CN218385353U - Winding electric core - Google Patents

Abstract

The utility model discloses a coiling electricity core, coiling electricity core includes: the diaphragm is arranged between the first pole piece and the second pole piece, the second pole piece is located on the innermost layer, the first pole piece comprises a plurality of plane sections and bending sections which are alternately connected, the surface, close to the innermost layer, of at least one bending section is provided with a positive electrode material coating, and the gram volume of the positive electrode material coating is 110-150mAh/g. The first pole piece and the second pole piece are both provided with a plurality of bending sections after being wound, and the anode material coating with low gram capacity and good safety performance is arranged between the bending sections of the first pole piece and the second pole piece. The positive electrode material with low gram capacity can reduce the quantity of lithium ions escaping from the bent section of the first pole piece, so that the failure problems of lithium precipitation and the like of the bent section of the second pole piece are reduced. In addition, the probability of failure of the R corner of the winding battery cell is reduced, so that the safety performance of the winding battery cell is improved.

Description

Winding electric core

Technical Field

The utility model relates to a battery manufacturing technology field especially relates to a coiling electricity core.

Background

The winding electric core is formed by combining in a winding mode, most of the winding electric cores in the related technology are positive single coatings, and multi-tab winding is carried out, on one hand, because the winding tension at the R corner is uneven, the structure is loose, the lithium precipitation problem is easy to occur due to the uneven distance between the positive pole piece and the negative pole piece at the R corner, on the other hand, at the R corner bending part, the NP ratio (the negative pole excess coefficient) of the positive pole piece corresponding to the negative pole is lower, the lithium precipitation problem is also easy to cause, the lithium precipitation problem not only reduces the battery performance, greatly shortens the cycle life, but also limits the quick charge capacity of the battery, and possibly causes serious hazards such as combustion, explosion and the like.

SUMMERY OF THE UTILITY MODEL

The present invention aims at solving one of the technical problems in the related art at least to a certain extent.

Therefore, the embodiment of the utility model provides a coiling electric core, this coiling electric core have factor of safety height and the difficult characteristics of separating out lithium.

The utility model discloses coiling electricity core includes: the diaphragm is arranged between the first pole piece and the second pole piece, the second pole piece is located on the innermost layer, the first pole piece comprises a plurality of plane sections and bending sections which are connected alternately, the surface, close to the innermost layer, of at least one bending section is provided with a positive electrode material coating, and the gram capacity of the positive electrode material coating is 110-150mAh/g.

The utility model discloses coiling electricity core, first pole piece and second pole piece are coiled and are all had a plurality of bending sections after setting up, set up gram volume low, the positive pole material coating that the security performance is good between the bending section of first pole piece and second pole piece. The positive electrode material with low gram capacity can reduce the quantity of lithium ions escaping from the bent section of the first pole piece, so that the failure problems of lithium precipitation and the like of the bent section of the second pole piece are reduced. Moreover, the probability of failure at the R corner of the winding battery cell is reduced, so that the safety performance of the winding battery cell is indirectly improved.

Therefore, the utility model discloses coiling electricity core has solved R angle department and has become invalid easily and the problem that the security performance is low.

In some embodiments, a conductive glue coating layer is further arranged between the positive electrode material coating layer and the separator.

In some embodiments, the surface of the curved section away from the innermost layer of the second pole piece is provided with a ternary positive electrode material coating; and/or a ternary anode material coating is arranged on the surface of the plane section, which is far away from the innermost layer of the second pole piece; and/or the surface of the plane section, which is close to the innermost layer of the second pole piece, is provided with a ternary positive pole material coating.

In some embodiments, the surface of the curved section away from the innermost layer of the second pole piece is provided with the ternary positive electrode material coating, the surface of the planar section away from the innermost layer of the second pole piece and the surface of the planar section close to the innermost layer of the second pole piece are both provided with the ternary positive electrode material coating, and the ternary positive electrode material coating on the surface of the planar section close to the innermost layer of the second pole piece is connected with the positive electrode material coating.

In some embodiments, the battery further comprises a plurality of first tabs and a plurality of second tabs, wherein the plurality of first tabs are connected with the first pole piece, the plurality of first tabs are arranged on the first pole piece at intervals along the winding direction, the plurality of second tabs are connected with the second pole piece, and the plurality of second tabs are arranged on the second pole piece at intervals along the winding direction.

