CN101246970A - Winding method of lithium ion battery core - Google Patents

Abstract

The invention relates to a winding method of a lithium ion battery core, comprising unwinding a first diaphragm (10) and a second diaphragm (11) simultaneously by respective unwinding mechanisms (20, 21), so that the two The sources of the diaphragms are bonded together and sent to be clamped between the upper pressing block (30) and the lower pressing block (31) of the winding machine, and then threading the winding needle, inserting the two electrode sheets and other steps, and then driving the upper pressing block (30) and the lower pressing block (31). The pressure block (30) and the lower pressure block (31) are relatively close to clamp the next first diaphragm (10) and second diaphragm (11), and make the two diaphragms stick together at the clamped part, and start the diaphragm Cutter (60) cuts off the two diaphragms, and the coil core prototype that has been rolled is compressed and bound into a lithium-ion battery coil core. Compared with the prior art, the present invention can greatly reduce the cost of lithium battery winding cores, while being applicable to semi-automatic and full-automatic winding equipment, and improving production efficiency.

Description

Winding method of lithium ion battery core

technical field

The invention relates to a manufacturing method of a secondary battery, in particular to a winding method of a lithium ion battery winding core.

Background technique

The winding of lithium-ion battery electrode group winding core has always been an important aspect that affects the cost and production efficiency of lithium-ion batteries. The winding methods of lithium-ion battery cores in the prior art mainly include the following three methods:

1. As shown in Figure 1, use a single roll of diaphragm to unwind. When threading the needle, as shown in Figure 1A, the upper and lower rolls of needles 2 and 3 clamp the diaphragm 1 in the middle, and the first half of the diaphragm 1 bypasses the lower The winding needle 3 is then folded back to wrap the lower winding needle 3, so that the diaphragm 1 can be directly loaded to achieve winding; as shown in Figure 1B, the winding needle is rotated clockwise by an angle, and the first electrode piece 4 is inserted; as shown in Figure 1B As shown in 1B, turn the winding needle counterclockwise, insert the second electrode sheet 5, and then turn the winding needle continuously to wind out the battery core. This method has the advantage of saving the diaphragm and thus reducing the cost of the battery, but it also has the following disadvantages: the diaphragm 1 needs to be unrolled to a certain length or cut off in advance, and then the diaphragm is wound up when winding, and the diaphragm is operated twice, which is easy to use when winding by hand. The diaphragm is damaged, and it is difficult to establish a constant tension or ensure that the tension of the two diaphragms is consistent when the diaphragm bypasses the needle during automatic winding, and the unwinding and winding of the diaphragm are not carried out at the same time, it is difficult to ensure the efficient operation of the equipment, and the production efficiency is low. Generally, only Suitable for manual operation.

2. As shown in Figure 2, two rolls of separator are used to unwind at the same time. When the roll needle is threaded, the upper and lower roll needles 2 and 3 sandwich the two layers of separator 100 in the middle. In the figure, 4 is the first electrode sheet , 5 is the second electrode piece, the method of clamping the diaphragm by the rolling needle is to control and adjust the small gap between the upper and lower rolling needles 2 and 3 planes so that the two rolling needles clamp the diaphragm 100, and insert the two electrode pieces apart Then turn over the winding needle repeatedly to wind out the lithium-ion battery core. The advantage of this method is that the tension of the two diaphragms can be controlled exactly the same, and it is easy to realize automation; the disadvantage is that four layers of diaphragms will be wasted before inserting the first electrode sheet 4, and the cationic diaphragm is a relatively expensive material, which greatly increases the battery life of the lithium battery. the cost of.

3. As shown in Figure 3, two rolls of diaphragms are also used to unwind at the same time. When the needles are threaded, two layers of diaphragms 100 are sandwiched between the upper and lower rolls of needles 2 and 3, and the two layers of diaphragms 100 are stretched out at the same time. The length corresponding to the width of the rolling needle, in the figure, 4 is the first electrode piece, 5 is the second electrode piece, the way that the rolling needle clamps the diaphragm is, before inserting the first electrode piece 4, make the gap between the two rolling needles The gap can be appropriately enlarged, so that the diaphragm 100 can slide between the two roll needles. When the roll needle is turned over, the separator 100 is folded back through the edge of the roll needle, and then the first electrode sheet 4 is inserted, and then the roll needle is turned over, and the second electrode sheet 5 is inserted. , and then continuously turn over the needle to wind out the core. The tension of the two diaphragms in this way can be controlled to be completely consistent, and it is easy to realize automation; compared with the second method, some diaphragms can be saved relatively; however, two layers of diaphragms will be wasted before inserting the first electrode sheet 4, and the lithium battery Costs are still high.

