CN110048078B

CN110048078B - Electrode component, electrode assembly, battery cell, battery and preparation method of electrode component

Info

Publication number: CN110048078B
Application number: CN201910438216.9A
Authority: CN
Inventors: 程君
Original assignee: Sichuan Fulaiwei New Energy Technology Co ltd
Current assignee: Sichuan Fulaiwei New Energy Technology Co ltd
Priority date: 2019-05-23
Filing date: 2019-05-23
Publication date: 2024-03-08
Anticipated expiration: 2039-05-23
Also published as: CN110048078A

Abstract

The application relates to an electrode part, an electrode assembly, an electric core, a battery and a preparation method of the electrode part, and belongs to the field of batteries. The electrode assembly comprises pockets made of separator film and pole pieces arranged alternately in each pocket, furthermore pole pieces may also be arranged outside the pockets. Because the pole piece is placed in the bag, when the electrode part is rocked, the bag can play a role in blocking the pole piece, so that the pole piece is prevented from sliding out of the bag, the risks of cladding and short circuit caused by dislocation of the movement of the pole piece inside are reduced, and the safety of the secondary battery and the secondary capacitor is improved.

Description

Electrode component, electrode assembly, battery cell, battery and preparation method of electrode component

Technical Field

The application belongs to the field of batteries, and particularly relates to an electrode component, an electrode assembly, an electric core, a battery and a preparation method of the electrode component.

Background

With the development of small-sized mobile devices (such as mobile phones, notebook computers and cameras) and the enhancement of functions, and with the development of high-power mobile electric equipment (such as unmanned aerial vehicles, electric vehicles and hybrid electric vehicles), the performance requirements of people on energy sources of the mobile devices are also higher and higher.

The current mobile device energy sources are mainly lithium ion/lithium polymer secondary batteries and secondary capacitors as auxiliary energy sources. Electrode parts are included in the interior of both the conventional secondary battery and the secondary capacitor, and a separator is almost included in the electrode parts to separate the positive and negative electrode sheets. However, when the secondary battery and the secondary capacitor are moved, the pole pieces inside the electrode member are easily dislocated due to shaking, and thus the risk of shorting the positive and negative electrodes may be caused, affecting the safety of the secondary battery and the secondary capacitor.

Disclosure of Invention

In view of the foregoing, an object of the present application is to provide an electrode assembly, a battery cell, a battery, and a method for manufacturing the electrode assembly, which alleviate the problem that the electrode assembly is prone to short circuit.

Embodiments of the present application are implemented as follows:

in a first aspect, embodiments of the present application provide an electrode assembly, where the electrode assembly is any one of the following structures: structure a: the electrode part comprises 2n-1 bags formed by 2n layers of diaphragms, n positive electrode plates and n-1 negative electrode plates which are alternately aligned in the 2n-1 bags, and 1 negative electrode plate which is respectively aligned outside the bags positioned at the top and the bags positioned at the bottom; structure B: the electrode part comprises 2n-1 bags formed by 2n layers of diaphragms, n negative electrode plates and n-1 positive electrode plates which are alternately aligned in the 2n-1 bags, and 1 positive electrode plate which is respectively aligned outside the bags positioned at the top and the bags positioned at the bottom; structure C: the electrode part comprises 2n-1 bags formed by 2n layers of diaphragms, and n negative electrode pieces and n-1 positive electrode pieces which are alternately arranged in the 2n-1 bags; wherein n is a positive integer, and the uppermost membrane and the lowermost membrane form a closed cavity or a semi-closed cavity, the next upper membrane and the next lower membrane form a closed cavity or a semi-closed cavity, and so on. When the electrode part is rocked, each bag can play a role in blocking the electrode plate, so that the electrode plate is prevented from sliding out of the bag, and the cladding and short circuit risks caused by dislocation of the movement of the electrode plate inside are reduced.

