Composite current collector battery and production process thereof

Abstract

The invention discloses a composite current collector battery which comprises a composite current collector, the composite current collector comprises an organic polymer film, metal foils are arranged on the two sides of the organic polymer film respectively, the two sides of the composite current collector are coated with active substances, and the active substances on the two sides are intermittently coated on the composite current collector. A first coating gap and a second coating gap are respectively formed on two sides of the composite current collector, and a first tab and a second tab are respectively welded on the first coating gap and the second coating gap. On one hand, the coating gap is directly reserved on the composite current collector in an intermittent coating mode, and a thermal decomposition adhesive tape does not need to be pasted on the composite current collector; and on the other hand, the tabs are ultrasonically welded on the coating gaps on the two sides of the composite current collector in a manner of overturning the composite current collector, so that the production process of the composite current collector battery is simplified, the tabs of the composite current collector battery can be welded by equipment for welding the tabs of the traditional lithium battery, and the production cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of lithium batteries, and in particular relates to a composite current collector battery and a production process thereof. Background Art

[0002] With the development of science and technology, lithium battery technology has also ushered in innovation. As a new technology in the lithium battery industry, the composite current collector battery adopts a "sandwich" structure of the current collector, that is, a polymer material layer in the middle and a metal conductive layer on both sides, which significantly improves the energy density, safety and economy of the battery. This technology overcomes the limitations of traditional metal current collectors in weight, cost and safety, and has become an important development direction for the battery industry. Due to the difference between the structure of the composite current collector battery and the structure of the traditional lithium battery, due to its special "sandwich" structure, it is impossible to directly weld a single pole ear like traditional foil to achieve conduction between the foils on both sides. If ultrasonic welding is used to directly weld the pole ear through the middle structural layer to make the conductors on both sides conductive, there is a problem of frequent cleaning of the welding die and reduced die service life; in severe cases, the pole ear and the welding die will stick together, and the problem of being unable to achieve automated film production will be unfavorable for post-process production.

[0003] In the prior art, for example, the patent document with publication number CN117317533A discloses a composite current collector welding pole ear method, which is to apply a thermal decomposition tape to the pole ear area of ​​the composite current collector, remove the thermal decomposition tape after the composite current collector is baked, obtain a blank pole ear area, and then weld the pole ear to the blank pole ear area by radium welding, and apply additional foil and active material slurry on the welded pole ear. Although this method enhances the bending resistance of the pole ear and prevents the bending of the pole ear from causing a short circuit in the battery, its production process is quite different from that of traditional lithium batteries, and requires additional research and development or the purchase of a new production line, and the production cost is high. Summary of the invention

[0004] In response to the problems in the prior art, the present invention proposes a composite current collector battery and a production process thereof. On the one hand, a coating gap is directly reserved on the composite current collector by intermittent coating, and there is no need to stick a thermal decomposition tape on the composite current collector. On the other hand, the composite current collector is flipped over and the pole ears are ultrasonically welded to the coating gaps on both sides of the composite current collector, thereby simplifying the production process of the composite current collector battery and making the production process of the composite current collector battery similar to that of traditional lithium batteries. Furthermore, the equipment for welding the pole ears of traditional lithium batteries can be used to weld the pole ears of the composite current collector battery, without the need for additional research and development or purchase of new production equipment, thereby reducing production costs.

[0005] The present invention is implemented as follows: a composite current collector battery, including a composite current collector, formed by winding the composite current collector, the composite current collector including an organic polymer film, metal foils are respectively provided on both sides of the organic polymer film, both sides of the composite current collector are coated with active materials, and the active materials on both sides are intermittently coated on the composite current collector, so that the two sides of the composite current collector form a first coating gap and a second coating gap respectively. In the coating process of the existing composite current collector battery, it is necessary to apply a thermal decomposition tape on the composite current collector before coating, and then continuously coat the composite current collector with the decomposition tape, and then remove the thermal decomposition tape to obtain a blank pole ear area. Compared with the traditional lithium battery coating process, there are more steps of applying the thermal decomposition tape and removing the thermal decomposition tape. The traditional lithium battery coating equipment does not have a corresponding station, and it is impossible to apply and remove the thermal decomposition tape. It is necessary to develop or purchase new coating equipment, and the production cost is high. The present application forms a coating gap directly on the composite current collector by intermittent coating, which simplifies the coating process of the composite current collector, makes traditional lithium battery coating equipment suitable for the production of current collector batteries, and reduces production costs.

