CN218602472U - Pole piece and battery pole group - Google Patents

Abstract

The embodiment of the application discloses pole piece and battery utmost point group, the pole piece is through setting up two at least utmost points ears in width direction one side at the substrate, the middle section on the relative both sides limit that sets up of utmost point ear forms the bellying along same direction protrusion respectively, thereby make utmost point ear have arrow point shape, the pole piece is under the expansion state of laying flat, two utmost point ears at least arrange at the interval in proper order, the pole piece is under the coiling state, present partial laminated structure through between two at least utmost point ears, reduce the interference phenomenon between the two adjacent utmost point ears, be convenient for the electrolyte base soaks the pole piece, be convenient for coil, smooth, compare with rubbing flat extrusion, the production of metal clastic with the dust has been reduced, the safety risk of battery utmost point group has been reduced.

Description

Pole piece and battery pole group

Technical Field

The application relates to the technical field of batteries, in particular to a pole piece and a battery pole group.

Background

For the design of the full-tab structure of the circular lithium ion battery, the design is that the margin of the foil on the edge of the pole piece is reserved, then the foil with enough length is reserved at the two ends of the positive pole and the negative pole of the pole group by winding through the winding equipment, and finally the foil at the two ends of the pole group is kneaded and extruded, so that the pole group reaches a certain length. The disadvantages of this approach are:

1. in the process of kneading and extruding the foil, a large amount of foil metal fragments can be generated, so that the self-discharge of the lithium ion battery is high, and the risk that the metal fragments are kneaded and extruded into the battery pole group exists, so that the safety risk is caused;

2. the two ends of the battery pole group are covered by thick and compact metal foils after the battery pole group is rolled flat and extruded, so that the difficulty of wetting the pole piece and the diaphragm by the electrolyte is greatly increased, and the safety performance and the electrochemical performance are greatly influenced.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a pole piece and a battery pole group, and can solve the problems that safety risks exist in the process of kneading and extruding edge foil of the existing pole piece and the difficulty of soaking electrolyte is large.

The embodiment of the application provides a pole piece, include: a main body portion including a base material having a longitudinal direction and a width direction orthogonal to each other, one end of the main body portion in the longitudinal direction being a starting end; one end of each tab is connected with one side of the base material in the width direction, each tab is provided with two side edges which are oppositely arranged along the length direction, and the middle sections of the two side edges respectively protrude towards the same direction to form a protruding part; the pole piece is provided with a flat unfolding state and a winding state around the starting end, at least two pole lugs are sequentially arranged at intervals in the unfolding state, and at least two pole lug parts are arranged in a layered overlapping mode in the winding state.

Optionally, a distance exists between the tab close to the starting end of the at least two tabs and the starting end, the distance is L1, and L1 is greater than or equal to 300mm and less than or equal to 800mm.

Optionally, one end of the main body portion opposite to the starting end in the length direction is a tail end; and a space exists between the lug close to the tail end in the at least two lugs and the tail end, wherein the space is L2, and L2 is more than or equal to 100mm and less than or equal to 300mm.

Optionally, the distance between the end of the tab connected with the substrate and the end of the tab far away from the substrate is H1, and H1 is greater than or equal to 4mm and less than or equal to 10mm.

Optionally, the length of one end of the tab, which is far away from the base material, is W1, and W1 is not less than 4mm and not more than 9mm.

Optionally, when the number of the tabs is more than three, the distance between the adjacent sides of two adjacent tabs is equal, and is 0.01 mm-0.5 mm.

Optionally, the side edge includes a first section and a second section connected in sequence, an included angle between the second section and the length direction is α, α is greater than 0 ° and less than 90 °, an included angle between the first section and the length direction is β, β is greater than 90 ° and less than 180 °.

Optionally, the shape of the convex part is a circular arc, the radius of the circular arc is R0, and R0 is greater than or equal to 0 and less than or equal to 10mm.

Optionally, the main body further includes a coating layer disposed on at least one surface of the base material, and a gap is left between the coating layer and the tab.

Meanwhile, the embodiment of the application also provides a battery pole group, which comprises a positive pole piece, a negative pole piece and a diaphragm, wherein the positive pole piece, the negative pole piece and the diaphragm are laminated and wound to form the battery pole group, and the diaphragm is arranged between the positive pole piece and the negative pole piece; wherein at least one of the positive electrode plate and the negative electrode plate is the electrode plate as described above.

