SECONDARY BATTERY

07-04-2016 дата публикации
Номер:
KR1020160038176A
Принадлежит:
Контакты:
Номер заявки: 01-14-102030394
Дата заявки: 29-09-2014

[1]

The present invention refers to relates to secondary battery.

[2]

Secondary battery (rechargeable battery) controls the charge the projection unit is inserted into the primary battery alternatively charging and discharging is a secondary battery. Notebook computer or cellular phone secondary battery doses and a small size is rail groove and usable in electronic devices wherein, mass cell a hybrid vehicle that mass or motor driving power supply such as at least two images is used as power storage device.

[3]

Constitution of high energy density using nonaqueous electrolyte solution which are developed high power secondary battery, said charged high power secondary battery e.g. a device as a required force, such as electric vehicle motor of a they can be used in series connecting the antenna units, a plurality of secondary battery consists of large capacity battery module. Such a cylindrical secondary battery such as square and is made by.

[4]

Conductive material such as the case (e.g.: conductive nail) penetrate into the electrode assembly through the electrode assembly when structure is (short-cut) short anode and a cathode.

[5]

The, secondary short electric current generated inside the battery by nozzle of a print head temperature rise electrode assembly is is ignited. the problem or explosion.

[6]

the present invention refers to said one of the upper and lower surfaces so as, the present purpose of the invention short electric current generated by firing or explosions by-shaped secondary battery is provided to prevent a structure that can including secondary battery is intended to.

[7]

One embodiment of the present invention: an secondary battery which, as electrode assembly, process of a cap assembly and closing the aperture of, electrode assembly cap is electrically connected to connection are provided a gasket, terminal lower panel is arranged cap plate to plate and the cap plate and the terminal plate is selectively operated according to one of said terminal plate and cap plate electrically connects the including body to a serpentine includes connecting member of.

[8]

Furthermore, body 12b plate and terminal terminals with the pattern to be electrically connected to the plate number 1 connection, 12b and cap plate pattern to be electrically connected to the cap plate number 2 connection and a connection number 1 number 2 connection and a may include bend.

[9]

Furthermore, bow of a body can be covered by a layer of an insulating coating.

[10]

Furthermore, body. may be part of the bending comes.

[11]

Furthermore, a terminal connection number 1 projecting in one aspect facing the plate includes a prominence can be number 1, number 2 the connection between the top one side of the cap located at the opposite side facing the plate number 2 a protrudent part 17b which protrudes mention can be includes a prominence.

[12]

Furthermore, a number 1 of bends aspect hereinafter height of the protrusion number 1 having a thickness of can be covered by a layer of coding insulating number 1, number 2 of bends a closely hereinafter height of the protrusion number 2 number 2 having a thickness of insulating coating can be covered by a layer of.

[13]

Furthermore, connecting member and the second function through through holes, on which a body of may include a.

[14]

Furthermore, terminal and electrode assembly including fuse part between the first collector may further include any member.

[15]

According to one embodiment of the present invention, short short-circuit current generated by outside electrode assembly can be consumption, electric current by explosion or is ignited-shaped secondary battery is provided can be to prevent.

[16]

According of conductive material of the present invention number 1 embodiment also Figure 1 shows a through which a secondary battery is a perspective view shown. Also Figure 2 shows a cut out along a line in Figure 1 II-II. whose cross section present. Figure 3 shows a perspective view of Figure 1 is of comecting member of secondary battery. Also 4a is plane view of the connecting member of Figure 3. Also connecting member 4b is bottom view of the of Figure 3. Figure 5 shows a cut out along a line also in Figure 1 V-V. whose cross section present. According to of the present invention number 2 embodiment also Figure 6 shows a is perspective view of connecting member. Figure 7 shows a connecting member of is elevational view of Figure 6. According of the present invention number 3 embodiment also Figure 8 shows a is perspective view of a threaded member. Figure 9 shows a bottom view of Figure 8 is of connecting member.

[17]

Hereinafter, based on a text content of the drawing with reference to a person with skill in the art in the present invention is in the field of the easily embodiment of the present invention embodiment can be. as further described thereby, the cold air flows. However the present invention refers to variety of different embodied in the form described hereinafter can be embodiment aspect is not limited.