In a second aspect, embodiments of the present application provide an electrode assembly comprising two electrode parts as described in the first aspect, and the number of the electrode parts is at least two; the two electrode parts are sequentially and alternately laminated together to form a structure with alternately arranged positive and negative plates; or the electrode assembly further comprises a continuous diaphragm, and the two electrode components are wound by the diaphragm alternately in turn, so that each electrode component of the two electrode components is separated from each other, and a structure with alternately arranged positive and negative electrode plates is formed. Because the pole piece in the electrode component is blocked by the bag and is not easy to slide out from the bag, the cladding and short circuit risks caused by the movement dislocation inside the pole piece are reduced, and the safety of the electrode component is improved.

In combination with the second aspect example, in a possible implementation manner, when the two electrode parts are alternately stacked in turn, one of the electrode parts is the structure B, and the other electrode part is the structure C.

In combination with the second aspect example, in a possible implementation, when the electrode assembly further includes the continuous separator, one of the electrode parts is the structure a and the other of the electrode parts is the structure B.

In combination with the second aspect example, in one possible implementation, the continuous separator is rolled around the electrode member in one direction or in both directions, such that the continuous separator after rolling takes on a swirl shape.

In combination with the second aspect example, in a possible implementation, the continuous separator is wound around the electrode member in a zigzag shape.

In combination with the second aspect example, in one possible implementation, the continuous separator is centered on its midpoint, from which the electrode part is wound in one direction.

In a third aspect, embodiments provide a battery cell including a housing and an electrode assembly as in any one of the possible embodiments of the second aspect, the housing accommodating the electrode assembly. Because the pole piece in the electrode part is blocked by the bag and is not easy to slide out from the bag, the cladding and short circuit risks caused by the movement dislocation inside the pole piece are reduced, and the safety of the battery cell is improved.

In a fourth aspect, embodiments of the present application provide a battery, including the cell as described in the third aspect and a housing, where the cell is disposed in the housing. Because the pole piece in the electrode part is blocked by the bag and is not easy to slide out from the bag, the risks of cladding and short circuit caused by moving dislocation inside the pole piece are reduced, and the safety of the battery is improved.

In a fifth aspect, embodiments of the present application provide a method for preparing an electrode component, the method including: arranging the multi-layer diaphragms in parallel to form a plurality of interlayers; a pole piece is arranged in each of the interlayers, or a pole piece is arranged below the lowest layer of the diaphragm and in each of the interlayers, wherein the pole piece is arranged in a way that: a plurality of positive plates or negative plates are arranged at equal intervals along the same direction, so that the polarities of the plates on the upper side and the lower side of each diaphragm are opposite, the number is the same, and the positions are in one-to-one correspondence; arranging a plurality of pole pieces on the topmost membrane along the direction as topmost pole pieces; the polarity of the topmost pole piece is opposite to that of the secondary top pole piece under the topmost membrane, the number of the topmost pole pieces is half of that of the secondary top pole pieces, and the positions of the topmost pole pieces are corresponding to each other; cutting the diaphragm and the pole pieces into a plurality of laminated segments along the direction with the width of each two rows of electrodes as the interval, wherein each laminated segment is provided with one pole piece at the topmost layer, and two pole pieces at other layers; folding each laminated segment in half in the direction towards the top pole piece, so that the positions of the positive pole piece and the negative pole piece in the folded laminated segments correspond; and heat-sealing the discontinuous diaphragms of the folded laminated segments, and then integrally hot-pressing to form a closed cavity or a semi-closed cavity by the uppermost diaphragm and the lowermost diaphragm, and forming a closed cavity or a semi-closed cavity by the secondary upper diaphragm and the secondary lower diaphragm, and so on. Because the pole piece in the electrode component is blocked by the bag and is not easy to slide out from the bag, the cladding and short circuit risks caused by the movement dislocation inside the pole piece are reduced, and the safety of the electrode component is improved.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the embodiments of the application. The objects and other advantages of the present application may be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art. The above and other objects, features and advantages of the present application will become more apparent from the accompanying drawings. Like reference numerals refer to like parts throughout the several views of the drawings. The drawings are not intended to be drawn to scale, with emphasis instead being placed upon illustrating the principles of the present application.

