Rechargeable battery

Abstract

One aspect of the present invention provides a rechargeable battery that reduces resistance at a connection portion between an uncoated portion and a lead tab to achieve high output in an electrode assembly. A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly wound by providing a separator between electrodes; a lead tab connected to the electrode; and a housing that accommodates the electrode assembly and has a lead tab led out to the outside, wherein the lead tab includes: a first tab connected to an uncoated portion of the electrode and formed with a first width and a first thickness; and a second tab connected to the first tab and formed with a second width less than or equal to the first width and a second thickness greater than or equal to the first thickness.

Description

Technical Field

[0001] The present disclosure relates to a rechargeable battery in which a lead tab connected to an uncoated portion of an electrode is pulled to the outside of a case. Background Art

[0002] As technological development improves and demand for mobile devices increases, demand for rechargeable batteries as energy sources is rapidly increasing. Unlike primary batteries, rechargeable batteries are batteries that are repeatedly charged and discharged.

[0003] A small-capacity rechargeable battery is used in portable small electronic devices such as mobile phones, laptop computers, and video cameras, and a large-capacity rechargeable battery may be used as a power source for driving a motor for hybrid vehicles and electric vehicles.

[0004] For example, a rechargeable battery includes an electrode assembly that performs charge and discharge operations, a case that accommodates the electrode assembly, and a lead tab that leads the electrode assembly to the outside of the case. The electrode assembly is formed by welding the lead tab to the uncoated portion and winding the electrode and the separator.

[0005] However, in the electrode assembly, resistance increases at a portion where the uncoated portion and the lead tab are connected, interfering with high output of the electrode assembly. Summary of the invention

[0006] Technical issues

[0007] An aspect of the present invention is to provide a rechargeable battery that achieves high output of an electrode assembly by reducing resistance at a connection portion of a non-coating portion and a lead tab.

[0008] Technical Solution

[0009] A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly wound by arranging a separator between electrodes; a lead tab connected to the electrodes; and a shell accommodating the electrode assembly, and the lead tab is led to the outside of the shell, and the lead tab includes: a first tab formed with a first width and a first thickness and connected to an uncoated portion of the electrode; and a second tab formed with a second width equal to or less than the first width and a second thickness equal to or greater than the first thickness, and connected to the first tab.

[0010] The second thickness may be greater than the first thickness.

[0011] The first tab may be connected to the non-coating portion by surface contact with one surface and partially protrude outside the non-coating portion, and the second tab may be connected to one surface of the first tab by surface contact.

[0012] The second tab may be connected to the side end of the non-coating portion in a state separated from the side surface or in a state of partial contact.

[0013] The second tab may also be connected to the side end of the non-coating portion by surface contact with the side surface.

[0014] The first tab may be connected to an end non-coating portion of a first electrode (eg, a positive electrode) and an end non-coating portion of a second electrode (eg, a negative electrode) among the electrodes.

[0015] The first tab may be connected to a front uncoated portion and an end uncoated portion of a first electrode (eg, a positive electrode) among the electrodes and to a front uncoated portion and an end uncoated portion of a second electrode (eg, a negative electrode).

[0016] The first tab may also be connected to the middle non-coating portion of the first electrode, and may also be connected to the middle non-coating portion of the second electrode.

[0017] The first tab may be connected to a front end uncoated portion of a first electrode (eg, a positive electrode) and a terminal end uncoated portion of a second electrode (eg, a negative electrode) among the electrodes.

[0018] The first tab may be connected to an end uncoated portion of a first electrode (eg, a positive electrode) and a front uncoated portion of a second electrode (eg, a negative electrode) among the electrodes.

[0019] The first tab may be connected to a middle uncoated portion of a first electrode (eg, a positive electrode) and a front uncoated portion and an end uncoated portion of a second electrode (eg, a negative electrode) among the electrodes.

[0020] The first tab may be connected to a front end uncoated portion and an end uncoated portion of a first electrode (eg, a positive electrode) among the electrodes, and may also be connected to a middle uncoated portion of a second electrode (eg, a negative electrode).