[18]

In drawing, for disambiguating of the dimensions of the layer or region can be illustrated exaggerated. One layer or elements the interconnection layer has a connection wire or substrate the wall of the rectangular "on" or in gastric directly, another therebetween a and a liquid crystal layer will understood. And, one layer of different layers are "below" the that the generally downwardly or directly, layer at least one other layer therebetween via a is it will be appreciated to be. Furthermore, one layer consists of two layers, in that the "between" the one layer between layers of two only layer or, layer at least one other layer therebetween a interposed between them will understood. The drawing and specification the same sign in exhibits and the same components.

[19]

Figure 1 shows a through which of the present invention number 1 embodiment also of conductive material according to a secondary battery and shown a perspective view, cut out along a line Figure 2 in Figure 1 II-II. whose cross section present.

[20]

Also 1 and 2 to the surface of glass by referring to, secondary battery according to the present embodiment (100) the electrode assembly (10), cap plate (20), case (26) and number 1 terminal portion (30) and a number 2 terminal portion (40) including a terminal portion (30,40), fuse part (51a) including number 1 a collector member (50a) and a number 2 collector member (50b) including a collector member (50) and number 1 and 2 lower insulating members (60a, 60b) including a lower insulating member (60) includes.

[21]

The present embodiment: an electrode assembly (10) the number 1 electrode (11) and number 2 electrode (12) and separators (13) wound together can be in the form of jelly roll.

[22]

Wherein, number 1 electrode (11) and a negative-electrode-side layer number 2 electrode (12) can be an anode.

[23]

Furthermore, electrode number 1 (11) and number 2 electrode (12) a sheet metal each metal foil consisting of respective current collectors is an electrode comprising a collector and coated to the front surface of the substrate may include an active material which.

[24]

Specifically, electrode number 1 (11) and number 2 electrode (12) to a current collector to active materials coated which has simple structure, in jelly roll is disposed at both sides of the coating an aquapotin electrode number 1 a are not coated active materials non-fat part (11a) and number 2 electrode non-fat part (12a) can be is partitioned.

[25]

Just, the present embodiment: an electrode assembly (10) takes the form of the jelly roll without limit to an, electrode number 1 (sheet) made of plurality of sheet (11) and number 2 electrode (12) through a separator (13) separating members, wherein the stacked-layer structure may consist of..

[26]

The present embodiment: an case (26) and an opening is formed in, case (26) inside the inserted through the opening in an electrode assembly (10) can be is accommodated.

[27]

The present embodiment a cap plate according to (20) the case (26) coupled opening of gear case (26). determining whether to intra.

[28]

Furthermore, cap plate (20) has an electrolyte inlet (21), at an electrolyte inlet (21) which seals the sealing plug (22), case (26) in which a set pressure's internal pressure when above being attached opposed vent plate (24) and vent plate (24) of an automatic transmission is provided to vent hole (23) may comprise an.

[29]

The present embodiment according terminal parts (30,40) the terminal and thereby (31,41), terminal plate (32,42), connecting member (33) or terminals insulating member (43) and gasket (34,44) includes.

[30]

Specifically, terminal portion (30,40) of number 1 terminal portion (30) the number 1 terminal (31), number 1 terminal plate (32), connecting member (33) and number number 1 gasket (34) may include a.

[31]

Wherein, number 1 terminal (31) the number 1 collector member (50a) through electrode assembly (10) of number 2 electrode (12) is electrically connected to cap plate (20) is provided through the. Furthermore, number 1 terminal plate (32) the number 1 terminal (31) is coupled to terminal number 1 (31) by means of which electrode assembly (10) of number 2 electrode (12) is electrically connected to.

[32]

Furthermore, connecting member (33) the number 1 terminal (31) and a cap plate (20) is selectively operated according to one of number 1 terminal plate (32) and a cap plate (20) electrically connects the a serpentine body (33a) includes.

[33]

Furthermore, number 1 gasket (34) the number 1 terminal (31) and a cap plate (20) is selectively operated according to one of terminal number 1 (31) and a cap plate (20) electrically insulates to.

[34]

Terminal portion (30,40) of number 2 terminal portion (40) the number 2 terminal (41), number 2 terminal plate (42), number 2 terminal insulating member (43) and number number 2 gasket (44) may include a

[35]

Wherein, number 2 terminal portion (40) the number 2 terminal insulating member (43) except for a number 1 terminal portion (30) be at 500 configuration identical to the.