In some embodiments, a plurality of positioning coating blocks are arranged on the first pole piece, the positioning coating blocks are located between two adjacent first pole lugs, and/or the positioning coating blocks are located on one side of the first pole lug in the winding direction, and the positioning coating blocks are used for positioning the conductive adhesive coating layer and the positive electrode material coating layer.

In some embodiments, the widths of the conductive glue layer and the coating of positive electrode material on the curved section at different positions gradually increase from inside to outside along the winding direction of the first pole piece.

In some embodiments, the thickness of the ternary positive electrode material coating is equal to the sum of the thicknesses of the conductive glue coating and the positive electrode material coating.

In some embodiments, the positive electrode material coating is a lithium iron phosphate coating or a sodium ion positive electrode material coating, the conductive glue coating is a mixture coating of polyvinylidene fluoride and a conductive agent, and the conductive agent is conductive carbon black and/or conductive graphite.

In some embodiments, the first pole piece is a positive pole piece and the second pole piece is a negative pole piece.

Drawings

Fig. 1 is a schematic top cross-sectional view of a wound electrical core according to an embodiment of the present invention.

Fig. 2 is a schematic top cross-sectional view of the wound electric core according to the embodiment of the present invention after the first pole piece is unfolded.

Fig. 3 is a schematic front view of the wound electric core according to the embodiment of the present invention after the first pole piece is unfolded.

Fig. 4 is a schematic back view of the wound electric core according to the embodiment of the present invention after the first pole piece is unfolded.

Reference numerals:

a first pole piece 1, a plane section 11, a bending section 12, a positive pole material coating 121, a conductive glue coating 122, a ternary positive pole material coating 123,

A second pole piece 2, a second plane section 21, a second bending section 22,

A diaphragm 3,

The device comprises a first tab 4, a second tab 5 and a positioning coating block 6.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

The following describes the winding electric core according to an embodiment of the present invention with reference to the drawings.

As shown in fig. 1, the winding electric core of the embodiment of the present invention includes: the first pole piece 1, the second pole piece 2 and the diaphragm 3 are arranged in a winding mode.

The diaphragm 3 is arranged between the first pole piece 1 and the second pole piece 2, the first pole piece 1 comprises a plurality of plane sections 11 and bent sections 12 which are alternately connected, the second pole piece 2 is positioned at the innermost layer, the surface of at least one bent section 12, which is close to the innermost layer of the second pole piece 2, is provided with a positive pole material coating 121, and the gram capacity of the positive pole material coating 121 is 110-150mAh/g.

It should be understood that, when the electric core of the embodiment of the present invention is in the expanded state, the bottom layer is the membrane 3, and the first pole piece 1 is arranged above the membrane 3. A layer of diaphragm 3 is laid above the first pole piece 1, and a layer of second pole piece 2 is arranged above the diaphragm 3.

Therefore, after the cell is wound, as shown in fig. 1, the outermost layer is the separator 3, and the innermost layer is the second pole piece 2, that is, the cell sequentially includes from inside to outside: second pole piece 2-membrane 3-first pole piece 1-membrane 3. In other words, the first pole piece 1 is sandwiched between two layers of membrane 3, the second pole piece 2 being arranged inside the membrane 3 located in the innermost layer. In addition, by arranging two layers of diaphragms 3, and the length of the diaphragm 3 is greater than that of the first pole piece 1 and the second pole piece 2, it is ensured that the first pole piece 1 and the second pole piece 2 are both coated by the diaphragm 3 after the cell is wound, and are also separated by the diaphragm 3.

The surface of the bending section 12 of the first pole piece 1, which is close to the innermost second pole piece 2, is provided with a coating 121 of a positive electrode material. It should be understood that the first pole piece 1 has a thickness, and in the cell unfolded state, an upper surface of the first pole piece 1 is a surface close to the second pole piece 2, and a lower surface of the first pole piece 1 is a surface far from the second pole piece 2. In a cell winding state, the second pole piece 2 is located at the innermost layer of the cell, the upper surface of the first pole piece 1 is the surface close to the innermost layer of the second pole piece 2, and the lower surface of the first pole piece 1 is the surface far away from the innermost layer of the second pole piece 2.

