Secondary batteries

Abstract

This invention relates to a secondary battery. The secondary battery according to the invention includes: an electrode assembly; an electrolyte; and a battery housing for accommodating the electrode assembly and the electrolyte, wherein the battery housing includes: a main body having a housing space therein for accommodating the electrode assembly and the electrolyte; an additional electrolyte housing having a storage space formed therein for accommodating the additional electrolyte; a connecting portion having a moving channel through which the additional electrolyte is supplied from the additional electrolyte housing to the main body; and an electrolyte impregnation member disposed in the connecting portion and impregnated with the additional electrolyte.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0005637, filed on January 15, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention relates to a secondary battery. Background Technology

[0005] Unlike primary batteries, secondary batteries are rechargeable, and they offer significant potential for miniaturization and high capacity. Therefore, much research has been conducted on secondary batteries recently. With technological advancements and increasing demands for mobile devices, the need for secondary batteries as an energy source is rapidly growing.

[0006] Rechargeable batteries are classified according to the shape of their casing into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch batteries. A secondary battery houses the electrode assembly and the electrolyte. In this type of secondary battery, the electrode assembly installed in the battery casing is a rechargeable and discharging power generation device with a structure consisting of stacked electrodes and separators.

[0007] Electrode assemblies can be broadly classified as follows: roller-type electrode assemblies, in which separators are inserted between the positive and negative electrodes, each separator being configured as a sheet coated with active material, and then the positive electrode, separators, and negative electrode are wound together; stacked electrode assemblies, in which multiple positive electrodes and multiple negative electrodes are stacked in sequence, with separators between the positive and negative electrodes; and stacked / folded electrode assemblies, in which stacked cell cells are wound together with a separator membrane having a long length.

[0008] Recently, pouch cells with stacked / folded electrode assemblies built into the pouch cell housing and set as aluminum stacks have attracted much attention due to their low manufacturing cost, light weight, and easy deformation, and their applications are gradually increasing.

[0009] However, with the use of secondary batteries, there is a problem of performance degradation due to the gradual consumption of electrolyte. The electrolyte may vaporize with repeated charging and discharging of the secondary battery and be gradually consumed by accumulating in the form of polymers.

[0010] [Prior Art Documents] (Patent Documents) Korean Patent Publication No. 10-2014-0015647 Summary of the Invention

[0011] Technical issues

[0012] One aspect of the present invention is to provide a secondary battery that can easily supply additional electrolyte to a secondary battery.

[0013] Technical solution

[0014] A secondary battery according to an embodiment of the present invention includes an electrode assembly, an electrolyte, and a battery housing configured to accommodate the electrode assembly and the electrolyte. The battery housing includes: a main body having a accommodating space for accommodating the electrode assembly and the electrolyte; an additional electrolyte accommodating portion having a storage space for accommodating the additional electrolyte; a connecting portion configured to form a moving channel through which the additional electrolyte is supplied from the additional electrolyte accommodating portion to the main body; and an electrolyte impregnation member disposed on the connecting portion and impregnated with the additional electrolyte.

[0015] The battery pack according to an embodiment of the present invention includes a secondary battery according to an embodiment of the present invention.

[0016] Beneficial effects

[0017] According to the present invention, an additional electrolyte reservoir can be provided in a secondary battery, wherein a storage space for accommodating an additional electrolyte is formed, so as to facilitate the supply of additional electrolyte and prevent degradation of cycle performance.

[0018] Furthermore, an electrolyte-impregnated component with an additional electrolyte can be provided on the connecting part, through which the additional electrolyte is supplied from the additional electrolyte reservoir to the main body containing the electrolyte, so as to supply the additional electrolyte more smoothly and thus improve performance more effectively. Attached Figure Description

[0019] Figure 1 This is a perspective view of a secondary battery according to a first embodiment of the present invention.

[0020] Figure 2 This is an exploded perspective view showing a state in which a portion of the secondary battery according to a first embodiment of the present invention has been removed.

[0021] Figure 3 This is a perspective view of a secondary battery according to a second embodiment of the present invention.

