WO2017213352A1

WO2017213352A1 - Rechargeable battery

Info

Publication number: WO2017213352A1
Application number: PCT/KR2017/004837
Authority: WO
Inventors: 권민형; 박용진
Original assignee: 삼성에스디아이 주식회사
Priority date: 2016-06-09
Filing date: 2017-05-10
Publication date: 2017-12-14
Also published as: KR102620809B1; KR20170139351A

Abstract

A rechargeable battery according to an embodiment of the present invention comprises: an electrode assembly for charging and discharging; a case for housing the electrode assembly and an electrolyte; a cap plate coupled to an opening of the case; an electrode terminal installed on the cap plate; a current collector connected to an non-coating portion of the electrode assembly by an electrode connection part and to the electrode terminal by a terminal connection part; and an inner case which accommodates a part of the electrode assembly on a side opposing the cap plate and is housed in the case while being coupled to the electrode connection part.

Description

Secondary battery

The present disclosure relates to a secondary battery, and more particularly, to a secondary battery that prevents a current collector connected to an uncoated portion of an electrode assembly from being deformed inside and outside of the electrode assembly.

A rechargeable battery is a battery that repeatedly performs charging and discharging, unlike a primary battery. Small capacity secondary batteries can be used in portable electronic devices such as mobile phones, notebook computers and camcorders, and large capacity secondary batteries can be used as power sources for driving motors of hybrid vehicles and electric vehicles.

For example, a secondary battery includes an electrode assembly for charging and discharging, a case accommodating an electrode assembly and an electrolyte, a cap plate coupled to an opening of the case, an electrode terminal provided on the cap plate, and an electrode assembly electrically connected to the electrode terminal. And a current collecting member.

The current collecting member includes a terminal connection part coupled to the electrode terminal and an electrode connection part connected to the electrode assembly. The electrode connection is welded to the uncoated portion of the electrode assembly. That is, the plane of the electrode connecting portion is welded to the plane of the plain portion.

Therefore, when the electrode assembly is inserted into the case, the current collector members are disposed on both sides of the inside of the case. And the plane of the electrode connection part and the plane of the plain part are arranged side by side toward the wide wall of the case which is a substantially rectangular parallelepiped, and the end of the electrode connection part and the end part of the plain part are arranged vertically toward the narrow wall of the case. do.

Therefore, when the external force is pressed in the vertical direction to the narrow wall of the case facing the end of the uncoated portion welded to each other and the end of the electrode connecting portion, the narrow wall of the case collapses and enters the inside of the electrode assembly. At this time, the electrode connecting portion welded to the plain portion is deformed inside and outside the electrode assembly by the collapse of the narrow wall.

If the electrode connection is deformed and intruded into the electrode assembly, a short circuit may occur inside the electrode assembly. For the safe use of the secondary battery, it is necessary to prevent the electrode connecting portion from deforming inside and outside of the electrode assembly, and to prevent the electrode connecting portion from entering the inside of the electrode assembly.

One aspect of the present invention is to provide a secondary battery that prevents the electrode connection portion of the current collecting member from being deformed at the inside or the inside and the outside of the electrode assembly when an external force is crushed in a direction perpendicular to the narrow wall of the case.

A secondary battery according to an embodiment of the present invention, an electrode assembly for charging and discharging, a case containing the electrode assembly and the electrolyte, a cap plate coupled to the opening of the case, an electrode terminal installed on the cap plate, A current collecting member connected to an uncoated portion of the electrode assembly by an electrode connection part and connected to the electrode terminal by a terminal connection part, and an interior receiving part of the electrode assembly on the opposite side of the cap plate and being coupled to the electrode connection part and embedded in the case; Include the case.

The electrode connection portion is connected to the plain portion to form a first coupling groove at the boundary between an inner portion disposed inside the plain portion and an outer portion disposed outside the plain portion, and the first coupling groove is formed at an end of the inner case. Can be combined.

The outer side portion adjacent to the first coupling groove may form a curved portion that is bent in a direction away from one surface of both surfaces of the uncoated portion.

The electrode connection part may be provided in plural, and the electrode assembly may be provided in plural and connected to the electrode connection part, respectively.

