Battery cell, winding equipment, battery and power utilization device

Abstract

The utility model relates to the technical field of battery manufacturing, and particularly discloses a battery cell, winding equipment, a battery and an electric device, the battery cell sequentially comprises a first diaphragm, a first pole piece, a second diaphragm and a second pole piece; wherein at least one end of the first diaphragm and at least one end of the second diaphragm are fused and connected through an adhesive tape, the end face of the first pole piece is wrapped, and the wrapped end of the first pole piece is limited to deviate relative to the two diaphragms. The battery cell, the winding equipment, the battery and the electric device provided by the utility model can effectively solve the problems that the production efficiency of the existing battery cell is lower, the pole piece is easy to fall powder and puncture a diaphragm, and the pole piece is easy to drift and shift.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery manufacturing technical field especially relates to a kind of electric core, winding equipment, battery and electric device. BACKGROUND

[0002] The electric core is formed by laminating a cathode sheet, an anode sheet and two separators, and then winding them up, wherein the separator is between the cathode sheet and the anode sheet, used to separate the cathode sheet and the anode sheet of the battery, to prevent the cathode sheet and the anode sheet from being short-circuited

[0003] Currently, in the battery production, the steps of the winding process are as follows:

[0004] ①First, pre-wind the separator for 1-2 turns;

[0005] ②Then, insert the anode sheet and the cathode sheet in sequence for winding;

[0006] ③After winding, first cut the cathode sheet, continue to wind the anode sheet for one turn to cover the cathode sheet, then cut the anode sheet, and then cut the separator.

[0007] The above winding method has the following problems:

[0008] ①In order to avoid the position deviation between the starting end of the anode sheet and the separator, it is necessary to first perform the separator pre-winding operation, and the step-by-step feeding method of pre-winding the separator first and then feeding the anode sheet, resulting in low production efficiency of winding;

[0009] ②When cutting the anode sheet, the anode sheet end face will produce active material and metal burrs that are easy to fall off, and during subsequent winding, the active material is easy to fly everywhere, thereby affecting the electrical performance of the electric core, at the same time, the metal burrs also have a high risk of piercing the separator, which will also cause the performance of the electric core to decline;

[0010] ③After the cathode sheet and the anode sheet are cut in advance, there is a situation of head and tail swinging, that is, when the head of the pole piece is fed and the tail is finished, the end of the pole piece after cutting is in a free state, and the pole piece is easy to deviate in the width direction (commonly known as "pole piece deviation"); Pole piece deviation may cause Overhang problem (Overhang refers to the part of the negative pole piece length and width direction beyond the positive and negative pole pieces) on the width; The electric core with Overhang problem may have the risk of lithium precipitation when applied to the battery.

[0011] Therefore, it is necessary to improve the existing electric core to solve the problems of low production efficiency, easy powder falling and piercing of the anode sheet, and easy tail swinging of the anode sheet.

[0012] The above information disclosed in this Background section is only for enhancing the understanding of the background of the present disclosure, and therefore can include information that does not form the prior art known to those of ordinary skill in the art. Utility model content

[0013] An object of the present utility model is to provide an electric core, a winding device, a battery and an electric device, which can effectively solve the problems of low production efficiency, easy powder falling and diaphragm piercing of the pole piece, and easy tail whipping and deviation of the pole piece.

[0014] To achieve the above object, on the one hand, the present utility model provides an electric core, which comprises a first diaphragm, a first pole piece, a second diaphragm and a second pole piece in sequence.

[0015] In the present utility model, at least one end of the first diaphragm and the second diaphragm is connected by fusion connection through adhesive tape, which wraps the end face of the first pole piece and limits the deviation of the wrapped end of the first pole piece relative to the two diaphragms.

[0016] In some embodiments, before fusion: the thickness of the first diaphragm is D1, the thickness of the second diaphragm is D2, and the thickness of the adhesive tape is D3.

[0017] After fusion:

[0018] At the connection, the total thickness T of the first diaphragm, the second diaphragm and the adhesive tape is less than (D1+D2+D3).

[0019] At the non-connection, the total thickness T of the first diaphragm, the second diaphragm and the adhesive tape is equal to (D1+D2+D3).

[0020] In some embodiments, the adhesive tape comprises:

[0021] A glue part, which is bonded with the first pole piece;

[0022] A connecting substrate, one end of which is bonded with the glue part, and the other end extends to the outside of the end face of the first pole piece to connect the first diaphragm and the second diaphragm.

[0023] In some embodiments, the connecting substrate, the first diaphragm and the second diaphragm are fusion connected.

[0024] In some embodiments, the length of the first diaphragm and the second diaphragm is equal, and the length of both is greater than the length of the first pole piece, so that the end of the first diaphragm and the second diaphragm extends to the outside of the end face of the first pole piece.

[0025] The first diaphragm and the second diaphragm are fused to the connecting substrate at the part extending out of the end surface of the first electrode plate.

[0026] In some embodiments, the thickness of the part of the connecting substrate adhering to the adhesive part is smaller than the thickness of the part of the connecting substrate extending out of the first electrode plate.

[0027] In some embodiments, the first diaphragm and / or the second diaphragm are made of the same material as the connecting substrate.

[0028] In the second aspect, a winding device for producing the battery cell is provided, comprising:

[0029] A first cutting mechanism for cutting the continuous sheet into two first electrode plates;

[0030] A first connecting mechanism for connecting the two first electrode plates cut by the adhesive tape;

[0031] A winding mechanism for winding the first diaphragm, one of the first electrode plates, the second diaphragm, and the second electrode plate;

[0032] A second cutting mechanism for fusing the first diaphragm, the adhesive tape, and the second diaphragm at the part of the first diaphragm, the adhesive tape, and the second diaphragm cut by the second cutting mechanism.

[0033] In some embodiments, the second cutting mechanism comprises a hot cutter, and the hot cutting temperature of the hot cutter is 130-300℃.

