KR101532136B1 - Anode, method of fabricating the same and rechargeable battery - Google Patents

Abstract

Embodiments of the present invention relate to a negative electrode, a method of manufacturing the same, and a secondary battery using the same. The negative electrode according to an embodiment of the present invention includes a current collecting plate, a conductive inner surface electrically coupled to the current collecting plate, the conductive inner surface providing an electrochemical reaction site by electrodeposition and desorption of lithium ions, Each of the plurality of cavities comprising: And an electrically insulative pattern that electrically passivates and separates the openings between adjacent ones of the plurality of cavities.

Description

[0001] The present invention relates to a negative electrode, a method of manufacturing the same, and a secondary battery including the same,

The present invention relates to a secondary battery technology, and more particularly, to a negative electrode, a method for manufacturing the same, and a secondary battery including the same.

Recently, the development of portable information technology devices, such as smart phones and portable computers, and the popularization of smart grids or electric vehicles have led to a significant increase in demand for secondary batteries. The secondary battery may be a lithium ion secondary battery, a rechargeable nickel cadmium battery, a nickel metal hydride battery, or a lead acid battery, depending on the anode active material. Among these secondary batteries, lithium ion secondary batteries have high electromotive force, capacity, and energy density, and thus their applications are expanding not only as small portable devices but also as power sources for medium to large-sized devices.

In portable small apparatuses requiring high capacity and high energy density, a combination of LiCoO ₂ as a cathode active material and graphite as a negative electrode active material is mainly used. However, since the input / output performance of the graphite material is not sufficiently high, such a combination is difficult to apply to applications such as electric vehicles requiring high input / output. As an alternative technique, high input / output can be secured by using carbon material which is not graphitized rather than high crystalline graphite material as negative electrode active material. However, in this case, the capacity of the battery is somewhat reduced.

Therefore, it is ideal to use the lithium metal itself as an anode active material as an effective way to improve the input / output performance and the capacity at the same time. In this case, since the standard electrode potential of lithium metal can be used as an electromotive force as it is, a high output cell can be obtained, and a theoretical capacity (3,861 mAh / g) So that the energy density can be maximized. However, in the case of the lithium active material, a lithium dendrite, which is a crystalline protrusion, is grown on the cathode according to a cyclic chemical reaction by charging and discharging the battery. When the dendritic lithium is excessively grown, the dendritic lithium passes through the separator and the positive electrode and the negative electrode of the battery are separated from each other. The negative electrode is short-circuited to cause an explosion or fire.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a negative electrode having reliability and improved lifetime by suppressing the formation of dendritic lithium so that lithium itself can be used as an anode active material.

In addition, another technical problem to be solved by the present invention is to provide a method of manufacturing a negative electrode having the above-described advantages.

Another object of the present invention is to provide a secondary battery using the negative electrode having the above-described advantages.

According to an aspect of the present invention, there is provided a negative electrode comprising: a conductive inner surface electrically coupled to a current collecting plate, the conductive inner surface providing an electrochemical reaction site by electrodeposition and desorption of lithium ions; The plurality of cavities each including an opening for exposing; And an electrically insulative pattern that electrically passivates and separates the openings between adjacent ones of the plurality of cavities.

In one embodiment, the surface of the current collector plate may provide at least a portion of the conductive inner surface of the plurality of cavities. Further, the current collecting plate may include an electrically insulating pattern layer on which the plurality of cavities are formed, and the electrically insulating pattern may be provided by the upper surface of the electrically insulating pattern layer.

In another embodiment, the current collector plate may be patterned in a depth direction to define the plurality of cavities, and openings of the electrically insulating pattern are formed on the current collector plate so as to be aligned with the plurality of cavities. In some embodiments, a polymer chain layer having pores inside the plurality of cavities may be provided.

According to another aspect of the present invention, there is provided a method of manufacturing an electrode, comprising: providing a current collector; Forming an insulating layer on the current collecting plate; And a plurality of cavities having a conductive inner surface for providing an electrochemical reaction site by electrodeposition and desorption of lithium ions on any one of the current collector plate and the insulating layer, And patterning the collector plate or the insulating layer to electrically passivate between the openings adjacent to each other and to separate the openings.

According to another aspect of the present invention, there is provided a secondary battery including: a cathode; A positive electrode facing the negative electrode; And a separator between the anode and the cathode. In one embodiment, the secondary electrons may be a lithium metal battery.

