

welding a plurality of positive lugs in a first preset area of the positive plate, and welding a plurality of negative lugs in a second preset area of the negative plate, wherein the positive lugs and the negative lugs are arranged in a staggered manner;

according to preset the figure to keeping apart each other and piling up positive plate and negative pole piece are convoluteed, and a plurality of positive ear after convoluteing pile up and constitute a lithium battery electricity core's an at least positive terminal, a plurality of negative pole ears pile up and constitute a lithium battery electricity core's an at least negative pole end, and a plurality of positive ear that pile up connect in parallel and set up, and a plurality of negative pole ears that pile up connect in parallel and set up.

10. The method of claim 9, further comprising:

preparing a battery cell unit, wherein the battery cell unit comprises a positive plate, a diaphragm and a negative plate which are sequentially stacked;

the positive plate and the negative plate which are isolated from each other are cut according to a preset graph, and the cutting method comprises the following steps:

dividing the battery cell unit into a winding part and a special-shaped part according to a preset pattern;

and cutting the battery cell unit according to the divided winding part and the special-shaped part, and forming a gap at a preset position of the winding part, wherein the extending direction of the gap is the same as the winding direction of the winding part.

11. The method of claim 9, further comprising:

and packaging the wound lithium battery cell to form the lithium battery.

12. A lithium battery comprising a lithium battery cell as claimed in any of claims 1 to 8.

13. A lithium battery produced according to the method of making a lithium battery cell of any of claims 9-11.

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