[0034] In some embodiments, the second cutting mechanism further comprises two hot pressing plates arranged oppositely, and the space between the two hot pressing plates is used for passing the first diaphragm, the adhesive tape, and the second diaphragm.

[0035] In some embodiments, the hot cutter is accommodated in one of the hot pressing plates, and the hot cutter can extend out of or retract into the hot pressing plate along the cutting direction.

[0036] In some embodiments, the hot pressing temperature of the hot pressing plate is 70-110℃.

[0037] In the third aspect, a battery is provided, comprising a shell and the battery cell in the shell, or the battery cell produced by the winding device.

[0038] In the third aspect, a battery is provided, comprising a shell and the battery cell in the shell, or the battery cell produced by the winding device.

[0039] The utility model discloses a beneficial effect lies in: provide a battery, winding equipment, electric device,

[0040] First, the structure design of the adhesive tape makes the first diaphragm, the first pole piece and the second diaphragm can be synchronously fed and wound, thereby the problem of low production efficiency caused by step-by-step feeding in the prior art can be solved.

[0041] Secondly, the first diaphragm and the second diaphragm are connected by the adhesive tape and wrap the end face of the first pole piece, on the one hand, after wrapping the end face of the first pole piece, the active material at the end face position of the first pole piece can be prevented from flying everywhere, on the other hand, the adhesive tape is further arranged between the end position of the first pole piece and the diaphragm, thereby reducing the risk that the metal burrs at the end face of the first pole piece directly pierce the diaphragm, thereby the problems that the first pole piece is easy to drop powder and pierce the diaphragm in the prior art can be solved.

[0042] Furthermore, since the first diaphragm and the second diaphragm are connected by the adhesive tape and wrap the end face of the first pole piece, the first pole piece cannot be offset in the width direction relative to the first diaphragm and the second diaphragm, thereby the problem that the first pole piece is easy to swing tail and offset in the prior art can be solved.

[0043] Therefore, the battery, winding equipment, electric device and the like provided by the utility model can effectively solve the problems of low production efficiency, easy dropping of powder and piercing of the diaphragm by the pole piece and easy swing tail and offset of the pole piece in the prior art winding method. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained according to these drawings without creative labor for those skilled in the art.

[0045] Figure 1 The flow chart of the winding method provided for the embodiment is shown in the figure.

[0046] Figure 2 The process schematic diagram of the continuous sheet cutting and gluing provided for the embodiment is shown in the figure.

[0047] Figure 3 The structure schematic diagram of the winding equipment provided for the embodiment is shown in the figure.

[0048] Figure 4 The electric cell state change schematic diagram before and after the second cutting mechanism hot cutting provided for the embodiment is shown in the figure.

[0049] Figure 5 The electric cell structure schematic diagram provided for the embodiment is shown in the figure.

[0050] Figure 6 The schematic diagram of the blank area of the connecting base material provided for the embodiment is thicker.

[0051] In the drawings:

[0052] 1, continuous sheet; 1a, first pole piece of the front section; 1b, first pole piece of the rear section;

[0053] 2, adhesive tape; 201, adhesive part; 202, connecting base material; 2021, blank area; 2a, connecting body;

[0054] 3, first diaphragm;

[0055] 4, second diaphragm;

[0056] 5, second pole piece;

[0057] 6, cutting mechanism; 601, pole piece clamping and fixing mechanism; 602, first cutting mechanism; 603, first connecting mechanism;

[0058] 7, winding mechanism; 701, first unwinding mechanism; 702, second unwinding mechanism; 703, third unwinding mechanism; 704, fourth unwinding mechanism; 705, winding mechanism; 7051, rotating disc; 7052, first winding needle; 7053, second winding needle; 706, third cutting mechanism;

[0059] 8, second cutting mechanism; 801, hot press plate; 802, hot cutter. DETAILED DESCRIPTION

[0060] In the present application, terms such as "first" and "second" are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, primary or secondary, or order relationship between the entities or operations.

[0061] Unless otherwise explicitly specified or limited, the terms "mounting", "connecting", "connecting", "fixing", "setting", and the like used in the description of the embodiments of the present application should be understood in a broad sense. For example, the "connection" can be fixed connection, or detachable connection, or integrated setting; it can be mechanical connection, or electrical connection, or communication connection; it can be direct connection, or indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0062] The utility model provides a winding method, winding equipment, electric core, battery and electric device, be applicable to the application scene of winding into electric core with first diaphragm, first pole piece, second diaphragm and second pole piece, and it can effectively solve the problem of low production efficiency, pole piece is easy to drop powder and pierce diaphragm, and pole piece is easy to whip tail and deviate of existing winding method.

[0063] Embodiment 1

[0064] The embodiment provides a winding method, which is executed by the winding equipment provided in embodiment 2, and is used for winding first diaphragm 3, first pole piece, second diaphragm 4 and second pole piece 5 into the electric core in embodiment 3.

[0065] Referring to Figure 1 , the winding method provided in the embodiment comprises the following steps S10-S30:

[0066] S10: after the continuous sheet 1 is cut, the two cut pole piece segments are connected through the adhesive tape 2 to obtain the first pole piece;

[0067] In the embodiment, the pole piece is in a continuous state when it is delivered, and after being cut, the pole piece is wound again. In order to distinguish, the continuous whole before cutting is called "continuous sheet 1", the two disconnected parts after cutting according to the preset length are called "cut pole piece segments", and the whole obtained by connecting the two cut pole piece segments through the adhesive tape 2 is called "first pole piece".

[0068] One of the cut pole piece segments is a front segment pole piece 1a being wound, and the other cut pole piece segment is a rear segment pole piece 1b being continuously unwound.

[0069] In some embodiments, referring to Figure 2 , the step S10 comprises:

[0070] S101: the continuous sheet 1 is cut to form two mutually independent cut pole piece segments;

[0071] S102: the two cut pole piece segments are pulled apart to a preset distance;

[0072] S103: the two cut pole piece segments are connected through the adhesive tape 2.