[0022] Figure 4 This is an exploded perspective view showing a state in which a portion of the secondary battery according to a second embodiment of the present invention has been removed.

[0023] Figure 5 This is a perspective view of a secondary battery according to a third embodiment of the present invention.

[0024] Figure 6 This is an exploded perspective view showing a state in which a portion of the secondary battery according to a third embodiment of the present invention has been removed.

[0025] Figure 7 This is a perspective view of the secondary battery based on Comparative Example 1.

[0026] Figure 8 This is a perspective view of the secondary battery based on Comparative Example 2. Detailed Implementation

[0027] The objectives, specific advantages, and novel features of the present invention will become clearer from the following detailed description taken in conjunction with the accompanying drawings. It should be noted that throughout this specification, reference numerals are used as much as possible to denote the parts of the drawings added to this specification, even those shown in other drawings. Furthermore, the invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. In the following description of the invention, detailed descriptions of related technologies that may unnecessarily obscure the spirit of the invention will be omitted.

[0028] First Embodiment

[0029] Figure 1 This is a perspective view of a secondary battery according to a first embodiment of the present invention, and Figure 2 This is an exploded perspective view showing a state in which a portion of the secondary battery according to a first embodiment of the present invention has been removed.

[0030] refer to Figure 1 and Figure 2 The secondary battery 100 according to a first embodiment of the present invention relates to a secondary battery 100 including an electrolyte and a battery casing 110. The battery casing 110 includes a main body 111 housing an electrode assembly 120 and an electrolyte, an additional electrolyte housing 112 housing an additional electrolyte, a connecting portion 113 forming a movement channel 113d from the additional electrolyte housing 112 to the main body 111, and an electrolyte impregnation member 130 disposed in the connecting portion 113. Furthermore, the secondary battery 100 according to the first embodiment of the present invention may also include a sealing portion 114.

[0031] More specifically, the secondary battery 100 according to the first embodiment of the present invention includes an electrode assembly 120, an electrolyte, and a battery casing 110 for housing the electrode assembly 120 and the electrolyte.

[0032] The electrode assembly 120 may be a rechargeable and dischargeable power generation element and may include alternatingly stacked electrodes 123 and separators 124.

[0033] Electrode 123 may include a positive electrode 121 and a negative electrode 122. Here, electrode assembly 120 may have a structure in which positive electrode 121 / separator 124 / negative electrode 122 are alternately stacked. In addition, electrode leads may include a positive electrode lead connected to the positive electrode 121 and a negative electrode lead connected to the negative electrode 122.

[0034] The positive electrode 121 may include a positive current collector and a positive active material stacked on the positive current collector.

[0035] The positive current collector can be made of aluminum foil.

[0036] The positive electrode active material may include lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, or a compound or mixture containing at least one of the above materials.

[0037] The negative electrode 122 may include a negative electrode current collector and a negative electrode active material stacked on the negative electrode current collector.

[0038] The negative current collector can be made of, for example, a foil made of copper (Cu) material.

[0039] The negative electrode active material can be a compound or mixture containing graphite-based materials.

[0040] The separator 124 is made of an insulating material to electrically insulate the positive electrode 121 from the negative electrode 122. Here, the separator 124 may be made of a polyolefin-based resin film, such as polyethylene or polypropylene with micropores.

[0041] The battery casing 110 may include a main body 111, an additional electrolyte container 112, a connecting part 113, and an electrolyte impregnation member 130.

[0042] A containing space 111a for accommodating the electrode assembly 120 and the electrolyte can be formed in the main body 111.

[0043] A storage space 112a for accommodating an additional electrolyte can be formed in the additional electrolyte container 112. Here, the additional electrolyte may have the same composition as the electrolyte contained in the container space 111a of the main body 111.

[0044] In addition, the supplementary electrolyte container 112 may have the same length as the main body 111.

[0045] Furthermore, the additional electrolyte container 112 can be formed as a hollow rectangular column shape.

[0046] The connecting part 113 can form a moving channel 113d, through which the additional electrolyte is supplied from the additional electrolyte container 112 to the main body 111.