FIG. 1 shows one of the schematic structural diagrams of an electrode assembly provided in an embodiment of the present application;

FIG. 2 shows a second schematic structural view of an electrode assembly according to an embodiment of the present disclosure;

FIG. 3 is a third schematic view of an electrode assembly according to an embodiment of the present disclosure;

FIG. 4 shows one of the process diagrams for preparing an electrode assembly according to an embodiment of the present application;

FIG. 5 shows a second process diagram of a manufacturing process of an electrode assembly according to an embodiment of the present application;

FIG. 6 is a third view showing a process of manufacturing an electrode assembly according to an embodiment of the present application;

FIG. 7 shows a fourth schematic structural view of an electrode assembly according to an embodiment of the present disclosure;

FIG. 8 shows a flowchart of a method of manufacturing an electrode assembly provided by an embodiment of the present application;

fig. 9 shows a schematic structural view of an electrode assembly exhibiting a laminated structure according to an embodiment of the present application;

fig. 10 shows one of the schematic structural views of an electrode assembly in a rolled configuration provided in the embodiment of the present application;

FIG. 11 shows a second schematic view of an electrode assembly in a rolled configuration according to an embodiment of the present application;

FIG. 12 shows a third schematic view of an electrode assembly in a rolled configuration according to an embodiment of the present application;

FIG. 13A shows one of the schematic diagrams of a winding manner provided in the embodiments of the present application;

FIG. 13B is a second schematic view of a winding method according to the embodiment of the present application;

FIG. 14 shows a third schematic view of a winding method according to an embodiment of the present disclosure;

FIG. 15 shows a fourth schematic view of a winding method according to an embodiment of the present disclosure;

fig. 16 shows a schematic structural diagram of a battery cell according to an embodiment of the present application.

Icon: 100-electrode parts; 110-a membrane; 111-bags; 120-pole pieces; 121-a positive plate; 122-a negative plate; 130-stacking the segments; 131-folded laminated segments; 200-electrode assembly; 300-cell; 310-housing.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. It will be apparent that the described embodiments are some, but not all, embodiments of the invention.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Furthermore, the term "and/or" in this application is merely an association relation describing an association object, and indicates that three relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone.

The drawbacks of the secondary battery and the secondary capacitor in the prior art are the results of the practice and careful study of the applicant, and therefore, the discovery process of the above problems and the solutions presented in the following examples of the present application for the above problems should be all contributions of the applicant to the present application during the present application.

In order to solve the above problems, the embodiments of the present application provide an electrode assembly, so as to reduce the risk of short circuit caused by dislocation of pole pieces inside the electrode assembly.

The structure of the electrode assembly will be described below for ease of understanding.

Referring to fig. 1, 2 and 3, in general, the electrode assembly 100 may include a plurality of pockets 111 formed by a membrane 110, and a pole piece 120 disposed within each pocket 111.

Wherein one pole piece 120 is disposed within each pocket 111. The polarity of the electrode sheet 120 may be positive (positive electrode sheet 121) or negative (negative electrode sheet 122), and the polarities of the electrode sheets 120 in the adjacent two bags 111 are opposite, that is, the positive electrode sheet 121 and the negative electrode sheet 122 are alternately stacked in order.

Of course, it is worth noting that the positions of the individual pole pieces 120 disposed within the pouch 111 are all aligned.

Depending on the difference in the arrangement of the pole pieces 120 within the electrode assembly 100, the electrode assembly 100 may have a variety of configurations, such as configuration a, configuration B, and configuration C. These three structures will be described below, respectively.

Referring to fig. 1, in the structure a, the electrode assembly 100 includes 2 n-layer separators 110, and the 2 n-layer separators 110 may form 2n-1 bags 111, with n positive electrode sheets 121 and n-1 negative electrode sheets 122 alternately aligned in the 2n-1 bags 111, and 1 negative electrode sheet 122 also aligned outside the bags 111 at the top and the bags 111 at the bottom, respectively. The bags 111 and 111 are bonded together by heat and pressure.