[0006] The first and second pole tabs are welded to the first coating gap and the second coating gap, respectively; high-temperature tapes are provided on both sides of the composite current collector, and the high-temperature tapes on each side are respectively attached to the first coating gap and the second coating gap, and completely cover the first coating gap and the second coating gap. In the existing composite current collector battery pole tab welding process, high-temperature quick-drying glue is usually applied at the coating gap, and then the pole tab is welded to the coating gap, and then high-temperature quick-drying glue is applied again at the overlapping part of the composite current collector and the pole tab welding, and additional foil is attached to improve the anti-bending ability of the pole tab. Compared with the traditional lithium battery pole tab welding process, there are more steps of applying high-temperature quick-drying glue multiple times and attaching additional foil. The traditional lithium battery welding pole tab equipment does not have the corresponding workstation, and it is impossible to apply high-temperature quick-drying glue multiple times and attach additional foil. It is necessary to develop or purchase new pole tab welding equipment, which increases the production cost. The pole ear of the present application is provided with multiple embossings protruding toward one side, which improves the bending resistance of the pole ear and is directly welded to the coating gap by ultrasonic welding, without the need for multiple coatings of high-temperature quick-drying glue and additional covering foil, thereby simplifying the pole ear welding process of the composite current collector battery and reducing production costs.

[0007] Preferably, the projections of the first electrode tab and the second electrode tab on the composite current collector are staggered or overlapped;

[0008] When the projections of the first pole ear and the second pole ear on the composite current collector are misaligned, a pole ear welding spacing is formed between the first pole ear and the second pole ear, and the pole ear welding spacing is W, W = the inner circle diameter before the composite current collector is wound * π * correction coefficient. Since the composite current collector battery is formed by winding, a pre-rolled diaphragm is provided on the composite current collector. When the projections of the first pole ear and the second pole ear on the composite current collector are misaligned, the spacing between the two is the circumference of the composite current collector pre-rolled diaphragm after winding, so that the first pole ear and the second pole ear overlap after winding, making the pole ears easier to assemble and improving the convenience of subsequent processes.

[0009] Specifically, the inner circle diameter of the composite current collector before winding = (winding needle diameter + diaphragm thickness*2*diaphragm pre-winding number of turns*2+negative electrode thickness*negative electrode pre-winding number of turns*2)*correction coefficient.

[0010] Specifically, when the projections of the first pole ear and the second pole ear on the composite current collector are misaligned, the active material on the corresponding side of the outer side of the second pole ear is taken as the origin, the distance from the outer side of the first pole ear to the origin is G2, and the distance from the outer side of the second pole ear to the origin is G1, where G2 = pole ear welding spacing W + pole ear width + G1, G1 = inner circle diameter before winding of the second pole ear * π * correction coefficient. And the landing point of the outer side of the first pole ear does not fall on the maximum winding stress to prevent the pole piece from breaking. Since the composite current collector battery is formed by winding, when the first pole ear or the second pole ear is wound, it will tilt in the winding direction. If the first pole ear or the second pole ear is too close to the active material, there is a risk of contact, and the active material usually has a high resistivity. When the first pole ear or the second pole ear contacts the active material, the internal resistance of the composite current collector battery will increase, resulting in the generation of additional heat during the charge and discharge process of the composite current collector battery, reducing the efficiency and service life of the composite current collector battery.