[0047] In addition, the connecting portion 113 may have the same thickness as each of the main body 111 and the additional electrolyte container 112.

[0048] In addition, the connecting part 113 can connect the upper part, lower part and central part of the supplementary electrolyte container 112 to each other.

[0049] Here, the connecting portion 113 may include a first connecting portion 113a that connects the main body 111 to the uppermost side of the supplementary electrolyte container 112, a second connecting portion 113b that connects the main body 111 to the lowermost side of the supplementary electrolyte container 112, and a third connecting portion 113c that connects the main body to the center side of the supplementary electrolyte container 112.

[0050] Here, each of the first connecting part 113a, the second connecting part 113b, and the third connecting part 113c can be formed into a rectangular column shape.

[0051] The electrolyte impregnation member 130 can be provided on the connecting part 113 and can be impregnated with additional electrolyte.

[0052] Therefore, when the amount of electrolyte contained in the receiving space 111a of the main body 111 decreases, the electrolyte impregnation member 130 can guide the additional electrolyte provided in the additional electrolyte receiving part 112 to be supplied to the receiving space 111a of the main body 111.

[0053] Additionally, one side 132 of the electrolyte impregnation member 130 may extend further into the storage space 112a of the additional electrolyte container 112.

[0054] Additionally, the electrolyte impregnation member 130 may include one or more of nonwoven fabric, separation membrane, and cloth. Here, the separation membrane used in the electrolyte impregnation member 130 may be made of the same material as the separator 124 used in the electrode assembly 120.

[0055] The electrolyte impregnation member 130 may include an impregnation portion 131 disposed on the connection portion, a side portion 132 that extends further into the storage space 112a of the additional electrolyte receiving portion 112, and another side portion 133 that extends further into the receiving portion of the body 111.

[0056] Here, one side 132 of the electrolyte impregnation member 130 may have dimensions corresponding to the length and width of the storage space 112a of the additional electrolyte receiving portion 112. Here, one side 132 of the electrolyte impregnation member 130 may be formed as a rectangular plate shape with a predetermined width.

[0057] Furthermore, the end of the other side 133 of the electrolyte impregnation member 130 can extend further into the receiving space of the main body 111. Here, the end of the other side 133 of the electrolyte impregnation member 130 can extend between the electrode 122 and the separator 124.

[0058] In addition, the electrolyte-impregnated member 130 can be formed in an "E" shape.

[0059] The impregnated portion 131 can be formed to have dimensions corresponding to the length and width of the moving channel 113d of the connecting portion 113.

[0060] Additionally, the impregnation portion 131 may include a first impregnation portion 131a disposed on the first connecting portion 113a and connected to the uppermost side of the other side portion 133, a second impregnation portion 131b disposed on the second connecting portion 113b and connected to the lowermost side of the other side portion 133, and a third impregnation portion 131c disposed on the third connecting portion 113c and connected to the center side of the other side portion 133.

[0061] A sealing portion 114 may be formed between the main body 111 (excluding the connecting portion 113) and the additional electrolyte container 112.

[0062] Additionally, the sealing portion 114 may include a first sealing portion 114a and a second sealing portion 114b. The first sealing portion 114a may be disposed between the uppermost first connecting portion 113a and the center connecting portion 113c, and the second sealing portion 114b may be disposed between the lowermost second connecting portion 113b and the center connecting portion 113c.

[0063] In addition, the sealing part 114 can be formed by the hot-melt battery casing 110.

[0064] According to a first embodiment of the present invention, a plurality of secondary batteries 100 can be electrically connected to each other to form a battery pack.

[0065] Second Embodiment

[0066] The secondary battery according to a second embodiment of the present invention will be described below.

[0067] Figure 3 This is a perspective view of a secondary battery according to a second embodiment of the present invention, and Figure 4 This is an exploded perspective view showing a state in which a portion of the secondary battery according to a second embodiment of the present invention has been removed.