[0073] In the embodiment, the two cut pole piece segments are arranged at intervals, that is, the two cut pole piece segments are connected through the adhesive tape 2 after being spaced apart by a preset distance. In other words, the adhesive tape 2 starts from the end position of one of the cut pole piece segments, spans the interval space between the two cut pole piece segments, and is connected to the end position of the other cut pole piece segment.

[0074] For the convenience of description, the positions where the adhesive tape 2 is attached to the two post-cut pole segments (i.e. the two ends of the adhesive tape 2) are referred to as "adhesion regions" and the middle position of the adhesive tape 2 across the interval space between the two post-cut pole segments is referred to as "blank region 2021". It can be understood that the blank region 2021 is located between the two post-cut pole segments so that the post-cut pole segments will not be cut when the blank region 2021 is cut later.

[0075] In this embodiment, the adhesive tape 2 includes two spaced adhesive parts 201 and a connecting substrate 202 connecting the two adhesive parts 201. That is, the two ends of the connecting substrate 202 are the adhesion regions, and the adhesion regions at the two ends of the connecting substrate 202 are each provided with an adhesive part 201 so as to be attached to the corresponding post-cut pole segment through the adhesive part 201. The middle position of the connecting substrate 202 is the blank region 2021, which is not provided with an adhesive.

[0076] In some embodiments, the adhesive tape 2 can be provided as a preform, and step S103 includes:

[0077] The adhesive part 201 at one end of the adhesive tape 2 is attached to one of the post-cut pole segments, and the adhesive part 201 at the other end of the adhesive tape 2 is attached to the other post-cut pole segment.

[0078] It should be noted that the adhesive tape 2 is provided as a preform, and a large number of adhesive tapes 2 are prepared in advance. During subsequent production, the preformed adhesive tape 2 can be directly attached and fixed to the two post-cut pole segments after being pulled apart, which is simple, fast and has high production efficiency.

[0079] In some embodiments, the adhesive part 201 and the connecting substrate 202 can also be fixed on site during winding. In this case, step S103 includes:

[0080] ① The adhesive part 201 (which can be attached with a back adhesive or coated with glue) is arranged at the end position of each of the two post-cut pole segments;

[0081] ② One end of the connecting substrate 202 is attached to the adhesive part 201 of one of the post-cut pole segments, and the other end of the connecting substrate 202 is attached to the adhesive part 201 of the other post-cut pole segment.

[0082] It should be noted that the adhesive part 201 is arranged at the end position of the post-cut pole segment first, and then the connecting substrate 202 is attached. This production method does not require preformed adhesive tapes 2 to be prepared in advance, and the length of the blank region 2021 can be flexibly adjusted according to production needs during the production process, which greatly reduces the inventory pressure of preforms.

[0083] In this embodiment, since each of the two sides of the cut polar piece segment is provided with a layer of separator, one adhesive tape 2 can be arranged on each of the upper and lower sides of the end position of the cut polar piece segment. At this time, two adhesive tapes 2 are arranged between the two layers of separators. Of course, in some other embodiments, only one adhesive tape 2 can be arranged on the upper side or the lower side of the end position of the cut polar piece segment. At this time, one adhesive tape 2 is arranged between the two layers of separators.

[0084] S20: winding the first separator 3, the first polar piece, the second separator 4, and the second polar piece 5, so that the first separator 3, the cut polar piece segment (i.e. the front segment polar piece 1a) being wound, and the second separator 4 wrap the second polar piece 5;

[0085] Referring to Figure 3 , in this embodiment, step S20 comprises:

[0086] S201: first winding the first separator 3, the first polar piece (i.e. the two cut polar piece segments connected by the adhesive tape 2), and the second separator 4 by a preset length (for example, 3-10 mm);

[0087] S202: then inserting the second polar piece 5 for winding;

[0088] S203: cutting the second polar piece 5;

[0089] S204: continuing to wind the first separator 3, the first polar piece, and the second separator 4 by several turns (for example, half a turn) to wrap the second polar piece 5.

[0090] The winding start end of the second polar piece 5 is slightly shorter than the winding start end of the cut polar piece segment, so as to ensure that the Overhang requirement is met in the length direction between the two, so as to prevent the lithium precipitation of the battery cell. Further, the distance difference between the winding start end of the cut polar piece segment and the winding start end of the second polar piece 5 is 3-10 mm. Setting the distance difference in this range can not only ensure the energy density of the battery cell, but also ensure that the Overhang requirement is met. The winding end of the first separator 3, the winding end of the cut polar piece segment, and the winding end of the second separator 4 are aligned, and the winding end of the cut polar piece segment exceeds the winding end of the second polar piece 5 by half a turn. Such a design is also to ensure the Overhang requirement between the cut polar piece segment and the second polar piece 5.

[0091] The end position of the cut polar piece segment is attached with an outwardly extending adhesive tape 2, and the outwardly extending adhesive tape 2 forms the winding start end and the winding end of the cut polar piece segment.

[0092] In S20, the first separator 3, the first polar piece, and the second separator 4 are synchronously fed and start to be wound, so as to solve the problem of low production efficiency caused by step-by-step feeding in the prior art.

[0093] In this embodiment, the first pole piece is an anode piece, and the second pole piece 5 is a cathode piece.

[0094] In other embodiments, the first pole piece can also be a cathode piece, and the second pole piece 5 can be an anode piece. That is, the tape 2 is arranged at the cathode piece, and after the second separator 4, the tape 2 and the first separator 3 are hot fusion, the end face of the cathode piece is wrapped. At this time, in order to prevent the lithium precipitation of the battery cell, the outermost circle of the battery cell needs to be an anode piece, therefore, the length of the tape 2 connected to the cathode piece needs to be greater than the length of the anode piece of the outermost circle, which will increase the difficulty of using the tape 2 to connect two cathode pieces to a certain extent. In addition, the anode piece is softer than the cathode piece, and the head and tail of the pole piece are more likely to occur during cutting, therefore, it is more valuable to solve the problem of the head and tail of the anode piece, and the more optimal solution is that the first pole piece is an anode piece, and the second pole piece 5 is a cathode piece.