[36]

Wherein, the present embodiment: an number 2 terminal insulating member (43) the number 2 terminal plate (42) and a cap plate (20) is selectively operated according to one of number 2 terminal plate (42) and a cap plate (20) to electrically insulate a..

[37]

Therefore, the present embodiment according to cap plate (20) has a threaded member (33) via electrode number 2 (12) is formed in the active, case (26) has a cap plate (20) via electrode number 2 (12) electrically may be connected to.

[38]

Hereinafter in the present embodiment a threaded member according to (33) on the.

[39]

Comecting member of and perspective view of Figure 3 shows a secondary battery, also connecting member of Figure 3 is plane view of the 4a, 4b also of connecting member of Figure 3 is the bottom view of Figure 1.

[40]

4b also to 3 also performance to the surface of glass by reference to an, the present embodiment a threaded member according to (33) has a cap plate (20) and a number 1 terminal plate (32) disposed between the a serpentine body (33a) includes.

[41]

Wherein, connecting member (33) body of (33a) the number 1 connection (33a1), number 2 connection (33a2), bends (33a3) and number 1 terminal (32) through through holes, on which a (33a4) may include a.

[42]

Furthermore, connecting member (33) body of (33a) one surface terminals plate (32) and a face-to-face when it burns, this cap plate (20) and a which are opposed to the terminal plate (32) and a cap plate (20) is provided between a.

[43]

Connection number 1 according to the present embodiment (33a1) the terminal and thereby plate (32) and a body (33a) formed on one surface of the, number 2 connection (33a2) has a cap plate (20) and a body (33a) is plays a role of a drift.

[44]

Therefore, number 1 connection (33a1) the number 1 terminal plate (32) and a 12b number 1 terminal plate (32) are connected is electrically connected to the bump.

[45]

Furthermore, number 2 connection (33a2) has a cap plate (20) and a cap plate 12b (20) are connected is electrically connected to the bump.

[46]

Furthermore, connection number 1 (33a1) and a number 2 connection (33a2) has bend (33a3) may be connected to means of which said scale.

[47]

Wherein, bends (33a3) has tortuous shape, for example thin long plates wrinkling or a coil shape can be formed being wound on.

[48]

Furthermore, bends (33a2) the insulating coating layer (33a5,33a6) can be covered.

[49]

Insulating coating layer (33a5,33a6) the number 1 insulating coating layer (33a5) and number 2 insulating coating layer (33a6) may include a.

[50]

Specifically, number 1 insulating coating layer (33a5) the number 1 terminal plate (32) and a body (33a) of number 1 during one surface of connection (33a1) is positioned around the coating is.

[51]

Furthermore, number 2 insulating coating layer (33a6) the cap plate (20) and a body (33a) at the position of number 2 connection (33a2) located in the coating the part is.

[52]

Wherein, number 1 terminal plate (32) the number 1 insulating coating layer (33a5) by bends (33a3) and a collection surfaces conducting electricity are electrically insulated, cap plate (20) the number 2 insulating coating layer (33a6) by bends (33a4) is insulating is electrically connected to the bump.

[53]

Therefore, the present embodiment according example example number 1 terminal (32) and a cap plate (20) and electrically connecting connection number 1 (33a1), bends (33a3) and number 2 connection (33a2) a current pass is connecting member (33) can be formed to.

[54]

Also 4 reference to an surface, the present in the embodiment a number 1 electrode (11) comprises an elongated support plate (10) is positioned on at in order to expose the bonding pad.

[55]

Wherein, number 1 electrode (11) and a negative-electrode-side layer number 2 electrode (12) since an anode may be, connecting member (33) via electrode number 2 (12), which are connected electrically to a case (26) comprises a positive electrode can be charged.

[56]

Furthermore, the anode charged case (26) and a cathode a number 1 electrode (11) the separator (13) between the separator (13) located on either side of..

[57]

Therefore, conductive material (70) (e.g.: nail) is secondary battery (100) through the surface, conductive material (70) a case (26), separator (13), number 1 electrode (11) and number 2 electrode (12) for sequentially penetrate electrode number 1 (11) and number 2 electrode (12) is between the short-circuit current.