A plurality of electrode connecting portions may respectively form the first coupling grooves, and the inner case may be continuously coupled to the plurality of first coupling grooves.

The outer side portions may each form the curved portions at the outer side of the first coupling groove, and the curved portions respectively formed may be bent in a symmetrical direction to face the inner surface of the narrow wall of the case.

The secondary battery of one embodiment of the present invention may further include a band member disposed around the electrode connecting portion and the inner case and tightened at an outer side of the first coupling groove.

The outer portion may further form a second coupling groove corresponding to the band member to accommodate the band member.

The electrode connecting portion is provided with a plurality of, the plurality of electrode connecting portions respectively form the first coupling groove, the inner case is continuously coupled to the plurality of first coupling groove, the band member is a plurality of the first It can be accommodated continuously in two coupling grooves.

The electrode connecting portion, the inner case and the band member form an inner space therebetween to face the inner wall of the narrow width wall of the case, and the band member and the inner wall of the narrow wall receive the inner space therebetween. The outer space can be formed.

According to an embodiment of the present invention, since the inner case receives a part of the electrode assembly and couples the electrode connection portion of the current collecting member connected to the electrode assembly to the inner case, the external force may compress in a vertical direction to the narrow wall of the case (crush). Also, the electrode connection portion of the current collecting member can be effectively prevented from being deformed inside or inside and outside the electrode assembly.

1 is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

3 is a perspective view illustrating a connection state of an electrode assembly and a current collecting member in FIG. 2.

4 is a perspective view illustrating a coupling state of an inner case and a current collector member accommodating the electrode assembly of FIG. 3.

5 is a cross-sectional view taken along the line VV of FIG. 4.

FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 4.

FIG. 7 is a perspective view illustrating a coupling state between an inner case accommodating an electrode assembly and a current collector member in a rechargeable battery according to a second exemplary embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

Throughout the specification, when a part is "connected" to another part, it includes not only "directly connected", but also "indirectly connected" between other members. In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

1 and 2, a rechargeable battery according to an embodiment includes an electrode assembly 10 for charging and discharging a current, a case 15 containing an electrode assembly 10 and an electrolyte, and an opening of the case 15. A cap plate 20 coupled to the cap plate 20,

electrode terminals

21 and 22 installed on the cap plate 20,

current collector members

51 and 52 connecting the

electrode terminals

21 and 22 to the electrode assembly 10, and It includes an inner case 70 for receiving a portion of the electrode assembly 10 is embedded in the case 15.

For example, the electrode assembly 10 arranges electrodes (for example, the cathode 11 and the anode 12) on both sides of the separator 13 as an insulator, and the cathode 11, the separator 13, and the anode (12) is formed by curling in a jellyroll state, and is impregnated into the electrolyte solution in the case 15.

Well, the

anodes

11 and 12 are respectively coated

portions

11a and 12a in which an active material is applied to a current collector of metal foil (for example, Cu and Al foils), and a current collector in a portion exposed by not applying the active material. And the

plain portions

11b and 12b to be formed.

The uncoated portion 11b of the negative electrode 11 is formed at one end of the negative electrode 11 along the negative electrode 11 to be wound. The uncoated portion 12b of the anode 12 is formed at one end of the anode 12 along the anode 12 to be wound. The uncoated

portions

11b and 12b are disposed at both ends of the electrode assembly 10, respectively.

The case 15 is made of a substantially rectangular parallelepiped to set a space for accommodating the electrode assembly 10 and the inner case 70 therein. An opening of the case 15 is formed at one side of the rectangular parallelepiped to allow the electrode assembly 10 and the inner case 70 to be inserted into the inner space from the outside.

Specifically, the case 15 has a rectangular bottom 151 facing the opening and having a rounded corner, a pair of wide wall 152 set between the bottom 151 and the opening and facing each other, and one pair The narrow width wall 152 of the pair includes a narrow width wall 153 facing each other.

The cap plate 20 is installed in the opening of the case 15 to seal the case 15. For example, the case 15 and the cap plate 20 may be made of aluminum and welded to each other. That is, after the electrode assembly 10 and the inner case 70 are inserted into the case 15, the cap plate 20 may be welded to the opening of the case 15.

