WO2016072617A1

WO2016072617A1 - Secondary battery having step cell structure

Info

Publication number: WO2016072617A1
Application number: PCT/KR2015/010151
Authority: WO
Inventors: 김경준; 김인중; 김유신; 최승호; 정택주
Original assignee: 주식회사 루트제이드
Priority date: 2014-11-04
Filing date: 2015-09-25
Publication date: 2016-05-12
Also published as: KR101616426B1

Abstract

The present invention relates to a secondary battery comprising: a first electrode assembly in which a plurality of first pocketing cathode bodies and first anode bodies having the same size are alternately stacked; and a second electrode assembly in which a plurality of second pocketing cathode bodies and second anode bodies having the same size are alternately stacked, and which is formed to be smaller than the first electrode assembly so as to be provided on the first electrode assembly, wherein the second electrode assembly has an accommodation unit recessed into an intagliated shape. The accommodation unit is formed in the second pocketing cathode bodies and the second anode bodies of the second electrode assembly excluding the second anode body disposed at the lowest end of the second electrode assembly, and the size of a cathode plate of a third pocketing cathode body can be formed to be the same as or smaller than the size of an anode plate of the second anode body, and formed to be smaller than the size of a cathode plate of the first pocketing cathode body.

Description

Secondary Battery with Step Cell Structure

The present invention relates to a secondary battery having a step cell structure, and more particularly, to a lithium ion secondary battery having a step cell structure configured to make maximum use of a storage space in an electronic device in which a secondary battery is accommodated or mounted.

As the market for portable electronic devices such as mobile phones, camcorders, and notebook computers expands and diversifies, demand for rechargeable rechargeable batteries is increasing. Miniaturization, weight reduction, high performance, and multifunctionality of portable electronic devices require continuous improvement of energy storage density of secondary batteries used as power sources. Accordingly, as a result of many years of research to satisfy this problem, a lithium ion secondary battery employing a carbon cathode capable of reversible insertion and release of lithium and a cathode material capable of reversible insertion and release of lithium has emerged.

The lithium ion secondary battery is rapidly becoming a new energy source of portable electronic devices in recent years because of its relatively high energy density and charge / discharge life per unit weight, compared to conventional aqueous solutions such as nickel-cadmium and nickel-hydrogen. It replaces existing battery. However, with the rapid development and diversification of portable electronic devices, the demand for higher energy densities and battery selection of various standards is rapidly increasing. Currently, lithium ion secondary batteries do not satisfy such demands.

In particular, while the rapid thinning and miniaturization of electronic devices are rapidly expanding the demand for thinner, thinner lithium ion secondary batteries, if the conventional method of assembling the cylindrical or square lithium ion secondary batteries is adopted as it is, The drop in energy density is too large. Therefore, development of a thin lithium ion secondary battery having a high energy density per volume is considered essential for achieving miniaturization, weight reduction, and thickness reduction of various portable electronic devices.

Accordingly, the present applicant has developed a secondary battery using a pocketed electrode body in order to solve this problem, and Korean Patent Nos. 10-1168651 and 10-0337707 filed and registered by the present applicant have been developed. Disclosed is a lithium ion secondary battery and a manufacturing technology using the prepared electrode body.

Although the prior patents have solved the above problems to some extent, the lithium ion secondary battery using the pocketing electrode body has a typical shape such as a coin type, a flat type such as a button type or a button type, or a pouch type. Since it is common to manufacture, there is still a problem that a secondary battery having a typical shape cannot be used when the shape or shape of the electronic device in which the secondary battery is used is changed.

Recently, since the design of electronic devices takes a large part in consumer's selection criteria, a lot of stylish and beautiful curved electronic devices have been released in recent years.

However, when a conventional secondary battery is accommodated in the curved electronic device, or an electronic device inevitably formed by the uneven part space by the electronic components, the secondary battery cannot fill the secondary battery storage space in the electronic device. Remaining space will remain.

In addition, when the protrusion is formed on the inner surface of the case in which the secondary battery is accommodated, the space in which the secondary battery can be accommodated by the protrusion decreases, resulting in a case in which the storage space is not properly utilized.

Accordingly, since the existing secondary battery does not efficiently utilize the remaining space of the storage space, the secondary battery has a space formed by a curved electronic device, an uneven portion space or a protrusion in terms of battery capacity or usage time. It does not reach a satisfactory level to apply to.

Accordingly, the present applicant has a form and structure that can effectively utilize the remaining space of the storage space to increase the battery capacity or use time of the secondary battery and to reduce the restriction on the form of the electronic device in which the secondary battery is used. It is intended to propose a lithium ion secondary battery having a stepped cell structure.

The present invention, in order to solve the above problems, make the best use of the storage space of the electronic device in which the secondary battery is stored without degrading the performance of the battery, and also can be used compatible with the shape of the storage space, It is possible to provide a secondary battery having a step cell structure which can minimize the shape constraints of the electronic device in which the secondary battery is used.

The present invention includes a first electrode assembly in which a plurality of first pocketing anode bodies and first cathode bodies having the same size are alternately stacked; And a second electrode assembly in which a plurality of second pocketing anodes and a second cathode body having the same size are alternately stacked and formed smaller than the first electrode assembly and provided on an upper side of the first electrode assembly. The second electrode assembly may have a receiving portion recessed in an intaglio.

And a third pocketing anode disposed between a lower end of the second electrode assembly and an upper end of the first electrode assembly, wherein the anode plate of the third pocketing anode body is equal to or smaller than the cathode plate of the second cathode body. It may be formed, and may be formed smaller than the positive plate of the first pocketing positive electrode.

