Disclosure of Invention
One of the objects of the present invention is: aiming at the defects of the prior art, the preparation method of the multi-polar ear lithium ion battery is provided, the problem that an auxiliary material area and a blank foil area in a zebra coating process are different in extension is effectively solved, cathode and anode sheets required by the multi-polar ear battery are efficiently prepared, and the battery reaches better levels in the aspects of energy density, charging time, multiplying power discharging capacity, discharging temperature rise and the like.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a multi-electrode ear lithium ion battery comprises the following steps:
s1, preparing battery slurry, uniformly stirring the battery slurry, and coating the battery slurry on the foil by adopting a transverse double-gap coating method, so that the surface of the foil is provided with a plurality of coating areas and coating gaps which are alternately distributed;
s2, obtaining a plurality of initial pole pieces with the same size through rolling and slitting processes, wherein the surface of each initial pole piece is provided with a plurality of coating areas and coating gaps which are arranged at intervals;
s3, removing a top material area of the initial pole piece by adopting a die cutting process, and reserving a plurality of coating gaps to obtain a plurality of welding foil areas so as to manufacture a multi-pole-lug cathode piece and a multi-pole-lug anode piece;
s4, winding the multi-tab cathode sheet, the diaphragm and the multi-tab anode sheet into a bare cell;
and S5, welding, top-side sealing, liquid injection, formation, secondary sealing and capacity grading to obtain the multi-tab finished product battery cell.
The coating mode of the transverse double-gap coating method is as follows: first, coating of a length of a1 was performed, then the gap to obtain a length of B was broken, then coating of a length of a2 was performed again, then the gap to obtain a length of B was broken again, so that in this transversely repeated manner, coating of a1 length was sequentially performed, then breaking to obtain a gap of B length was performed, coating of a2 length was performed, then breaking to obtain a gap of B length, and coating was repeated. The lengths of A1 and A2 are determined according to the width of the battery cell and the tab outlet mode (full tab and half tab), when the full tab is adopted, A1 is not equal to A2, and when the half tab is adopted, A1 is equal to A2.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S5 further includes: in the welding process, a plurality of welding foil regions of a multi-tab cathode piece and a plurality of welding foil regions of a multi-tab anode piece are bent to form a folded tab, and a metal strip tab is welded to the folded tab, wherein the width of the selected metal strip tab is 0.8-1.25 times of the length of a coating gap, so that the metal strip tab forms a leading-out tab of a bare cell.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S4 further includes: make a plurality of welding foil district of the multi-tab negative pole piece of naked electric core and a plurality of welding foil district of multi-tab positive pole piece not contact each other, and make the bottom side or the top side of whole welding foil district distribution at naked electric core.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S1 further includes: in the transverse double gap coating, a plurality of coating regions having the same coating length are obtained by the transverse double gap coating method.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S1 further includes: in the transverse double-gap coating, the coating length of the previous coating area and the next coating area on the surface of the foil is different by adopting a transverse double-gap coating method, and the two specifications with different coating lengths are adopted to alternately coat on the surface of the foil in sequence.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S1 further includes: in the transverse double-gap coating, the coating width of the coating area on the surface of the foil is 3-8 times of the width of the pole piece required by the finished product battery core, so that a plurality of initial pole pieces with the same size are obtained by the slitting process.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S2 further includes: in the rolling process, the side edge empty foil of the pole piece is cut off before the cathode piece is rolled, and in the slitting process, the slitting width of the pole piece is the sum of the width of the pole piece required by the finished product battery core and the length of the welding foil area.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S3 further includes: in the die-cutting process, the spacing of adjacent ones of the plurality of welding foil sections is made the same or different.
As an improvement of the method for preparing the multi-polar ear lithium ion battery of the present invention, the S3 further includes: and when the top material area of the initial pole piece is removed in the die cutting process, a pole piece widening area is cut between the adjacent welding foil areas.
The second purpose of the invention is: the battery comprises pole pieces and a diaphragm, wherein the diaphragm is arranged between the pole pieces with opposite polarities, and the battery is prepared by the preparation method.
The invention has the beneficial effects that: the invention adopts a transverse double-gap coating method to prepare the pole piece, on one hand, the double gaps of the method are transverse and have smaller size, so that the transverse double-gap coating method can effectively shield the problem that the extension of an auxiliary material area and a hollow foil area in a zebra coating process is different, and the excellent rate of the battery is greatly improved.
Detailed Description
As used in this specification and the appended claims, certain terms are used to refer to particular components, and it will be appreciated by those skilled in the art that a manufacturer may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", horizontal ", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The present invention will be described in further detail with reference to the accompanyingdrawings 1 to 7 and specific examples, but the present invention is not limited thereto.
Example 1
A method for manufacturing a multi-electrode ear lithium ion battery, as shown in fig. 1 to 5, comprising the steps of:
s1, preparing battery slurry, uniformly stirring the battery slurry, and coating the battery slurry on the foil by adopting a transverse double-gap coating method, so that the surface of the foil is provided with a plurality ofcoating areas 1 andcoating gaps 2 which are alternately distributed;
s2, obtaining a plurality of initial pole pieces with the same size through rolling and slitting processes, wherein the surface of each initial pole piece is provided with a plurality ofcoating areas 1 andcoating gaps 2 which are arranged at intervals;
s3, removing a top material area of the initial pole piece by adopting a die cutting process, and reserving a plurality ofcoating gaps 2 to obtain a plurality of welding foil areas so as to manufacture a multi-pole-lug cathode piece and a multi-pole-lug anode piece;
s4, winding the multi-tab cathode sheet, the diaphragm and the multi-tab anode sheet into a bare cell;
and S5, welding, top-side sealing, liquid injection, formation, secondary sealing and capacity grading to obtain the multi-tab finished product battery cell.