Contents of the invention

The technical problem to be solved by the present invention is to avoid the disadvantages of the above-mentioned prior art and propose a winding method for lithium-ion battery winding cores. By adopting the winding method of the present invention, the cost of lithium batteries can be greatly reduced, and at the same time It can also ensure high production efficiency, and can be adapted to semi-automatic or fully automatic winding equipment.

The present invention solves described technical problem and can realize by adopting following technical scheme:

A winding method for a lithium-ion battery winding core is proposed, comprising the steps of:

A. Unwind the first diaphragm and the second diaphragm at the same time by their respective unwinding mechanisms, so that the sources of the two diaphragms are bonded together and sent to be clamped between the upper pressing block and the lower pressing block of the winding machine. Tight, at this time, the first diaphragm and the second diaphragm intersect at the source to form an angle α;

B. Drive the upper and lower needles to stretch out to clamp the first diaphragm, so that the lower needle passes between the two diaphragms, and the upper needle is located on the top of the first diaphragm, and then the upper The briquetting block and the lower briquetting block are relatively separated to loosen the source where the two diaphragms are bonded together;

C. Insert the first electrode sheet between the lower surface of the lower winding needle and the second diaphragm, and drive the upper and lower winding needles to turn over so that the winding needle and the first diaphragm form an angle β, Then insert the second electrode sheet between the needle and the first diaphragm;

D. Drive the upper and lower roll needles to turn over continuously so that the two diaphragms and two electrode sheets are wound on the two roll needles to form the core prototype, and then drive the upper and lower roll needles to drive the core prototype to move to the upper pressing block and the lower pressing the outside of the block;

E. Drive the upper pressing block and the lower pressing block relatively close to clamp the next first diaphragm and the second diaphragm, and make the two diaphragms stick together at the clamped part, start the diaphragm cutter to cut off the two diaphragms , the prototype of the rolled core is compressed and wrapped into a lithium-ion battery core, and the upper and lower roll needles are driven to retract and then pulled out of the core, and the core is then sent to the receiving hopper;

F. The two septums cut off in step E are glued together at the front end of the cutting part, and become the winding source of the next winding core, and the upper and lower winding needles move back to the original position and stretch out the The first diaphragm is clamped, return to step B, and so on.

In the winding method of the lithium-ion battery core of the present invention, in the step C, the first electrode sheet and the second electrode sheet are pre-cut to a given length as required before being inserted.

In the winding method of the lithium-ion battery core of the present invention, in the steps A and E, the two diaphragms are bonded together by ultrasonic welding, that is, any one of the upper pressing block and the lower pressing block is made into an ultrasonic welding method. welding head.

In the winding method of the lithium-ion battery core of the present invention, in the steps A and E, the method of blanching the two diaphragms can also be used, specifically, heating the diaphragm cutter so that the temperature is sufficient to The two diaphragms are scalded together.

When the two diaphragms are bonded together by blanching, the temperature of the diaphragm cutter is controlled between 150°C and 250°C.

As a further improvement of the present invention, the value range of the top surface width b of the head of the diaphragm cutter is 0.2 to 2.0 mm, and the value range of the angle formed by the head rake surface and the horizontal plane, that is, the rake angle ε is 0 to 30°, and the angle between the rear slope of the head and the horizontal plane.

As a further improvement of the present invention, step A1 is also included between step A and step B: when the source of the two diaphragms bonded together is clamped by the upper pressing block and the lower pressing block, drive an upper guide roller Move down and press the first diaphragm to increase the diaphragm tension between the upper guide roller and the pressure block; in the step C, before inserting the second electrode piece, step C1 is included: drive the guide roller to move up and push the upper first diaphragm Two diaphragms are attached to the first diaphragm, and the upper guide rollers also move upwards synchronously.

Compared with the prior art, the technical effects of the winding method of the lithium-ion battery winding core of the present invention are: 1. Two rolls of diaphragms are adopted to unwind simultaneously, so that the tension of the two diaphragms is consistent and the unwinding and winding are synchronized , suitable for semi-automatic and fully automatic winding equipment, which improves production efficiency; more importantly, after winding a battery core and before cutting the separator, the starting point of the two separators for the next core is ultrasonic welding or They are bonded together by hot ironing, so that the diaphragm can be directly stressed after the coil needle penetrates, and can be wound after inserting the electrode sheet. At least two layers of diaphragms wound on the rolling needle; among the raw materials of lithium batteries, diaphragms are relatively expensive materials. According to the current price calculation, the winding method of the present invention can reduce the cost of each lithium battery by at least a few cents , the larger the volume of the lithium battery, the greater the cost savings; 2. Set up the upper guide roller and the lower guide roller, which act on the diaphragm together with the upper and lower pressure blocks to increase the tension of the diaphragm, so that the diaphragm will maintain a stable state without drifting. Thereby ensuring the reliability of being clamped by the upper and lower winding needles.