First and second negative electrode bodies may be disposed at upper and lower ends of the first electrode assembly, respectively, and second negative electrode bodies may be disposed at upper and lower ends of the second electrode assembly.

The accommodation part may be formed in the remaining second cathode body and the second pocketing anode body of the second electrode assembly except for the second cathode body disposed at the lowermost end of the second electrode assembly.

The second pocketing positive electrode of the second electrode assembly may include a positive electrode plate having a coating layer of a lithium or lithium metal composite oxide as a positive electrode active material and a plain protrusion and having a first through hole; A pair of separators covering both surfaces of the positive electrode plate while exposing only the plain protrusion; And an insulating polymer film positioned between the pair of separators at an entire circumference or a part of the circumference of the positive electrode plate and bonded to the pair of separators.

The first negative electrode of the first electrode assembly and the second negative electrode of the second electrode assembly include a negative electrode plate having a carbonaceous negative electrode active material coating layer capable of occluding and releasing lithium and a non-projection portion, wherein the second electrode A second through hole corresponding to or communicating with the first through hole may be formed in the negative plate of the second negative electrode body except for the negative plate of the second negative electrode body disposed at the bottom of the assembly.

The punching space of the insulating polymer film of the first pocketing anode and the third pocketing anode is the same, and the size or area of the punching space formed in the insulating polymer film of the third pocketing anode is 1 may be the same as or smaller than the size or area of the punching space formed in the insulating polymer film of the pocketing anode.

In the first pocketing anode body, the second pocketing anode body, and the third pocketing anode body, the distance between the cathode plate and the insulating polymer film may be equally formed.

A hole corresponding to the through hole is not formed in the separator provided in the second pocketing anode body of the second electrode assembly.

A portion of the separator provided in the second pocketing anode of the second electrode assembly, corresponding to the first through hole and the second through hole, is formed on the negative electrode plate of the second negative electrode body disposed at the bottom of the second electrode assembly. It can be pressurized to adhere to the surface.

The accommodating part may be formed by an inner surface of the cathode plate forming the first through hole, an inner surface of the anode plate forming the second through hole, and an upper surface of the cathode plate disposed at the lowermost end of the second electrode assembly.

The first negative electrode body disposed on the upper and lower ends of the first electrode assembly, and the negative electrode active material coating layer formed on the second negative electrode body disposed on the upper and lower ends of the second electrode assembly, respectively, are formed on the upper end of the first electrode assembly. A bottom surface of the first cathode body disposed on the top surface of the first cathode body disposed on the bottom of the first electrode assembly, a bottom surface of the second cathode body disposed on the top of the second electrode assembly, and the second electrode assembly; It may be formed on the upper surface of the second cathode body disposed at the bottom of the.

A positioning member may be provided on the upper side of the first electrode assembly to guide the stacking position of the second electrode assembly stacked on the upper side of the first electrode assembly.

The positioning member may have a through hole through which the second electrode assembly may pass.

The second pocketing positive electrode may include an auxiliary insulating polymer film which is positioned between the pair of separators in the whole or part of the inner circumference of the positive electrode plate on which the first through hole is formed and is bonded to the pair of separators. It may include.

In addition, the auxiliary insulating polymer film and the insulating polymer film may be connected via a connection film.

In addition, a cutout portion into which the connection film may be inserted may be formed in the positive electrode plate having the first through hole formed therein.

A secondary battery having a step cell structure according to an embodiment of the present invention includes a secondary battery accommodating space or an electronic component of an electronic device having a plurality of electrode assemblies having different sizes, stacked in multiple stages, and having a curved curved space. Since the height according to the arrangement can be accommodated in the secondary battery receiving space of the electronic device having the uneven portion or the protrusion, it is possible to take full advantage of the secondary battery storage space in the electronic device.

In addition, the secondary battery having a step cell structure according to an embodiment of the present invention can maximize the remaining space of the secondary battery storage space of the electronic device, thereby increasing battery capacity and battery usage time.

In addition, since the secondary battery having the step cell structure according to the embodiment of the present invention does not limit the secondary battery storage space of the electronic device to an existing square or cylinder, the electronic device can be designed in various designs. .

1 is a perspective view of a secondary battery having a step cell structure according to an embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view of the secondary battery illustrated in FIG. 1 viewed in the direction of arrow A-A '.

3 is a plan view of a first pocketing anode according to an embodiment of the present invention.

4 is a plan view of a third pocketing anode according to an embodiment of the present invention.

5 is a plan view of a second pocketing anode according to an embodiment of the present invention.

6 is a plan view of a third pocketing anode according to another embodiment of the present invention.

7 is a view showing a state in which a secondary battery having a step cell structure is accommodated inside an electronic device having a curved shape.

8 is a view showing a state in which a secondary battery having a step cell structure is accommodated inside a secondary battery case having a curved shape.

9 is a cross-sectional view of a secondary battery having a step cell structure according to another embodiment of the present invention.

10 is a perspective view showing a state in which the second electrode assembly is laminated on the first electrode assembly by the positioning member according to the embodiment of the present invention.

11 is a cross-sectional view showing a second electrode assembly is guided by a positioning member laminated on the first electrode assembly according to an embodiment of the present invention.

12 is a plan view and a cross-sectional view showing a state in which an auxiliary insulating polymer film is provided on a second pocketing anode according to an embodiment of the present invention.

FIG. 13 is a plan view illustrating a state in which the auxiliary insulating polymer film and the insulating polymer film shown in FIG. 12 are connected by a connection film.