Optionally, the surface of at least one of the bent segments 12 is provided with a coating 121 of the positive electrode material, and the bent segment 12 is the first bent segment 12 from inside to outside along the winding direction, that is, the innermost bent segment 12 on the first pole piece 1 of the battery cell.

Optionally, as shown in fig. 1, after the first pole piece 1 is wound, the surface of all the bent sections 12 on the first pole piece 1, which is close to the innermost second pole piece 2, is provided with a coating 121 of positive electrode material.

Further, the gram volume of the positive electrode material coating layer 121 is 110-150mAh/g, and the positive electrode material coating layer 121 is made of lithium iron phosphate or sodium ion positive electrode material.

In addition, the first pole piece 1, the second pole piece 2 and the diaphragm 3 after being wound are all composed of a plurality of plane sections 11 and bent sections 12 which are alternately connected. For ease of understanding and description, the planar section 11 of the first pole piece 1 is referred to as the first planar section, and the curved section 12 of the first pole piece 1 is referred to as the first curved section. The planar section of the second pole piece 2 is referred to as a second planar section 21 and the curved section of the second pole piece 2 is referred to as a second curved section 22. The planar section of the membrane 3 is called the third planar section and the curved section of the membrane 3 is called the third curved section.

For example, as shown in fig. 1, the first pole piece 1 is a positive pole piece, the second pole piece 2 is a negative pole piece, and a lithium iron phosphate positive pole material coating 121 is disposed on a surface of the first bending section of the wound positive pole piece, the surface being close to the innermost second pole piece 2.

Because the safety coefficient of the material of the lithium iron phosphate anode material coating 121 is high, the overcharge resistance is high, and the gram volume is low. Therefore, under the action of the lithium iron phosphate positive electrode material coating 121, the lithium ion release amount of the first bending section of the positive electrode piece is reduced, and the negative electrode excess coefficient of the second bending section 22 corresponding to the negative electrode piece is indirectly improved, so that the probability of failure of negative electrode lithium precipitation at the R-angle of the winding battery cell is reduced.

Specifically, as shown in fig. 1, an end portion located at the innermost layer of the wound cell is taken as a head end, and an end portion located at the outermost layer of the wound cell is taken as a tail end. The head end and the tail end of the first pole piece 1 are both the plane sections 11, the head end of the second pole piece 2 is a second plane section 21, and the tail end of the second pole piece 2 is a second bending section 22. The second pole piece 2 has three second bending sections 22 corresponding to the bending sections 12 on the first pole piece 1, that is, three portions of the first pole piece 1 coated with the lithium iron phosphate positive electrode material coating 121. In other words, the number of R corners of the wound core to which the lithium iron phosphate positive electrode material coating layer 121 needs to be applied is three.

The utility model discloses coiling electricity core, first pole piece 1 coiling have a plurality of bending sections 12 after setting up, have a plurality of second bending sections 22 after the setting up of second pole piece 2 coiling, set up gram capacity low, the positive pole material coating 121 that the security performance is good between the bending section 12 of first pole piece 1 and the second bending section 22 of second pole piece 2. The positive electrode material with low gram capacity can reduce the quantity of lithium ions escaping from the bent section 12 of the first pole piece 1, so that the failure problems of lithium precipitation and the like of the second bent section 22 of the second pole piece 2 are reduced. Moreover, the probability of failure at the R corner of the winding battery cell is reduced, so that the safety performance of the winding battery cell is indirectly improved.

In some embodiments, as shown in fig. 1, a conductive rubberized layer 122 is also provided between the coating of positive electrode material 121 and the separator 3.

It can be understood that lithium is easy to precipitate at the R-angle bend of the wound cell, on the one hand, because the NP ratio (negative electrode excess factor) of the positive electrode sheet to the negative electrode is lower inside the R-angle. On the other hand, the winding tension at the R corner is uneven, the structure is loose, and lithium precipitation is easy to occur due to uneven spacing between the positive electrode plate and the negative electrode plate at the R corner.

Optionally, as shown in fig. 1, a conductive glue coating layer 122 is disposed between the positive electrode material coating 121 and the separator 3, where the separator 3 is the separator 3 between the first pole piece 1 and the second pole piece 2, and is not the separator 3 at the outermost layer of the cell.