Description of drawings

Fig. 1 is a schematic diagram of a lithium-ion battery core winding method in the prior art, including Fig. 1A to Fig. 1C;

Fig. 2 is a schematic diagram of another lithium-ion battery core winding method in the prior art, including Fig. 2A to Fig. 2C;

Fig. 3 is a schematic diagram of another lithium-ion battery core winding method in the prior art, including Fig. 2A to Fig. 2C;

Fig. 4 is a schematic view of the winding process of the winding method of the lithium ion battery core of the present invention, including Fig. 4A to Fig. 4C;

5 is a schematic diagram of the principle of the winding method of the lithium-ion battery core;

FIG. 6 is a schematic longitudinal sectional view of the separator cutter 60 in the winding method.

Detailed ways

Below in conjunction with the best embodiment shown in the accompanying drawings, it will be further described in detail.

The winding method of the lithium-ion battery core of the present invention can be applied to fully automatic or semi-automatic lithium-ion battery core winding equipment, as shown in Figure 4 and Figure 5, including the following steps:

A. Unwind the first diaphragm 10 and the second diaphragm 11 by their respective unwinding mechanisms 20 and 21 at the same time, so that the two

The source of the diaphragm is bonded together and clamped between the upper pressing block 30 and the lower pressing block 31 of the winding machine. At this time, the first

The strip diaphragm 10 and the second strip diaphragm 11 intersect at the source to form an angle α, as shown in FIG. 4A;

In this step, two methods can be used to bond the two diaphragms together: one is to use ultrasonic welding, that is, to make either one of the upper pressing block 30 and the lower pressing block 31 into an ultrasonic welding joint. The second is to adopt a blanching method, specifically, heating the diaphragm cutter 60 so that its temperature is sufficient to scald the two diaphragms together. When the blanching method is adopted, resistance heating is generally used, and the temperature of the diaphragm cutter 60 is controlled at Between 150°C and 250°C, that is, as long as the temperature of the diaphragm cutter 60 is guaranteed to melt the diaphragm. The specific implementations of ultrasonic welding and hot blanching all belong to the prior art, and will not be repeated here.

In order to make the state of the first diaphragm 10 more stable and to be accurately and reliably clamped by the upper and lower roll needles 40, 41, after step A, step A1 is also included: when the two diaphragms are bonded together, After the source is clamped by the upper pressing block 30 and the lower pressing block 31, an upper guide roller 70 is driven to move down to press the first diaphragm 10 to increase the diaphragm tension between the upper guide roller 70 and the pressing block; The strip diaphragm 10 can be tightened without drifting, and it is convenient to be accurately clamped by the upper and lower roll needles 40, 41, improving the processing accuracy and production efficiency of the equipment;

B. As shown in Figure 4B, drive the upper and lower rolling needles 40, 41 to stretch out to clamp the first diaphragm 10, so that the lower rolling needle 41 is passed between the two diaphragms, and the upper rolling needle is located at the second diaphragm. On the top of a diaphragm 10, the upper pressing block 30 and the lower pressing block 31 are relatively separated to loosen the source where the two diaphragms are bonded together;

C. As shown in Figure 4C and Figure 4D, the first electrode sheet 50 is inserted between the lower surface of the lower rolling needle 41 and the second diaphragm 11, and the upper and lower rolling needles 40, 41 are driven to turn over to make The winding needle forms an angle β with the first separator, and then inserts the second electrode sheet 51 between the winding needle and the first separator 10 (see FIG. 5B in conjunction);

In this step C, before inserting the second electrode sheet 51, step C1 is included: drive the guide roller 71 to move up the second separator 11 so as to make it stick to the first separator 10, and the upper guide roller 70 It also moves upwards synchronously; and, the first electrode sheet 50 and the second electrode sheet 51 are all cut into a given length as required before insertion, and the given length is just enough to be wound into a battery core length.

D. Referring to Fig. 4D, drive the upper and lower roll needles 40, 41 to turn over continuously so that the two diaphragms and the two electrode sheets are wound on the two roll needles to form a core prototype (as shown in Fig. 5C), and then drive the upper and lower roll needles. The lower two roll needles 40, 41 drive the roll core prototype to move to the outside of the upper pressing block 30 and the lower pressing block 31;

E. Drive the upper pressing block 30 and the lower pressing block 31 to be relatively close to clamp the next first diaphragm 10 and the second diaphragm 11, and make the two diaphragms stick together at the clamped position (glue here) The connection method is the same as in step A), start the diaphragm cutter 60 to cut off the two diaphragms, the rolled core prototype is compressed and wrapped into a lithium-ion battery core, and the upper and lower rolling needles 40, 41 are driven to shrink and then Pull out to the outside of the core, and then the core is sent into the receiving hopper;

F. The two diaphragms cut off in step E are glued together at the front end of the cutting part, and become the winding source of the next winding core, and the upper and lower winding needles 40, 41 move back to the initial position and stretch out Clamp the first diaphragm 10 (return to FIG. 4A ), return to step B, and so on.