[0095] Of course, the tape 2 can also be attached to both the anode piece and the cathode piece, which can simultaneously solve the problems of low production efficiency, easy powder falling and piercing the separator, and easy tailing and deviation of the anode piece and the cathode piece.

[0096] S30: performing a fusion cutting process at a position between the two cut pole piece segments, so that the first separator, the tape 2 and the second separator 4 are fused and connected after being cut; at this time, the end portions of the two cut pole piece segments close to each other are covered by the first separator 3, the tape 2 and the second separator 4 after being cut.

[0097] In this embodiment, step S30 not only needs to cut the first separator 3, the tape 2 and the second separator 4, but also needs to connect the first separator 3 and the second separator 4 through the tape 2, so as to wrap the end face of the cut pole piece segment.

[0098] Referring to Figure 4 After cutting the first separator 3, the tape 2 and the second separator 4, the tape 2 is divided into two, forming two connecting bodies 2a, each connecting body 2a corresponding to the end face of one cut pole piece segment (one connecting body 2a protruding from the end face of the front segment pole piece 1a, and the other connecting body 2a protruding from the end face of the rear segment pole piece 1b).

[0099] In this embodiment, the step of performing a fusion cutting process at a position between the two cut pole piece segments includes:

[0100] First, the middle position (i.e. the blank area 2021) of the tape 2 is hot pressed for a long time, specifically, the length of the hot pressing time is controlled to be sufficient to make the first separator 3 and the second separator 4 hot fusion through the blank area 2021; the first separator 3 and the second separator 4 after hot fusion form a bag, which in turn wraps the end face of the cut pole piece segment;

[0101] Then, the blank area 2021 is cut using a hot knife, and the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4 are cut at the same time.

[0102] It should be noted that cold cutting may cause stress on the material, leading to edge cracks, affecting the integrity and performance of the product. Therefore, after completing the hot pressing step, although the first diaphragm and the second diaphragm have formed a bag through the blank area to wrap the end surface of the cut pole piece segment, hot cutting is still performed. Hot cutting can provide more accurate and neat cutting effect, reduce the risk of material tearing, and ensure the sealing of the cutting edge, thereby ensuring the stability and long-term reliability of the internal structure of the battery.

[0103] In another embodiment, the step of performing a fusion treatment at a position between the two cut pole piece segments includes:

[0104] First, the middle position of the adhesive tape 2 is hot pressed for a short time, so that the first diaphragm 3 and the second diaphragm 4 are pre-connected through the middle position of the adhesive tape 2. It should be noted that due to the short hot pressing time, the first diaphragm 3, the second diaphragm 4, and the adhesive tape 2 are not fully and sufficiently hot fused, and only the surface is hot pressed and connected after being heated.

[0105] Then, the middle position of the adhesive tape 2 is hot cut, so that the first diaphragm 3 and the second diaphragm 4 are hot fused through the middle position of the adhesive tape 2 while wrapping the end surfaces of the two cut pole piece segments close to each other, and the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4 are cut at the same time.

[0106] First, hot pressing pre-connection can reduce the gap between the diaphragm and the connecting substrate 202, thereby shortening the movement distance of the diaphragm and the connecting substrate 202, which is beneficial to improve the hot fusion effect of the diaphragm and the connecting substrate 202.

[0107] In yet another embodiment, the step of performing a fusion treatment at a position between the two cut pole piece segments includes:

[0108] The middle position of the adhesive tape 2 is hot cut, so that the first diaphragm 3 and the second diaphragm 4 are hot fused through the middle position of the adhesive tape 2 while the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4 are cut at the same time.

[0109] Directly using a hot knife 802 can hot fuse the first diaphragm 3, the second diaphragm 4, and the blank area 2021 at the same time, and conveniently cut the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4.

[0110] The hot cutting cutter can reduce the cutting resistance, improve the cutting efficiency of the hot cutting cutter, and further simplify the production process and improve the production efficiency.

[0111] It should be noted that the "hot melting fusion" in the embodiment is not a simple bonding, but a mutual fusion of the base material 202 and the diaphragm, and the two are in a mutual intermingling state. Simple bonding is only a physical level connection, and the connection effect is poor. The battery cell made by applying this method is prone to connection failure when in use due to the influence of the use conditions, such as jolting and impact, which can cause the diaphragm and the pole piece to deviate, leading to short circuit and lithium precipitation risk. The hot melting fusion of the utility model belongs to a micro-level material fusion, and the connection effect is stronger. Even in harsh conditions, the battery cell made by applying the technical solution of the utility model can ensure the bonding strength of the diaphragm and the pole piece, avoid connection failure, and improve the safety performance of the battery cell.

[0112] The hot melting fusion specifically refers to the recombination of the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4 after being heated and melted to form a whole, that is:

[0113] Before fusion: the thickness of the first diaphragm 3 is D1, the thickness of the second diaphragm 4 is D2, and the thickness of the adhesive tape 2 at the cutting position is D3;

[0114] After fusion:

[0115] At the cutting position, the total thickness T of the first diaphragm 3, the second diaphragm 4, and the adhesive tape 2 at the cutting position is less than (D1+D2+D3);

[0116] At the non-cutting position, the total thickness T of the first diaphragm 3, the second diaphragm 4, and the adhesive tape 2 at the cutting position is (D1+D2+D3).

[0117] It can be understood that, on the one hand, after the first diaphragm 3 and the second diaphragm 4 are connected by the adhesive tape 2 and wrap the end face of the cut pole piece segment, the active material at the end face position of the cut pole piece segment can be prevented from flying around,

[0118] On the other hand, the end position of the cut pole piece segment and the diaphragm are provided with the adhesive tape 2, which can avoid direct contact between the metal burrs and the diaphragm, thereby reducing the risk of the metal burrs at the end face of the cut pole piece segment directly piercing the diaphragm. Thus, the problem of the cut pole piece segment easily falling off and piercing the diaphragm in the prior art can be solved.