[58]

The, number 1 electrode (11) and number 2 electrode (12) between the conductive material (70), case (26) a cap that is joined to the plate (20), connecting member (33), number 1 terminal plate (32), number 1 terminal (31), number 1 collector member (50a) through the intermediary of either short-circuit current electrode assembly (10) discharged to the outside of electric current pass is is formed.

[59]

Wherein, number 1 electrode (11) and number 2 electrode (12) formed between the current pass paragraph is determined by generating the paragraph may change even if the is, conductive material (70) by electrode number 1 (11) and number 2 electrode (12) state of a short circuit of the is maintained electrode assembly (10) inside the electrode number 1 (11) and number 2 electrode (12) flowing between is premise, and remain short-circuit current.

[60]

Therefore, electrode assembly (10) wall inclined towards a electric current by electrode assembly (10) for preventing the explosion or is ignited is electrode assembly order (10) wall inclined towards a electric current minimizing the amount of is necessary that.

[61]

According to the present embodiment, number 1 electrode (11) and number 2 electrode (12) formed between the current pass paragraph is determined by generating the paragraph constituting a connecting member for connecting (33) since consumed effective short-circuit current in electrode assembly (10) electric current wall inclined towards a can be the minimal amount of substrate to.

[62]

Specifically, the present embodiment electrode number 1 according to (11) and number 2 electrode (12) the power input through paragraph is determined by generating the paragraph current electric current pass the electrode through the assembly (10) is forced from number 1 terminal plate (32) and a cap plate (20) installed between the connecting member (33) be consumed in.

[63]

I.e., number 1 electrode (11) and number 2 electrode (12) current pass paragraph is determined by generating the paragraph formed between the electric current passing through the electrode assembly (10) is forced from case (26), cap plate (20), cap plate (20) electrically connected to a connection number 2 (33a2), bend tortuous (33a3) and number 1 terminal plate (32) electrically connected to a connection number 1 (33a1) through a.

[64]

The, number 1 electrode (11) and number 2 electrode (12) paragraph is determined by generating the paragraph formed between the electric current passing through the current pass have some a connecting member (33) of number 2 connection (33a2), bend tortuous (33a3) and number 1 connection (33a1) is consumption during passing through the.

[65]

Wherein, number 1 electrode (11) and number 2 electrode (12) method of electric current passing through the current pass number 1 during collector member (50a) fuse part in (51a) the amount of electric current passing through the connecting member (33) electric current connected with the LCD panel, resulting in proportion to amount of small.

[66]

Therefore, the present embodiment connecting member according to (33) in current consumption due to short fuse part (51a) passing through the amount of electric current per unit of time since is not longer than the second set, fuse part (51a) can be a time for electric of molten.

[67]

Furthermore, the present embodiment arrangement such as fuse part (51a) when a time for electric of molten number 1 number 2 electrode and electrode (12) between short-circuit current paths have fuse part (51a) of molten delay time and during a period in which such a corresponding can continue.

[68]

Therefore, the present embodiment electrode number 1 according to (11) and number 2 electrode (12) of short-circuit current generated by short fuse part (51a) of molten broadcasting signal electric current pass the electrode through the assembly (10) is discharged to the outside and a coupling member (33) is consumption in, fuse part (51a) to melt into electric current pass disappear after electrode assembly (10) the remaining electric current the minimal amount of substrate to can be.

[69]

Eventually, conductive material according to the present embodiment (70) due to penetration of the number 1 electrode (11) and number 2 electrode (12) of short-circuit current generated by short fuse part (51a) of molten broadcasting signal electric current pass the electrode through the assembly (10) can be discharge is sufficiently external, fuse part (51a) current pass have shorted by not depending upon melting of the electrode assembly after disappear (10) the remaining electric current by electrode assembly (10) is is ignited or explosion can be is inhibited against exhaustion from the housing.

[70]

Figure 6 shows a perspective view of connecting member according to of the present invention number 2 embodiment also and, is front of Figure 7 shows a connecting member of Figure 6.

[71]

The present embodiment a threaded member according to (130) has a cap plate (20) and a number 1 terminal plate (32) disposed between the a serpentine body (130a) includes.

[72]

Wherein, connecting member (130) body of (130a) the number 1 connection (131), number 2 connection (132), bends (133) and number 1 terminal (32) through through holes, on which a (134) may include a.