[0021] Beneficial Effects

[0022] According to an embodiment of the present invention, since the lead tab is formed of a first tab and a second tab (an inner tab and an outer tab), and the first tab is formed with a first width and a first thickness, the second tab is formed with a second thickness equal to or greater than the first thickness and a second width equal to or less than the first width, the first tab (inner tab) is connected to the uncoated portion, and the second tab (outer tab) is connected to the first tab, resistance can be reduced at the connection portion of the uncoated portion and the lead tab. That is, high output of the electrode assembly can be achieved.

[0023] In addition, according to an embodiment, the side surface of the second tab (external tab) is further connected to the side end of the uncoated portion in a separated state or a partially contacted state to facilitate the working process. In addition, according to an embodiment, since the side surface of the second tab (external tab) is further connected to the side end of the uncoated portion through surface contact, the resistance can be further reduced at the connection portion of the uncoated portion and the lead tab. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is an exploded perspective view showing a rechargeable battery according to a first embodiment of the present invention.

[0025] Figure 2 It is along Figure 1 A sectional view taken along line II-II.

[0026] Figure 3 is expanded and shows the application Figure 1 A plan view of the two surfaces of the electrodes of an electrode assembly.

[0027] Figure 4 yes Figure 3 Side view of the electrode shown in .

[0028] Figure 5 It is along Figure 3 A cross-sectional view taken along line VV of FIG.

[0029] Figure 6 Shown along Figure 3 Another form of a cross-sectional view taken along line VV.

[0030] Figure 7 is a plan view developed and showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a second embodiment of the present invention.

[0031] Figure 8 is a plan view developed and showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a third embodiment of the present invention.

[0032] Fig. 9 is a plan view developed and showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a fourth embodiment of the present invention.

[0033] Fig.10 is a plan view developed and showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a fifth embodiment of the present invention.

[0034] Fig.11 is a plan view developed and showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a sixth embodiment of the present invention.

[0035] Fig.12 is a plan view developed and showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a seventh embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the scope of the present invention. The accompanying drawings and description are to be considered illustrative and non-restrictive in nature. Throughout the specification, the same reference numerals represent the same elements.

[0037] Figure 1 is an exploded perspective view showing a rechargeable battery according to a first embodiment of the present invention, Figure 2 It is along Figure 1 A cross-sectional view taken along line II-II. Figure 1 and Figure 2 The rechargeable battery according to the first embodiment includes an electrode assembly 110 that charges and discharges current, a lead tab connected to the electrode assembly 110, and a case (as an example, referred to as a "pouch 120") that accommodates the electrode assembly 110 and electrolyte. The lead tab is led to the outside of the pouch 120.

[0038] The electrode assembly 110 is formed to be accommodated in the internal space of the bag 120 by arranging and winding electrodes (i.e., a first electrode (for convenience, referred to as a "positive electrode") 11 and a second electrode (for convenience, referred to as a "negative electrode") 12) on both sides with a separator 13 interposed therebetween, and then pressing the outer peripheral surface of the winding.

[0039] The lead tabs include a first lead tab (for convenience, referred to as a "positive electrode tab") 14 and a second lead tab (for convenience, referred to as a "negative electrode tab") 15. The positive electrode tab 14 is electrically connected to the positive electrode 11, and the negative electrode tab 15 is electrically connected to the negative electrode 12.

[0040] Figure 3 is expanded and shows the application Figure 1 A plan view of the two surfaces of the electrodes of the electrode assembly, Figure 4 yes Figure 3 For convenience, the side view of the electrode shown in Figure 3 and Figure 4 Diaphragm 13 is omitted.

[0041] Reference Figure 3 and Figure 4The positive electrode 11 includes an 11th coating portion 11a and a 12th coating portion 11b and a first uncoated portion 11d and a second uncoated portion 11e (as an example, a front uncoated portion and a terminal uncoated portion), and the 11th coating portion 11a and the 12th coating portion 11b are formed by applying a positive electrode active material to both surfaces of a current collector 11c of a metal sheet, and because the positive electrode active material is not applied, the first uncoated portion 11d and the second uncoated portion 11e are set to be exposed to the front end and the terminal of the current collector 11c. For example, the current collector 11c of the positive electrode 11 may be made of aluminum (Al), and the positive electrode tab 14 connected to the positive electrode 11 may also be made of aluminum (Al).