According to the embodiment of the present invention, the oxidation and reduction reactions of lithium are localized in the plurality of cavities, and the openings of the adjacent cavities are electrically passivated, so that the dendritic growth of lithium due to repeated charge and discharge A suppressed cathode can be provided. Further, according to the embodiment of the present invention, the conductive inner surface in the plurality of cavities can expand the electrochemical reaction site compared to the surface of the conventional two-dimensional collector plate, so that a negative electrode having a high capacity and high output can be provided .

Further, according to another embodiment of the present invention, a method of manufacturing a negative electrode capable of easily manufacturing a negative electrode having the above-described advantages can be provided.

In addition, according to another embodiment of the present invention, it is possible to provide a lithium metal battery having a long life while ensuring an energy density close to the theoretical capacity of lithium by suppressing dendrite growth of lithium while drastically reducing the internal resistance of the battery.

1 is an exploded perspective view for explaining a battery chemical reaction of an electrode assembly of a lithium metal battery.
2A and 2B are cross-sectional views illustrating a cathode and a method of manufacturing the same according to an embodiment of the present invention.
FIGS. 3A and 3B are cross-sectional views illustrating cathodes according to an embodiment of the present invention. FIG. 3A shows a charged state of the cathodes, and FIG. 3B shows discharge states of cathodes.
4A to 4C are cross-sectional views illustrating cathodes according to other embodiments of the present invention.
5 is a cross-sectional view illustrating cathodes according to still another embodiment of the present invention.
6A and 6B are cross-sectional views illustrating cathodes according to still another embodiment of the present invention.
7 is an exploded perspective view illustrating a battery including a cathode according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, The present invention is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more faithful and complete, and will fully convey the scope of the invention to those skilled in the art.

In the following drawings, thickness and size of each layer are exaggerated for convenience and clarity of description, and the same reference numerals denote the same elements in the drawings. As used herein, the term "and / or" includes any and all combinations of any of the listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

As used herein, the term " separator " includes a separator commonly used in a liquid electrolyte cell using a liquid electrolyte having a low affinity for the separator. In addition, the 'separator' used herein may include an intrinsic solid electrolyte membrane and / or a gel electrolyte membrane in which the electrolyte is strongly bound to the separator, and the electrolyte and the separator are recognized as being identical. Therefore, the term separation membrane used in this specification should be construed to include all of them unless clearly distinguished from the solid electrolyte membrane and the gel electrolyte membrane.

1 is an exploded perspective view for explaining a battery chemical reaction of an electrode assembly 100 of a lithium metal battery.

Referring to FIG. 1, an electrode assembly 100 according to an embodiment is a laminate including a cathode 10, an anode 20, and a separator 30 therebetween. The cathode 10 includes a current collector plate 10-1 and a cathode layer 10_2 provided on one main surface of the current collector plate 10_1. The current collecting plate 10_1 may be made of any one of copper, titanium, stainless steel, nickel, platinum, gold, silver, ruthenium, tantalum, niobium, hafnium, zirconium, vanadium, indium, cobalt, tungsten, tin, beryllium, molybdenum, And a metal foil such as a sieve. Alternatively, the current collecting plate 10_1 may include a conductive oxide such as indium tin oxide, a conductive polymer, or a carbon-based electrode material, but the present invention is not limited thereto. Although not shown, these current collecting plates 10_1 may be made thin, and a separate insulating layer may be provided for supporting them. For example, the current collecting plate may be a flexible polymer insulating substrate and a metal thin film formed thereon.

The cathode layer 10_2 includes an electric insulating pattern 10P for electrically passivating a plurality of spaced apart cavities 10_C and openings OP of the plurality of cavities 10_C. As shown in Fig. 1, the openings OP of the cavities 10_C are defined by the electrically insulating pattern 100P and can be spaced apart from each other. At least a part of the inner surface 10C_S of the plurality of cavities 10_C is conductive and is electrically coupled to the current collecting plate 10_1.

The bottom of the cavities 10_C is conductive or the side walls are all conductive along with the bottom so that the conductive surface of the cavities 10_C and the current collecting plate 10_1 contact each other or the surface of the collecting plate 10_1 Themselves may be exposed as the inner surface 10C_S of the cavities 10_C or may be connected to each other by another conductive member so that electrical coupling therebetween can be achieved. Therefore, the electrons involved in the oxidation and reduction reaction of lithium in the cavities 10_C can flow through the current collecting plate 10_1 through the conductive surface of the cavities 10_C. The collector plate 10_1 may be formed with a tab or a lead (see TA in FIG. 6) for electrical connection with an external circuit.