In addition, the cap plate 20 has one or more openings and includes, for example, terminal holes H1 and H2, vent holes 24, and an electrolyte injection hole 27. The electrode terminals (for example, the negative electrode terminal 21 and the positive electrode terminal 22) are respectively installed in the terminal holes H1 and H2 of the cap plate 20, and are electrically connected to the electrode assembly 10.

The positive and

negative terminals

21 and 22 are electrically connected to the

plate terminals

21c and 22c disposed outside the cap plate 20 in correspondence to the terminal holes H1 and H2, and the current collecting

members

51 and 52, respectively. And

rivet terminals

21a and 22a which are riveted to the

plate terminals

21c and 22c through the terminal holes H1 and H2.

The

plate terminals

21c and 22c have through holes H3 and H4. The

rivet terminals

21a and 22a are inserted into the through holes H3 and H4 through the terminal holes H1 and H2 upward. Well, the

anode terminals

21 and 22 further include

flanges

21b and 22b which are formed integrally with the

rivet terminals

21a and 22a inside the cap plate 20.

On the side of the negative electrode terminal 21, the external insulating member 31 interposed between the plate terminal 21c and the cap plate 20 electrically insulates the plate terminal 21c and the cap plate 20. That is, the cap plate 20 is maintained in an electrically insulated state from the current collector member 51 of the electrode assembly 10 and the cathode 11.

The insulating member 31 and the plate terminal 21c are joined to the upper end of the rivet terminal 21a to rivet or weld the upper end, so that the insulating member 31 and the plate terminal 21c are placed on the upper end of the rivet terminal 21a. Is fastened. The plate terminal 21c is installed outside the cap plate 20 with the insulating member 31 interposed therebetween.

On the positive terminal 22 side, the conductive top plate 46 interposed between the plate terminal 22c and the cap plate 20 connects the plate terminal 22c and the cap plate 20 in an electrically conductive structure. That is, the cap plate 20 maintains the state of being electrically connected to the electrode assembly 10 and the current collector member 52 of the positive electrode 12.

By combining the top plate 46 and the plate terminal 22c to the top of the rivet terminal 22a and riveting or welding the top, the top plate 46 and the plate terminal 22c are connected to the top of the rivet terminal 22a. Is fastened. The plate terminal 22c is installed outside the cap plate 20 with the top plate 46 interposed therebetween.

The

gaskets

36 and 37 are provided between the

rivet terminals

21a and 22a of the negative and

positive terminals

21 and 22 and the inner surfaces of the terminal holes H1 and H2 of the cap plate 20, respectively. It seals between 22a) and the cap plate 20, and electrically insulates it.

The

gaskets

36 and 37 are further extended between the

flanges

21b and 22b and the inner surface of the cap plate 20 to further seal and electrically insulate between the

flanges

21b and 22b and the cap plate 20. . That is, the

gaskets

36 and 37 provide negative and

positive terminals

21 and 22 to the cap plate 20 to prevent leakage of electrolyte through the terminal holes H1 and H2.

The

current collecting members

51 and 52 electrically connect the negative and

positive terminals

21 and 22 to the negative and

positive electrodes

11 and 12 of the electrode assembly 10, respectively. For example, the

current collecting members

51 and 52 are connected to the

plain portions

11b and 12b of the electrode assembly 10 by the

electrode connecting portions

512 and 522, and the terminal connecting portions are connected to the negative and

positive terminals

21 and 22. 511, 521.

That is, by coupling the

terminal connecting portions

511 and 521 to the lower ends of the

rivet terminals

21a and 22a and caulking the lower ends, the

terminal connecting portions

511 and 521 are supported by the

flanges

21b and 22b while being riveted to the terminal 22a. , 22a).

The insulating

members

61 and 62 are provided between the terminal connecting

portions

511 and 521 and the cap plate 20 of the

current collecting members

51 and 52, respectively, to electrically connect the

terminal connecting portions

511 and 521 and the cap plate 20. Insulate

In addition, the insulating

members

61 and 62 are coupled to the cap plate 20 on one side and surround the

terminal connecting portions

511 and 521 and the

rivet terminals

21a and 22a and the

flanges

21b and 22b on the other side thereof. Strengthen the structure.