In fig. 1, n is 2. Of course, n may also be other positive integers, for example n is an integer between 2 and 10. It should be noted that in the structure a, the uppermost membrane 110 and the lowermost membrane 110 enclose a closed cavity, the sub-upper membrane 110 and the sub-lower membrane 110 enclose a closed cavity, and so on.

Referring to fig. 2, in structure B, the electrode assembly 100 includes 2n layers of separator 110, and the 2n layers of separator 110 may form 2n-1 pockets 111. In the structure B, n negative electrode sheets 122 and n-1 positive electrode sheets 121 are alternately aligned in 2n-1 bags 111, and 1 positive electrode sheet 121 is also aligned outside the bag 111 at the top and the bag 111 at the bottom, respectively, unlike the structure a. The bags 111 and 111 are bonded together by heat and pressure.

In fig. 2, n is 2. Of course, n may also be other positive integers, for example n is an integer between 2 and 10. It should be noted that in the structure B, the uppermost membrane 110 and the lowermost membrane 110 enclose a closed cavity, the sub-upper membrane 110 and the sub-lower membrane 110 enclose a closed cavity, and so on.

Referring to fig. 3, in structure C, the electrode assembly 100 includes 2n layers of separator 110, and the 2n layers of separator 110 may form 2n-1 pockets 111. In structure C, n negative electrode sheets 122 and n-1 positive electrode sheets 121 are alternately aligned in 2n-1 bags 111, unlike structure a and structure B. That is, in structure C, pole piece 120 is no longer provided outside of bag 111 at the top and bag 111 at the bottom.

In fig. 3, n is 2. Of course, n may also be other positive integers, for example n is an integer between 2 and 10. It is noted that in structure C, the uppermost membrane 110 and the lowermost membrane 110 form a closed cavity, the sub-upper membrane 110 and the sub-lower membrane 110 form a closed cavity, and so on.

Of the three structures of the electrode part 100, one closed cavity forms one bag 111 or two bags 111, for example, in the structure a shown in fig. 1, the closed cavity enclosed by the sub-upper membrane 110 and the sub-lower membrane 110 forms one bag 111, and the closed cavity enclosed by the uppermost membrane 110 and the lowermost membrane 110 forms two bags 111. The pole pieces 120 are placed in the pockets 111 to effectively prevent dislocation due to shaking.

The following description will be made with respect to the fabrication process of the three structures of the electrode assembly 100, defining an interlayer between the two separators 110 for convenience of description.

Corresponding to the structure A, pole pieces 120 on the top-most membrane 110 are removed, the pole pieces 120 on the upper side and the lower side of each membrane 110 are opposite in polarity, the same in number and in one-to-one correspondence in position; the polarity of the pole pieces 120 on the topmost membrane 110 is opposite to the polarity of the sub-top pole pieces 120 under the topmost membrane 110, and the number of the topmost pole pieces 120 is half the number of the sub-top pole pieces 120, and the positions correspond.

In the arrangement stage of the diaphragm 110 and the pole piece 120, as an alternative embodiment, the arrangement of the pole piece 120 and the arrangement of the diaphragm 110 may be performed alternately, that is, the arrangement of the pole piece 120-the arrangement of the diaphragm 110-the arrangement of the pole piece 120-the arrangement of the diaphragm 110 … … -the arrangement of the pole piece 120-the arrangement of the diaphragm 110-the arrangement of the pole piece 120.

In this embodiment, taking n=2 as an example in fig. 4, on a continuous line, with PET (Polyethylene terephthalate, high temperature resistant mylar) as a base (not shown), the negative electrode sheets 122 are arranged at the same intervals (for example, 10 mm), then the separator 110 is arranged, then the positive electrode sheet 121 is arranged on the separator 110 at a position corresponding to the negative electrode sheets 122, then a separator 110 is arranged, and then the negative electrode sheets 122 are arranged at the uppermost position corresponding to every other sheet 120.

Of course, as an alternative embodiment, in the stage of arranging the membrane 110 and the pole piece 120, a mode of arranging a plurality of membranes 110 to form an interlayer first and a mode of arranging the pole piece 120 later, that is, arranging the pole piece 120 after arranging the membranes 110, may be adopted.