The conductive surface of the cavities 10_C provides an electrochemical reaction site for the oxidation and reduction of lithium which is involved in the charging and discharging of the cell. The lithium ion Li ⁺ delivered from the anode 20 at the time of charging the battery is supplied to the cathode 10 through the separator 30 having ion conductivity as shown by the arrow A. The lithium ion Li ⁺ reaching the cathode 10 side is electrodeposited on the conductive surface inside the conductive cavities 10_C exposed through the openings OP of the cavities 10_C. Thereby, the reduced lithium is gradually filled in the conductive cavities 10_C, and the reduction reaction of lithium ions for charging the battery is completed.

The lithium metal filled in the cavities 10_C of the cathode 10 is oxidized and the lithium ion Li ⁺ is transferred to the anode 20 through the separator 30 as shown by the arrow B at the time of discharging the battery. The anode 20 may include a suitable cathode active material capable of reversibly intercalating and deintercalating lithium ions, and a discharging reaction can be performed by occluding lithium ions transferred at the time of charging.

The cathode active material is composed of, for example, at least one of Ni, Co, Mn, Al, Cr, Fe, Mg, Sr, V, La, and Ce and O, F, S, P, And a Li compound including at least one non-metallic element selected from the group consisting of Li. For example, a lithium salt such as a lithium manganese oxide, a lithium cobalt oxide, or a compound that is a lithium ion. However, the present invention is not limited thereto. For example, since a cathode can secure a high capacity and high efficiency by using lithium metal itself as an active material, a low-cost active material such as VO _x may be used as the cathode active material.

In some embodiments, a conductive material may be added with the cathode active material. The conductive material may include, for example, carbon black and ultrafine graphite particles, fine carbon such as acetylene black, nano metal particle paste, or ITO (indium tin oxide) paste, , But the present invention is not limited thereto.

The anode 20 may have a stacked structure of a current collector plate 20_1 and a cathode layer 20_2 having a two-dimensional planar structure as shown in FIG. The current collecting plate 20_1 may be formed of any one of aluminum, titanium, stainless steel, nickel, platinum, gold, silver, ruthenium, tantalum, niobium, hafnium, zirconium, vanadium, indium, cobalt, tungsten, tin, beryllium, molybdenum, It may be a metal foil such as a sieve. However, this is merely an example, and the current collecting plate 20_1 may include another conductive oxide, a conductive polymer, or a laminate thereof. On the collector plate 20_1, the above-described cathode active material is laminated to provide a cathode layer 20_2. A tab or a lead (see TA in FIG. 6) for electrical connection with an external terminal may be coupled to the positive electrode collector layer 20_1.

In another embodiment, the anode 20 may have a three-dimensional electrode structure other than the two-dimensional surface structure such as the current collector plate 20_1 and the anode layer 20_2 described above. For example, the three-dimensional electrode structure may be a foam structure such as a fibrous structure or foam including pores therein, such as woven, meshed or nonwoven structure of conductive fibers replacing the current collector, An active material may be coated on the surface of the fibrous structure or foam or impregnated in the form of particles in the pores or spaces. The three-dimensional structure has an advantage that the flexibility of the entire electrode assembly 100 can be improved in the battery pack.

As described above, according to the embodiment of the present invention, during the repeated charging and discharging, the oxidation and reduction reactions of lithium ions occurring in the cathode 10 are carried out by using an electrically passivated electric insulating pattern 10P) and can only occur locally on the conductive surfaces in the cavities 10_C. Since the conductive surface is three-dimensionally extended in the depth direction, the area is increased compared to the electrode structure of the two-dimensional planar type, and accordingly, the area of the reaction sites of the oxidation and reduction of lithium is expanded, And capacity can be improved.

Further, according to the embodiment of the present invention, oxidation and reduction of lithium do not occur around the openings of the cavities 10_C passivated by the electrical insulating pattern 10P, so that the redox reaction The dendrite formation due to the non-uniform electrodeposition and desorption of lithium occurring in the resulting planar current collector structure does not occur and even if the dendritic lithium is generated, it is trapped in the concave internal space of the cavities 10_C, which hinders practical use of the conventional lithium metal battery The growth of the resinous phase can be suppressed.