[0068] refer to Figure 3 and Figure 4 The secondary battery 200 according to a second embodiment of the present invention relates to a secondary battery 200 including an electrolyte and a battery casing 210. The battery casing 210 includes a main body 211 for accommodating an electrode assembly 120 and an electrolyte, an additional electrolyte accommodating portion 212 for accommodating additional electrolyte, a connecting portion 213 forming a movement channel 212d from the additional electrolyte accommodating portion 212 to the main body 211, and an electrolyte impregnation member 230 disposed in the connecting portion 213. Furthermore, the secondary battery 200 according to the second embodiment of the present invention may also include a sealing portion 214.

[0069] Except for the shape of the connecting portion 213, the secondary battery 200 according to the second embodiment of the present invention is the same as the secondary battery according to the first embodiment of the present invention. Therefore, in the second embodiment of the secondary battery 200, the content that is repeated in the secondary battery of the first embodiment of the present invention will be omitted or briefly described, and the differences between them will be mainly described.

[0070] More specifically, the secondary battery 200 includes an electrode assembly 120, an electrolyte, and a battery casing 210 that houses the electrode assembly 120 and the electrolyte.

[0071] The battery casing 210 may include a main body 211, an additional electrolyte container 212, a connecting part 213, and an electrolyte impregnation member 230.

[0072] A containing space 211a for accommodating the electrode assembly 120 and the electrolyte can be formed in the main body 211.

[0073] A storage space 212a for accommodating additional electrolyte can be formed in the additional electrolyte container 212. Here, the additional electrolyte container 212 can be formed as a hollow rectangular column shape.

[0074] In addition, the supplementary electrolyte container 212 may have the same length as the main body 211.

[0075] The connecting part 213 can form a moving channel 212d, through which the additional electrolyte is supplied from the additional electrolyte container 212 to the main body 211.

[0076] The connecting portion 213 may have the same thickness as each of the main body 211 and the additional electrolyte container 212.

[0077] The connecting part 213 can connect the upper and lower parts of the additional electrolyte container 212 to each other.

[0078] The connecting portion 213 may include a first connecting portion 213a that connects the main body 211 to the uppermost side of the supplementary electrolyte container 212 and a second connecting portion 213b that connects the main body 211 to the lowermost side of the supplementary electrolyte container 212.

[0079] Each of the first connecting part 213a and the second connecting part 213b can be formed into a rectangular column shape.

[0080] The electrolyte impregnation member 230 can be provided on the connecting part 213 and can be impregnated with additional electrolyte.

[0081] Therefore, when the amount of electrolyte contained in the receiving space 211a of the main body 211 decreases, the electrolyte impregnation member 230 can guide the additional electrolyte provided in the additional electrolyte receiving part 212 to be supplied to the receiving space 211a of the main body 211.

[0082] Additionally, one side 232 of the electrolyte impregnation member 230 may extend further into the storage space 212a of the additional electrolyte containment 212.

[0083] Additionally, the electrolyte impregnation member 230 may include one or more of nonwoven fabric, separation membrane, and cloth. Here, the separation membrane used in the electrolyte impregnation member 230 may be made of the same material as the separator 224 used in the electrode assembly.

[0084] Additionally, the electrolyte impregnation member 230 may include an impregnation portion 231 disposed on the connecting portion 213, a side portion 232 extending further into the storage space 212a of the additional electrolyte receiving portion 212, and another side portion 233 extending further into the receiving portion of the main body 211.

[0085] Here, one side 232 of the electrolyte impregnation member 230 may have dimensions corresponding to the length and width of the storage space 212a of the additional electrolyte receiving portion 212. Here, one side 232 of the electrolyte impregnation member 230 may be formed as a rectangular plate shape with a predetermined width.

[0086] Furthermore, the end of the other side portion 233 of the electrolyte impregnation member 230 can extend further into the receiving space of the main body 211. Here, the end of the other side portion 233 of the electrolyte impregnation member 230 can extend between the electrode 122 and the separator 124.

[0087] In addition, the electrolyte impregnation component 230 can be formed as shape.

[0088] The impregnated portion 231 can be formed to have dimensions corresponding to the length and width of the moving channel 213d of the connecting portion 213.