In this embodiment, taking n=2 as an example in fig. 4, on a continuous line, two separators 110 are arranged first such that one interlayer is formed between the two separators 110, then negative electrode sheets 122 are arranged at the same interval (for example, 10 mm) under the lowermost separator 110, then positive electrode sheets 121 are arranged in the interlayer corresponding to the number and positions of the negative electrode sheets 122 such that the number of the negative electrode sheets 122 is the same as that of the positive electrode sheets 121, and the positions are in one-to-one correspondence, and then negative electrode sheets 122 are arranged at the corresponding positions of every other sheet 120 on the uppermost separator 110. So that the number of negative electrode sheets 122 on the topmost separator 110 is half the number of positive electrode sheets 121 in the interlayer, and the positions correspond.

After the separator 110 and the pole pieces 120 are arranged, the separator 110 and the pole pieces 120 are cut into a plurality of laminated segments 130 along the dotted line in fig. 4 at intervals of the width of each two columns of the pole pieces 120. Wherein each lamination segment 130 has one topmost pole piece 120 on the topmost layer and two pole pieces 120 on the other layers.

Each laminated segment 130 is folded in half in a direction toward the top-layer pole piece 120 (i.e., in the direction of the arrow in the drawing) so that the positions of the positive electrode tab 121 and the negative electrode tab 122 correspond in the folded-in laminated segment 131.

After the folded laminated segment 131 is obtained, the discontinuous separator 110 of the folded laminated segment 131 is heat-sealed to form the pouch 111. The pole piece 120 is encased within the pouch 111 and is not easily removed. The heat-sealed lamination segment 130 is then integrally heat-pressed to prevent the outermost pole piece 120 from falling off.

Wherein the hot pressing temperature can be 45-120 ℃, and the heat sealing temperature can be 130-250 ℃.

Referring to fig. 5, the main difference between the manufacturing process of the structure B and the manufacturing process of the structure a is that in the structure B, the polarities of the bottommost pole piece 120 and the topmost pole piece 120 are positive, and the rest are the same, so that the details will not be described here again to avoid repetition.

Referring to fig. 6, the main difference between the fabrication process of the structure C and the fabrication process of the structure B is that the pole piece 120 is not disposed under the lowermost membrane 110, and the rest is the same. To avoid repetition, a detailed description is not provided herein.

In addition, as an alternative embodiment, for the above-mentioned structures a, B and C, the uppermost membrane 110 and the lowermost membrane 110 may also form a semi-closed cavity as shown in fig. 7 (fig. 7 only shows structure a), i.e. an opening is reserved at one side of the bag 111, but the opening is enough to limit the pole piece 120 placed in the bag 111.

In the electrode component 100 provided in the embodiment of the application, since the electrode piece 120 is placed in the bag 111, when the electrode component 100 is rocked, the bag 111 can play a role in blocking the electrode piece 120, preventing the electrode piece 120 from sliding out of the bag 111, reducing the risk of cladding and short circuit caused by moving dislocation inside the electrode piece 120, and improving the safety of the secondary battery and the secondary capacitor.

In addition, since the separator 110 is contracted at high temperature, there is also a possibility that the positive and negative electrodes are short-circuited. By adopting the preparation method, the fixing effect of the bag 111 on the pole piece 120 can provide resistance when the diaphragm 110 is in thermal contraction, so that the thermal contraction and high temperature resistance of the diaphragm 110 are improved, the possibility that the positive pole piece 121 is in contact with the negative pole piece 122 is reduced, the risk of high-temperature short circuit is reduced, and the high-temperature safety of the electrode component 100 is improved.

In addition, referring to fig. 8, an embodiment of the present application further provides a method for preparing the electrode component 100, which includes:

step S110: the multilayer separator is arranged in parallel to form a plurality of interlayers.

Step S120: a pole piece is arranged in each of the interlayers, or a pole piece is arranged below the lowest layer of the diaphragm and in each of the interlayers, wherein the pole piece is arranged in a way that: and a plurality of positive plates or negative plates are arranged at equal intervals along the same direction, so that the polarities of the plates on the upper side and the lower side of each diaphragm are opposite, the number is the same, and the positions are in one-to-one correspondence.