The utility model provides a beneficial effect lies in, a pole piece and battery utmost point group that has this pole piece are provided, the pole piece is through setting up two at least utmost points ear in width direction one side at the substrate, the middle section on the relative both sides limit that sets up of utmost point ear forms the bellying along same direction protrusion respectively, thereby make utmost point ear have arrow point shape, the pole piece is under the expansion state of laying flat, two utmost point ears arrange at least at the interval in proper order, the pole piece is under the coiling state, through presenting partial laminated structure between two at least utmost point ears, reduce the interference phenomenon between two adjacent utmost point ears, be convenient for the electrolyte base soaks the pole piece, be convenient for convolute, smooth, compare with the extrusion of rubbing flat, the production of metal clastic and dust has been reduced, the safety risk of battery utmost point group has been reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a pole piece in an unfolded state according to an embodiment of the present disclosure;

FIG. 2 is an enlarged schematic view of FIG. 1 at A;

FIG. 3 is a schematic structural diagram of a substrate and a coating layer according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating a structure of a battery pole group wound in a pressing process according to an embodiment of the present disclosure;

fig. 5 is a top view of a battery pole group provided in an embodiment of the present application.

Description of reference numerals:

1. a battery pole group;

100. a pole piece, 110, a main body part, 110a, a starting end, 110b, a tail end, 111, a base material, 111a, a coating area, 111b, a blank area, 112, a coating layer, 120, a tab, 121, a side edge, 1211, a first section, 1212, a second section, 122 and a convex part;

100a, a positive pole piece, 100b, a negative pole piece, 200 and a diaphragm;

x, length direction, Y, width direction.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. Furthermore, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the invention, are given by way of illustration and explanation only, and are not intended to limit the scope of the invention. In this application, where the context requires otherwise, the words "upper" and "lower" used in relation to the device in use or operation will generally refer to the upper and lower extremities of the device, particularly as oriented in the drawing figures; while "inner" and "outer" are with respect to the outline of the device. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features.

The embodiment of the application provides a pole piece and have battery utmost point group of this pole piece, the pole piece is through setting up two at least utmost points ear in width direction one side at the substrate, the middle section on the relative both sides limit that sets up of utmost point ear is along same direction protrusion formation bellying respectively, thereby make utmost point ear have arrow point shape, the pole piece is under the expansion state of laying flat, two at least utmost point ears are arranged at the interval in proper order, the pole piece is under the coiling state, present partial laminated structure through between two at least utmost point ears, reduce the interference phenomenon between two adjacent utmost point ears, be convenient for the electrolyte base soaks the pole piece, be convenient for convolute, smooth, compare with the extrusion of rubbing flat, the production of metal clastic with the dust has been reduced, the safety risk of battery utmost point group has been reduced. As a typical application, the battery pole group is applied to a single battery, and the single battery can be applied to an electric vehicle to provide electric energy for the electric vehicle.

In an embodiment of the present application, a pole piece 100 is provided, referring to fig. 1 to 2, the pole piece 100 includes: a body portion 110 and a tab 120.

Referring to fig. 1, the main body 110 includes a base 111, the main body 110 has a longitudinal direction X and a width direction Y perpendicular to each other, one end of the main body 110 in the longitudinal direction X is a starting end 110a, and the other end of the main body 110 in the longitudinal direction X is a terminal end 110b. The substrate 111 is a foil, which may be an aluminum foil or a copper foil.

The tab 120 extends along the width direction Y, and one end of the tab 120 in the width direction Y is connected to one side of the substrate 111 in the width direction Y, the tab 120 has two sides 121 oppositely disposed along the length direction X, and middle sections of the two sides 121 respectively protrude in the same direction along the length direction X to form a protruding portion 122, where the term "middle section" refers to a middle section of the length of the side 121, and two middle sections of the two sides 121 respectively protrude in the same direction along the length direction X to form a protruding portion 122, in other implementations, the two middle sections of the two sides 121 may protrude in other directions, but protruding directions of the middle sections of the two sides 121 need to be the same.

The pole piece 100 has two states, one is an unfolded state in which it is laid flat, and the other is a wound state in which it is wound around the start end 110a in a plurality of turns. Accordingly, the tab 120 also has two states, one is an upright state in which the tab 120 extends in the width direction Y when the pole piece 100 is in the unfolded state, and the other is a collapsed state in which the tab 120 is perpendicular to the thickness direction of the pole piece 100 when the pole piece 100 is in the wound state.