[0042] The negative electrode 12 includes the 21st coating portion 12a and the 22nd coating portion 12b and the third uncoated portion 12d and the fourth uncoated portion 12e (as an example, the front end uncoated portion and the terminal end uncoated portion), the 21st coating portion 12a and the 22nd coating portion 12b are formed by applying the negative electrode active material to both surfaces of the current collector 12c of the metal thin plate, and because the negative electrode active material is not applied, the third uncoated portion 12d and the fourth uncoated portion 12e are set to be exposed to the front end and the terminal of the current collector 12c. For example, the current collector 12c of the negative electrode 12 can be made of copper (Cu), and the negative electrode tab 15 connected to the negative electrode 12 can also be made of copper (Cu).

[0043] The positive electrode tab 14 and the negative electrode tab 15 include a first tab (referred to as an inner tab 141 and 151 for the sake of convenience) and a second tab (referred to as an outer tab 142 and 152 for the sake of convenience).

[0044] The inner tabs 141 and 151 are connected to the positive electrode 11 and the negative electrode 12 by ultrasonic welding or laser welding, and are led to the outside of the electrode assembly 110 and are disposed inside the pouch 120 .

[0045] The external tabs 142 and 152 are connected to the internal tabs 141 and 151 by ultrasonic welding or laser welding outside the electrode assembly 110, and are pulled to the outside of the pouch 120. That is, the external tabs 142 and 152 extend inside and outside the pouch 120.

[0046] Figure 5 It is along Figure 3 A cross-sectional view taken along line VV of FIG. Figures 1 to 5 In the positive electrode tab 14 and the negative electrode tab 15, the inner tabs 141 and 151 are welded to the terminal uncoated portion 11e of the positive electrode 11 and the terminal uncoated portion 12e of the negative electrode 12 and are led to the outside of the electrode assembly 110, and the outer tabs 142 and 152 are welded to the inner tabs 141 and 151 outside the electrode assembly 110.

[0047] For convenience, the negative electrode tab 15 is not shown, and the positive electrode tab 14 is shown. The inner tabs 141 and 151 are formed with a first width W1 and a first thickness t1, and are connected to the terminal uncoated portion 11e of the positive electrode 11 and the terminal uncoated portion 12e of the negative electrode 12. The inner tabs 141 and 151 are connected to one surface of each of the terminal uncoated portions 11e and 12e by surface contact, and partially protrude outside the terminal uncoated portions 11e and 12e.

[0048] The external tabs 142 and 152 are formed with a second width W2 (W2≤W1) equal to or less than the first width W1 and a second thickness t2 (t1≤t2) equal to or greater than the first thickness t1, and are connected to the internal tabs 141 and 151. The external tabs 142 and 152 are connected to one surface of each of the internal tabs 141 and 151 by surface contact. In order to reduce resistance to current, the second thickness t2 may also be greater than the first thickness t1 (t1 <t2)。

[0049] Since the inner tabs 141 and 151 are welded to the end uncoated portions 11e and 12e by surface contact with the first width W1 of a sufficient size, resistance of current flowing between the end uncoated portions 11e and 12e and the inner tabs 141 and 151 may be reduced.

[0050] In addition, since the outer tabs 142 and 152 are welded to the inner tabs 141 and 151 by surface contact with the second thickness t2 (t1≤t2) equal to or greater than the first thickness t1, it is possible to reduce resistance to current flowing between the inner tabs 141 and 151 and the outer tabs 142 and 152. That is, since the outer tabs 142 and 152 increase the outer surface area by the second thickness t2, resistance to current is reduced.

[0051] As such, since resistance at the terminal uncoated portions 11e and 12e, the connection portions of the inner tabs 141 and 151 and the outer tabs 142 and 152, and the outer tabs 142 and 152 themselves is reduced, high output of the electrode assembly 110 may be achieved.

[0052] At the same time, the external tabs 142 and 152 are further connected to the side ends of the terminal uncoated portions 11e and 12e by surface contact with the side surfaces. That is, since the external tabs 142 and 152 are in surface contact with the internal tabs 141 and 151 (the internal tabs 141 and 151 are in surface contact with the terminal uncoated portions 11e and 12e) and in surface contact with the side surfaces of the terminal uncoated portions 11e and 12e, the contact area of ​​the external tabs 142 and 152 with the terminal uncoated portions 11e and 12e increases.