[0119] Furthermore, since the first diaphragm 3 and the second diaphragm 4 are fused and connected by the adhesive tape 2 and wrap the end face of the cut pole piece segment, the cut pole piece segment cannot deviate in the width direction relative to the first diaphragm 3 and the second diaphragm 4, thereby solving the problem of the cut pole piece segment easily deviating in the tail in the prior art.

[0120] In some embodiments, the first diaphragm 3 and / or the second diaphragm 4 are made of the same material as the connecting base material 202, so as to improve the connection reliability when the diaphragm and the connecting base material 202 are heat-pressed.

[0121] In the embodiment, since the connecting base material 202 only needs to be provided with the adhesive part 201 at both ends and the middle position is left blank, no adhesive will be adhered to the cutter whether the cutter is a conventional cutter or a hot cutter 802 is used to cut in the blank area 2021, which is beneficial to prolong the service life of the cutter. Of course, in some other embodiments, the blank area 2021 can also be provided with adhesive, which is not limited in the utility model.

[0122] In summary, the winding method provided by the embodiment has the following advantages:

[0123] (1) The first diaphragm 3, the first pole piece, and the second diaphragm 4 are synchronously fed and start to be wound, which solves the problem of low production efficiency caused by step-by-step feeding in the prior art;

[0124] (2) The first diaphragm 3 and the second diaphragm 4 are fused and connected by the connecting body 2a formed by the adhesive tape 2, and wrap the end surface of the cut pole piece segment, which can prevent the active material at the end surface position of the cut pole piece segment from being scattered everywhere, and make the cut pole piece segment unable to shift the pole piece in the width direction relative to the first diaphragm 3 and the second diaphragm 4;

[0125] (3) The adhesive tape 2 is arranged between the end position of the cut pole piece segment and the diaphragm, which avoids direct contact between the metal burr and the diaphragm and reduces the risk that the metal burr at the end surface of the cut pole piece segment directly pierces the diaphragm;

[0126] (4) The connecting base material 202 only needs to be provided with the adhesive part 201 at both ends and the middle position is left blank, no adhesive will be adhered to the cutter whether the cutter is a conventional cutter or a hot cutter 802 is used to cut in the blank area 2021, which is beneficial to prolong the service life of the cutter;

[0127] (5) The connecting base material 202 is made of the same material as the diaphragm, so as to improve the connection reliability when the diaphragm and the connecting base material 202 are heat-pressed.

[0128] Embodiment 2

[0129] The embodiment provides a winding device for producing the battery cell provided in Embodiment 3 by the winding method provided in Embodiment 1.

[0130] Referring to Figure 3 , the winding device provided in the embodiment comprises a cutting mechanism 6, a winding mechanism 7, and a second cutting mechanism 8.

[0131] The cutting and pasting mechanism 6 is used to cut the continuous sheet 1 into two cut pole segments, and connect the two cut pole segments by the adhesive tape 2. The winding mechanism 7 is used to wind the first diaphragm 3, the first pole segment, the second diaphragm 4, and the second pole segment 5, so that the first diaphragm 3, the first pole segment, and the second diaphragm 4 wrap the second pole segment 5. The second cutting mechanism 8 is used to melt the first pole segment between the two cut pole segments, so that the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4 are fused and connected at the melting position, and the two cut pole segments are wrapped by the first diaphragm 3, the adhesive tape 2, and the second diaphragm 4.

[0132] In this embodiment, the winding mechanism 7 includes a first unwinding mechanism 701 for releasing the first diaphragm 3, a second unwinding mechanism 702 for releasing the first pole segment, a third unwinding mechanism 703 for releasing the second diaphragm 4, a fourth unwinding mechanism 704 for releasing the second pole segment 5, a winding mechanism 705 for winding the first diaphragm 3, the first pole segment, the second diaphragm 4, and the second pole segment 5, and a third cutting mechanism 706 for cutting the second pole segment 5.

[0133] The cutting and pasting mechanism 6 includes two pole segment clamping and fixing mechanisms 601, a first cutting mechanism 602 for cutting the continuous sheet 1 into two cut pole segments, and a first connecting mechanism 603 for pasting the adhesive tape 2 to the two cut pole segments.

[0134] After the pole segment clamping and fixing mechanism 601 clamps and fixes the cut pole segments, the first cutting mechanism 602 can cut the continuous sheet 1 to cut the continuous sheet 1 into two cut pole segments.

[0135] Further, regarding the first connecting mechanism 603:

[0136] In some embodiments, when the adhesive tape 2 is a pre-made product, the first connecting mechanism 603 is a mechanical hand that can grab and transfer the adhesive tape 2;

[0137] In some embodiments, when it is necessary to fix the adhesive part 201 and the connecting substrate 202 on site during winding, the first connecting mechanism 603 includes a back adhesive pasting device or a glue coating device for fixing the adhesive part 201 (the adhesive part 201 is a back adhesive or a glue coating) on the cut pole segment, and a mechanical hand for pasting the connecting substrate 202 to the two adhesive parts 201.

[0138] In this embodiment, regarding the second cutting mechanism 8:

[0139] In some embodiments, when the first hot pressing and then cutting are required, the second cutting mechanism 8 includes two oppositely arranged hot pressing plates 801 and a hot cutter 802 for cutting the adhesive tape 2 and the separator.

[0140] The first separator 3, the blank area 2021 of the adhesive tape 2 and the second separator 4 are first hot pressed by the two oppositely arranged hot pressing plates 801 (the hot pressing temperature of the hot pressing plates 801 is 70-110°C) so that the first separator 3, the blank area 2021 of the adhesive tape 2 and the second separator 4 are hot fused or pre-connected, and then cut by the hot cutter 802 (the temperature of the hot cutter 802 is instantaneously up to 130-300°C).