14 is an exploded perspective view of a second pocketing positive electrode provided with an auxiliary insulating polymer film.

FIG. 15 is a cross-sectional view of a secondary battery having a step cell structure including a second pocketing positive electrode provided with an auxiliary insulating polymer film. FIG.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims.

For reference, the secondary battery 100 having a step cell structure according to an embodiment of the present invention includes a lithium ion secondary battery, but is not limited to the lithium ion secondary battery. Hereinafter, for convenience of description, the case where the secondary battery 100 according to an embodiment of the present invention is a lithium ion secondary battery will be described as an example.

Hereinafter, a secondary battery 100 having a step cell structure according to an embodiment of the present invention will be described with reference to FIGS. 1 and 7.

1 and 2, the secondary battery 100 having a step cell structure according to an embodiment of the present invention has a structure in which a plurality of electrode assemblies having different sizes are stacked in a vertical direction. In an embodiment of the present invention, a case where two electrode assemblies having different sizes are stacked on top of each other will be described as an example.

In the secondary battery 100 according to an embodiment of the present invention, the first electrode assembly 200 in which a plurality of first pocketing anodes 210 and first cathode bodies 220 having the same size are alternately stacked. The second pocketing anode 310 and the second cathode 320 having the same size are alternately stacked, and are formed to have a size smaller than that of the first electrode assembly 200. The second electrode is provided on the upper side of the electrode assembly 200, the receiving portion 350 is formed to accommodate the protrusions 21 (see Fig. 7) protruding from the inner surface of the electronic device 20, the secondary battery 100 is mounted The electrode assembly 300 and the second electrode assembly 300 may include a third pocketing anode 410 disposed between the lower end and the upper end of the first electrode assembly 200.

It is preferable that the electrical resistance of the relatively smaller electrode assembly 300 among the first electrode assembly 200 and the second electrode assembly 300 is smaller than the electrical resistance of the relatively large electrode assembly 200. This is because the relatively small electrode assembly 300 is likely to degenerate first and lose its function as a battery. The electrode assembly 200 having a large function maintenance period as a battery by reducing the electrical resistance of the small electrode assembly 300 is large. You can keep it similar to

Here, the positive electrode plate 411 of the third pocketing positive electrode body 410 is formed to be the same or smaller than the negative electrode plate 321 of the second negative electrode body 320, and the positive electrode plate of the first pocketing positive electrode body 210. It may be formed smaller than (211).

The third pocketing anode body 410 is disposed between the first electrode assembly 200 and the second electrode assembly 300, and thus the first pocketing anode body 410 contacts the third pocketing anode body 410. The first cathode body 220 and the second cathode body 320 may be disposed at an uppermost end of the electrode assembly 200 and at a lower end of the second electrode assembly 300.

In addition, the accommodating part 350 formed in the second electrode assembly 300 includes the second electrode assembly 300 except for the second cathode body 320 disposed at the lowermost end of the second electrode assembly 300. The second pocketing anode 310 and the second cathode body 320 may be formed.

As shown in FIGS. 2 to 4, the first pocketing anode body 210 and the third pocketing anode body 410 are coated with a lithium or lithium metal composite oxide, which is a cathode active material, and the uncoated protrusions 211a and 411a. ) And a pair of

separators

212 and 412 covering both surfaces of the

positive electrode plates

211 and 411 while exposing only the

plain protrusions

211a and 411a with the

positive electrode plates

211 and 411 and the

positive plate

211 and 411. The insulating

polymer films

213 and 413 may be disposed between the pair of

separators

212 and 412 at the entire circumference or a part of the circumference thereof and adhered to the pair of

separators

212 and 412.

In addition, as illustrated in FIG. 5, the second pocketing anode 310 of the second electrode assembly 300 has a coating layer of a lithium or lithium metal composite oxide, which is a cathode active material, and a plain protrusion 311a. The positive electrode plate 310 having the first through hole 311b into which the protrusion 11 formed in the inner surface of the electronic device on which the secondary battery 100 is mounted is inserted, and exposing only the plain protrusion 311a of the positive electrode plate 311. An insulating polymer bonded between the pair of separators 312 covering the both sides and the pair of separators 312 at the entire circumference or a part of the circumference of the positive electrode plate 311 and bonded to the pair of separators 312 Film 313.

In addition, punching

spaces

213a, 313a, and 413a in which the

positive electrode plates

211, 311, and 411 may be accommodated may be formed in the insulating

polymer films

213, 313, and 413, respectively.

The punching

spaces

213a, 313a, and 413a have a shape or size in which the

positive plates

211, 311, and 411 can be accommodated. In one embodiment of the present invention, the punching

spaces

213a, 313a, and 413a have a rectangular shape corresponding to the shape of the positive plate 211. It may be formed in a shape.

In addition, the

positive electrode plates

211, 311, and 411 accommodated in the

punching spaces

213a, 313a, and 413a respectively form insulating

polymer films

213, 313, and 413 forming the punching

spaces

213a, 313a, and 413a. It may be accommodated in the punching space (213a, 313a, 413a) with a predetermined interval spaced apart from the edge of.

The insulating

polymer films

213, 313, and 413 are polyolefin resin films, polyester resin films, polystyrene resin films, polyimide films, polyamide films, fluorocarbon resin films, ABS films, poly It may include any one selected from the group consisting of acrylic film, acetal film, polycarbonate film.