[0053] Therefore, resistance to current flowing between the terminal uncoated portions 11 e and 12 e and the inner and outer tabs 141 and 151 and 142 and 152 is further reduced, and furthermore, high output of the electrode assembly 110 may be further achieved.

[0054] In this case, the terminal uncoated portions 11e and 12e and the connection portions of the inner tabs 141 and 151 and the outer tabs 142 and 152 are electrically insulated by the diaphragm 13. In addition, the terminal uncoated portions 11e and 12e and the inner tabs 141 and 151 are welded to each other, and as a result, mutual contact can also be firmly formed.

[0055] Figure 6 Shown along Figure 3 Another form of the cross-sectional view taken along the line VV. Figure 3 and Figure 6 When describing, the external wiring tabs 142 and 152 can also be further connected to the side ends of the terminal non-coating parts 11e and 12e in a state separated from the side surface or in a state of partial contact. In this case, the connection task process becomes easier than the above-mentioned case where the external wiring tabs 142 and 152 are in surface contact with the side ends of the terminal non-coating parts 11e and 12e.

[0056] Although not shown, the external terminal tab may be in surface contact with the opposite surface of the internal terminal tab. In this case, since the side surfaces of the external terminal tab and the terminal uncoated portion are not in surface contact with each other, the contact area formed between the terminal uncoated portion and the external terminal tab is smaller than Figure 5 The contact area formed in.

[0057] Return to reference Figure 1 and Figure 2 , the bag 120 contains the electrode assembly 110, and the outer portion is thermally fused to form a rechargeable battery. In this case, the outer tab 142 of the positive electrode terminal 14 and the outer tab 152 of the negative electrode terminal 15 are covered by the insulating members 143 and 153, and are led to the outside of the bag 120 through the fused portion.

[0058] That is, the insulating members 143 and 153 electrically insulate the external tabs 142 and 152 of the positive and negative electrode tabs 14 and 15 and electrically insulate the external tabs 142 and 152 of the positive and negative electrode tabs 14 and 15 from the pouch 120 .

[0059] The pouch 120 may be formed in a multi-layered sheet structure covering the outside of the electrode assembly 110. For example, the pouch 120 includes a polymer sheet 121, a nylon sheet 122, and a metal sheet 123.

[0060] The polymer sheet 121 forms the inner surface of the bag 120 and is insulated and heat-fused, the nylon sheet 122 forms the outer surface of the bag 120 and performs a protective function, and the metal sheet 123 provides mechanical strength to the bag 120 .

[0061] The nylon sheet 122 may also be formed of a polyethylene terephthalate (PET) sheet or a PET-nylon composite sheet. The metal sheet 123 is interposed between the polymer sheet 121 and the nylon sheet 122, and may also be formed of an aluminum sheet as an example.

[0062] In addition, the bag 120 includes a first shell 201 and a second shell 202. The first shell 201 and the second shell 202 may be formed of a polymer sheet 121, a nylon sheet 122, and a metal sheet 123 of the same layer structure.

[0063] For example, the first case 201 is formed in a concave structure to accommodate the electrode assembly 110. The second case 202 covers the electrode assembly 110 accommodated in the first case 201 and is formed in parallel to be thermally fused to the first case 201 outside the electrode assembly 110.

[0064] Although not shown, the second housing may be integrally connected to the first housing in one of four directions on a plane and separated in the remaining three directions, and thus, the sealing property can be further enhanced in one connection direction.

[0065] Hereinafter, various embodiments of the present invention will be described. For convenience, descriptions of the same configurations as the first embodiment and the previously described embodiments will be omitted, and different configurations will be described.

[0066] Figure 7 2 is a plan view showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a second embodiment of the present invention. Figure 7 In the second embodiment, in the positive electrode tabs 14 and 16 of the positive electrode 61, the inner tabs 141 and 161 are respectively connected to the terminal uncoated portion 11e and the front end uncoated portion 11d of the positive electrode 61. That is, the positive electrode tabs 14 and 16 form a plurality of tabs. In addition, in the negative electrode tabs 15 and 17 of the negative electrode 62, the inner tabs 151 and 171 are respectively connected to the terminal uncoated portion 12e and the front end uncoated portion 12d of the negative electrode 62. That is, the negative electrode tabs 15 and 17 form a plurality of tabs.