[0141] The hot pressing plates 801 act on the entire connecting substrate 202, which can make the blank area 2021 of the entire connecting substrate 202 and the separator closely adhere, increase the connecting and fixing area of the connecting substrate 202 and the separator, and further increase the connecting reliability of the cut pole piece segment and the separator, so as to ensure that the winding starting end of the cut pole piece segment and the winding starting end of the separator are fully combined together, and the winding ending end of the cut pole piece segment and the winding ending end of the separator are also fully combined together, thereby avoiding the situation that the end of the cut pole piece segment and the end of the separator are in a free end state lacking mutual constraint and positioning, and causing the situation of shaking head and tail.

[0142] Further, in order to improve the compactness of the second cutting mechanism 8, a containing groove sufficient to accommodate the hot cutter 802 can be arranged at the middle position of one of the hot pressing plates 801, and the hot cutter 802 is installed in the containing groove. When hot pressing is required, the hot cutter 802 is completely accommodated in the containing groove, so that the two hot pressing plates 801 can be as closely adhered as possible to complete the hot pressing. After the hot pressing is completed, the two hot pressing plates 801 are not separated, but the hot cutter 802 is driven to extend out of the containing groove by a linear module such as a pneumatic cylinder or a motor lead screw, so as to cut the separator and the adhesive tape 2.

[0143] Regarding the temperature of the hot cutter 802, if the temperature of the hot cutter 802 is too high, the adhesive tape 2 and the separator may not be hot fused at the cutting position, and if the temperature of the hot cutter 802 is too low, the adhesive tape 2 and the separator cannot reach the hot fusion temperature and cannot be hot fused. Therefore, the temperature of the hot cutter 802 needs to be set within a suitable range. The hot cutting temperature of the hot cutter of the utility model is 130-300°C.

[0144] On the basis of ensuring the realization of hot melting, in order to further ensure the hot melting effect of the adhesive tape and the diaphragm, through the unremitting efforts of the utility model person, the utility model person finds that the cutting knife temperature is set to 180-240 DEG C, the hot melting connection effect of the adhesive tape and the diaphragm is best, and the diaphragm type suitable for the temperature range is also the most extensive, and the temperature range is suitable for a variety of common diaphragm types on the market: for example, PP diaphragm, PE diaphragm and the like.Specifically, the cutting knife temperature can be 180 DEG C, 185 DEG C, 190 DEG C, 195 DEG C, 200 DEG C, 205 DEG C, 210 DEG C, 215 DEG C, 220 DEG C, 225 DEG C, 230 DEG C, 235 DEG C or 240 DEG C, but is not limited to the listed values, and other unlisted values in the value range are also applicable.

[0145] In some embodiments, when cutting is performed while hot pressing is required, the second cutting mechanism 8 can also be provided with only a hot cutter 802, and the two hot pressing plates 801 are omitted.The hot cutter 802 directly cuts the first diaphragm 3, the blank area 2021 of the adhesive tape 2 and the second diaphragm 4, thereby realizing cutting while hot melting.

[0146] Further, regarding the specific operation mode of pulling apart the two post-cut pole pieces to a preset distance, the following is explained: after the first cutting mechanism 602 cuts the continuous sheet 1 into the front pole piece 1a and the rear pole piece 1b, the rear pole piece 1b stops feeding forward, and the winding mechanism 705 can continue to wind the front pole piece 1a, thereby making the front pole piece 1a continue to move forward so as to be pulled apart from the rear end post-cut pole piece to a preset distance.Then, the front pole piece 1a and the rear pole piece 1b are connected by the adhesive tape 2, at this time, the winding mechanism 705 continues to wind the front pole piece 1a, so that the rear pole piece 1b is also continuously fed forward by the adhesive tape 2.

[0147] The winding mechanism 705 provided in the embodiment includes a rotating disc 7051 and a first winding needle 7052 and a second winding needle 7053 installed on the rotating disc 7051.The winding process of the winding mechanism 705 is as follows:

[0148] ①The winding start end of the second diaphragm 4, the first pole piece, the first diaphragm 3 is aligned and synchronized with the feeding of the first winding needle 7052, the winding start end of the second pole piece 5 is inserted into the first winding needle 7052, and is kept at a distance of 3-10 mm from the head of the post-cut pole piece, the first winding needle 7052 (at this time located at the first station) clamps the first diaphragm 3, the first pole piece, the second diaphragm 4 and the second pole piece 5 to wind together, and after winding to a specified length, the third cutting mechanism 706 cuts the second pole piece 5;

[0149] ②Then, the rotating disc 7051 rotates, so that the first winding needle 7052 drives the battery core to rotate to the second station, at the same time, the second winding needle 7053 originally located at the second station rotates to the first station;

[0150] ③In the process of rotating the battery cell to the second station by the first winding needle 7052, the hot cutter 802 of the second cutting mechanism 8 extends, and the first diaphragm 3, the adhesive tape 2 and the second diaphragm 4 are cut. After cutting, the winding end of the cut pole piece segment of the previous battery cell and the winding starting end of the cut pole piece segment of the next battery cell are formed;

[0151] More specifically, the hot cutter 802 cuts the adhesive tape into the first connecting body 2a and the second connecting body 2a. The second connecting body 2a is bonded to the tail of the cut pole piece segment of the previous battery cell, and the first connecting body 2a is bonded to the head of the cut pole piece segment of the next battery cell. Due to the temperature of the hot cutter 802 reaching 130-300℃ in an instant when cutting, the adhesive tape and the diaphragm are successfully cut and hot fused together. The first winding needle 7052 starts to rotate and complete the battery cell unloading;

[0152] ④While the first winding needle 7052 is performing the above operation, the adhesive taping mechanism 6 completes the taping, the second pole piece 5 completes the insertion, the second winding needle 7053 clamps the second diaphragm 4, the first pole piece, the first diaphragm 3 and the second pole piece 5, and repeats the winding operation of the first winding needle 7052. Thus, the continuous winding operation without stopping can be achieved.