In addition, the insulating

polymer films

213, 313, and 413 are high-temperature melting type composed of ethylene vinyl acetate, ethylene ethyl acetate, ethylene acrylic acid compound, ionomer compound, polyethylene, polyvinyl acetate, and polyvinyl butyral. It is preferred to include any one of the adhesive components selected from the group of adhesive materials.

In addition, since the positive electrode plate 411 of the third pocketing positive electrode body 410 is formed smaller than the positive electrode plate 211 of the first pocketing positive electrode body 210, the third pocketing positive electrode body 410 is formed on the positive electrode plate 410. When the size or area of the punching space 413a formed is the same as the size or area of the punching space 213a formed in the first pocketing anode body 210, the positive plate of the third pocketing anode body 410 ( The gap d1 formed between the 411 and the insulating polymer film 413 is longer than the gap d2 formed between the positive electrode plate 211 and the insulating polymer film 213 of the first pocketing anode body 210. It can be formed large.

When the size or area of the punching space 413a of the third pocketing anode body 410 is the same as the size or area of the punching space 213a of the first pocketing anode body 210, the Since the insulating polymer film 413 used for the third pocketing anode body 410 and the insulating polymer film 213 used for the first pocketing anode body 210 are compatible with each other in the same shape, the insulating film In the process of manufacturing the

polymer films

213 and 413, there is an advantage that a separate production line of the polymer film is not required.

However, the space or area formed by the gap d1 between the positive electrode plate 411 of the third pocketing positive electrode 410 and the insulating polymer film 413 is the positive electrode plate of the first pocketing positive electrode 210. Since it is larger than the area or space formed by the gap d2 between the 211 and the insulating polymer film 213, between the positive electrode plate 411 and the insulating polymer film 413 of the third pocketing anode body 410. The pair of separators 412 may be deformed to partition the area or space formed by the interval d1 of the battery, thereby degrading the performance of the battery.

Therefore, as shown in FIG. 6, the size or area of the punching space 413a formed in the insulating polymer film 413 of the third pocketing anode body 410 is determined by the first pocketing anode body 210. A gap d1 between the positive electrode plate 411 of the third pocketing anode body 410 and the insulating polymer film 413 by being smaller than the size or area of the punching space 213a formed in the insulating polymer film 213 of FIG. ) Can also be reduced.

The width d3 of the plain protrusion 411a of the third pocketing anode body 410 is the width d4 of the plain protrusion 211a of the first pocketing anode body 210 and the second pocketing. It is preferable that the width d5 is equal to the width d5 of the plain protrusion 311a of the positive electrode body 310.

In addition, the protruding length d6 of the plain protrusion 411a protruding from the positive electrode plate 411 of the third pocketing positive electrode 410 protrudes from the positive electrode plate 211 of the first pocketing positive electrode 210. Is formed equal to or longer than the protruding length (d7) of the plain projection (211a), the same as the protruding length (d8) of the plain projection (311a) protruding from the positive electrode plate 311 of the second pocketing anode (310) Or small.

Accordingly, the plain protrusion 211a of the first pocketing anode body 210, the plain protrusion 311a of the second pocketing anode body 310, and the plain protrusion of the third pocketing anode body 410. 411a may be stacked aligned with each other having the same width as shown in FIG. 1.

In addition, the first cathode body 220 of the first electrode assembly 200 may include a cathode plate 221 having a carbonaceous anode active material capable of occluding and releasing lithium and an uneven protrusion (not shown). .

The plain protrusion 221a formed on the negative electrode plate 221 of the first cathode body 220 may be disposed at a position spaced apart from the plain protrusion 211a of the first pocketing anode body 210.

In addition, the second negative electrode body 320 of the second electrode assembly 300 may also include a negative electrode plate 321 having a carbonaceous negative electrode active material coating layer capable of occluding and releasing lithium and a plain protrusion 321a.

In addition, a second through hole 321 b corresponding to the first through hole 311 b formed in the second positive electrode 320 may be formed in the negative electrode plate 321 of the second negative electrode body 320.

A protrusion 11 protruding from an inner surface of the electronic device may be inserted into the second through hole 321b.

The second through hole 321 b is not formed in the second cathode body 320 disposed on the lowermost side of the second electrode assembly 300.

Therefore, as described above, the second pocketing anode 310 and the second cathode body 320 except for the second cathode body 320 disposed on the lowermost side of the second electrode assembly 300 are made of The first through hole 311b and the second through hole 321b are connected to each other so as to communicate with each other.

Accordingly, the accommodating part 350 formed in the second electrode assembly 300 forms an inner surface of the positive electrode plate 311 forming the first through hole 311b and the second through hole 321b. It may be formed to be surrounded by the inner surface of the negative electrode plate 321 and the upper surface of the negative electrode plate 321 disposed at the lowermost end of the second electrode assembly 200.

The negative electrode plate 321 of the second negative electrode body 320 is configured to stably occlude lithium ions emitted from the positive electrode plate 311 of the second pocketing positive electrode 310. It is necessary to form larger than the size of the positive electrode plate 311 of 310.

In addition, the plain protrusion 321a formed on the negative electrode plate 321 of the second cathode body 320 is disposed at a position spaced apart from the plain protrusion 311a of the second pocketing anode body 310, Aligned with the plain protrusion 221a formed on the negative electrode plate 221 of the negative electrode body 220 may be stacked.

In addition, as described above, the negative electrode plate 321 of the second negative electrode body 320 may be formed to be the same as or larger than the size of the positive electrode plate 411 of the third pocketing positive electrode body 410.