[0067] In this way, the two positive electrode tabs 14 and 16 are respectively connected to the terminal uncoated portion 11e and the front end uncoated portion 11d of the positive electrode 61, and the two negative electrode tabs 15 and 17 are respectively connected to the terminal uncoated portion 12e and the front end uncoated portion 12d of the negative electrode 62. Therefore, since each of the positive electrode tabs 14 and 16 and the negative electrode tabs 15 and 17 is provided in two, the resistance is further reduced compared to the first embodiment to more effectively achieve a high output of the electrode assembly.

[0068] That is, compared with the first embodiment, since the resistance of the connecting parts of the inner terminal tabs 161 and 171 and the outer terminal tabs 162 and 172 and the outer terminal tabs 162 and 172 themselves are further reduced at the front end uncoated parts 11d and 12d, the resistance is further reduced, so that the high output of the electrode assembly can be more effectively achieved.

[0069] Figure 8 2 is a plan view showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a third embodiment of the present invention. Figure 8 In the third embodiment, compared with the structures of the positive electrode 61 and the negative electrode 62 in the second embodiment, the positive electrode 71 and the negative electrode 72 further include intermediate uncoated portions 11f and 12f.

[0070] In the positive electrode tabs 14, 16 and 18 of the positive electrode 71, the inner tabs 141, 161 and 181 are respectively connected to the terminal uncoated portion 11e, the front end uncoated portion 11d and the middle uncoated portion 11f of the positive electrode 71. In addition, in the negative electrode tabs 15, 17 and 19 of the negative electrode 72, the inner tabs 151, 171 and 191 are respectively connected to the terminal uncoated portion 12e, the front end uncoated portion 12d and the middle uncoated portion 12f of the negative electrode 72.

[0071] Therefore, the three positive electrode tabs 14, 16 and 18 are respectively connected to the end uncoated portion 11e, the front end uncoated portion 11d and the middle uncoated portion 11f of the positive electrode 71, and the three negative electrode tabs 15, 17 and 19 are respectively connected to the end uncoated portion 12e, the front end uncoated portion 12d and the middle uncoated portion 12f of the negative electrode 72.

[0072] Therefore, since each of the positive electrode tabs 14, 16, and 18 and the negative electrode tabs 15, 17, and 19 is provided in three, the resistance is reduced to more effectively achieve a high output of the electrode assembly compared to the second embodiment.

[0073] That is, compared with the second embodiment, since the resistance of the intermediate uncoated portions 11f and 12f, the connecting portions of the inner tabs 181 and 191 and the outer tabs 182 and 192, and the outer tabs 182 and 192 themselves are further reduced, the high output of the electrode assembly can be more effectively achieved.

[0074] Fig. 9 2 is a plan view showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a fourth embodiment of the present invention. Fig. 9 In the fourth embodiment, in the positive electrode tab 16 of the positive electrode 63, the inner tab 161 is connected to the front end uncoated portion 11d of the positive electrode 63. In addition, in the negative electrode tab 15 of the negative electrode 64, the inner tab 151 is connected to the terminal uncoated portion 12e of the negative electrode 64.

[0075] Therefore, one positive electrode tab 16 is connected to the front end uncoated portion 11d of the positive electrode 63, and one negative electrode tab 15 is connected to the terminal uncoated portion 12e of the negative electrode 64. Therefore, each of the positive electrode tab 16 and the negative electrode tab 15 is provided as one, and the positive electrode tab 16 and the negative electrode tab 15 are arranged to cross at the front end and the terminal, and as a result, ... Figure 7 ) compared to the first embodiment (see Figure 3 ) to effectively achieve high output of the electrode assembly by reducing resistance.