2A and 2B are cross-sectional views illustrating cathodes 10A and 10B and a method of manufacturing the same according to an embodiment of the present invention.

Referring to Fig. 2A, the cathode 10A includes an electrically insulating pattern layer 10_2L having cavities 10_C on the main surface of the current collecting plate 10_1. The electrically insulating pattern layer 10_2L may be formed of various polymer materials such as polyethylene, polystyrene, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin and phenol resin; Insulating inorganic material; Or a composition in which two or more of the foregoing materials are mixed. Preferably, the electrically insulating pattern layer 10_2L may be the above-described polymeric material for providing a soluble cathode.

The surface of the current collecting plate 10_1 is exposed at the bottom portion 10_2B of the cavities 10_C and thereby a conductive surface for the oxidation and reduction reaction of lithium ions can be provided inside the cavity 10_C. For example, the electrically insulating pattern layer 10_2L may be a partition wall pattern for defining the cavities 10_C. The partition pattern may be patterned to have a rectangular opening OP, as shown in FIG. 2A.

In another embodiment, the barrier rib pattern may have a polygonal opening such as a circle, an ellipse, a triangle, a pentagon, or a honeycomb. Further, the barrier rib pattern may be a line pattern for forming a trench-like groove, or may be a pattern for providing an opening shape in which examples of the above-described openings are combined. These cavities may be arranged in a two-dimensional array as shown. In yet another embodiment, the electrically insulative pattern layer 10_2L may be a pattern having an irregular cavity and an opening. For example, the electrically insulating pattern layer 10_2L may have an indefinite opening and an indefinite through-hole from the top surface to the bottom surface.

The electrically insulating pattern layer 10_2L may be provided by laminating the electrical insulating layer on the current collecting plate 10_1 and performing patterning to form the cavities 10_C. For example, after an electric insulating layer formed of a resin material, preferably a flexible resin material, is formed on the main surface of the current collector plate 10_1 by spin coating, spraying, or laminating, The electrically insulating pattern layer 10_2L can be provided by performing patterning for forming the cavity 10_C by flitting, punching, laser processing, embossing using molding, or etching.

In another embodiment, after the through hole is formed in advance from the upper surface to the lower surface of the electric insulating layer, the electric insulating pattern layer 10_2L is formed by laminating the electric insulating layer having the through hole on the collecting plate 10_1 May be provided. The through-hole may have an opening, such as a circle or an ellipse; Polygonal openings such as triangular, pentagonal or honeycomb; An irregular opening; Or they may have openings combined therewith. In another embodiment, the electrically insulating pattern layer 20_2L may be formed by a screen print, a drill bit, an inkjet printing, an embossing process using a mold, and the present invention is not limited to these manufacturing methods.

In the embodiments described above with reference to Fig. 2A, the surface of the current collecting plate 10_1 is exposed through the bottom portion 10_2B of the cavity 10_C. As a result, only the bottom portion 10_2B of the inner surfaces of the cavities 10_C can be provided with the cathode 10A having a conductive surface. In this structure, expansion of reaction sites for charging and discharging is not expected, but the oxidation and reduction of lithium occur locally only in the concave inner space of the cavities 10_C, so that the resinous growth of lithium can be suppressed. However, it will be understood through the following embodiments that the surface area of the current collecting plate 10_1 can be expanded by patterning the surface of the collecting plate 10_1.

Referring to FIG. 2B, a conductive liner 10_2WL electrically connected to the current collecting plate 10_1 may be formed on the inner sidewall 10_2W of the cavities 10_C of the electrically insulating pattern layer 10_2L. In this case, the interior surfaces of the cavities 10_C are both conductive surfaces, including the bottom 10_2B and the side walls 10_2W. The conductive liner 10_2WL may be a metal layer or a conductive polymer layer. The metal layer may be formed of a metal such as copper, titanium, stainless steel, nickel, platinum, gold, silver, ruthenium, tantalum, niobium, hafnium, zirconium, vanadium, indium, cobalt, tungsten, tin, beryllium, molybdenum, Or a laminate. The conductive polymer layer may be a single polymer or two or more different polymers, and the polymer may be a positive charge carrier or a negative charge carrier, but the present invention is not limited thereto.