[0153] When the adhesive tape 2 is used to connect the cathode sheet (i.e. the cut pole piece segment is a cathode sheet), the device does not need to be replaced. Since the outermost circle needs to be an anode sheet (to prevent lithium precipitation), the taping length of the cathode sheet needs to be greater than the length of the outermost anode sheet when cutting and taping.

[0154] The winding device provided in the embodiment has at least the following advantages:

[0155] ①The hot pressing and hot cutting technology is adopted to realize the effective fusion between the diaphragm and the pole piece, thereby enhancing the safety and reliability of the product and reducing the risk of short circuit and lithium precipitation caused by connection failure during use;

[0156] ②The design of the double winding needles alternately working realizes continuous winding without stopping, thereby greatly improving the production efficiency;

[0157] ③The hot cutter 802 is installed in the accommodation groove in the middle of the hot pressing plate 801, thereby improving the compactness of the structure of the second cutting mechanism 8 and saving space;

[0158] ④The temperature setting of the hot cutter 802 is optimized to ensure the hot fusion effect of the adhesive tape and the diaphragm, and the device is suitable for various types of diaphragms, thereby improving the versatility of the device.

[0159] The specific working process and beneficial effects of the winding device provided in the embodiment are described in detail in Embodiment 1. The features not explained in the present embodiment are explained in Embodiment 1 and have the same beneficial effects, and thus will not be described here again.

[0160] Embodiment 3

[0161] The present embodiment provides an electric core, a battery and an electric device, wherein the electric core is produced by the winding device provided in Embodiment 2 through the winding method provided in Embodiment 1.

[0162] The battery comprises a shell and an electric core in the shell. The electric device comprises an electric mechanism and a power supply mechanism for supplying power to the electric mechanism; wherein the power supply mechanism comprises the electric core or the battery.

[0163] The specific structure of the electric core is described below.

[0164] Referring to Figure 5 The electric core provided in the present embodiment comprises a first diaphragm 3, a first pole piece, a second diaphragm 4 and a second pole piece 5 in sequence; wherein at least one end of the first diaphragm 3 and the second diaphragm 4 is fused and connected by a connecting body 2a, which wraps the end face of the first pole piece and limits the relative displacement of the two diaphragms on the end part of the first pole piece wrapped.

[0165] It should be noted that, since the winding process is a continuous process, when describing the winding process, the first diaphragm 3, the second diaphragm 4 and the second pole piece 5 refer to continuous sheets in a continuous state, and the first pole piece refers to the whole obtained after connecting two cut pole piece segments. Each electric core is formed by cutting the continuous first diaphragm 3, the first pole piece, the second diaphragm 4 and the second pole piece 5 after winding, that is, each electric core is composed of a segment of the first diaphragm 3, a segment of the first pole piece, a segment of the second diaphragm 4 and a segment of the second pole piece. For the convenience of understanding, the present scheme is also named as "first diaphragm 3, first pole piece, second diaphragm 4 and second pole piece 5" when describing the structure of the electric core.

[0166] It can be understood that the continuous first pole piece can include N (N is greater than 2) post-cut pole segments, and N battery cells can be continuously produced. Among them, in the continuous first pole piece, the adjacent two post-cut pole segments are connected by the adhesive tape 2, the first post-cut pole segment is connected by the adhesive tape 2 only at the winding end, the last post-cut pole segment is connected by the adhesive tape 2 only at the winding starting end, and the winding starting end and the winding end of the remaining post-cut pole segments are both connected by the adhesive tape 2. Correspondingly, the first battery cell produced is only fused and connected by the connecting body 2a at the winding end of the first diaphragm 3 and the second diaphragm 4, the last battery cell produced is only fused and connected by the connecting body 2a at the winding starting end of the first diaphragm 3 and the second diaphragm 4, and the winding starting end and the winding end of the first diaphragm 3 and the second diaphragm 4 of the remaining battery cells are all fused and connected by the corresponding connecting body 2a.

[0167] The beneficial effects of the battery cell provided in the embodiment can refer to the description in Embodiments 1-2, which will not be repeated here.

[0168] In some embodiments, the connecting body 2a includes an adhesive part 201 and a connecting base material 202. The adhesive part 201 is bonded to the first pole piece; one end of the connecting base material 202 is bonded to the adhesive part 201, and the other end extends to the outside of the end surface of the first pole piece to connect the first diaphragm 3 and the second diaphragm 4.

[0169] Specifically, the connecting base material 202, the first diaphragm 3, and the second diaphragm 4 are fused and connected. For example, it can be hot cutting hot melting fusion or ultrasonic hot melting fusion, etc., which is not limited in the embodiment.

[0170] Further, the length dimensions of the first diaphragm 3 and the second diaphragm 4 are equal, and the length dimensions of both are greater than the length dimension of the first pole piece, so that the end portions of the first diaphragm 3 and the second diaphragm 4 extend to the outside of the end surface of the first pole piece; wherein the parts of the first diaphragm 3 and the second diaphragm 4 extending to the outside of the end surface of the first pole piece are hot melt fused with the connecting base material 202.

[0171] In the embodiment, the material of the first diaphragm 3 and / or the second diaphragm 4 is the same as that of the connecting base material 202, for example, the diaphragm material is PP, and the material of the connecting base material 202 is also PP. Hot melting fusion of the same material is easier, and the connection reliability is better. Especially when the adhesive is not provided in the white space area 2021, the object cut by the hot cutting knife 802 is the connecting base material 202 and the diaphragm of the same material, which can minimize the influence of the heat shrinkage of the cutting part of the connecting base material 202 and the diaphragm on the hot melting fusion, and avoid the difficulty of hot melting fusion of different materials

[0172] The surface of the first pole piece close to the first diaphragm 3 and / or the surface of the first pole piece close to the second diaphragm 4 has the connecting body 2a fixedly attached.