[0011] Specifically, when the projections of the first pole ear and the second pole ear on the composite current collector overlap, the weld mark of the first pole ear and the weld mark of the second pole ear are arranged side by side along the width direction of the composite current collector, thereby preventing the weld mark of the first pole ear from overlapping with the weld mark of the second pole ear, resulting in secondary welding of a partial area of ​​the first pole ear or the second pole ear, thereby reducing the risk of the first pole ear and the second pole ear being welded through.

[0012] Preferably, the first pole lug and the second pole lug include pure aluminum pole lugs, pure nickel pole lugs, and copper-plated nickel pole lugs. The length of the pole lugs conforms to industry common sense, the width of the pole lugs is 2 to 5 mm, and the thickness of the pole lugs is 0.05 to 0.20 mm.

[0013] Preferably, the types of composite current collectors include composite copper foil current collectors and composite aluminum foil current collectors. On the one hand, composite copper foil and composite aluminum foil are lighter than traditional metal current collectors because their polymer material layers have low density and light weight. This lightweight design can significantly reduce the overall weight of the battery, thereby increasing the energy density of the battery under the same volume; on the other hand, the raw material cost of composite copper foil and composite aluminum foil is relatively low, which can reduce production costs.

[0014] A production process of a composite current collector battery, applied to the above-mentioned composite current collector battery, comprises the following steps:

[0015] S1: Homogenize, stir the active substance evenly;

[0016] S2: coating, spraying the stirred active material intermittently on the composite current collector;

[0017] S3: Rolling, passing the composite current collector sprayed with the active material through two rollers, and pressing the active material sprayed on the composite current collector to a set density through the rollers;

[0018] S4: Slitting, cutting the composite current collector after rolling into a set width;

[0019] S5: sheeting, welding the tabs to both sides of the composite current collector;

[0020] S6: Winding, winding the composite current collector after welding the pole ears into a columnar shape, and the pole ears after winding overlap each other to form a wound battery cell;

[0021] S7: Assembling, welding the battery cap to the wound battery cell to form a preliminary battery cell;

[0022] S8: baking, baking the preliminary battery cells to remove moisture in the preliminary battery cells;

[0023] S9: Liquid injection, injecting electrolyte into the baked preliminary electric box to form a liquid-injected battery cell;

[0024] S10: Formation, the first charge and discharge of the liquid-filled battery cell is performed to activate the internal active substances and form a stable solid electrolyte interface film on the surface of the negative electrode to form a finished battery cell.

[0025] Preferably, step S5 specifically includes the following steps:

[0026] S5-1: loading, unwinding the composite current collector by driving the motor, and correcting the composite current collector during unwinding;

[0027] S5-2: welding the pole ear for the first time, the unwound composite current collector passes through the first super welding upper mold and the first super welding bottom mold, and the first super welding upper mold and the first super welding bottom mold weld the pole ear to one side of the composite current collector to form a single pole ear pole piece;

[0028] S5-3: Flipping, winding the single-pole ear pole piece between a plurality of rollers to flip the single-pole ear pole piece;

[0029] S5-4: Secondary welding of the pole ear, passing the flipped single pole ear pole piece through the second super welding upper mold and the second super welding bottom mold, and the second super welding upper mold and the second super welding bottom mold weld the other pole ear to the other side of the single pole ear pole piece.

[0030] Specifically, step S5 also includes the following steps:

[0031] S5-5: Identify the welding spacing of the tabs, detect the welding spacing of the tabs on the bipolar tabs, and attach alignment / misalignment labels to the corresponding areas to distinguish good and defective products.

[0032] Beneficial effects of the present invention:

[0033] The present invention proposes a composite current collector battery and a production process thereof. On the one hand, a coating gap is directly reserved on the composite current collector by intermittent coating, so that the composite current collector forms a structure in which active substances and coating gaps are arranged in sequence in a cycle, and a welding area for a pole ear can be reserved without sticking a thermal decomposition tape on the composite current collector; on the other hand, the pole ears are ultrasonically welded to the coating gaps on both sides of the composite current collector by flipping the composite current collector, thereby simplifying the production process of the composite current collector battery and making the production process of the composite current collector battery similar to that of a traditional lithium battery, thereby enabling the equipment for welding the pole ears of a traditional lithium battery to weld the pole ears of a composite current collector battery, without the need for additional research and development or purchase of new production equipment, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagrams of the front and side surfaces of the composite current collector battery of the present invention;