The inner case 70 is formed of an electrical insulating material to receive a portion of the lower side of the electrode assembly 10 at the bottom 151 opposite to the cap plate 20, and the electrodes of the

current collecting members

51 and 52 through the upper opening thereof. Are coupled to the

connections

512, 522.

Therefore, when the external force is crushed in a direction perpendicular to the narrow wall 153 on the narrow wall 153 side of the case 15, the inner case 70 supports the

electrode connecting portions

512 and 522, thereby providing an electrode connecting portion ( It is possible to prevent the 512 and 522 from being deformed inside or inside and outside the electrode assembly 10.

The vent hole 24 is closed by the vent plate 25 to discharge the internal gas and the internal pressure generated by the charging and discharging of the secondary battery. When the internal pressure of the secondary battery reaches the set pressure, the vent plate 25 is cut open to open the vent hole 24. The electrolyte injection opening 27 is sealed with a stopper 29 after the electrolyte injection.

3 is a perspective view illustrating a connection state of the electrode assembly and the current collecting member in FIG. 2, and FIG. 4 is a perspective view illustrating a coupling state of the inner case and the current collecting member accommodating the electrode assembly of FIG. 3. For convenience, the current collector member 52 connecting the positive electrode 12 and the positive electrode terminal 22 will be described as an example.

3 and 4, the electrode connecting portion 522 of the current collecting member 52 is connected to the plain portion 12b of the electrode assembly 10 and is disposed inside the

plain portion

12b, 221. The outer side part 222 arrange | positioned at the outer side of the plain part 12b, and the 1st coupling groove G1 formed in the boundary line of the inner side and

outer side parts

221 and 222 is included. The inner portion 221 is fixedly connected to the plain portion 12b by welding, and the outer portion 222 is exposed to the outside of the plain portion 12b.

The first coupling groove G1 formed at the lower end of the electrode connection part 522 is coupled to the end portion 71 which forms an opening at an upper side of the inner case 70 in the vertical direction. That is, the end portion 71 of the inner case 70 has the first coupling groove G1 of the electrode connecting portion 522 on the narrow wall 153 side of the case 15 in the vertical direction (y-axis direction) of the narrow wall 153. Support).

Accordingly, the electrode case 522 penetrates the inside of the electrode assembly 10 against the external force F acting on the inner case 70 and the end 71 in the vertical direction (y-axis direction) to the narrow wall 153. It is possible to suppress the deformation inside the electrode assembly 10.

A portion adjacent to the first coupling groove G1 of the outer portion 222 forms a curved portion 223 that is bent in a direction away from one surface (x-axis direction) of both surfaces of the plain portion 12b. The curved portion 223 forms a contact surface between the first coupling groove G1 and the end portion 71 of the inner case 70 to increase the resistance to the external force F acting in the y-axis direction. That is, the electrode connecting portion 522 may be further prevented from penetrating into or deforming into the electrode assembly 10.

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 4.

3 to 6, a plurality of electrode connecting portions 522 are provided in the current collector member 52 and are connected to the uncoated portions 12b of the electrode assembly 10. The plurality of electrode connection parts 522 form first coupling grooves G1, respectively. The end 71 of the inner case 70 is coupled to the plurality of first coupling grooves G1 to continuously support the plurality of first coupling grooves G1.

On the side of the narrow wall 153 of the case 15, the plurality of electrode connecting portions 522 are coupled to and supported by the end 71 of the inner case 70 by the first coupling groove G1, so that the electrode connecting portions 522 and the electrode connecting portions 522 are supported. The inner case 70 forms a stronger resistance to external force F acting in the y-axis direction. That is, the electrode connecting portion 522 may be further prevented from penetrating into or deforming into the electrode assembly 10.