Therefore, under the action of the conductive glue coating layer 122, the adhesiveness of the bent section 12 of the first pole piece 1 is increased, and the bent section 12 of the first pole piece 1 and the third bent section of the diaphragm 3 are bonded with each other, so that the first pole piece 1, the diaphragm 3 and the second pole piece 2 can be compactly arranged, the problem of loose structure at the bent section 12 of the first pole piece 1 is avoided, and failure caused by overlarge distance between the positive pole and the negative pole of the battery cell is caused.

When the electric core is in the winding circulation process, the conductive glue coating layer 122 can ensure that the bending section 12 of the first pole piece 1 is tightly attached to the diaphragm 3 between the first pole piece 1 and the second pole piece 2, so that the condition that wrinkles appear at the third bending section of the diaphragm 3 due to the expansion of the winding circulation is avoided.

In some embodiments, as shown in fig. 1 and 2, the surface of the curved section 12 remote from the innermost second pole piece 2 is provided with a coating 123 of a ternary positive electrode material; and/or the surface of the plane section 11 far away from the innermost second pole piece 2 is provided with a ternary anode material coating 123; and/or the surface of the plane section 11 close to the innermost second pole piece 2 is provided with a ternary positive electrode material coating 123.

It can be understood that the first pole piece 1 is further coated with a ternary positive electrode material coating 123, and the gram capacity of the ternary positive electrode material coating 123 is higher than that of the lithium iron phosphate positive electrode material coating 121. Consequently, through carrying out the coating of different materials to first pole piece 1, under the prerequisite that ensures that first pole piece 1's bending section 12 possesses good security performance, still guarantee the utility model discloses the holistic energy density of coiling electricity core of embodiment.

For example, the surface of the first pole piece 1 close to the innermost second pole piece 2 is provided with a positive electrode material coating 121, and the surface of the first pole piece 1 far from the innermost second pole piece 2 is provided with a ternary positive electrode material coating 123.

Specifically, as shown in fig. 1, the surface of the curved section 12 of the first pole piece 1 away from the innermost second pole piece 2 is provided with a coating 123 of a ternary positive electrode material. The surface of the plane section 11 of the first pole piece 1, which is far away from the innermost layer second pole piece 2, and the surface of the plane section 11 of the first pole piece 1, which is close to the innermost layer second pole piece 2, are both provided with the ternary anode material coating 123, and the ternary anode material coating 123 on the surface of the plane section 11 of the first pole piece 1, which is close to the innermost layer second pole piece 2, is connected with the anode material coating 121 on the surface of the curved section 12 of the first pole piece 1, which is close to the innermost layer second pole piece 2.

It is to be understood that, as shown in fig. 1, the surface of the first pole piece 1 close to the innermost second pole piece 2 has a plurality of positive electrode material coatings 121 and a plurality of ternary positive electrode material coatings 123, and each positive electrode material coating 121 is connected with the adjacent ternary positive electrode material coating 123. That is, the two opposite surfaces of the bent section 12 on the first pole piece 1, the surface close to the innermost second pole piece 2 is coated with the positive electrode material coating 121, and the surface far from the innermost second pole piece 2 is coated with the ternary positive electrode material coating 123. The two opposite surfaces of the planar section 11 on the first pole piece 1 are coated with the ternary positive pole material coating 123. In some embodiments, as shown in fig. 1, a first tab 4 and a second tab 5 are also included.

The first pole lugs 4 are multiple and are all connected with the first pole piece 1, and the multiple first pole lugs 4 are arranged on the first pole piece 1 at intervals along the winding direction. The second pole lugs 5 are multiple and are all connected with the second pole piece 2, and the second pole lugs 5 are arranged on the second pole piece 2 at intervals along the winding direction.

The first pole piece 1 is a positive pole piece of the winding battery cell, and the first tab 4 is a positive pole tab of the winding battery cell. The second tab 2 is a negative tab of the winding cell, and the second tab 5 is a negative tab of the winding cell. Utmost point ear is used for the guide to convolute the electric current on the positive and negative pole piece of electric core, through set up a plurality of first utmost point ears 4 and set up a plurality of second utmost point ears 5 on second pole piece 2 on first pole piece 1, thereby improve the utility model discloses the electric conductivity and the conduction speed of coiling electric core.