[0035] Figure 2 It is a schematic diagram of the development of Example 1 of the composite current collector battery of the present invention;

[0036] Figure 3 It is a schematic diagram of the development of Example 2 of the composite current collector battery of the present invention;

[0037] Figure 4 It is a schematic diagram of the development of Example 3 of the composite current collector battery of the present invention;

[0038] Figure 5 The overall flow chart of the composite current collector battery production process of the present invention;

[0039] Figure 6 is a specific flow chart of step S5 of the composite current collector battery production process of the present invention;

[0040] Figure 7 It is a schematic diagram of the belt conveying in step S5 of the composite current collector battery production process of the present invention.

[0041] Reference numerals:

[0042] 1. Composite current collector; 2. Active material; 3. First pole ear; 4. Second pole ear; 5. High temperature tape. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] like Figure 1-Figure 2 As shown, a composite current collector battery comprises a composite current collector 1, which is formed by winding the composite current collector 1, wherein the composite current collector 1 comprises an organic polymer film, and metal foils are respectively provided on both sides of the organic polymer film.

[0046] In this embodiment, the composite current collector 1 is a composite copper foil current collector. On the one hand, the composite copper foil is lighter than the traditional metal current collector because their polymer material layer has low density and light weight. This lightweight design can significantly reduce the overall weight of the battery, thereby increasing the energy density of the battery under the same volume; on the other hand, the raw material cost of the composite copper foil is relatively low, which can reduce the production cost.

[0047] Both sides of the composite current collector 1 are coated with active materials 2, and the active materials 2 on both sides are intermittently coated on the composite current collector 1, so that the first coating gap and the second coating gap are formed on both sides of the composite current collector 1, respectively. In the coating process of the existing composite current collector 1 battery, it is necessary to apply a thermal decomposition tape on the composite current collector 1 before coating, and then continuously coat the composite current collector 1 with the decomposition tape, and then remove the thermal decomposition tape to obtain a blank pole ear area. Compared with the traditional lithium battery coating process, there are additional steps of applying and removing the thermal decomposition tape. The traditional lithium battery coating equipment does not have a corresponding station, and it is impossible to apply and remove the thermal decomposition tape. It is necessary to develop or purchase new coating equipment, and the production cost is high. However, the present application directly forms a coating gap on the composite current collector 1 by intermittent coating, simplifies the coating process of the composite current collector 1, makes the traditional lithium battery coating equipment suitable for the production of current collector batteries, and reduces the production cost.

[0048] The first coating gap and the second coating gap are respectively welded with a first electrode tab 3 and a second electrode tab 4;

[0049] In this embodiment, the first pole tab 3 and the second pole tab 4 are respectively a pure aluminum pole tab and a pure nickel pole tab, the length of the pole tabs is in line with the common sense in the industry, the width of the pole tabs is 3 mm, and the thickness of the pole tabs is 0.10 mm.

[0050] Both sides of the composite current collector 1 are provided with high-temperature adhesive tapes 5, and the high-temperature adhesive tapes 5 on each side are respectively attached to the first coating gap and the second coating gap, and completely cover the first coating gap and the second coating gap. In the existing composite current collector 1 battery tab welding process, high-temperature quick-drying glue is usually applied at the coating gap, and then the tab is welded to the coating gap, and then high-temperature quick-drying glue is applied again at the overlapped part of the composite current collector 1 and the tab welding, and additional foil is attached to improve the tab's anti-bending ability. Compared with the traditional lithium battery tab welding process, there are more steps of applying high-temperature quick-drying glue multiple times and attaching additional foil. The traditional lithium battery welding tab equipment does not have the corresponding workstation, and it is impossible to apply high-temperature quick-drying glue multiple times and attach additional foil. It is necessary to develop or purchase new tab welding equipment, which increases the production cost. The pole ear of the present application is provided with multiple stamps protruding toward one side, which improves the bending resistance of the pole ear and is directly welded to the coating gap by ultrasonic welding, without the need for multiple coatings of high-temperature quick-drying glue and additional covering foil, thereby simplifying the pole ear welding process of the composite current collector 1 battery and reducing production costs.