In addition, the plurality of outer portions 222 respectively form curved portions 223 at the outer side of the first coupling groove G1. Each curved portion 223 is bent in a symmetrical structure in the x-axis direction with respect to the z-axis direction and supported by the end portion 71 of the inner case 70, and the narrow wall 153 of the case 15 is formed. Towards the inside

In this case, the plurality of curved portions 223 form a contact surface between the plurality of first coupling grooves G1 and the end portion 71 of the inner case 70 to be curved symmetrically to the left and right in the x-axis direction based on the z-axis direction. . That is, the end 71 may symmetrically and firmly support the plurality of first coupling grooves G1 of the electrode connection part 522.

Therefore, the inner case 70 and the electrode connecting portion 522 form a strong resistance against the external force F acting in the vertical direction (y-axis direction) on the narrow wall 153. In the crush test in the y-axis direction for the secondary battery, the inner deformation of the electrode connection portion 522 is improved.

Hereinafter, a second embodiment of the present invention will be described. By comparing the first and second embodiments, descriptions of the same configurations will be omitted, and different configurations will be described.

FIG. 7 is a perspective view illustrating a coupling state between an inner case accommodating an electrode assembly and a current collector member in a rechargeable battery according to a second exemplary embodiment of the present invention, and FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7. to be.

7 and 8, the secondary battery of the second embodiment is disposed around the electrode connecting portion 532 and the inner case 70 at the outside of the first coupling groove G21 formed in the current collecting member 53. It further includes a band member 80 for tightening action.

That is, the band member 80 is formed of an electrical insulating material and tightens the electrode connecting portion 532 at the outside of the inner case 70 and the electrode connecting portion 532 that accommodate the electrode assembly 10. Therefore, the electrode connecting portion 532 may be prevented from being deformed inside and outside the electrode assembly 10 with respect to the external force F acting in the vertical direction (y-axis direction) on the narrow wall 153.

The outer portion 324 further includes a second coupling groove G2 corresponding to the band member 80 to accommodate the band member 80 that tightens. Therefore, the band member 80 may stably tighten the electrode connecting portion 532 in the second defect groove G2 without slipping.

Accordingly, the electrode member 532 of the band assembly 80 and the second defect groove G2 have an external force F acting in the vertical direction (y-axis direction) on the narrow wall 153. It is possible to suppress the deformation inside and outside.

That is, in addition to the coupling of the end 71 of the inner case 70 and the first coupling groove G21, the band member 80 is coupled to the second coupling groove G2 of the outer portion 324 to tighten the electrode connection portion ( 532 can be further suppressed from deforming inside and outside of the electrode assembly 10.

The electrode connection part 532 is provided in plurality, and the plurality of electrode connection parts 532 form a first coupling groove G21, respectively. The inner case 70 is continuously coupled to the plurality of first coupling grooves G21, and the band member 80 is continuously received in the plurality of second coupling grooves G2.

On the narrow wall 153 side of the case 15, the plurality of electrode connecting portions 532 are coupled to and supported by the end 71 of the inner case 70 by the first coupling groove G21, and the second coupling groove ( G2) is coupled to the band member 80 and tightened, so that the electrode connecting portion 532 and the inner case 70 form a stronger resistance against external force F acting in the y-axis direction. That is, the electrode connecting portion 532 may be further prevented from being deformed inside and outside the electrode assembly 10.

In addition, the plurality of electrode connection parts 532, the inner case 70, and the band member 80 form an inner space S1 therebetween to face the inner surface of the narrow wall 153 of the case 15. Moreover, the inner surface of the band member 80 and the narrow wall 153 forms the outer space S2 which accommodates the inner space S1 between each other.

The inner space S1 can absorb the external force F acting in the y-axis direction between the end 71 of the inner case 70 and the band member 80, and the outer space S2 is the band member 80. ) And the narrow wall 153 can absorb the external force (F) acting in the y-axis direction. That is, the inner and outer spaces S1 and S2 may absorb the external force F to prevent the electrode connection part 532 from being deformed inside and outside the electrode assembly 10.

The plurality of outer portions 324 form curved portions 325 on the outside of the first coupling groove G21, and each curved portion 325 has a symmetrical structure in the x-axis direction left and right with respect to the z-axis direction. It is bent and supported by the end 71 of the inner case 70, and faces the inner surface of the narrow wall 153 of the case 15.