In the present invention, as shown in FIG. 6, the value range of the width b of the top surface of the head of the diaphragm cutter 60 is 0.2-2.0 mm, and the included angle between the head rake surface and the horizontal plane is the rake angle ε. The value ranges from 0 to 30°, and the angle between the rear slope of the head and the horizontal plane, that is, the back tilt angle δ ranges from 10 to 60°.

Claims (7)

1. the method for winding of a lithium ion battery coil core is characterized in that, comprises the steps:

A. article one barrier film (10) and second barrier film (11) are unreeled simultaneously by separately unreeling structure (20,21) respectively, clamped between upper holder block (30) that the source of two barrier films is bonded together send into up-coiler and the lower lock block (31), at this moment, article one barrier film (10) intersects the α that has angle with second barrier film (11) in the place, source;

B. driving upper and lower two volume pins (40,41) stretches out described article one barrier film (10) is clamped, last volume pin (41) is through between two barrier films, and go up the volume pin be positioned at article one barrier film (10) above, make described upper holder block (30) and lower lock block (31) relative separation again and unclamp described two sources that barrier film bonds together;

C. first electrode slice (50) is inserted between the lower surface and second barrier film (11) of described last volume pin (41), drive upper and lower two volume pin (40,41) upsets and make volume pin and described article one barrier film form an angle β, then second electrode slice (51) is inserted between volume pin and article one barrier film (10);

D. driving upper and lower two volume pins (40,41) overturns continuously and makes two barrier films and two electrode slices be wound on two volumes to become volume core blank on the pins, drive upper and lower two volume pins (40,41) again and drive the outside that volume core blanks move to upper holder block (30) and lower lock block (31);

E. drive draw close relative of described upper holder block (30) and clamp ensuing article one barrier film (10) and second barrier film (11) with lower lock block (31), and two barrier films are being bonded together by the folder position, starting barrier film cutting knife (60) cuts off two barrier films, the volume core blank of having spooled is through compressing, wrap up into lithium ion battery coil core, drive upper and lower two volume pin (40,41) indentations and be drawn to and roll up outside the core, the volume core is admitted to recovering hopper again;

F. cut two barrier films are bonded in together at the cut-off part front end in the step e, become the coiling source of next volume core, described upper and lower two volume pins (40,41) are moved back into initial position again and stretch out described article one barrier film (10) is clamped, and get back to step B, and so forth.

2. the method for winding of lithium ion battery coil core as claimed in claim 1 is characterized in that: among the described step C, described first electrode slice (50) and second electrode slice (51) all cut into given length in advance on request before inserting.

3. the method for winding of lithium ion battery coil core as claimed in claim 1 or 2, it is characterized in that: among described steps A and the E, it is to adopt the ultrasonic bonding mode that two barrier films are bonded together, and any that is about in described upper holder block (30) and the lower lock block (31) made ultrasonic bonding head.

4. the method for winding of lithium ion battery coil core as claimed in claim 1 or 2, it is characterized in that: among described steps A and the E, two barrier films are bonded together be to adopt the blanching mode, specifically be, heat described barrier film cutting knife (60), its temperature is enough to described two barrier film blanchings together.

5. the method for winding of lithium ion battery coil core as claimed in claim 4 is characterized in that: the temperature of described barrier film cutting knife (60) is controlled at 150 degree Celsius to 250 degree.

6. the method for winding of lithium ion battery coil core as claimed in claim 4, it is characterized in that: the span of the head top surface width b of described barrier film cutting knife (60) is 0.2～2.0mm, the angle that the head rake is become with horizontal plane is that the span of top rake ε is 0～30 °, and the angle that the head back bevel is become with horizontal plane is that the span of back rake angle δ is 10～60 °.

7. the method for winding of lithium ion battery coil core as claimed in claim 1 or 2, it is characterized in that: also comprise steps A 1 between described steps A and the step B: after source that described two barrier films bond together is clamped by upper holder block (30) and lower lock block (31), drive on one deflector roll (70) and move down and push down article one barrier film (10) to strengthen the barrier film tension force between deflector roll (70) and the briquetting; Among the described step C, inserting second electrode slice (51) before, comprising step C1: drive and move on the lower guide roll (71) that second barrier film (11) is gone up on the top so that it is fitted with article one barrier film (10), described upward deflector roll (70) also moves up synchronously.

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