[0089] Additionally, the impregnation portion 231 may include a first impregnation portion 231a disposed on the first connecting portion 213a and connected to the uppermost side of the other side portion 233, and a second impregnation portion 231b disposed on the second connecting portion 213b and connected to the lowermost side of the other side portion 233.

[0090] The sealing part 214 may be formed between the main body 211 (excluding the connecting part 213) and the additional electrolyte container 212.

[0091] Third Embodiment

[0092] The secondary battery according to a third embodiment of the present invention will be described below.

[0093] Figure 5 This is a perspective view of a secondary battery according to a third embodiment of the present invention, and Figure 6 This is an exploded perspective view showing a state in which a portion of the secondary battery according to a third embodiment of the present invention has been removed.

[0094] refer to Figure 5 and Figure 6 The secondary battery 300 according to a third embodiment of the present invention relates to a secondary battery 300 including an electrolyte and a battery casing 310. The battery casing 310 includes a main body 311 for accommodating an electrode assembly 120 and an electrolyte, an additional electrolyte accommodating portion 312 for accommodating additional electrolyte, a connecting portion 313 forming a movement channel 312d from the additional electrolyte accommodating portion 312 to the main body 311, and an electrolyte impregnation member 330 disposed in the connecting portion 313. Furthermore, the secondary battery 300 according to the third embodiment of the present invention may also include a sealing portion 314.

[0095] Except for the shape of the connecting portion 313, the secondary battery 300 according to the third embodiment of the present invention is the same as the secondary battery according to the first and second embodiments of the present invention. Therefore, in the third embodiment of the secondary battery 300, the content that is repeated in the secondary battery according to the foregoing embodiments of the present invention will be omitted or briefly described, and the differences between them will be mainly described.

[0096] More specifically, the secondary battery 300 includes an electrode assembly 120, an electrolyte, and a battery casing 310 that houses the electrode assembly 120 and the electrolyte.

[0097] The battery casing 310 may include a main body 311, an additional electrolyte container 312, a connecting part 313, and an electrolyte impregnation member 330.

[0098] A containing space 311a for accommodating the electrode assembly 120 and the electrolyte can be formed in the main body 311.

[0099] A storage space 312a for accommodating additional electrolyte can be formed in the additional electrolyte container 312. Here, the additional electrolyte container 312 can be formed as a rectangular column shape with a hollow interior.

[0100] The additional electrolyte container 312 may have the same length as the main body 311.

[0101] The connecting part 313 can form a moving channel 312d, through which the additional electrolyte is supplied from the additional electrolyte container 312 to the main body 311.

[0102] In addition, the connecting portion 313 may have the same thickness as each of the main body 311 and the additional electrolyte container 312.

[0103] In addition, the connecting part 313 can be connected to the center of the additional electrolyte container 312.

[0104] Here, the connecting portion 313 may include a third connecting portion 313c that connects the main body 311 to the center side of the additional electrolyte container 312.

[0105] Here, the third connecting part 313c can be formed into a rectangular column shape.

[0106] The electrolyte impregnation member 330 can be provided on the connecting part 313 and can be impregnated with additional electrolyte.

[0107] Therefore, when the amount of electrolyte contained in the receiving space 311a of the main body 311 decreases, the electrolyte impregnation member 330 can guide the additional electrolyte provided in the additional electrolyte receiving part 312 to be supplied to the receiving space 311a of the main body 311.

[0108] Additionally, one side 332 of the electrolyte impregnation member 330 may extend further into the storage space 312a of the additional electrolyte container 312.

[0109] Additionally, the electrolyte impregnation member 330 may include one or more of nonwoven fabric, separation membrane, and cloth. Here, the separation membrane used in the electrolyte impregnation member 330 may be made of the same material as the separator 124 used in the electrode assembly 120.

[0110] The electrolyte impregnation member 330 may include an impregnation portion 331 disposed on the connecting portion 313, a side portion 332 extending further into the storage space 312a of the additional electrolyte receiving portion 312, and another side portion 333 extending further into the receiving portion of the main body 311.