[73]

Furthermore, connecting member (130) body of (130a) of which one side is number 1 terminal plate (32) and a face-to-face when it burns, this cap plate (20) and a which are opposed to the number 1 terminal plate (32) and a cap plate (20) is provided between a.

[74]

According to the embodiment number 1 connection (131) the number 1 terminal plate (32) and a body (130a) formed on one surface of the, number 2 connection (132) has a cap plate (20) and a body (130a) is plays a role of a drift.

[75]

Furthermore, connection number 1 (131) the number 1 terminal plate (32) projecting in one aspect and a protrusion number 1 (131a) may comprise, number 2 connection (132) one surface opposite the base cap plate (20) and a protrusion number 2 a protrudent part 17b which protrudes mention (132a) may comprise an.

[76]

According to the embodiment number 1 connection (131) of number 1 protrusion (131a) and a number 1 terminal plate (32) can, for example, be can be fitted and, number 2 connection (132) of number 2 protrusion (132a) and a cap plate (20) can, for example, be. can be fitted.

[77]

Number 1 connection (131) and a number 2 connection (132) has bend (133) may be connected to means of which said scale.

[78]

Wherein, bends (133) has tortuous shape, for example thin long plates wrinkling or a coil shape can be formed being wound on.

[79]

Furthermore, bends (133) the insulating coating layer (135,136) can be covered.

[80]

Insulating coating layer (135,136) the number 1 insulating coating layer (135) and number 2 insulating coating layer (136) may include a.

[81]

Specifically, number 1 insulating coating layer (135) the number 1 terminal plate (32) and a body (130a) during one surface of number 1 connection (131) is placed around the can be coating.

[82]

Wherein, number 1 insulating coating layer (135) the thickness of the connection number 1 (131) of number 1 protrusion (131a) is equal to or smaller than the height of the item may be.

[83]

Furthermore, number 2 insulating coating layer (136) the cap plate (20) and a body (130a) at the position of number 2 connection (132) is placed around the can be coating.

[84]

Wherein, number 2 insulating coating layer (136) the thickness of the connection number 2 (132) of number 2 protrusion (132a) is equal to or smaller than the height of the item may be.

[85]

Therefore, number 1 terminal plate (32) the number 1 insulating coating layer (135) by bends (133) and a collection surfaces conducting electricity are electrically insulated, cap plate (20) the number 2 insulating coating layer (136) by bends (133) is insulating is electrically connected to the bump.

[86]

Number 1 connection (131) the number 1 protrusion (131a) through number 1 terminal plate (32) is electrically connected and a, number 2 connection (33a2) the number 2 protrusion (132a) through cap plate (20) are connected is electrically connected to the bump.

[87]

Therefore, the present embodiment according to connecting member (130) of number 1 protrusion (131a) and number 2 protrusion (132a) by number 1 terminal plate (32) and a cap plate (20) is electrically stably may be connected to.

[88]

According to Figure 8 shows a perspective view of a threaded member of the present invention number 3 embodiment also and, Figure 9 shows a connecting member of the bottom section of the elastic is of Figure 8.

[89]

Also surface reference to an 8 and 9, the present embodiment a threaded member according to (230) has a cap plate (20) and a number 1 terminal plate (32) disposed between the a serpentine body (230a) includes.

[90]

Wherein, connecting member (230) body of (230a) the number 1 connection (231), number 2 connection (232), bends (233) and number 1 terminal (32) through through holes, on which a (234) may include a.

[91]

Furthermore, connecting member (230) body of (230a) one surface terminals plate (32) and a face-to-face when it burns, this cap plate (20) and a which are opposed to the terminal plate (32) and a cap plate (20) is provided between a.

[92]

Connection number 1 according to the present embodiment (231) the terminal and thereby plate (32) and a body (230a) formed on one surface of the, number 2 connection (232) has a cap plate (20) and a body (230a) is plays a role of a drift.

[93]

Therefore, number 1 connection (231) the number 1 terminal plate (32) and a 12b number 1 terminal plate (32) are connected is electrically connected to the bump.

[94]

Furthermore, connection number 2 (232) has a cap plate (20) and a cap plate 12b (20) are connected is electrically connected to the bump.

[95]

Furthermore, connection number 1 (231) and a connection number 2 (232) has bend (233) may be connected to means of which said scale.