[0051] In this embodiment, the projections of the first electrode tab 3 and the second electrode tab 4 on the composite current collector 1 are staggered;

[0052] In this embodiment, the first coating gap is located on the upper side of the composite current collector 1, and the first pole ear 3 is located on the left side of the first coating gap; the second coating gap is located on the lower side of the composite current collector 1, and the second pole ear 4 is located on the right side of the second coating gap, so that the projections of the first pole ear 3 and the second pole ear 4 on the composite current collector 1 are staggered.

[0053] When the projections of the first pole tab 3 and the second pole tab 4 on the composite current collector 1 are misaligned, a pole tab welding spacing is formed between the first pole tab 3 and the second pole tab 4, and the pole tab welding spacing is W, where W=the inner circle diameter of the composite current collector 1 before winding*π*correction coefficient. Since the composite current collector 1 battery is formed by winding, a pre-rolled diaphragm is provided on the composite current collector 1. When the projections of the first pole tab 3 and the second pole tab 4 on the composite current collector 1 are misaligned, the spacing between the two is the circumference of the pre-rolled diaphragm of the composite current collector 1 after winding, so that the first pole tab 3 and the second pole tab 4 after winding overlap, making the pole tabs easier to assemble and improving the convenience of subsequent processes.

[0054] Specifically, the inner circle diameter of the composite current collector 1 before winding = (winding needle diameter + diaphragm thickness*2*diaphragm pre-winding number of turns*2+negative electrode thickness*negative electrode pre-winding number of turns*2)*correction coefficient.

[0055] Specifically, when the projections of the first pole ear 3 and the second pole ear 4 on the composite current collector 1 are misaligned, the active material on the corresponding side of the outer side of the second pole ear 4 is taken as the origin, the distance from the outer side of the first pole ear 3 to the origin is G2, and the distance from the outer side of the second pole ear 4 to the origin is G1, where G2 = pole ear welding spacing W + pole ear width + G1, G1 = inner circle diameter before winding of the second pole ear * π * correction coefficient. And the landing point of the outer side of the first pole ear does not fall at the maximum winding stress to prevent the pole piece from breaking. Since the composite current collector 1 battery is formed by winding, when the first pole ear 3 or the second pole ear 4 is wound, it will tilt in the winding direction. If the first pole ear 3 or the second pole ear 4 is too close to the active material 2, there is a risk of contact, and the active material 2 usually has a high resistivity. When the first pole ear 3 or the second pole ear 4 contacts the active material 2, the internal resistance of the composite current collector 1 battery will increase, resulting in the generation of additional heat during the charging and discharging process of the composite current collector 1 battery, thereby reducing the efficiency and service life of the composite current collector 1 battery.

[0056] Example 2

[0057] like Figure 3 As shown, one of the embodiments of the present invention, the main technical scheme of this embodiment is the same as that of embodiment 1, and the features not explained in this embodiment are explained in embodiment 1, and will not be repeated here. The difference between this embodiment and embodiment 1 is:

[0058] In this embodiment, the first coating gap is located at the lower side of the composite current collector 1, and the first pole ear 3 is located on the left side of the first coating gap; the second coating gap is located at the upper side of the composite current collector 1, and the second pole ear 4 is located on the right side of the second coating gap, so that the projections of the first pole ear 3 and the second pole ear 4 on the composite current collector 1 are staggered.