[0111] Here, one side 332 of the electrolyte impregnation member 330 may have dimensions corresponding to the length and width of the storage space 312a of the additional electrolyte receiving portion 312. Here, one side 332 of the electrolyte impregnation member 330 may be formed as a rectangular plate shape with a predetermined width.

[0112] Furthermore, the end of the other side portion 333 of the electrolyte impregnation member 330 can extend further into the receiving space of the main body 311. Here, the end of the other side portion 333 of the electrolyte impregnation member 330 can extend between the electrode 122 and the separator 124.

[0113] In addition, the electrolyte impregnation component 330 can be formed as The shape.

[0114] The impregnation portion 331 can be formed to have dimensions corresponding to the length and width of the moving channel 312d of the connecting portion 313.

[0115] Additionally, the impregnation portion 331 may include a third impregnation portion 331c disposed on the third connecting portion 313c and connected to the center side of the other side portion 333.

[0116] The sealing part 314 may be formed between the main body 311 (excluding the connecting part 313) and the additional electrolyte container 312.

[0117] Manufacturing Example 1

[0118] <Manufacturing the Negative Electrode>

[0119] A negative electrode mixture slurry was prepared by adding 92% (by weight) of negative electrode active material (graphite:SiO = 7:3), 3% (by weight) of acetylene black (denka black) (conductive agent), 3.5% (by weight) of SBR (binder) and 1.5% (by weight) of CMC (thickener) to water.

[0120] The prepared negative electrode mixture slurry is coated on both surfaces of a copper current collector, then dried and rolled to prepare the negative electrode.

[0121] <The Manufacturing of the Positive Electrode>

[0122] 97.5% (by weight) of LiNi 0.8 Co 0.1 Mn 0.1 O2, as the positive electrode active material, 1% (by weight) acetylene carbon black (conductive agent) and 1.5% (by weight) PVdF (binder) are added to NMP to prepare a positive electrode mixture slurry.

[0123] The prepared positive electrode mixture slurry is coated on both surfaces of an aluminum current collector, then dried and rolled to prepare the positive electrode.

[0124] Assembly of Secondary Batteries

[0125] An electrode assembly (in which the prepared positive and negative electrodes are stacked, and a separator (polypropylene) is placed between the positive and negative electrodes) is placed in a battery casing, and 2 wt% of fluoroethylene carbonate (FEC) is added to a solvent (in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are mixed in a volume ratio of 3:7). Then, 4 ml of electrolyte containing 1 M LiPF6 is injected, and the battery casing is sealed to manufacture a secondary battery.

[0126] Here, with and like Figure 1The secondary battery shown is manufactured with the same configuration as the secondary battery according to the first embodiment of the present invention.

[0127] That is, a secondary battery includes: a main body housing an electrode assembly and an electrolyte; an additional electrolyte reservoir having a storage space for accommodating an additional electrolyte; a connecting portion connecting a moving channel to an uppermost, lowermost, and central side, wherein the additional electrolyte is supplied from the additional electrolyte reservoir to the main body through the moving channel; and an electrolyte-impregnated member disposed on the connecting portion and impregnated with the additional electrolyte. A sealing portion is formed between the main body and the additional electrolyte reservoir, excluding the connecting portion. Here, the additional electrolyte is of the same composition as the electrolyte, and the electrolyte disposed in the additional electrolyte reservoir is defined as the additional electrolyte.

[0128] Manufacturing Example 2

[0129] In manufacturing example 2, except that the shape of the battery casing is different from that of the battery casing according to manufacturing example 1, the secondary battery is manufactured in the same manner as in manufacturing example 1.

[0130] Here, with and like Figure 3 The secondary battery shown is manufactured with the same configuration as the secondary battery according to the second embodiment of the present invention.