[96]

Wherein, bends (233) has tortuous shape, for example thin long plates wrinkling or a coil shape can be formed being wound on.

[97]

Furthermore, bends (233) the insulating coating layer (235,236) can be covered.

[98]

Insulating coating layer (235,236) the number 1 insulating coating layer (235) and number 2 insulating coating layer (236) may include a.

[99]

Specifically, insulating coating layer number 1 (235) the number 1 terminal plate (32) and a body (230a) during one surface of number 1 connection (231) located in the is coating around the.

[100]

Furthermore, number 2 insulating coating layer (236) the cap plate (20) and a body (230a) at the position of number 2 connection (232) located in the coating the part is.

[101]

Wherein, number 1 terminal plate (32) the number 1 insulating coating layer (235) by bends (233) and a collection surfaces conducting electricity are electrically insulated, cap plate (20) the number 2 insulating coating layer (236) by bends (233) is insulating is electrically connected to the bump.

[102]

Therefore, the present embodiment according example example number 1 terminal (32) and a cap plate (20) and electrically connecting connection number 1 (231), bends (233) and number 2 connection (232) a current pass is connecting member (230) can be formed to.

[103]

To standardize the focuses of the present invention not described but a preferred embodiment, the present invention refers to claim at limited to a and appends detailed description of the invention and within range of the drawings embodiment the hole to which the variously it is possible the disc spin speed value within a range. of course in addition of the present invention.

[104]

100: secondary battery 10: electrode assembly 11: number 1 electrode 12: number 2 electrode 13: separator 30,230: number 1 terminal portion 31,231: number 1 terminal 32: number 1 terminal plate 33, 130, 230: connecting member 33a, 130a, 230a: body 33a1, 131, 231: number 1 connection 33a2, 132, 232: number 2 connection 33a3, 133, 233: bends 33a4, 134, 234: through hole 33a5, 135, 235: number 1 insulating coding layer 33a6, 136, 236: number 1 insulating coding layer Gasket 34: number 1 40: number 2 terminal portion 41: number 2 terminal 42: number 2 terminal plate 43: number 2 terminal insulating member Gasket 44: number 2 50: collector member 50a: number 1 collector member 50b: collector member number 2 60: lower insulating member 60a: number 1 lower insulating member 60b: lower insulating member number 2 70: conductive material



[1]

To prevent the explosion of a secondary battery, a secondary battery according to an embodiment of the present invention includes a case, an electrode assembly accommodated in the case, a cap plate which seals an opening of the case, a terminal which is electrically connected to the electrode assembly and penetrates the cap plate, a terminal plate which is installed on the cap plate and is combined with the terminal, and a connection member which is installed between the cap plate and the terminal plate and includes a winding body connecting electrically the cap plate and the terminal plate.

[2]

COPYRIGHT KIPO 2016

[3]



Case; electrode assembly as said; process of a cap assembly and closing the aperture of said case; said electrode assembly electrically connected to said connection are provided through the cap plate; said cap plate lower panel is arranged said terminal to plate; and said cap plate and said terminal plate is selectively operated according to one of said cap plate and said terminal plate electrically connects the connecting member including body to a serpentine; including a secondary battery.

According to Claim 1, said body, said terminal plate and 12b said pattern to be electrically connected to the plate terminal number 1 connection, said cap plate 12b and said pattern to be electrically connected to the cap plate number 2 connection and connection said number 1 number 2 connection and a secondary battery including a bend.

According to Claim 2, said body said insulating part of the bending comes secondary battery covered by a layer of coating.

According to Claim 2, said part of the bending comes said body helical secondary battery.

According to Claim 2, the connection between the top said number 1 said projecting in one aspect facing the plate terminal includes a prominence and the number 1, the connection between the top said number 2 said one side of the cap plate located at the opposite side and facing the projections a protrudent part 17b which protrudes mention number 2 including secondary battery.

According to Claim 5, said bends of said number 1 is set to be hereinafter height of the protrusion said number 1 aspect having a thickness of and covered by a layer of coding insulating number 1, said bends of said number 2 a closely hereinafter height of the protrusion said number 2 number 2 having a thickness of insulating coating covered by a layer of a secondary battery.

According to Claim 1, said body of said connecting member said terminals secondary battery including the through hole.

According to Claim 6, said terminal and said electrode assembly including fuse part between the first collector member further including secondary battery.