Optionally, the number of first tabs 4 on the first pole piece 1 is the same as the number of second tabs 5 on the second pole piece 2. The first tab 4 on the first pole piece 1 and the second tab 5 on the second pole piece 2 are both located on the same side of the winding cell.

Further, as shown in fig. 2 and 3, the first pole piece 1 is in the unfolded state. A plurality of first tabs 4 are arranged at intervals along the length direction (left-right direction in fig. 3) of the first pole piece 1. And, the distance between the adjacent first tabs 4 gradually increases in the left-to-right direction.

In some embodiments, as shown in fig. 3 and 4, a plurality of positioning coating blocks 6 are provided on the first pole piece 1, the positioning coating blocks 6 are located between two adjacent first pole tabs 4, and/or the positioning coating blocks 6 are located on one side of the first pole tabs 4 in the winding direction, and the positioning coating blocks 6 are used for positioning the conductive adhesive coating layer 122 and the lithium iron phosphate positive electrode material coating layer 121.

It will be appreciated that the number of location pads 6 is determined by the number of winding turns of the wound core. In other words, the number of bent sections 12 on the first pole piece 1 is the same as the number of positioning pads 6.

As shown in fig. 3, the dotted line is a portion of the first pole piece 1 to be cut, and the positioning coating block 6 is disposed on the portion of the first pole piece 1 to be cut. The first pole piece 1 is in an unfolded state, and before the positive electrode material coating 121 is coated on the first pole piece 1, a plurality of positioning coating blocks 6 are coated on the first pole piece 1 by using a colored pigment. The positioning coating block 6 plays a role in positioning the subsequent coating of the positive electrode material 121 on the first pole piece 1. After the coating of the positive electrode material coating 121, the conductive glue coating 122 and the ternary positive electrode material coating 123 is completed, the empty foil at the dotted part on the first pole piece 1 is cut off, and then the first pole piece 1 is wound.

Optionally, the positioning coating block 6 is positioned between two adjacent first tabs 4. For example, the plurality of positioning blocks 6 are each located between two adjacent ones of the plurality of first tabs 4. Or, a positioning coating block 6 is arranged between every two adjacent first tabs 4 along the winding direction. Or a plurality of positioning coating blocks 6 are arranged between every two adjacent first tabs 4 along the winding direction.

Alternatively, the positioning coating block 6 is located on one side of the first tab 4 in the winding direction. It is understood that the plurality of positioning blocks 6 are all located at one side of the first tab 4 in the winding direction, or a part of the plurality of positioning blocks 6 is located at one side of the first tab 4 in the winding direction and the rest of the plurality of positioning blocks 6 is located at the other side of the first tab 4 in the winding direction.

Specifically, as shown in fig. 3, the number of positioning blocks 6 is three. In an unfolded state of the first pole piece 1, two positioning coating blocks 6 are arranged between a first pole lug 4 and a second first pole lug 4 in the left-to-right direction, and one positioning coating block 6 is arranged between the second first pole lug 4 and a third first pole lug 4.

Consequently, through set up location coating block 6 on the medial surface of the bending section 12 of first pole piece 1, guaranteed the validity of anodal material coating 121 location, thereby improved the utility model discloses the production efficiency of coiling electricity core. In some embodiments, as shown in fig. 1 to 4, the widths of the conductive glue coating 122 and the coating 121 of positive electrode material on the curved section 12 at different positions gradually increase from inside to outside along the winding direction of the first pole piece 1.

It can be understood that, as shown in fig. 1, after the cell is wound, the radius of the curved section 12 of the first pole piece 1 gradually increases from inside to outside along the winding direction of the first pole piece 1, so that the widths of the conductive glue coating 122 and the positive electrode material coating 121 on the curved section 12 of the first pole piece 1 gradually increase from inside to outside along the winding direction of the first pole piece 1. The widths of the conductive glue coating layer 122 and the lithium iron phosphate positive electrode material coating layer 121 refer to the lengths in the left-right direction as shown in fig. 3.

In some embodiments, as shown in fig. 2, the thickness of the ternary positive electrode material coating 123 is equal to the sum of the thicknesses of the conductive glue coating 122 and the positive electrode material coating 121. Wherein the thickness refers to a distance in the up-down direction as shown in fig. 2.