Accordingly, when the second cathode body 320 positioned at the bottom of the second electrode assembly 300 is stacked on the third pocketing anode body 170 stacked on the top of the first electrode assembly 200, The negative electrode plate 321 of the second negative electrode body 320 may occlude the entire area of the positive electrode plate 311 of the third pocketing positive electrode 310 and stably occlude lithium ions emitted from the positive electrode plate 311. .

On the other hand, a hole corresponding to the receiving portion 350 is not formed in the separator 312 of the second pocketing anode 310 of the second electrode assembly 300. That is, the separator 312 is formed to completely cover the entire positive plate 311. In the state in which the plurality of second pocketing anodes 310 are stacked in the second electrode assembly 300, the separators 312 are all pressed toward the upper surface of the negative electrode plate 321 of the second cathode body 320. To this end, the heating and pressing means (not shown) is put in the receiving portion 350 to press toward the negative electrode plate 321 of the second negative electrode body 320. In this case, the separation membrane of the second pocketing anode body 310 ( The 312 are heated and bonded to each other to be positioned on the upper surface of the negative electrode plate 321 of the second negative electrode body 320. In other words, a portion corresponding to the first through hole 311b and the second through hole 321b of the separation membrane 312 provided in the second pocketing anode 310 of the second electrode assembly 300. The pressure may be formed to adhere to the surface of the negative electrode plate 321 of the second negative electrode body 320 disposed at the lowermost end of the second electrode assembly 300.

FIG. 8 is a view illustrating a protrusion 11 formed on an inner surface of the case 10 of the secondary battery 100 inserted into a receiving portion of the second electrode assembly 400. As such, the protrusion 11 formed on the inner surface of the case 10 of the secondary battery 100 is inserted into the accommodation part to prevent the second electrode assembly 400 from being moved in the stacked state on the first electrode assembly 300. It may be.

Hereinafter, a secondary battery 500 having a step cell structure according to another embodiment of the present invention will be described with reference to FIG. 9.

As shown in FIG. 9, the secondary battery 500 having the step cell structure according to another embodiment of the present invention is similar to the secondary battery 100 having the step cell structure according to the embodiment of the present invention. The electrode assembly 200 ′ and the second electrode assembly 300 ′ may be included.

However, the secondary battery 500 having the step cell structure according to another embodiment of the present invention may include a plurality of pocketing anodes constituting the first electrode assembly 200 ′ and the second electrode assembly 300 ′ ( 210 ', 310') and the arrangement relationship between the cathode body 220 ', 320' is different from the secondary battery 100 having a step cell structure according to an embodiment of the present invention, due to this arrangement relationship The electrode assemblies 200 'and 300' having different sizes may be stacked up and down without having the third pocketing anode body 410 described in the embodiment.

That is, in the secondary battery 500 having the step cell structure according to another embodiment of the present invention, as shown in FIG. 9, the plurality of first pocketing cathode bodies 210 ′ and the first cathode having the same size are shown. A first electrode assembly 200 'in which sieves 220' are alternately stacked; The plurality of second pocketing anodes 310 ′ and the second cathode bodies 320 ′ having the same size are alternately stacked, and have a size smaller than that of the first electrode assembly 200 ′. And a second electrode assembly 300 'provided on an upper side of the first electrode assembly 200', and formed at upper and lower ends of the first electrode assembly 200 'and the second electrode assembly 300'. The first cathode body 220 ′ and the second cathode body 320 ′ may be further disposed.

For reference, the first electrode assembly 200 ′ and the second electrode assembly 300 ′ may include the first electrode assembly 130 and the first electrode assembly 130 of the secondary battery 200 having a step cell structure according to an exemplary embodiment of the present invention. Since the structure of the two-electrode assembly 160 is the same, a detailed description thereof will be omitted below.

The first cathode body 220 ′ disposed at the top and bottom of the first electrode assembly 200 ′ and the second cathode body 320 ′ disposed at the top and bottom of the second electrode assembly 300 ′ are provided in the first cathode assembly 220 ′. The first electrode assembly 200 and the second electrode of the secondary battery 100 having a step cell structure according to an embodiment of the present invention is that a carbonaceous negative electrode active material capable of occluding and releasing lithium is coated and coated on one surface thereof. Different from assembly 300.

That is, as shown in FIG. 9, the first cathode body 220 'and the first electrode having the same polarity are formed at the uppermost end of the first electrode assembly 200' and at the lowest end of the second electrode assembly 300 '. The second cathode body 320 'is disposed, and accordingly, at the top of the first electrode assembly 200' during the lamination process of the first electrode assembly 220 'and the second electrode assembly 320'. Since the first cathode body 220 'disposed and the second cathode body 220' disposed at the lowermost end of the first electrode assembly 200 'contact each other, the first cathode body 220' and the second cathode body 220 'are contacted with each other. The negative electrode active material does not need to be coated and coated on the surface where the second negative electrode body 320 ′ contacts each other.

In addition, one surface of the first cathode body 220 ′ disposed at the bottom end of the first electrode assembly 200 ′ and the second cathode body 320 ′ disposed at the top of the second electrode assembly 300 ′ may be formed. Since it is in contact with the secondary battery casing (not shown), the anode active material does not need to be coated and coated on the surface in contact with the secondary battery casing.

Therefore, the bottom of the first cathode body 220 'disposed on the top of the first electrode assembly 200' and the bottom of the first electrode assembly 200 'of the first cathode assembly 220' is disposed. The anode active material is coated and coated only on an upper surface thereof, and is disposed on the bottom surface of the second cathode body 320 ′ disposed on the top of the second electrode assembly 300 ′ and on the bottom of the second electrode assembly 300 ′. Since the negative electrode active material is coated and coated only on the upper surface of the second negative electrode body 320 ′, the material cost required to manufacture the first electrode assembly 200 ′ and the second electrode assembly 300 ′ may be reduced. have.