Step S130: arranging a plurality of pole pieces on the topmost membrane along the direction as topmost pole pieces; the polarity of the topmost pole piece is opposite to that of the secondary top pole piece under the topmost membrane, the number of the topmost pole pieces is half of that of the secondary top pole pieces, and the positions of the topmost pole pieces are corresponding to each other.

Step S140: and cutting the diaphragm and the pole pieces into a plurality of laminated segments along the direction with the width of each two rows of electrodes as the interval, wherein each laminated segment is provided with one pole piece at the topmost layer, and two pole pieces at other layers.

Step S150: and folding each laminated segment in half in the direction towards the top pole piece, so that the positions of the positive pole piece and the negative pole piece in the folded laminated segments correspond.

Of course, as an alternative embodiment, in order to prevent the positive and negative plates from being dislocated during the folding, before the folding, each lamination segment may be integrally hot-pressed, so that the positions of the positive and negative plates remain relatively fixed.

Step S160: and heat-sealing the discontinuous diaphragms of the folded laminated segments, and then integrally hot-pressing to form a closed cavity or a semi-closed cavity by the uppermost diaphragm and the lowermost diaphragm, and forming a closed cavity or a semi-closed cavity by the secondary upper diaphragm and the secondary lower diaphragm, and so on.

Wherein, because the preparation process adopts at least 2 layers of diaphragms when preparing, the process for preparing the multi-layer bag is higher in efficiency, combines procedures and reduces energy consumption when guaranteeing the same effect compared with the traditional process for preparing the single-layer bag.

The preparation method of the electrode assembly 100 according to the embodiment of the present application has the same implementation principle and technical effects as the aforementioned physical structure embodiment, and for the sake of brevity, reference may be made to the corresponding content in the aforementioned physical structure embodiment where the method embodiment is not mentioned.

Further, referring to fig. 9-12, an electrode assembly 200 is also provided, which includes at least two electrode assemblies 100.

Alternatively, the electrode assembly 200 may take a stacked structure, i.e., the structure shown in fig. 9, or a rolled structure, i.e., the structure shown in fig. 10-12.

As an alternative embodiment, referring to fig. 9, when the electrode assembly 200 is a laminated structure, two different electrode parts 100 are alternately laminated together in sequence, forming a structure in which positive electrode sheets 121 and negative electrode sheets 122 are alternately arranged. In this embodiment, when two kinds of electrode members 100 are alternately laminated in sequence, one electrode member 100 is a structure B and the other electrode member 100 is a structure C. Of course, the number of the electrode parts 100 stacked is not limited to 6 shown in fig. 9, and the number of the electrode parts 100 may be more or less.

The bag 111 for playing a fixing role is assisted in the laminated structure, so that the displacement of the positive electrode plate 121 and the negative electrode plate 122 is avoided, the short circuit caused by loose folding of the diaphragm 110 is prevented, and the potential safety hazard is avoided. The laminated structure has stable structure and high safety, and is beneficial to ensuring the good quality of the battery cell 300.

As an alternative embodiment, referring to fig. 10-12, when the electrode assembly 200 is in a rolled configuration, the electrode assembly 200 further includes a continuous separator 110. The two electrode parts 100 are alternately wound by successive separators 110 in order such that each electrode part 100 of the two electrode parts 100 is spaced apart from each other, forming a structure in which positive electrode sheets 121 and negative electrode sheets 122 are alternately arranged. In this embodiment, one electrode assembly 100 is of structure a and the other electrode assembly 100 is of structure B.

Referring to fig. 13A-15, there may be various ways of winding.

In fig. 13A, the continuous separator 110 is wound around each electrode member 100 in one direction (the direction indicated by the arrow), so that the continuous separator 110 after winding takes on a vortex shape.

In fig. 13B, the continuous separator 110 is wound around the electrode part 100 in two directions (directions indicated by arrows), so that the continuous separator 110 after winding takes on a vortex shape.

In fig. 14, the continuous separator 110 is wound around the electrode member 100 in a zigzag shape in the direction indicated by the arrow.