[0173] Since each side of the first tab is provided with a layer of diaphragm, one connecting body 2a can be arranged on each side of the first tab end position, and two connecting bodies 2a are arranged between the two layers of diaphragm. Of course, in some other embodiments, only one connecting body 2a can be arranged on the upper side or the lower side of the first tab end position, and one connecting body 2a is arranged between the two layers of diaphragm.

[0174] In some other embodiments, the connecting substrate 202 can also be provided with adhesive near both ends of the side close to the second diaphragm 4 or the first diaphragm 3 (the middle position is still left blank to avoid affecting the service life of the hot cutter 802 later), that is, before hot pressing cutting, the connecting substrate 202 is not only bonded to the first tab, but also bonded to the corresponding diaphragm. By such arrangement, the adhesive tape 2 and the diaphragm can be pre-bonded together, which is beneficial to one-cut implementation.

[0175] In the embodiment, referring to Figure 6 , the thickness of the connecting area at both ends of the connecting substrate 202 is thin, and the thickness of the blank area 2021 in the middle position is thick, that is, the connecting substrate 202 as a whole presents a convex structure. Since the blank area 2021 is the main hot melting area, thickening the blank area 2021 can increase the amount of connecting substrate 202 participating in hot melting, thereby improving the reliability of hot melting. Of course, in some embodiments, for the convenience of processing, the connecting substrate 202 can also be arranged as a straight structure with uniform thickness as shown in Figure 2 .

[0176] Further, when the thickness of the blank area 2021 in the middle position of the connecting substrate 202 is thick, the adhesive tape 2 can be arranged on only one side of the cut tab segment. Because the thick blank area 2021 can contact the second diaphragm 4 and the first diaphragm 3 on both sides, respectively, thereby realizing reliable hot melting between the second diaphragm 4, the first diaphragm 3 and the connecting substrate 202.

[0177] The specific manufacturing process of the battery cell provided in the embodiment is described in detail in Embodiment 1 and Embodiment 2. On the basis of Embodiment 1, the features not explained in the embodiment are explained in Embodiment 1 and have the same beneficial effects, which will not be described here.

[0178] Finally, it should be noted that the above embodiments have been described in the specification and drawings of the application, but this does not limit the patent protection scope of the application. Any equivalent structure or equivalent process replacement or modification based on the essential concept of the application, using the content described in the specification and drawings of the application, and directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of the application.

Claims

1. An electric cell, characterized by, The first diaphragm (3), the first pole piece, the second diaphragm (4), and the second pole piece (5) are sequentially arranged; At least one end of the first diaphragm (3) and the second diaphragm (4) is fused and connected by the adhesive tape (2), the end surface of the first pole piece is wrapped, and the end of the first pole piece wrapped is limited from being offset relative to the two diaphragms.

2. The battery cell of claim 1, wherein, Before fusion: the thickness of the first diaphragm (3) is D1, the thickness of the second diaphragm (4) is D2, and the thickness of the adhesive tape (2) is D3; After fusion: At the connection, the total thickness T of the first diaphragm (3), the second diaphragm (4), and the adhesive tape (2) is less than (D1+D2+D3); At the non-connection, the total thickness T of the first diaphragm (3), the second diaphragm (4), and the adhesive tape (2) is equal to (D1+D2+D3).

3. The electric cell of claim 1, wherein, The adhesive tape (2) comprises: An adhesive part (201) that is bonded to the first pole piece; A connecting substrate (202) that is bonded to one end of the adhesive part (201) and extends to the outside of the end surface of the first pole piece to connect the first diaphragm (3) and the second diaphragm (4).

4. The cell of claim 3, wherein, The connecting substrate (202), the first diaphragm (3), and the second diaphragm (4) are fused and connected.

5. The electric cell of claim 4, wherein, The length of the first diaphragm (3) and the second diaphragm (4) is equal, and the length of both is greater than the length of the first pole piece, so that the end of the first diaphragm (3) and the second diaphragm (4) extends to the outside of the end surface of the first pole piece; The part of the first diaphragm (3) and the second diaphragm (4) extending to the outside of the end surface of the first pole piece is fused and connected with the connecting substrate (202).

6. The electric cell of claim 5, wherein, The thickness of the part of the connecting substrate (202) bonded to the adhesive part (201) is less than the thickness of the part of the connecting substrate (202) extending to the outside of the first pole piece.

7. The electric cell of claim 4, wherein, The material of the first diaphragm (3) and / or the second diaphragm (4) is the same as that of the connecting substrate (202).

8. A winding apparatus characterized by comprising: It comprises: A first cutting mechanism (602) for cutting a continuous sheet (1) into two first pole pieces; A first connecting mechanism (603) for connecting the two first pole pieces cut by the adhesive tape (2); A winding mechanism (7) for winding the first diaphragm (3), one of the first pole pieces, the second diaphragm (4), and the second pole piece (5); A second cutting mechanism (8) for fusing and cutting the first diaphragm (3), the adhesive tape (2), and the second diaphragm (4) to fuse and connect the first diaphragm (3), the adhesive tape (2), and the second diaphragm (4) at the cutting position.

9. The winding apparatus according to claim 8, characterized by The second cutting mechanism (8) comprises a hot cutter (802) with a hot cutting temperature of 130-300°C.

10. The winding apparatus according to claim 9, characterized by The second cutting mechanism (8) further comprises two opposite hot plates (801) with a space between them for passing the laminated first separator (3), the adhesive tape (2) and the second separator (4).

11. The winding apparatus according to claim 10, characterized by The hot cutter (802) is accommodated in one of the hot plates (801) and can extend or retract out of the hot plate (801) along the cutting direction.

12. The winding apparatus according to claim 10, characterized by, The hot pressing temperature of the hot plate (801) is 70-110℃.

13. A battery, characterized by The battery cell comprises a shell and the battery cell as claimed in any one of claims 1-7 or prepared by the winding device as claimed in any one of claims 8-12.

14. An electrical device, characterized by The battery comprises the battery cell as claimed in claim 13.

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