Lead tab for bonding to electrode tab and all-solid-state battery including structure having lead tab bonded to electrode tab

Abstract

Disclosed are a lead tab for bonding to an electrode tab and an all-solid-state battery including a structure having the lead tap bonded to an electrode tab, wherein an issue regarding the stripping of an anode protective layer can be solved by bonding a lead tap of a predetermined material to the electrode tap by using low welding energy, and no lithiation reaction is caused since an electrolyte and the lead tap are not in contact with each other in the all-solid-state battery including a structure having the lead tab bonded to the electrode tab. The lead tab for bonding to an electrode tab is bonded to an electrode tab of an electrode assembly for an all-solid-state battery to form a bonding portion, and a lead included in the bonding portion contains aluminum.

Description

An all-solid-state battery comprising a lead tab for electrode tab bonding and a structure in which the lead tab is bonded to the electrode tab

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0104686, filed August 10, 2023, and Korean Patent Application No. 10-2024-0105049, filed August 7, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an all-solid-state battery including a lead tab for electrode tab bonding and a structure in which the lead tab is bonded to the electrode tab, and more particularly, to an all-solid-state battery including a lead tab for electrode tab bonding and a structure in which the lead tab is bonded to the electrode tab, wherein the problem of a negative electrode protective layer being detached can be solved by bonding a lead tab of a specific material to the electrode tab with low welding energy, and further, in the all-solid-state battery including the structure in which the lead tab and the electrode tab are bonded, the electrolyte and the lead tab do not come into contact, and thus a lithiation reaction is not induced.

[0003] As interest in energy storage technology grows, its applications expand to include energy storage in mobile phones, tablets, laptops, and camcorders, as well as electric vehicles (EVs) and hybrid electric vehicles (HEVs). This has led to a surge in research and development on electrochemical devices. Electrochemical devices are receiving the most attention in this regard, and within this field, the development of rechargeable and rechargeable secondary batteries is a key focus. Recently, research and development has focused on novel electrode and battery designs to improve capacity density and specific energy.

[0004] When manufacturing such secondary batteries, a welding operation is performed to bind tabs between unit electrodes in order to obtain output suitable for the intended use, and at this time, a process of joining the electrode tabs and the lead tabs is performed. Fig. 1 is a perspective view showing the appearance of the electrode tabs and the lead tabs joined in a typical secondary battery, and Fig. 2 is a plan view of the lead tabs joined to the electrode tabs in a typical secondary battery. As illustrated in Fig. 1, a typical secondary battery requires an electrode tab (positive electrode tab or negative electrode tab, 2) to electrically connect the positive and negative electrode plates constituting the electrode assembly (1) with an external device, and this electrode tab (2) is joined to a lead tab (positive electrode lead tab or negative electrode lead tab, 3) as illustrated in Fig. 2 by welding. And, as shown in Fig. 2, the lead tab (3) includes a metal lead (3a) and a lead film (3b) locally positioned on one or both sides thereof, and the metal lead (3a) positioned on one side thereof is joined to overlap with the electrode tab.

[0005] More specifically, most secondary batteries adopt a method of joining the negative tab (copper) or positive tab (aluminum) that extends outward from the electrode of the electrode assembly and protrudes outward, and the lead tab (copper, nickel), which is a separate member, through ultrasonic welding, laser welding, or resistance welding. For example, lithium ion batteries join the electrode tab and the lead tab by applying copper (Cu) as the negative tab and welding it to the lead tab (Ni).

[0006] Meanwhile, in terms of safety, an all-solid-state battery, which has no risk of explosion compared to a lithium secondary battery, refers to a battery that replaces the electrolyte from liquid to solid, and therefore does not use flammable solvents, so there is no risk of fire or explosion due to decomposition reactions of conventional electrolytes, which can significantly improve safety. Since these all-solid-state batteries can use lithium metal or lithium alloy as the anode material, they have the advantage of being able to dramatically improve the energy density for the mass and volume of the battery. In addition, a protective layer (specifically, a layer located between the anode active material and the solid electrolyte to block contact between them) is located on the surface of this lithium metal anode. At this time, when the anode tab and the lead tab (copper, nickel) are welded, the problem of the anode protective layer being detached occurs. This is because high welding energy is applied in an environment where the adhesive strength between the anode and the anode protective layer is inevitably low. Therefore, a method is required to join the electrode tab and the lead tab by welding without causing the cathode protective layer to detach.