In fig. 15, the continuous separator 110 is wound around the electrode member 100 in one direction (the direction indicated by the arrow) from the center around its midpoint.

In each of the winding manners shown in fig. 13A to 15, only a case of winding 5 or 6 electrode parts 100 with the continuous separator 110 is drawn, and of course, in practical applications, the number of the electrode parts 100 to be wound may not be limited thereto, and it is apparent that further electrode parts 100 may be continued to be wound in the same manner.

In addition, referring to fig. 16, the embodiment of the present application further provides a battery cell 300, including a housing 310 and the electrode assembly 200 in any of the above embodiments, wherein the housing 310 accommodates the electrode assembly 200. The housing 310 may be made of an aluminum plastic film, a steel shell, or an aluminum shell.

After the electrode assembly 200 is prepared, the electrode assembly 200 is welded with the tab, and then the electrode assembly is placed into the case 310 to undergo the processes of sealing, drying, liquid adding, heat sealing, formation, encapsulation, etc., thereby obtaining the battery cell 300. The above processes are all conventional in the art, and are not described herein.

In addition, the embodiment of the application also provides a battery, which comprises the battery cell 300 and the shell, wherein the battery cell 300 is arranged in the shell.

It is noted that for safety reasons, the battery has various protection circuits or other electronic devices that function to stabilize the voltage or current during use. In this application, the cell 300 refers to the portion of the electrochemical assembly that does not include a protection circuit; and the battery refers to the electrochemical component part including the basic protection circuit and the cell 300. The electronic device described herein refers only to a device that is subject to the action of limiting, stabilizing voltage or current for the purpose of protecting the cell 300.

In summary, the embodiment of the application provides an electrode assembly 100, an electrode assembly 200, a battery cell 300, a battery, and a method for manufacturing the electrode assembly 100, in which, in the electrode assembly 100, since the electrode sheet 120 is placed in the bag 111, when the electrode assembly 100 is swayed, the bag 111 can play a role in blocking the electrode sheet 120, preventing the electrode sheet 120 from sliding out of the bag 111, reducing the risk of cladding and short circuit caused by dislocation of movement inside the electrode sheet 120, and improving the safety of the secondary battery and the secondary capacitor. In addition, by adopting the preparation method, resistance can be provided when the diaphragm 110 is thermally contracted, and the high-temperature safety of the electrode part 100 is improved. Similarly, the electrode assembly 200, the battery cell 300, and the battery including the electrode assembly 100 are also provided with higher safety.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application.

It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

Claims

1. A method of making an electrode assembly, the method comprising:

arranging the multi-layer diaphragms in parallel to form a plurality of interlayers;

a pole piece is arranged in each of the interlayers, or a pole piece is arranged below the lowest layer of the diaphragm and in each of the interlayers, wherein the pole piece is arranged in a way that: a plurality of positive plates or negative plates are arranged at equal intervals along the same direction, so that the polarities of the plates on the upper side and the lower side of each diaphragm are opposite, the number is the same, and the positions are in one-to-one correspondence;

arranging a plurality of pole pieces on the topmost membrane along the direction as topmost pole pieces; the polarity of the topmost pole piece is opposite to that of the secondary top pole piece under the topmost membrane, the number of the topmost pole pieces is half of that of the secondary top pole pieces, and the positions of the topmost pole pieces are corresponding to each other;

cutting the diaphragm and the pole pieces into a plurality of laminated segments along the direction with the width of each two rows of electrodes as the interval, wherein each laminated segment is provided with one pole piece at the topmost layer, and two pole pieces at other layers;

folding each laminated segment in half in the direction towards the top pole piece, so that the positions of the positive pole piece and the negative pole piece in the folded laminated segments correspond;

and heat-sealing the discontinuous diaphragms of the folded laminated segments, and then integrally hot-pressing to form a closed cavity or a semi-closed cavity by the uppermost diaphragm and the lowermost diaphragm, and forming a closed cavity or a semi-closed cavity by the secondary upper diaphragm and the secondary lower diaphragm, and so on.