In this case, the plurality of curved portions 325 may form a contact surface between the plurality of first coupling grooves G21 and the inner case 70 of the end portion 71 to be curved symmetrically in the x-axis direction based on the z-axis direction. . That is, the end 71 may symmetrically and firmly support the plurality of first coupling grooves G21 of the electrode connection part 532.

Accordingly, the inner case 70, the electrode connecting portion 532, and the band member 80 form a strong resistance to the external force F acting in the vertical direction (y-axis direction) on the narrow wall 153. During the crush test in the y-axis direction for the secondary battery, the inner and outer deformation of the electrode connection portion 532 is improved.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

Description of the sign

10: electrode assembly 11: cathode

11a, 12a: coating

part

11b, 12b: plain part

12: anode 13: separator

15: case 20: cap plate

21, 22: um,

positive terminal

21a, 22a: rivet terminal

21b, 22b:

flange

21c, 22c: plate terminal

24: vent hole 25: vent plate

27: electrolyte injection hole 29: plug

31: insulation member 36, 37: gasket

46:

top plate

51, 52, 53: current collector member

61, 62: insulation member 70: inner case

71: end 80: band member

151: floor 152: wide wall

153: narrow wall 221: inner side

222, 324: outer portion 223, 325: curved portion

511, 521:

terminal connection

512, 522, 532: electrode connection

F: external force G1, G21: first coupling groove

G2: 2nd coupling groove H1, H2: terminal hole

H3, H4: Through hole S1, S2: Inner and outer space

Claims

An electrode assembly that functions to charge and discharge;

A case containing the electrode assembly and the electrolyte;

A cap plate coupled to the opening of the case;

An electrode terminal installed on the cap plate;

A current collecting member connected to the uncoated portion of the electrode assembly by an electrode connection part and connected to the electrode terminal by a terminal connection part; And

An inner case accommodating a part of the electrode assembly on the opposite side of the cap plate and coupled to the electrode connection part and embedded in the case

Secondary battery comprising a.
The method of claim 1,

The electrode connection portion

A first coupling groove is formed at a boundary between an inner side portion connected to the plain portion and disposed at an inner side of the plain portion and an outer side portion disposed at an outer side of the plain portion,

A secondary battery coupled to the end of the inner case by the first coupling groove.
The method of claim 2,

The outer portion adjacent to the first coupling groove

A secondary battery that forms a curved portion bent in a direction away from one surface of both surfaces of the plain.
The method of claim 3,

The electrode connection portion is provided in plurality,

The electrode assembly is provided with a plurality of secondary batteries connected to each of the electrode connecting portion.
The method of claim 4, wherein

A plurality of electrode connecting portion to form the first coupling groove, respectively

The inner case is a secondary battery continuously coupled to the plurality of first coupling grooves.
The method of claim 5,

A plurality of said outer parts

Respectively forming the curved portions at the outer side of the first coupling groove,

Each of the curved parts formed may be bent in a symmetrical direction to each other to face the inner wall of the narrow width wall of the case.
The method of claim 2,

And a band member disposed around the electrode connecting portion and the inner case and tightened at an outer side of the first coupling groove.
The method of claim 7, wherein

The outer portion

The secondary battery further includes a second coupling groove corresponding to the band member to accommodate the band member.
The method of claim 8,

The electrode connection portion is provided in plurality,

A plurality of electrode connecting portion to form the first coupling groove, respectively

The inner case is continuously coupled to the plurality of first coupling grooves,

The band member is a secondary battery continuously received in a plurality of the second coupling groove.
The method of claim 9,

A plurality of the electrode connecting portion, the inner case and the band member

The inner space is formed between each other to face the inner narrow wall of the case,

The band member and the inner narrow wall is

A secondary battery forming an outer space for accommodating the inner space therebetween.
The method of claim 9,

A plurality of said outer parts

Respectively forming the curved portions at the outer side of the first coupling groove,

Each of the curved parts formed may be bent in a symmetrical direction to each other to face the inner wall of the narrow width wall of the case.