[0007] Accordingly, the purpose of the present invention is to provide a lead tab for electrode tab bonding, which can solve the problem of a negative electrode protective layer being detached by bonding a lead tab of a specific material to an electrode tab with low welding energy, and also to provide an all-solid-state battery including a structure in which the lead tab and the electrode tab are bonded, in which the electrolyte and the lead tab do not come into contact with each other and thus a lithiation reaction is not induced.

[0008] In order to achieve the above object, the present invention provides a lead tab for joining an electrode tab of an electrode assembly for an all-solid-state battery to form a joint, wherein a lead included in the joint comprises aluminum.

[0009] In addition, the present invention provides an all-solid-state battery including a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode, and a structure in which the lead tab is joined to the electrode tab.

[0010] According to the present invention, an all-solid-state battery including a lead tab for electrode tab bonding and a structure in which the lead tab is bonded to the electrode tab can solve the problem of a negative electrode protective layer being detached by bonding a lead tab of a specific material to the electrode tab with low welding energy, thereby increasing the assembly stability of the battery.

[0011] In addition, according to the all-solid-state battery including the lead tab for electrode tab bonding and the structure in which the lead tab is bonded to the electrode tab according to the present invention, the all-solid-state battery including the structure in which the lead tab and the electrode tab are bonded has the advantage of not causing a lithiation reaction because the electrolyte and the lead tab do not come into contact.

[0012] Figure 1 is a perspective view showing the electrode tab and lead tab connected in a typical secondary battery.

[0013] Figure 2 is a plan view of a lead tab connected to an electrode tab in a conventional secondary battery.

[0014] Figure 3 is a plan view showing the electrode tab and lead tab connected in a secondary battery.

[0015] Figure 4 is a graph showing the performance of a battery according to one embodiment and a comparative example of the present invention.

[0016] Figure 5 is a graph showing the life performance of a battery according to one embodiment of the present invention.

[0017] Figure 6 is a graph showing the life performance of a battery according to a comparative example.

[0018] Hereinafter, the present invention will be described in detail.

[0019] A lead tab for electrode tab bonding according to the present invention is bonded to an electrode tab of an electrode assembly for an all-solid-state battery to form a bonding portion, and a lead included in the bonding portion includes aluminum.

[0020] In general, when manufacturing a secondary battery, a welding operation is performed to bind tabs between unit electrodes in order to obtain an output suitable for the intended use. At this time, a process of joining a conventional lead tab, such as that illustrated in FIG. 2, to an electrode tab by welding, as illustrated in FIG. 1, is necessary. In addition, most secondary batteries generally adopt a method of joining between a negative tab (copper) or a positive tab (aluminum) and a lead tab (copper, nickel) by ultrasonic welding, laser welding, or resistance welding. For example, a lithium ion battery joins an electrode tab and a lead tab by applying copper (Cu) as a negative tab and welding it to a lead tab (Ni).

[0021] Meanwhile, in terms of safety, all-solid-state batteries, which have no risk of explosion compared to lithium secondary batteries, are batteries that replace the electrolyte from liquid to solid. Since these all-solid-state batteries can use lithium metal or lithium alloy as the anode material, they have the advantage of being able to dramatically improve the energy density in relation to the mass and volume of the battery. In addition, a protective layer is located on the surface of this lithium metal anode, and when the anode tab and the lead tab (copper, nickel) are welded, the problem of the anode protective layer being detached occurs. This is because high welding energy is applied in an environment where the adhesive strength between the anode and the anode protective layer is bound to be low.

[0022] Accordingly, the present applicant has invented a method of joining an electrode tab and a lead tab by welding, wherein the lead included in the joint formed by joining the electrode tab of an electrode assembly for an all-solid-state battery comprises aluminum, thereby preventing the cathode protective layer from being detached. Hereinafter, the lead tab for joining the electrode tab according to the present invention will be described in more detail.