[0131] That is, a secondary battery includes: a main body housing an electrode assembly and an electrolyte; an additional electrolyte reservoir having a storage space for accommodating additional electrolyte; a connecting portion connecting a moving channel to an uppermost and a lowermost side, wherein the additional electrolyte is supplied from the additional electrolyte reservoir to the main body through the moving channel; and an electrolyte-impregnated member disposed on the connecting portion and impregnated with the additional electrolyte. In this case, a sealing portion is formed between the main body and the additional electrolyte reservoir, excluding the connecting portion.

[0132] Manufacturing Example 3

[0133] In manufacturing example 3, except that the shape of the battery casing is different from that of the battery casing according to manufacturing example 1, the secondary battery is manufactured in the same manner as in manufacturing example 1.

[0134] Here, with and like Figure 5 The secondary battery shown is manufactured with the same configuration as the secondary battery according to the third embodiment of the present invention.

[0135] That is, a secondary battery includes: a main body housing an electrode assembly and an electrolyte; an additional electrolyte reservoir having a storage space for accommodating additional electrolyte; a connecting portion connecting a movement channel to a central side, through which the additional electrolyte is supplied from the additional electrolyte reservoir to the main body; and an electrolyte-impregnated member disposed on the connecting portion and impregnated with the additional electrolyte. In this case, a sealing portion is formed between the main body and the additional electrolyte reservoir, excluding the connecting portion.

[0136] Comparative Example 1

[0137] Figure 7 This is a perspective view of the secondary battery based on Comparative Example 1.

[0138] refer to Figure 7 In Comparative Example 1, the secondary battery was manufactured in the same manner as in Manufacturing Example 1, except that the additional electrolyte containment, connection and sealing parts were not formed in the battery casing according to Manufacturing Example 1.

[0139] That is, a secondary battery 400 is manufactured by forming only a body 411 containing electrode components and electrolyte in the battery casing 410.

[0140] Comparative Example 2

[0141] Figure 8 This is a perspective view of the secondary battery based on Comparative Example 2.

[0142] refer to Figure 8 In Comparative Example 2, the secondary battery was manufactured in the same manner as in Manufacturing Example 1, except that the connecting part and the sealing part were not formed in the battery casing according to Manufacturing Example 1.

[0143] That is, a secondary battery 500 is manufactured, which includes a main body 511 for accommodating electrode components and electrolyte and an additional electrolyte accommodating portion 512 in the battery casing 510. Here, the main body 511 and the additional electrolyte accommodating portion 512 are manufactured in a manner in which additional space is further formed in the side surface of the main body without being connected to each other by a connecting portion.

[0144] Experimental Example

[0145] The reversibility of charge / discharge was tested using an electrochemical charge / discharge apparatus on the secondary batteries prepared in Examples 1 to 3 and Comparative Examples 1 and 2. During charging, a current density of 0.1 charge rate (C-rate) was applied to 4.2V (vs. Li / Li). + The voltage was adjusted to 2.5V during discharge at the same current density. Table 1 shows the capacity retention rate after 300 cycles compared to the first cycle discharge capacity.

[0146] [Table 1]

[0147]

[0148] Referring to Table 1, in Manufacturing Examples 1 to 3, since there is excess electrolyte in the supplementary electrolyte space, the cycle degradation due to electrolyte depletion is not severe, and therefore, the capacity retention rate after 300 cycles is high. On the other hand, in Comparative Example 1, which involves a general secondary battery structure, it can be seen that since there is no excess electrolyte, the capacity retention rate after 300 cycles decreases by about 20% to about 23% due to electrolyte depletion. In Comparative Example 2, it can be seen that although an supplementary electrolyte space is formed and excess electrolyte is placed in the supplementary electrolyte space, no connection portion with an electrolyte-impregnated member is provided between the electrode portion and the supplementary electrolyte space, so the electrolyte is not guided, and no sealing portion is provided to reduce the electrode pressure caused by the battery casing. Therefore, the charging / discharging of the electrodes cannot be carried out well during charging and discharging, and the capacity retention rate after 300 cycles decreases by about 11% to about 40%. Therefore, it can be seen that since the capacity retention rate in Manufacturing Examples 1 to 3 is significantly higher than that in Comparative Examples 1 and 2, the battery capacity is improved.