[0059] Example 3

[0060] like Figure 4 As shown, one of the embodiments of the present invention, the main technical scheme of this embodiment is the same as that of embodiment 1, and the features not explained in this embodiment are explained in embodiment 1, and will not be repeated here. The difference between this embodiment and embodiment 1 is:

[0061] In this embodiment, in this embodiment, the projections of the first pole ear 3 and the second pole ear 4 on the composite current collector 1 overlap; when the projections of the first pole ear 3 and the second pole ear 4 on the composite current collector 1 overlap, the weld mark of the first pole ear 3 and the weld mark of the second pole ear 4 are arranged side by side along the width direction of the composite current collector 1, preventing the weld mark of the first pole ear 3 from overlapping with the weld mark of the second pole ear 4, resulting in secondary welding of part of the first pole ear 3 or the second pole ear 4, thereby reducing the risk of the first pole ear 3 and the second pole ear 4 being welded through.

[0062] Example 4

[0063] like Figure 5-Figure 7 As shown, a production process of a composite current collector 1 battery is applied to the composite current collector 1 battery described in Examples 1-3, comprising the following steps:

[0064] S1: homogenization, stirring the active substance 2 evenly;

[0065] S2: coating, spraying the stirred active material 2 intermittently on the composite current collector 1;

[0066] S3: Rolling, passing the composite current collector 1 sprayed with the active material 2 between two rollers, and pressing the active material 2 sprayed on the composite current collector 1 to a set density through the rollers;

[0067] S4: Slitting, cutting the composite current collector 1 after rolling into a set width;

[0068] S5: sheeting, welding the tabs to both sides of the composite current collector 1;

[0069] S6: Winding, winding the composite current collector 1 after welding the electrode tabs into a columnar shape, and the electrode tabs after winding overlap each other to form a wound battery cell;

[0070] S7: Assembling, welding the battery cap to the wound battery cell to form a preliminary battery cell;

[0071] S8: baking, baking the preliminary battery cells to remove moisture in the preliminary battery cells;

[0072] S9: Liquid injection, injecting electrolyte into the baked preliminary electric box to form a liquid-injected battery cell;

[0073] S10: Formation, charging and discharging the liquid-filled battery cell for the first time to activate the internal active material 2 and form a stable solid electrolyte interface film on the surface of the negative electrode to form a finished battery cell.

[0074] Preferably, step S5 specifically includes the following steps:

[0075] S5-1: loading, unwinding the composite current collector 1 by driving a motor, and correcting the unwinding composite current collector 1;

[0076] S5-2: welding the pole ear for the first time, the unwound composite current collector 1 passes through the first super welding upper mold and the first super welding bottom mold, and the first super welding upper mold and the first super welding bottom mold weld the pole ear to one side of the composite current collector 1 to form a single pole ear pole piece;

[0077] S5-3: Flipping, winding the single-pole ear pole piece between a plurality of rollers to flip the single-pole ear pole piece;

[0078] S5-4: Secondary welding of the pole ear, passing the flipped single pole ear pole piece through the second super welding upper mold and the second super welding bottom mold, and the second super welding upper mold and the second super welding bottom mold weld the other pole ear to the other side of the single pole ear pole piece.

[0079] Specifically, step S5 also includes the following steps:

[0080] S5-5: Identify the welding spacing of the tabs, detect the welding spacing of the tabs on the bipolar tabs, and attach alignment / misalignment labels to the corresponding areas to distinguish good and defective products.

[0081] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A composite current collector battery, comprising a composite current collector, which is formed by winding the composite current collector, the composite current collector comprising an organic polymer film, metal foils are provided on both sides of the organic polymer film, and active materials are coated on both sides of the composite current collector, characterized in that: The active materials on both sides are intermittently coated on the composite current collector, so that a first coating gap and a second coating gap are formed on both sides of the composite current collector, respectively, and a first electrode tab and a second electrode tab are welded on the first coating gap and the second coating gap, respectively; high-temperature tapes are provided on both sides of the composite current collector, and the high-temperature tapes on each side are respectively attached to the first coating gap and the second coating gap, and completely cover the first coating gap and the second coating gap.