[0023] The lead constituting the lead tab for joining the electrode tab according to the present invention is formed in a sheet form, similar to a conventional one, and can be joined or bonded to the electrode tab to form a joint. The lead constituting the lead tab for joining the electrode tab according to the present invention and simultaneously joining to the electrode tab (referred to as reference numeral 2 in FIG. 1) to form a joint corresponds to reference numeral 3a based on FIG. 2. That is, in the past, the lead of the lead tab was applied with copper or nickel, but in this case, in the existing all-solid-state battery, when the negative electrode tab and the lead tab are joined by welding, a problem occurs in that the negative electrode protective layer is delaminated. However, the present applicant solved the problem of the negative electrode protective layer being delaminated by applying the lead of the lead tab with aluminum, thereby joining it to the electrode tab even with low welding energy.

[0024] That is, the lead tab for electrode tab bonding of the present invention is bonded to the electrode tab of an electrode assembly for an all-solid-state battery to form a bonding portion, and the lead included in the bonding portion includes aluminum. At this time, the lead may include aluminum in a content of 50 to 100 wt%, preferably 70 to 100 wt%, more preferably 85 to 100 wt%, and most preferably 95 to 100 wt%, based on the total weight of the lead.

[0025] In addition, the lead may have a structure or form in which one metal is plated on the surface of another metal, for example, a form in which aluminum is plated on the surface of a metal such as copper, manganese, silicon, magnesium, zinc, and nickel.

[0026] And, when the lead contains aluminum in a content of less than 100 wt% based on the total weight of the lead, the lead may further contain one selected from the group consisting of copper, manganese, silicon, magnesium, zinc and nickel (here, this means a state of being uniformly mixed rather than plated).

[0027] The lead tab for electrode tab bonding of the present invention is preferably a lead tab for negative tab bonding as described above, but may also be applied for positive tab bonding if necessary. That is, the lead tab for electrode tab bonding may be applied to at least one of positive tab bonding and negative tab bonding. In particular, considering the ease of the bonding process, it may be preferable to apply the lead tab for electrode tab bonding to both positive tab bonding and negative tab bonding.

[0028] Meanwhile, the lead tab for electrode tab bonding according to the present invention is characterized by not being in contact with the electrolyte included in the electrode assembly, which will be described in detail in the 'all-solid-state battery' section to be described later.

[0029] In addition, the lead tab for electrode tab bonding of the present invention may further include a lead film (3b) locally positioned on one or both sides of the lead (3a), as illustrated in Fig. 2. The lead film may be made of a material used in lead films included in conventional lead tabs, and may be, for example, polypropylene.

[0030] And, it is preferable that the electrode tab of the above-mentioned 'electrode assembly for an all-solid-state battery' is an electrode tab of an electrode assembly for an all-solid-state battery of a sulfide type.

[0031] Next, an all-solid-state battery according to the present invention will be described.

[0032] The above-described all-solid-state battery includes a structure in which the lead tab described above is joined to an electrode tab. More specifically, the all-solid-state battery includes the lead tab described above, including a positive electrode lead tab joined to a positive electrode tab; and a negative electrode lead tab joined to a negative electrode tab; and at least one lead of the positive electrode lead tab and the negative electrode lead tab comprises aluminum and is joined to the electrode tab. In addition, the all-solid-state battery is preferably a sulfide-based all-solid-state battery.

[0033] In one embodiment of the present invention, the all-solid-state battery can be manufactured including a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode. Furthermore, the all-solid-state battery can be manufactured using a known method using a configuration known in the art.