In the present embodiment, the number of tabs 120 provided on each base 111 is 700 to 1000, forming a multi-tab pole piece. In the unfolded state of the pole piece 100, the tabs 120 in the upright state are sequentially arranged at intervals along the length direction X, specifically, two adjacent tabs 120 are continuously arranged at equal intervals, and the interval between the adjacent side edges 121 of two adjacent tabs 120 in the length direction X is 0.01mm to 0.5mm. The distance between two adjacent lugs 120 is small, the two adjacent lugs 120 in a lodging state are partially overlapped (namely, staggered and overlapped), no gap exists, and the risk of laser leakage when the current collecting disc is welded with the lugs is eliminated. The equidistant utmost point ear has reduced the production of metallic debris and dust, has greatly reduced the safety risk of battery. And the arrangement of the protruding part 122 enables the side edge 121 of the tab 120 to form a horizontal V shape, the tab 120 is integrally formed into an arrow head shape, the tab 120 is in an arrow head shape, and the tab 120 is beneficial to presenting a partial laminated structure between adjacent tabs in a lodging state, so that the interference phenomenon of the adjacent tabs is reduced.

In addition, referring to fig. 1, a gap is formed between the tab 120 close to the starting end 110a and the starting end 110a among the plurality of tabs 120, the gap is L1, L1 is equal to or larger than 300mm and equal to or smaller than 800mm, and L1 is designed such that a margin is formed between the tab 120 and the starting end 110a (i.e., the tab 120 is not provided here), and considering that the diameter of the inner ring formed by the initial winding of the pole piece 100 is about 3.5mm smaller, if the tab is provided at the margin, interference may occur between the tab and the tab at the margin after winding.

In addition, referring to fig. 1, a space is formed between the tab 120 near the end 110b and the end 110b among the plurality of tabs 120, the space is L2, L2 is 100mm ≦ L2 ≦ 300mm, and the design of L2 allows a margin to be formed between the tab 120 and the end 110b (i.e., the tab 120 is not provided here), and if the tab is provided at the margin, interference may occur between the tab and the tab at the margin after winding.

In addition, referring to fig. 1 and 2, the distance between the end of the tab 120 connected to the base material 111 and the end of the tab 120 far away from the base material 111 in the width direction Y is H1, and H1 is greater than or equal to 4mm and less than or equal to 10mm. The length of one end of the tab 120, which is far away from the base material 111, in the length direction X is W1, and W1 is more than or equal to 4mm and less than or equal to 9mm. The tab 120 with the size is easy to fall down, the deformation of the tab 120 after falling is small, the tab 120 is flatly attached to the end face of the tab group after being processed by the falling mechanism, the whole tab face is flat, the difficulty in welding the tab 120 and an external conductive structure (such as a current collecting disc) in subsequent processing is reduced, and the welding between the current collecting disc and the tab 120 is facilitated.

In addition, referring to fig. 2, each side edge 121 of the tab 120 includes a first section 1211 and a second section 1212 connected in sequence, the first section 1211 is connected to the substrate 111 at an end away from the second section 1212, an angle α between the second section 1212 and the length direction X is α,0 ° < α < 90 °, an angle β between the first section 1211 and the length direction X is β, and 90 ° < β < 180 °. The shape of the convex part 122 is a circular arc, the radius of the circular arc is R0, and R0 is more than or equal to 0 and less than or equal to 10mm. When at least one of α, β and R0 is within the above range, the tab 120 has an arrow shape, which is beneficial to form a partial laminated structure between adjacent tabs in a lodging state, and reduces the interference phenomenon of the adjacent tabs.

In addition, referring to fig. 1, the main body 110 further includes a coating layer 112, the coating layer 112 is disposed on at least one surface of the substrate 111, a gap is left between the coating layer 112 and the tab 120, the coating layer 112 is an active material layer, the electrolyte infiltrates the active material layer and reacts with an active material in the active material layer, when the pole piece 100 is a positive pole piece, the coating layer 112 is a positive active material layer, and when the pole piece 100 is a negative pole piece, the coating layer 112 is a negative active material layer.

In the present embodiment, the tab 120 and the substrate 111 are of an integrated structure. Specifically, referring to fig. 3, the base material 111 includes a coating region 111a and a blank region 111b spaced apart in the width direction Y, the coating region 111a is coated with the coating layer 112, both ends of the blank region 111b in the length direction X are cut off to form blanks having lengths L1 and L2, respectively, and the remaining blank region 111b is cut into a plurality of tab tabs 120 arranged at equal intervals in series as shown in fig. 1 and 2 through a laser die cutting process. The tab 120 in the shape of an arrow has a simple structure, and laser die cutting is easy to realize, thereby facilitating production and manufacturing. The tab 120 is formed by laser die cutting of the blank area 111b of the base material 111, so that the purpose of reducing metal scraps generated in the processing process of the tab 120 is achieved, the arrow shape required by the tab 120 can be accurately cut through the laser die cutting process, and material waste is avoided. In other implementations, the tab 120 and the substrate 111 may be integrally connected by welding.