Optionally, as shown in fig. 2, the first pole piece 1 is in an unfolded state, the inner side surface of the first pole piece 1 is coated with a positive electrode material coating 121 and a ternary positive electrode material coating 123, and the inner side surface of the positive electrode material coating 121 is coated with a conductive glue coating 122. The thickness of the ternary positive electrode material coating 123 on the inner side surface of the first pole piece 1 is equal to the sum of the thicknesses of the positive electrode material coating 121 and the conductive glue coating 122, so that the compactness of the structure between the first pole piece 1 and the diaphragm 3 is ensured.

In some embodiments, the conductive glue coat 122 is a mixture coating of polyvinylidene fluoride and a conductive agent. It can be understood that the conductive glue coating 122 increases the adhesion between the bent segment 12 of the first pole piece 1 and the diaphragm 3, and on the other hand, a small amount of conductive agent is blended to ensure conductivity, thereby avoiding the increase of internal resistance. For example, the conductive agent is conductive carbon black and/or conductive graphite.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

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 implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations to the above embodiments by those of ordinary skill in the art are intended to be within the scope of the present invention.

Claims (9)

1. The winding battery cell is characterized by comprising a first pole piece (1), a second pole piece (2) and a diaphragm (3) which are arranged in a winding mode, wherein the diaphragm (3) is arranged between the first pole piece (1) and the second pole piece (2), the second pole piece (2) is located on the innermost layer, the first pole piece (1) comprises a plurality of plane sections (11) and bending sections (12) which are connected in an alternating mode, a positive electrode material coating (121) is arranged on the surface, close to the innermost layer, of at least one bending section (12), and the gram capacity of the positive electrode material coating (121) is 110-150mAh/g.

2. The winding cell of claim 1, characterized in that a conductive glue layer (122) is further provided between the coating of positive electrode material (121) and the separator (3).

3. The winding cell according to claim 2, characterized in that the surface of the curved segment (12) remote from the innermost layer of the second pole piece (2) is provided with a coating (123) of a ternary positive electrode material;

and/or the surface of the plane section (11) far away from the innermost layer of the second pole piece (2) is provided with a ternary anode material coating (123);

and/or the surface of the plane section (11) close to the innermost layer of the second pole piece (2) is provided with a ternary positive pole material coating (123).

4. The wound cell of claim 3, characterized in that the surface of the curved section (12) remote from the innermost second pole piece (2) is provided with the ternary coating of positive electrode material (123), the surface of the planar section (11) remote from the innermost second pole piece (2) and the surface of the planar section (11) close to the innermost second pole piece (2) are both provided with the ternary coating of positive electrode material (123), and the ternary coating of positive electrode material (123) on the surface of the planar section (11) close to the innermost second pole piece (2) meets the coating of positive electrode material (121).

5. The winding cell of claim 2, further comprising:

the first pole lugs (4) are multiple and are connected with the first pole piece (1), and the multiple first pole lugs (4) are arranged on the first pole piece (1) at intervals along the winding direction;

the second pole lug (5), second pole lug (5) are a plurality of and all link to each other with second pole piece (2), a plurality of second pole lug (5) along the winding direction on second pole piece (2) interval arrangement.

6. The winding cell according to claim 5, wherein a plurality of positioning coating blocks (6) are arranged on the first pole piece (1), the positioning coating blocks (6) are located between two adjacent first pole lugs (4), and/or the positioning coating blocks (6) are located on one side of the first pole lugs (4) in the winding direction, and the positioning coating blocks (6) are used for positioning the conductive adhesive coating (122) and the positive electrode material coating (121).

7. The winding cell of claim 3, characterized in that the width of the conductive glue layer (122) and the coating of positive electrode material (121) on the curved section (12) at different positions increases gradually from the inside to the outside along the winding direction of the first pole piece (1).

8. The winding cell of claim 3, wherein the thickness of the ternary coating of positive electrode material (123) is equal to the sum of the thicknesses of the conductive glue layer (122) and the coating of positive electrode material (121).

9. The wound electric core according to any of claims 1 to 8, characterized in that the first pole piece (1) is a positive pole piece and the second pole piece (2) is a negative pole piece.

Images