[0034] The positive electrode may include an active material, a conductive material, and a binder in the form of granules, etc. As the positive electrode active material, any material that can be used as a positive electrode active material of a conventional lithium ion secondary battery may be used without limitation. In addition, the positive electrode active material may be a lithium transition metal oxide containing one or more transition metals. For example, the positive electrode active material may be LiCoO2, LiNiO2, LiMnO2, Li2MnO3, LiMn2O4, Li(Ni a Co b Mn c )O2(0 <a<1, 0<b<1, 0<c<1, a+b+c=1), LiNi 1-y Co y O2(O <y<1), LiCo 1-y Mn y O2, LiNi 1-y Mn y O2(O <y<1), Li(Ni a Co b Mn c )O4(0 <a<2, 0<b<2, 0<c<2, a+b+c=2), LiMn 2-z Ni z O4(0 <z<2), LiMn 2-zCo z O4(0 <z<2) 및 이의 조합으로 이루어진 군으로부터 선택되는 것일 수 있다.

[0035] The above-mentioned positive electrode conductive material may be used without limitation as long as it can be used as a positive electrode conductive material for a conventional lithium ion secondary battery. For example, the positive electrode conductive material may be a conventional material such as a carbon nanotube (single-walled carbon nanotube, multi-walled carbon nanotube) or carbon black.

[0036] The above-mentioned positive electrode binder is mixed with the positive electrode active material and the positive electrode conductive material to bind each component and help particle growth. The binder may be an organic binder, and the organic binder means a binder that is dissolved or dispersed in an organic solvent, particularly N-methylpyrrolidone (NMP), and is distinguished from an aqueous binder that uses water as a solvent or dispersion medium. For example, the binder may be selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polyimide, polyamideimide, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene butylene rubber, and fluororubber, but is not limited thereto. In addition, the weight ratio of the positive electrode active material, positive electrode conductive material, and binder included in the positive electrode also applies to the conventional one.

[0037] The above negative electrode may include a negative electrode active material usable in a conventional lithium ion secondary battery. For example, the negative electrode active material may include carbon such as non-graphitizable carbon, graphite carbon, etc.; Li x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1), Sn x Me 1-x Me' y Oz (Me: Mn,Fe,Pb,Ge; Me': Al, B, P, Si, elements of group 1, 2, and 3 of the periodic table, halogens; 0 <x≤1; 1≤y≤3; 1≤z≤8) 등의 금속 복합 산화물; 리튬 금속; 리튬 합금; 규소계 합금; 주석계 합금; SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4및 Bi2O5등의 금속 산화물; 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni계 재료; 티타늄 산화물; 리튬 티타늄 산화물; 등에서 선택된 어느 하나 이상을 포함한 것일 수 있다.

[0038] The solid electrolytes of all-solid-state batteries can be broadly classified into organic (polymer) solid electrolytes and inorganic solid electrolytes, and among these, inorganic solid electrolytes can be divided into sulfide and oxide solid electrolytes. In addition, the solid electrolyte that has undergone the most technological development is the sulfide solid electrolyte, and its development has progressed to the point where its ionic conductivity is close to that of organic electrolytes. Thus, among solid electrolytes, the sulfide solid electrolyte is ranked 10th. -3 S / cm to 10 -2 Not only does it have high ionic conductivity (S / cm), but it also has excellent thermal stability and interfacial compatibility, which is advantageous in improving resistance by making good contact with the interface due to its ductility.

[0039] All of the solid electrolytes described above can be applied to the present invention, but a sulfide-based solid electrolyte is more preferable. The sulfide-based solid electrolyte may include a lithium salt, and the lithium salt is an ionizable lithium salt such as Li + X - It can be expressed as . The anion of these lithium salts is not particularly limited, but F -<h2 style=";text-align:left;direction:ltr">, Cl<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , Br<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , I<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , NO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , N(CN)2<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , BF4<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , ClO4<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , PF6<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3)2PF4<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3)3PF3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3)4PF2<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3)5PF<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3)6P<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , CF3SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , CF3CF2SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3SO2)2N<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (FSO2)2N<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , <h2 style=";text-align:left;direction:ltr"> CF3CF2(CF3)2CO<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3SO2)2CH<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (SF5)3C<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , (CF3SO2)3C<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , CF3(CF2)7SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , CF3CO2<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , CH3CO2<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> , SCN<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> (CF3CF2SO2)2N<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> 등을 예시할 수 있다.<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0040] In addition, the sulfide-based solid electrolyte contains sulfur (S) and has the ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and may include Li-PS-based glass or Li-PS-based glass ceramic. Non-limiting examples of such sulfide-based solid electrolytes include Li2S-P2S5, Li2S-LiI-P2S5, Li2S-LiI-Li2O-P2S5, Li2S-LiBr-P2S5, Li2S-LiCl-P2S5, Li2S-Li2O-P2S5, Li2S-Li3PO4-P2S5, Li2S-P2S5-P2O5, Li2S-P2S5-SiS2, Li2S-P2S5-SnS, Li2S-P2S5-Al2S3, Li2S-GeS2, and Li2S-GeS2-ZnS, and the sulfide-based solid electrolyte may include any one or more of these. In addition, the sulfide-based solid electrolyte included as a base material in the solid electrolyte for an all-solid-state battery of the present invention is not limited thereto, and may be composed of those constituting a typical sulfide-based solid electrolyte.