2. A composite current collector battery according to claim 1, characterized in that: The projections of the first electrode tab and the second electrode tab on the composite current collector are arranged in a staggered manner or overlapped; When the projections of the first pole tab and the second pole tab on the composite current collector are misaligned, a pole tab welding distance is formed between the first pole tab and the second pole tab, and the pole tab welding distance is W, where W=the inner ring diameter of the composite current collector before winding*π*correction coefficient.

3. A composite current collector battery according to claim 2, characterized in that: The inner circle diameter of the composite current collector before winding = (winding needle diameter + diaphragm thickness*2*diaphragm pre-winding number of turns*2+negative electrode thickness*negative electrode pre-winding number of turns*2)*correction coefficient.

4. A composite current collector battery according to claim 2, characterized in that: When the projections of the first pole ear and the second pole ear on the composite current collector are misaligned, the active material on the corresponding side of the outer side of the second pole ear is taken as the origin, the distance from the outer side of the first pole ear to the origin is G2, and the distance from the outer side of the second pole ear to the origin is G1, wherein G2=pole ear welding spacing W+pole ear width+G1, G1=inner circle diameter of the second pole ear before winding*π*correction coefficient.

5. A composite current collector battery according to claim 2, characterized in that: When the projections of the first electrode tab and the second electrode tab on the composite current collector overlap, the weld mark of the first electrode tab and the weld mark of the second electrode tab are arranged side by side along the width direction of the composite current collector.

6. A composite current collector battery according to claim 1, characterized in that: The first pole tab and the second pole tab include a pure aluminum pole tab, a pure nickel pole tab, and a copper-plated nickel pole tab. The width of the pole tab is 2 to 5 mm, and the thickness of the pole tab is 0.05 to 0.20 mm.

7. A composite current collector battery according to claim 1, characterized in that: The types of composite current collectors include composite copper foil current collectors and composite aluminum foil current collectors.

8. A production process for a composite current collector battery, applied to the composite current collector battery of any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Homogenize, stir the active substance evenly; S2: coating, spraying the stirred active material intermittently on the composite current collector; S3: Rolling, passing the composite current collector sprayed with the active material between two rollers, and pressing the active material sprayed on the composite current collector to a set density through the rollers; S4: Slitting, cutting the composite current collector after rolling into a set width; S5: sheeting, welding the tabs to both sides of the composite current collector; S6: Winding, winding the composite current collector after welding the pole ears into a columnar shape, and the pole ears after winding overlap each other to form a wound battery cell; S7: Assembling, welding the battery cap to the wound battery cell to form a preliminary battery cell; S8: baking, baking the preliminary battery cells to remove moisture in the preliminary battery cells; S9: Liquid injection, injecting electrolyte into the baked preliminary electric box to form a liquid-injected battery cell; S10: Formation, the first charge and discharge of the liquid-filled battery cell is performed to activate the internal active substances and form a stable solid electrolyte interface film on the surface of the negative electrode to form a finished battery cell.

9. The production process of a composite current collector battery according to claim 8, characterized in that: Step S5 specifically includes the following steps: S5-1: loading, driving the composite current collector to unwind by a motor, and correcting the composite current collector during unwinding; S5-2: welding the pole ear for the first time, the unwound composite current collector passes through the first super welding upper mold and the first super welding bottom mold, and the first super welding upper mold and the first super welding bottom mold weld the pole ear to one side of the composite current collector to form a single pole ear pole piece; S5-3: Flipping, winding the single-pole ear pole piece between a plurality of rollers to flip the single-pole ear pole piece; S5-4: Secondary welding of the pole ear, passing the flipped single pole ear pole piece through the second super welding upper mold and the second super welding bottom mold, and the second super welding upper mold and the second super welding bottom mold weld the other pole ear to the other side of the single pole ear pole piece.

10. The production process of a composite current collector battery according to claim 9, characterized in that: Step S5 also includes the following steps: S5-6: Identify the welding spacing of the tabs, detect the welding spacing of the tabs on the bipolar tabs, and attach alignment / misalignment labels to the corresponding areas to distinguish good and defective products.

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