The coating mode of the transverse double-gap coating method is as follows: first, coating of a length of a1 was performed, then the gap to obtain a length of B was broken, then coating of a length of a2 was performed again, then the gap to obtain a length of B was broken again, so that in this transversely repeated manner, coating of a1 length was sequentially performed, then breaking to obtain a gap of B length was performed, coating of a2 length was performed, then breaking to obtain a gap of B length, and coating was repeated. The lengths of A1 and A2 are determined according to the width of the battery cell and the tab outlet mode (full tab and half tab), when the full tab is adopted, A1 is not equal to A2, and when the half tab is adopted, A1 is equal to A2.
Preferably, the step of S1 further includes: in the transverse double-gap coating, the length L1 of thepreset coating gap 2 is 0.5 cm-3 cm, a plurality ofcoating areas 1 with the same coating length L2 are obtained by adopting a transverse double-gap coating method, and the ratio of L1/L2 is more than or equal to 0.15 and less than or equal to 0.35.
Wherein, thecoating gap 2 is used for forming a welding foil area after die cutting of the pole piece, and the transverse double-gap coating method not only improves the preparation efficiency of the pole piece, but also enables the size of the pole piece to have higher controllability, and in addition, the step of S1 further comprises: in the transverse double-gap coating, the coating width L3 of thecoating area 1 on the surface of the foil is 3-8 times of the width L4 of the pole piece required by the finished battery cell, so that a plurality of initial pole pieces with the same size are obtained by the slitting process.
Further, the step S2 includes: in the rolling process, the side edge empty foil of the pole piece is cut off before the cathode piece is rolled, and in the cutting process, the strip width L5 of the pole piece is the sum of the width L4 of the pole piece required by the finished battery core and the length of the welding foil area L6.
In the method for manufacturing the battery, the plurality of welded foil regions obtained in the step S3 are integral tabs of the cathode and anode sheets, and the step S3 further includes: in the die cutting process, the distance between the adjacent welding foil areas of the plurality of welding foil areas is the same, so that the sizes of a plurality of tabs of the cathode sheet are equal, and the sizes of a plurality of tabs of the anode sheet are equal.
Preferably, the step of S4 further includes: make a plurality of welding foil district of the multi-tab negative pole piece of naked electric core and a plurality of welding foil district of multi-tab positive pole piece not contact each other, and make the bottom side or the top side of whole welding foil district distribution at naked electric core, can make the welding foil district weld in the strap utmost point ear more high-efficiently.
In the method for manufacturing a battery, the step S5 further includes: in the welding process, a plurality of welding foil regions of the multi-tab cathode piece and a plurality of welding foil regions of the multi-tab anode piece are bent to form a folded tab, and a metal strip tab is welded to the folded tab, wherein the width of the selected metal strip tab is 0.8-1.25 times of the length L1 of thecoating gap 2, so that the metal strip tab forms a leading-out tab of a bare cell.
The embodiment adopts a transverse double-gap coating method to prepare the pole piece, on one hand, the double gaps of the method are transverse and have smaller size, so that the transverse double-gap coating method can effectively shield the problem that an auxiliary material area and a blank foil area in a zebra coating process are different in extension, the excellent rate of the battery is greatly improved, on the other hand, the combination of the transverse double-gap coating method and a die cutting process can be used for efficiently preparing the cathode and anode pieces required by the multi-tab battery, the multi-tab battery has obvious advantages in various aspects such as charging time, internal resistance and battery core temperature rise, and the battery is ensured to have excellent charging efficiency and cycle performance.
Example 2
Unlike example 1, as shown in fig. 6, in the transverse double gap coating process in step S1 of the present example, the coating length L2 of theprevious coating region 1 and thenext coating region 1 on the surface of the foil is made different by the transverse double gap coating method, the foil is coated alternately in sequence by two different coating length specifications, and the spacing between the adjacent welding foil regions of the plurality of welding foil regions is made different in the die cutting process in step S3, so that the manufacturing method of the present example can be flexibly applied to the efficient manufacturing of batteries of different specification sizes.
Other steps in this embodiment are the same as those inembodiment 1, and are not described herein again.
Example 3
Unlikeembodiment 1, as shown in fig. 7, step S3 in this embodiment further includes: when the top material area of the initial pole piece is removed in the die cutting process, a pole piece widening area is cut between the adjacent welding foil areas, wherein the pole piece widening area is shorter than the welding foil areas, the welding foil areas can form integrated pole lugs of the pole piece, and an extra pole piece structure with a proper size is additionally arranged between the pole lugs, so that the internal space of the battery can be reasonably utilized, the energy density of the battery is effectively improved, and the charging efficiency and the cycle performance of the battery are improved.
Other steps in this embodiment are the same as those inembodiment 1, and are not described herein again.
Example 4
A multi-electrode ear lithium ion battery comprises pole pieces and a diaphragm, wherein the diaphragm is arranged between the pole pieces with opposite polarities, and the battery is prepared by the preparation method of the embodiment 1-3.
Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.