[0041] Meanwhile, according to the research results of the applicant, when a lead containing aluminum comes into contact with an electrolyte, a lithiation reaction occurs, causing a problem in which the battery cannot be operated. Therefore, the applicant has prevented the lead tab for joining an electrode tab included in an all-solid-state battery from coming into contact with the solid electrolyte, thereby preventing the lithiation reaction from occurring. More specifically, the applicant has solved the above problem by positioning the end of the lead tab in the direction of joining with the electrode tab at a distance of 1.1 to 5 times, preferably 1.2 to 3 times, and more preferably 1.5 to 2.5 times, the average distance between the end of the electrode and the end of the electrolyte from one end of the electrode assembly from which the electrode tab is drawn.

[0042] Fig. 3 is a plan view showing the appearance of an electrode tab and a lead tab being joined in a secondary battery. Referring to Fig. 3, the position of the end of the lead tab in the direction of joining with the electrode tab, etc. will be described in more detail. The end position of the lead tab (3a) in the direction of joining with the electrode tab means a position spaced apart from the electrode end (5) in the direction in which the electrode tab (2) is drawn out by the distance (S1 in Fig. 3) between the electrode end (5) and the end of the lead tab (3a). In addition, the average distance (S2 in Fig. 3) between the electrode end (5) and the electrolyte end (7) means a value obtained by adding the maximum distance and the minimum distance between the electrode end (5) and the electrolyte end (7) and dividing the result by 2.

[0043] In addition, the present invention provides a battery module including the all-solid-state battery as a unit battery, a battery pack including the battery module, and a device including the battery pack as a power source. Specific examples of the device include, but are not limited to, a power tool that is powered by an electric motor; an electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), etc.; an electric two-wheeled vehicle including an electric bicycle (E-bike) and an electric scooter (E-scooter); an electric golf cart; and a power storage system.

[0044] Hereinafter, preferred examples are presented to help understand the present invention, but the following examples are only illustrative of the present invention, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present invention, and it is also natural that such changes and modifications fall within the scope of the appended patent claims.

[0045] [Example 1] Manufacture of an all-solid-state battery

[0046] First, an electrode assembly was manufactured by stacking unit cells each comprising a positive electrode containing a lithium transition metal oxide as a positive electrode active material, a lithium metal negative electrode, and a solid electrolyte (Li6PS5Cl) interposed therebetween. At this time, the end of the lead tab in the direction of contact with the electrode tab was positioned at a distance twice the average distance between the electrode end and the electrolyte end from one end of the electrode assembly from which the electrode tab is drawn. Next, a lead made of aluminum was bonded to each of the positive and negative electrode tabs.

[0047] [Comparative Example 1] Manufacturing of an All-Solid-State Battery

[0048] An all-solid-state battery was manufactured in the same manner as in Example 1, except that nickel leads were bonded instead of aluminum leads to both the negative and positive tabs.

[0049] [Comparative Example 2] Manufacturing of an All-Solid-State Battery

[0050] An all-solid-state battery was manufactured in the same manner as in Example 1, except that the end of the lead tab in the direction of contact with the electrode tab was positioned at a distance of one time the average distance between the electrode end and the electrolyte end from one end of the electrode assembly from which the electrode tab is drawn, so that the electrolyte membrane contacts the lead.