[0149] Although the invention has been specifically shown and described with reference to exemplary embodiments thereof, it should be understood that the scope of the invention is not limited to the secondary battery according to the invention. Those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

[0150] Furthermore, the scope of protection of this invention will be defined by the appended claims.

[0151] [Explanation of reference numerals in the attached figures]

[0152] 100: Secondary battery

[0153] 110, 210, 310: Battery casing

[0154] 111, 211, 311: Main body

[0155] 111a: Accommodation space

[0156] 112, 212, 312: Additional electrolyte container

[0157] 112a: Storage space

[0158] 113, 213, 313: Connecting parts

[0159] 113a, 213a: First connecting part

[0160] 113b, 213b: Second connecting part

[0161] 113c, 313c: Third connecting part

[0162] 114, 214, 314: Sealing parts

[0163] 114a: First sealing part

[0164] 114b: Second sealing part

[0165] 120: Electrode assembly

[0166] 121: Positive electrode

[0167] 122: Negative electrode

[0168] 123: Electrode

[0169] 124: partition

[0170] 130, 230, 330: Electrolyte-impregnated components

[0171] 131, 231, 331: Impregnation section

[0172] 132, 232, 332: A side part

[0173] 133, 233, 333: The other side

Claims

1. A secondary battery, comprising an electrode assembly, an electrolyte, and a battery casing configured to house the electrode assembly and the electrolyte. in, The battery casing includes: The main body has a space for accommodating the electrode assembly and the electrolyte; An additional electrolyte container has a storage space for accommodating additional electrolytes; A connecting portion is configured to form a moving channel through which the additional electrolyte is supplied from the additional electrolyte reservoir to the main body; and An electrolyte-impregnated component is disposed on the connecting portion and impregnated with the additional electrolyte. The electrolyte impregnation component includes: An impregnated portion is provided on the connecting portion; A side portion, said side portion further extending into the storage space of the additional electrolyte containment; and On the other side, the end of the other side further extends into the receiving space of the body and extends between the alternating layers of electrodes and separators of the electrode assembly. The electrolyte-impregnated component includes one or more of nonwoven fabrics and cloths.

2. The secondary battery according to claim 1, wherein, When the amount of electrolyte contained in the containment space of the main body decreases, the electrolyte impregnation member guides the additional electrolyte disposed in the additional electrolyte containment portion to be supplied to the containment space of the main body.

3. The secondary battery according to claim 1, wherein, The connecting portion connects the main body to the upper and lower parts of the additional electrolyte container or the center part of the additional electrolyte container.

4. The secondary battery according to claim 1, wherein, The connecting portion connects the main body to the upper, lower, and central portions of the additional electrolyte container.

5. The secondary battery according to claim 4, wherein, The connecting part includes: A first connecting portion is configured to connect the main body to the uppermost side of the additional electrolyte container; The second connecting portion is configured to connect the main body to the lowermost side of the additional electrolyte container; and The third connection is configured to connect the main body to the center side of the additional electrolyte container.

6. The secondary battery according to claim 5, in, One side portion has dimensions corresponding to the length and width of the storage space of the additional electrolyte container, and The impregnated portion has dimensions corresponding to the length and width of the moving channel of the connecting portion.

7. The secondary battery according to claim 6, wherein, The other side has a rectangular plate shape, the rectangular plate shape having a predetermined width, and The impregnation section includes: The first impregnation portion is disposed on the first connecting portion and connected to the uppermost side of the other side portion; The second impregnation portion is disposed on the second connecting portion and connected to the lowest side of the other side portion; and The third impregnation part is provided on the third connecting part and connected to the center side of the other side part.

8. The secondary battery according to claim 1, wherein, The additional electrolyte container has the same length as the main body.

9. The secondary battery according to claim 1, further comprising a sealing portion located between the main body and the additional electrolyte containment portion, excluding the connecting portion.

10. The secondary battery according to claim 1, wherein, The connecting portion has the same thickness as each of the main body and the additional electrolyte container.

11. A battery pack comprising a secondary battery according to any one of claims 1 to 10.

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