Meanwhile, referring to fig. 4 and 5, an embodiment of the present application further provides a battery pole group 1, where the battery pole group 1 includes a positive pole piece 100a, a negative pole piece 100b, and a diaphragm 200, the positive pole piece 100a, the negative pole piece 100b, and the diaphragm 200 are stacked and wound to form the battery pole group 1, the battery pole group 1 has an axial direction Z, and the diaphragm 200 is disposed between the positive pole piece 100a and the negative pole piece 100 b; at least one of the positive electrode plate 100a and the negative electrode plate 100b is the electrode plate 100 as described above. In this embodiment, the positive electrode sheet 100a and the negative electrode sheet 100b are both the electrode sheets 100 as described above, and the tab 120 on the positive electrode sheet 100a and the tab 120 on the negative electrode sheet 100b are disposed opposite to each other along the axial direction Z. The material of the separator 200 may be PP (polypropylene) or PE (polyethylene).

In the process of stacking and winding the positive pole piece 100a, the negative pole piece 100b and the diaphragm 200, the tabs 120 of the positive pole piece 100a and the negative pole piece 100b are simultaneously laid under the action of the laying mechanism to present a laying state, and due to the arrow shape design of the tabs 120, the adjacent two tabs 120 in the laying state are partially stacked and arranged, compared with the direct rolling and extruding of foils at two ends of a pole group using full tabs, the tabs are sequentially folded and laid to realize the flattening of the end surface of the battery pole group 1 without rolling and extruding, so that metal fragments generated by rolling and extruding are reduced, the potential safety hazards of self-discharging or short circuit of the battery caused by the existence of the metal fragments are avoided, and the use performance and the safety performance of the battery are improved.

The above detailed description is made on a pole piece and a battery pole group provided in the embodiments of the present application, and specific examples are applied herein to explain the principle and the implementation of the present application, and the description of the above embodiments is only used to help understanding the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims (10)

1. A pole piece, comprising:

a main body part (110), wherein the main body part (110) comprises a base material (111), the base material (111) has a length direction (X) and a width direction (Y) which are mutually orthogonal, and one end of the main body part (110) in the length direction (X) is a starting end (110 a);

the electrode tab (120) is provided with two side edges (121) which are oppositely arranged along the length direction (X), and the middle sections of the two side edges (121) respectively protrude towards the same direction to form a protruding part (122);

the pole piece is provided with a flat spreading state and a winding state wound around the starting end (110 a), the at least two tabs (120) are sequentially arranged at intervals in the spreading state, and the at least two tabs (120) are partially stacked in the winding state.

2. The pole piece according to claim 1, characterized in that a spacing exists between the tab (120) of the at least two tabs (120) close to the starting end (110 a) and the starting end (110 a), wherein the spacing is L1, and L1 is greater than or equal to 300mm and less than or equal to 800mm.

3. The pole piece according to claim 2, characterized in that the end of the main body portion (110) disposed opposite to the starting end (110 a) in the length direction (X) is a terminal end (110 b);

a space exists between the lug (120) close to the tail end (110 b) and the tail end (110 b) in the at least two lugs (120), wherein the space is L2, and L2 is more than or equal to 100mm and less than or equal to 300mm.

4. The pole piece according to claim 1, characterized in that the distance between the end of the tab (120) connected with the base material (111) and the end of the tab (120) far away from the base material (111) is H1, H1 is more than or equal to 4mm and less than or equal to 10mm.

5. The pole piece according to claim 1, characterized in that the length of the end of the tab (120) facing away from the substrate (111) is W1, W1 is greater than or equal to 4mm and less than or equal to 9mm.

6. The pole piece of claim 1, characterized in that when the number of the pole lugs (120) is more than three, the distance between the adjacent sides (121) of two adjacent pole lugs (120) is equal and is 0.01 mm-0.5 mm.

7. Pole piece according to claim 1, characterized in that the side (121) comprises a first section (1211) and a second section (1212) connected in series, the second section (1212) being at an angle α with respect to the length direction (X), 0 ° < α < 90 °, the first section (1211) being at an angle β with respect to the length direction (X), 90 ° < β < 180 °.

8. Pole piece according to claim 1, characterized in that the shape of the projection (122) is a circular arc with a radius R0,0 ≦ R0 ≦ 10mm.

9. The pole piece according to claim 1, characterized in that the main body portion (110) further comprises a coating layer (112), the coating layer (112) being provided on at least one surface of the base material (111), the coating layer (112) leaving a gap with the tab (120).

10. A battery pole group is characterized by comprising a positive pole piece, a negative pole piece and a diaphragm, wherein the positive pole piece, the negative pole piece and the diaphragm are laminated and wound to form the battery pole group, and the diaphragm is arranged between the positive pole piece and the negative pole piece;

wherein at least one of the positive electrode sheet and the negative electrode sheet is the sheet according to any one of claims 1 to 9.

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