[0051] [Experimental Example 1] Performance Evaluation of All-Solid-State Battery

[0052] The all-solid-state batteries manufactured in the above Example 1, Comparative Examples 1 and 2 were driven under the following charge and discharge conditions at an operating voltage range of 4.25 V to 3.0 V and an operating temperature of 60°C, and their performances were evaluated for the first cycle (Fig. 1) or 100 cycles (Figs. 2 and 3), and the results are shown in Figs. 4 to 6.

[0053] - Charging conditions: 0.1C, 4.25V CC / CV, 0.05C cut-off

[0054] - Discharge conditions: 0.1C, 3.0V, CC

[0055] Fig. 4 is a graph showing the performance of a battery according to one embodiment and a comparative example of the present invention, Fig. 5 is a graph showing the life performance of a battery according to one embodiment (Example 1) of the present invention, and Fig. 6 is a graph showing the life performance of a battery according to a comparative example (Comparative Example 1). As a result of evaluating the performance of the all-solid-state batteries manufactured in Example 1, Comparative Examples 1 and 2, as shown in Fig. 4, the all-solid-state battery of Example 1, which used an aluminum lead and did not have the electrolyte membrane and the lead in contact, was able to perform normal charging and discharging, unlike the all-solid-state battery of Comparative Example 2, which used an aluminum lead but had the electrolyte membrane and the lead in contact.

[0056] Meanwhile, the all-solid-state battery of Comparative Example 1, which used nickel leads and did not have contact between the electrolyte membrane and the leads, also showed similar performance to Example 1 in the first cycle. However, as can be confirmed through the comparison and contrast of Figures 5 and 6, the performance of the all-solid-state battery of Comparative Example 1 rapidly deteriorated as the cycles repeated due to performance deviations caused by damage to the negative electrode. Therefore, it can be seen that in addition to the fact that the electrolyte and the leads do not come into contact, the purpose of the present invention can be achieved only by applying an aluminum lead.

Claims

1. A lead tab for joining an electrode tab of an electrode assembly for an all-solid-state battery to form a joint, wherein a lead included in the joint comprises aluminum.

2. A lead tab for electrode tab bonding, wherein the lead comprises aluminum in an amount of 50 to 100 wt% based on the total weight of the lead, in claim 1.

3. A lead tab for electrode tab bonding, wherein, in claim 2, if the lead comprises aluminum in a content of less than 100 wt% based on the total weight of the lead, the lead further comprises an element selected from the group consisting of copper, manganese, silicon, magnesium, zinc, and nickel.

4. A lead tab for electrode tab bonding, wherein the lead has a form in which aluminum is plated on the surface of a metal selected from the group consisting of copper, manganese, silicon, magnesium, zinc, and nickel, in claim 1.

5. A lead tab for electrode tab bonding, wherein the lead tab in claim 1 is applied to at least one of positive tab bonding and negative tab bonding.

6. A lead tab for electrode tab bonding, wherein the lead tab is applied simultaneously for positive tab bonding and negative tab bonding in claim 5.

7. A lead tab for electrode tab bonding, wherein the electrode tab of the electrode assembly for an all-solid-state battery according to claim 1 is an electrode tab of an electrode assembly for a sulfide-based all-solid-state battery.

8. An all-solid-state battery comprising a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode, and a structure in which the lead tab of claim 1 is joined to the electrode tab.

9. In claim 8, the all-solid-state battery includes a positive lead tab joined to a positive electrode tab and a negative lead tab joined to a negative electrode tab, and at least one lead of the positive lead tab and the negative electrode lead tab is joined to the electrode tab by including aluminum.

10. An all-solid-state battery according to claim 8, wherein the lead tab and the electrolyte included in the all-solid-state battery do not come into contact.

11. An all-solid-state battery according to claim 8, wherein the end of the lead tab in the direction of connection with the electrode tab is located at a distance of 1.1 to 5 times the average distance between the electrode end and the electrolyte end from one end of the electrode assembly from which the electrode tab is drawn.

12. An all-solid-state battery according to claim 8, wherein the all-solid-state battery is a sulfide-based all-solid-state battery.

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