In addition, as shown in FIGS. 10 and 11, the

secondary batteries

100 and 500 having the step cell structure according to the embodiment and the other embodiment of the present invention have the

second electrode assembly

300 and 300 ′. When the

second electrode assembly

300, 300 ′ is stacked on the upper side of the

first electrode assembly

200, 200 ′, the

second electrode assembly

300, 300 ′ may be placed at a predetermined position with respect to the

first electrode assembly

200, 200 ′. It may further include a positioning member 600 to enable.

For reference, FIGS. 10 and 11 illustrate that the positioning member 600 is applied to the secondary battery 100 having a step cell structure according to an embodiment of the present invention, but is not limited thereto. It may be applied to the secondary battery 500 having the step cell structure according to another embodiment of the present invention.

The positioning member 600 may be stacked on the upper side of the

first electrode assembly

200, 200 ′ while forming a through hole 610 through which the

second electrode assembly

300, 300 ′ may pass. have.

In addition, the overall shape of the positioning member 600 is preferably the same as that of the first electrode assembly 200. That is, length and width directions of the positioning member 600 are preferably the same as the length and width directions of the first electrode assembly 200 as shown in FIG. 10.

This is because the position of the positioning member 600 placed on the upper side of the first electrode assembly 130 must be constant and accurate so that the second electrode assembly 160 of the first electrode assembly 130, 130 ′ can be removed. This is because it can be stacked at a predetermined position from above.

The position of the through hole 610 formed in the positioning member 600 is changed according to the stacking positions of the second electrode assemblies 300 and 300 'placed on the first electrode assemblies 200 and 200'. Can be. Meanwhile, the positioning member 600 may be made of an insulating film, a tape, a plastic synthetic resin, or the like.

Accordingly, the positioning member 600 configured as described above is stacked above the first electrode assembly 200 to guide the stacking position of the second electrode assembly 300 stacked on the first electrode assembly 200. Since the second electrode assembly 300 can be stacked at a predetermined position with respect to the first electrode assembly 200, a simple and accurate operation can be performed.

On the other hand, the second pocketing anode body 310, as shown in Figures 12 to 15, in the whole or part of the inner circumference of the inner circumference of the positive electrode plate 311 is formed with the first through hole 311b The auxiliary insulating polymer film 314 may be further disposed between the pair of separators 312 and adhered to the pair of separators 312.

That is, the auxiliary insulating polymer film 314 may be inserted into the first through hole 311b formed in the positive electrode plate 311 and provided in the entire inner circumferential direction or a portion of the inner circumferential direction of the positive electrode plate 311. In this case, the auxiliary insulating polymer film 314 may be inserted into the first through hole 311b while being spaced apart from the inner surface of the positive electrode plate 311 by a predetermined distance.

In addition, an outer shape of the auxiliary insulating polymer film 314 may be formed in a shape corresponding to the shape of the first through hole 311b. For reference, in the exemplary embodiment of the present invention, as the first through hole 311b is formed in a rectangular shape, the auxiliary insulating polymer film 314 is also illustrated in the drawing as being manufactured in a rectangular frame shape. The shape of the first through hole 311b of the bipolar plate 311 may be formed in a circular or polygonal shape.

In addition, as shown in FIGS. 13 and 14, the auxiliary insulating polymer film 314 is preferably connected to the insulating polymer film 313 through a connection film 316. This is because the auxiliary insulating polymer film 314 may be placed at a predetermined position in the process of being inserted into the first through hole 311b formed in the positive electrode plate 311.

Here, as illustrated in FIG. 14, a cutout portion 311c into which the connection film 316 may be inserted may be formed in the positive electrode plate 311 having the first through hole 311b formed therein. The cutout 311c may have a size that the connection film 316 may be inserted into and accommodated, and may be formed at a position corresponding to the formation position of the connection film 316.

If the cutout portion 311c is not formed on the positive electrode plate 311, the insulating polymer film 313 and the auxiliary insulating polymer film 314 are disposed on the outer circumference and the inner circumference of the positive electrode plate 311, respectively. When the connection film 316 is stacked on the upper surface of the positive electrode plate 311, a gap is formed between the plurality of second pocketing anodes 310 and the second cathode body 320. This may occur to deteriorate the performance of the battery.

For reference, FIG. 14 illustrates a pair of the second pocketing anode 310 to show the insulating polymer film 313 and the auxiliary insulating polymer film 314 connected through the connecting film 316. The second pocketing anode body 314 is shown in a state where any one of the separators 312 is removed.

In addition, the connection film 316 is illustrated in the drawing as connecting the inner center of the insulating polymer film 313 and the outer center of the auxiliary insulating polymer film 314, but is not limited thereto. That is, the position or number of the connection film 316 is formed within the insulating polymer film 313 if the inner surface of the insulating polymer film 313 and the outer surface of the auxiliary insulating polymer film 314 can be connected to each other. It may be selected and formed in at least one portion of the lateral circumferential direction and the outer circumferential direction of the auxiliary insulating polymer film 314.

Hereinafter, a method of manufacturing the secondary battery 100 having a step cell structure according to an embodiment of the present invention will be described.