[0076] That is, the resistances of the front end uncoated portion 11d in the positive electrode 63, the connecting portion between the inner tab 161 and the outer tab 162, the outer tab 162 itself, and the terminal uncoated portion 12e in the negative electrode 64, the connecting portion between the inner tab 151 and the outer tab 152, and the outer tab 152 itself are reduced, and as a result, high output of the electrode assembly can be effectively achieved as in the first embodiment.

[0077] Fig.10 1 is a plan view that is developed and shows two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a fifth embodiment of the present invention. Fig.10 In the fifth embodiment, in the positive electrode tab 14 of the positive electrode 65, the inner tab 141 is connected to the terminal uncoated portion 11e of the positive electrode 65. In addition, in the negative electrode tab 17 of the negative electrode 66, the inner tab 171 is connected to the front end uncoated portion 12d of the negative electrode 66.

[0078] In this way, one positive electrode terminal tab 14 is connected to the terminal uncoated portion 11e of the positive electrode 65, and one negative electrode terminal tab 17 is connected to the front end uncoated portion 12d of the negative electrode 66. Therefore, each of the positive electrode terminal tab 14 and the negative electrode terminal tab 17 is provided as one, and the positive electrode terminal tab 14 and the negative electrode terminal tab 17 are arranged to cross at the terminal and the end, and as a result, the positive electrode terminal tab 14 and the negative electrode terminal tab 17 are arranged as the positive electrode terminal tab 14 and the negative electrode terminal tab 17 are arranged as the positive electrode terminal tab 14 and the negative electrode terminal tab 17. Figure 7 ) compared to the first embodiment (see Figure 3) to effectively achieve high output of the electrode assembly by reducing resistance.

[0079] That is, the resistances of the terminal uncoated portion 11e in the positive electrode 65, the connecting portion between the inner tab 141 and the outer tab 142, the outer tab 142 itself, and the front end uncoated portion 12d in the negative electrode 66, the connecting portion between the inner tab 171 and the outer tab 172, and the outer tab 172 itself are reduced, and as a result, high output of the electrode assembly can be effectively achieved as in the first embodiment.

[0080] Fig.11 2 is a plan view showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a sixth embodiment of the present invention. Fig.11 In the sixth embodiment, in the positive electrode tab 18 of the positive electrode 73, the inner tab 181 is connected to the middle uncoated portion 11f of the positive electrode 73. In addition, in the negative electrode tabs 15 and 17 of the negative electrode 74, the inner tabs 151 and 171 are connected to the terminal uncoated portion 12e and the front end uncoated portion 12d of the negative electrode 74, respectively.

[0081] In this way, one positive electrode tab 18 is connected to the middle uncoated portion 11f of the positive electrode 73, and two negative electrode tabs 15 and 17 are respectively connected to the terminal uncoated portion 12e and the front end uncoated portion 12d of the negative electrode 74. Therefore, since there is one positive electrode tab 18 and there are two negative electrode tabs 15 and 17, the resistance of the negative electrode 74 is further reduced compared to the first embodiment, and the high output of the electrode assembly is more effectively achieved.

[0082] That is, the resistance of the middle uncoated portion 11f in the positive electrode 73, the connecting portion of the inner terminal tab 181 and the outer terminal tab 182, the outer terminal tab 182 itself, the terminal uncoated portion 12e and the front end uncoated portion 12d in the negative electrode 74, the connecting portion of the inner terminal tabs 151 and 171 and the outer terminal tabs 152 and 172, and the outer terminal tabs 152 and 172 themselves are reduced, and as a result, a high output of the electrode assembly can be effectively achieved.

[0083] Fig.12 2 is a plan view showing two surfaces of an electrode of an electrode assembly applied to a rechargeable battery according to a seventh embodiment of the present invention. Fig.12 In the seventh embodiment, in the positive electrode tabs 14 and 16 of the positive electrode 75, the inner tabs 141 and 161 are respectively connected to the terminal uncoated portion 11e and the front end uncoated portion 11d of the positive electrode 75. In addition, in the negative electrode tab 19 of the negative electrode 76, the inner tab 191 is connected to the middle uncoated portion 12f of the negative electrode 76.