In the manufacturing method of the secondary battery 100 having the step cell structure according to the embodiment of the present invention, the first pocketing anode 210 and the first cathode body 220 are alternately stacked to form a first electrode assembly ( Preparing a second pocketing anode body 410 on the upper side of the first electrode assembly 200, and preparing the second pocketing anode body 310 and the second cathode body 320. Step cell structure comprising the step of alternately stacking to prepare a second electrode assembly 300 and the second electrode assembly 300 prepared in the step of laminating to the third pocketing anode body 410 Eggplant can provide a method of manufacturing a secondary battery.

In the preparing of the first electrode assembly 200, a plurality of positive electrode plates 211 having the same shape having a coating layer of the positive electrode active material capable of reversibly occluding and releasing lithium ions and the uncoated protrusion 211 a are prepared. Step, preparing a strip-shaped insulating polymer film 213 having a punching space (213a) that can accommodate each of the positive electrode plate 211, the punching space (213a) formed in the insulating polymer film (213) Positioning each of the positive electrode plates 211, preparing a strip-shaped separator 212 positioned on upper and lower surfaces of the positive electrode plate 211 and the insulating polymer film 213, respectively, and forming the strip-shaped separator 212. ) Is placed on the upper or lower surface of the positive electrode plate 211 except for the plain protrusion 211a of the positive electrode plate 211 to cover the positive electrode plate 211 and the positive plate 21 covered by the separator 212. 1) and the insulating polymer film 213 may be passed between a pressure roller (not shown) to obtain a first pocketing anode body 210.

In the step of passing the positive electrode plate 211 and the insulating polymer film 213 covered by the separator 212 between the pressure rollers to obtain the first pocketing positive electrode 210, the upper surface of the positive electrode plate 211 and The separation membranes 212 positioned on the bottom surface are pressed and heated by a pressure roller. At this time, the adhesive component contained in the insulating polymer film 213 is melted by heat and penetrates into the separation membrane 212. 213 and the separator 212 may be bonded to each other.

The preparing of the second electrode assembly 300 may include a coating layer of the positive electrode active material capable of reversibly occluding and releasing lithium ions and a non-projection portion 311a and protruding from an inner surface of the electronic device 20. Preparing a plurality of positive electrode plates 311 having the same shape having a first through hole 311b for accommodating the 21, and strip-shaped insulation having a punching space 311a for accommodating the positive electrode plates 311. Preparing a polymer film 313, positioning the positive electrode plates 311 in the punching space 313a formed in the insulating polymer film 313, of the positive electrode plate 311 and the insulating polymer film 313 Preparing a strip-shaped separator 312 positioned on the upper and lower surfaces, respectively, and forming the strip-shaped separator 312 on the upper and lower surfaces of the positive electrode plate 311 except for the plain protrusion 311a of the positive electrode plate 311. At each location Covering the positive electrode plate 311 and passing the positive electrode plate 311 and the insulating polymer film 313 covered by the separator 312 between the pressure rollers to obtain a second pocketing positive electrode 310. It may include.

In the step of passing the positive electrode plate 311 and the insulating polymer film 313 covered by the separator 312 between the pressure rollers to obtain a second pocketing positive electrode 310, the upper surface of the positive electrode plate 311 and The separators 312 respectively positioned on the lower surface are pressurized and heated by a pressure roller. At this time, the adhesive component contained in the insulating polymer film 313 is melted by heat and penetrates the separator 312 so that the insulating wire polymer film ( 313 and the separator 312 can be bonded.

The preparing of the second electrode assembly 300 may include a coating layer of a negative electrode active material capable of reversibly occluding and releasing lithium ions and accommodating a protrusion 21 protruding from an inner surface of the electronic device 20. Stacking the negative electrode plates 321 having the second through holes 321 b and the first through holes 311 b formed in the second pocketing anode body 310 and the second through holes formed in the negative electrode plates 321. Inserting and pressing a heating and pressing means (not shown) in the (321b) may comprise the step of forming the receiving portion (350).

Receiving portion 350 by inserting a heating and pressing means (not shown) into the first through hole 311b formed in the second pocketing anode body 310 and the second through hole 321b formed in the negative electrode plate 321. In the step of forming, the separation membrane 312 of the second pocketing anode body 310 while the heating and pressing means is inserted into the second through hole 321b and the first through hole 311b which are connected to each other. To the second cathode body 320. At this time, the separation membrane 312 that is pressurized by the heating and pressing means is bent, as shown in Figure 2, the positive electrode plate of the second pocketing anode body 310 to partition the first through hole 311b 311, the inner surface and the second through hole 312b are attached to the upper surface of the negative electrode plate 321 of the second negative electrode body 320. Accordingly, a receiving part 350 may be formed in the second electrode assembly 200, and as shown in FIG. 7, the receiving part 350 has a space in which the secondary electric is stored on the inner surface of the electronic device. A protrusion 11 protruding toward may be inserted.

A secondary battery having a step cell structure and a method of manufacturing the same according to an embodiment of the present invention having the above-described configuration include a plurality of

electrode assemblies

200 and 300 having different sizes, stacked in multiple stages, and having a curved shape. Secondary battery in the electronic device has a laminated structure that can be accommodated in the secondary battery storage space of the electronic device having a space, or the secondary battery storage space of the electronic device having the uneven portion or protrusion by the height according to the arrangement of the electronic components Make the most of your storage space.

In addition, the secondary battery having a step cell structure and a method of manufacturing the same according to an embodiment of the present invention can maximize the remaining space of the secondary battery storage space of the electronic device, thereby increasing the battery capacity and battery usage time.

In addition, the secondary battery having a step cell structure and a method of manufacturing the same according to an embodiment of the present invention, since the secondary battery storage space of the electronic device is not limited to the existing square or cylindrical, it is possible to design the electronic device in various designs It can be done.