[0084] In this way, two positive electrode tabs 14 and 16 are respectively connected to the terminal uncoated portion 11e and the front end uncoated portion 11d of the positive electrode 75, and one negative electrode tab 19 is connected to the middle uncoated portion 12f of the negative electrode 76. Therefore, since there are two positive electrode tabs 14 and 16 and one negative electrode tab 19, the resistance of the positive electrode 75 is further reduced compared to the first embodiment, and the high output of the electrode assembly is more effectively achieved.

[0085] That is, the resistances of the terminal uncoated portion 11e and the front end uncoated portion 11d in the positive electrode 75, the connecting portions of the inner tabs 141 and 161 and the outer tabs 142 and 162, the outer tabs 142 and 162 themselves, and the middle uncoated portion 12f in the negative electrode 76, the connecting portions of the inner tabs 191 and the outer tabs 192, and the outer tabs 192 themselves are reduced, and as a result, a high output of the electrode assembly can be effectively achieved.

[0086] While the present invention has been described in connection with what are presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0087] -Description of the symbol-

[0088] 10: Electrode assembly 11: First electrode (positive electrode)

[0089] 11a, 11b: 11th coating part, 12th coating part 11c: current collector

[0090] 11d: First uncoated portion (front end uncoated portion) 11e: Second uncoated portion (terminal end uncoated portion)

[0091] 11f: middle uncoated portion 12: second electrode (negative electrode)

[0092] 12a, 12b: 21st coating part, 22nd coating part 12c: current collector

[0093] 12d: third uncoated portion (front end uncoated portion) 12e: fourth uncoated portion (end end uncoated portion)

[0094] 12f: middle uncoated portion 13: diaphragm

[0095] 14, 16, 18: positive electrode tab (first lead tab) 15, 17, 19: negative electrode tab (second lead tab)

[0096] 61, 63, 65, 71, 73, 75: positive electrode 62, 64, 66, 72, 74, 76: negative electrode

[0097] 120: Shell (bag) 121: Polymer sheet

[0098] 122: Nylon sheet 123: Metal sheet

[0099] 141, 151, 161, 171, 181, 191: Inner terminal lug (first terminal lug)

[0100] 142, 152, 162, 172, 182, 192: External terminal lug (second terminal lug)

[0101] 143, 153: Insulating member 201: First housing

[0102] 202: second shell t1: first thickness

[0103] t2: second thickness W1: first width

[0104] W2: Second width

Claims

1. A rechargeable battery, comprising: an electrode assembly wound by arranging a separator between a first electrode and a second electrode; a first lead tab connected to the first electrode; a second lead tab connected to the second electrode; as well as a housing that accommodates the electrode assembly, and to which the lead tabs are led to the outside of the housing, Wherein, each of the first lead tab and the second lead tab comprises: a first terminal tab formed with a first width and a first thickness and connected to an uncoated portion of a corresponding electrode, and a second terminal piece formed with a second width equal to or less than the first width and a second thickness equal to or greater than the first thickness and connected to the first terminal piece, Wherein, the second terminal tab is further connected to the side end of the non-coating portion by surface contact with the side surface.

2. The rechargeable battery according to claim 1, wherein: The second thickness is greater than the first thickness.

3. The rechargeable battery according to claim 1, wherein: The first terminal piece is connected to the uncoated portion by surface contact with one surface and partially protrudes outside the uncoated portion, The second terminal tab is connected to one surface of the first terminal tab through a surface contact.

4. The rechargeable battery according to claim 3, wherein: The first tab is connected to a terminal uncoated portion of the corresponding electrode.

5. The rechargeable battery according to claim 3, wherein: The first tab is connected to the front end uncoated portion and the terminal end uncoated portion of the corresponding electrode.

6. The rechargeable battery according to claim 5, wherein: The first tab is also connected to the middle uncoated portion of the corresponding electrode.

7. The rechargeable battery according to claim 3, wherein: A first tab of one of the first and second lead tabs is connected to a front end uncoated portion of a corresponding electrode, and a first tab of the other of the first and second lead tabs is connected to a terminal uncoated portion of the corresponding electrode.

8. The rechargeable battery according to claim 3, wherein: The first tab of one of the first and second lead tabs is connected to the middle uncoated portion of the corresponding electrode, and the first tab of the other of the first and second lead tabs is connected to the front and end uncoated portions of the corresponding electrode.

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