One specific embodiment according to the present invention has been described so far, but various modifications are possible without departing from the scope of the present invention.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by the equivalents of the claims.

The present invention can be applied to a variety of electronic devices such as smartphones, cameras, notebooks, and can be sold to consumers or sold separately along with the electronic devices.

Claims

A first electrode assembly in which a plurality of first pocketing anode bodies and first cathode bodies having the same size are alternately stacked; And

And a second electrode assembly having a plurality of second pocketing anode bodies and a second cathode body having the same size, which are alternately stacked, and formed smaller than the first electrode assembly and provided on an upper side of the first electrode assembly.

The secondary battery having a step cell structure, wherein the second electrode assembly is provided with an indented recess.
The method of claim 1,

A third pocketing anode disposed between a lower end of the second electrode assembly and an upper end of the first electrode assembly,

The secondary battery having a step cell structure, wherein the positive electrode plate of the third pocketing positive electrode body is formed the same as or smaller than the negative electrode plate of the second negative electrode body and smaller than the positive electrode plate of the first pocketing positive electrode body.
The method of claim 1,

Secondary batteries having a step cell structure, wherein the first cathode body is disposed on the upper and lower ends of the first electrode assembly, respectively, and the second cathode body is disposed on the upper and lower ends of the second electrode assembly.
The method of claim 2,

The accommodating part is a secondary battery having a step cell structure, characterized in that formed on the remaining second cathode body and the second pocketing anode body of the second electrode assembly except the second cathode body disposed at the lowermost end of the second electrode assembly. .
The method of claim 4, wherein

The second pocketing anode of the second electrode assembly,

A positive electrode plate having a coating layer of a lithium or lithium metal composite oxide as a positive electrode active material and a plain protrusion, and having a first through hole formed therein;

A pair of separators covering both surfaces of the positive electrode plate while exposing only the plain protrusion; And

And an insulating polymer film positioned between the pair of separators in the entire circumference or a portion of the circumference of the positive electrode plate and bonded to the pair of separators.
The method of claim 5, wherein

The first cathode body of the first electrode assembly and the second cathode body of the second electrode assembly are:

A negative electrode plate having a carbonaceous negative electrode active material coating layer capable of occluding and releasing lithium and a plain protrusion;

The step cell structure is characterized in that a second through hole corresponding to or in communication with the first through hole is formed in the negative plate of the second negative electrode body except for the negative plate of the second negative electrode body disposed at the lowermost end of the second electrode assembly. With secondary battery.
The method of claim 2,

The punching space of the insulating polymer film of the first pocketing anode and the third pocketing anode is the same,

Step cell characterized in that the size or area of the punching space formed in the insulating polymer film of the third pocketing anode body is the same or smaller than the size or area of the punching space formed in the insulating polymer film of the first pocketing anode body Secondary battery having a structure.
The method of claim 2,

In the first pocketing positive electrode, the second pocketing positive electrode and the third pocketing positive electrode, the secondary cell having a step cell structure, characterized in that the interval between the positive electrode plate and the insulating polymer film is formed equally.
The method of claim 6,

The secondary battery having a step cell structure, characterized in that no hole corresponding to the through hole is formed in the separator provided in the second pocketing anode body of the second electrode assembly.
The method of claim 6,

A portion of the separator provided in the second pocketing anode of the second electrode assembly, corresponding to the first through hole and the second through hole, is formed on the negative electrode plate of the second negative electrode body disposed at the bottom of the second electrode assembly. Secondary battery having a step-cell structure, characterized in that formed to be pressed to adhere to the surface.
The method of claim 6,

The receiving portion,

And an inner surface of the anode plate forming the first through hole, an inner surface of the cathode plate forming the second through hole, and an upper surface of the cathode plate disposed at the lowermost end of the second electrode assembly. Secondary battery having a.
The method of claim 6,

In the first pocketing positive electrode, the second pocketing positive electrode and the third pocketing positive electrode, the secondary cell having a step cell structure, characterized in that the interval between the positive electrode plate and the insulating polymer film is formed equally.
The method of claim 6,

The first negative electrode body disposed on the upper and lower ends of the first electrode assembly, and the negative electrode active material coating layer formed on the second negative electrode body respectively disposed on the upper and lower ends of the second electrode assembly,

A bottom surface of the first cathode body disposed on the top of the first electrode assembly and an upper surface of the first cathode body disposed on the bottom of the first electrode assembly;

The secondary battery having a step cell structure, characterized in that formed on the bottom surface of the second cathode body disposed on the upper end of the second electrode assembly and the top surface of the second cathode body disposed on the bottom of the second electrode assembly.
The method of claim 1,

The secondary battery having a step cell structure, characterized in that the positioning member for guiding the stacking position of the second electrode assembly is stacked on the upper side of the first electrode assembly.
The method of claim 14,

The secondary battery having a step cell structure, characterized in that the positioning member is formed with a through hole through which the second electrode assembly can pass.
The method of claim 5, wherein

The second pocketing anode body,

And a second insulating polymer film positioned between the pair of separators in the entire inner circumference or a portion of the inner circumference of the bipolar plate in which the first through hole is formed and bonded to the pair of separators. Secondary battery having a.
The method of claim 16,

The secondary insulating polymer film and the insulating polymer film is a secondary battery having a step cell structure, characterized in that connected via a connecting film.
The method of claim 17,

The secondary battery having a step cell structure, characterized in that the first plate is formed in the positive electrode plate is formed with an incision that can be inserted into the connection film.