In terms of the manufacturing method, according to one embodiment, the conductive layer is conformally coated along the surface profile of the electrically insulating pattern layer 10_2L on the electrically insulating pattern layer 10_2L having the cavities 10_C with a uniform thickness The conductive layer can be left only in the cavities 10_C by selectively removing only the conductive layer on the upper surface of the electrically insulating pattern layer 10_2L except the inside of the cavities 10_C. The conductive layer remaining in the cavities 10_C becomes the conductive liner 10_2WL.

The selective removal of only the conductive layer on the upper surface of the electrically insulating pattern layer 10_2L may be performed by removing the conductive layer until a top surface of the electrically insulating pattern layer 10_2L is exposed through a polishing process or an etchback process Can be achieved. The conductive layer on the bottom surface of the cavities 10_C as well as the conductive layer on the upper surface of the electrically insulating pattern layer 10_2L is also removed so as to be electrically insulative The conductive liner 10_2WL may be formed only on the side wall 10_2W of the cavities 10_C of the pattern layer 10_2L.

In another embodiment, the cathode 10B in which the cavities 10_C are formed can be manufactured by first forming the electrically insulating pattern layer 10_2L on which the conductive liner 10_2WL is formed and laminating it on the current collector plate 10.

3A and 3B are sectional views showing a cathode 10C according to an embodiment of the present invention. FIG. 3A shows a charged state of the cathode 10C. FIG. 3B shows a state of discharge of the cathode 10C, Respectively.

Referring to FIG. 3A, a porous polymer network layer 11 may be provided inside the cavities 10_C of the cathode 10. The porous polymer network 11 may be a high-injection-chain layer. The porous polymer network 11 can be fixed in the cavities 10_C by bonding one end 11F of the polymer chain to the inner surface of the cavities 10_C. The bonding may be performed by chemical bonding when the inner wall of the cavities is a polymer material or by adsorption when the inner wall is a metal. The lithium can move through the pores of the porous polymer network 11.

The porous polymer network 11 may be formed of a non-conductive polymer, but is optionally formed of a conductive polymer. The conductive polymer may be, for example, a single polymer or two or more different polymers, and the polymer may be a positive charge carrier or a negative charge carrier, but the present invention is not limited thereto.

The conductive polymer may be at least one selected from the group consisting of polyaniline, polyoxyphenylene, polyphenylene sulfide, polythiophene, polyfuran, polypyrrole, polymethylpyrrole, ), Polystyrene and derivatives or copolymers thereof. These derivatives may be substituted derivatives thereof, for example, PEDOT (poly (3,4-ethylenedioxythiophene)). These materials are illustrative and the present invention is not limited thereto.

Further, additives such as polystyrenesulfonate (PSS) may be further added to any one of these materials. For example, PEDOT can be mixed with PEDOT. The PEDOT / PSS complex may have a form in which PEDOT is bound to the PSS matrix, or may be added in a form in which PEDOT is bound to the PEDOT / PSS. For PEDOT / PSS mixtures, PEDOT acts as a positive charge carrier and PSS acts as a negative charge carrier.

The porous polymer network 11 can be formed by filling a solution containing suitable monomers and additives for forming the porous polymer network 11 in the cavities 10_C and optionally adding a suitable polymerization initiator together, , And may be polymerized by applying energy such as oxidation or light irradiation.

The porous polymer network 11 can randomly disperse lithium ions that are transferred to the inside of the cavity through the pores when the battery is charged and can suppress the resinous growth of lithium metal caused by repeated charging and discharging. In one embodiment, the porous polymer network 11 may fill the entire interior space of the cavities 10_C uniformly, but the present invention is not limited thereto. For example, the porous polymer network 11 exists at a high density on the surface of the conductive inner wall, and can exist at a relatively low density at the center of the cavity 10_C. Alternatively, the porous polymer network 11 may be present at a high density at the bottom of the cavities 10_C and at a low density towards the opening OP. Alternatively, on the inner surface of the cavity 10_C, there is a relatively high density porous polymer network 11 as compared with the center portion of the cavity, and the density may be gradually decreased as the opening is opened.

The density change in the cavity of the porous polymer network 11 is more preferable when the porous polymer network 11 has conductivity than when it is non-conductive. For example, as the density of the porous polymer network 11 decreases toward the opening OP from the inside of the cavity 10_C, the porosity of the opening OP increases and the porosity decreases toward the conductive inner surface have. As a result, when the lithium ion is drawn into the cavity 10_C at the time of charging the battery, the mobility of lithium at the opening OP of the cavity 10_C is maximized, and as the lithium ions approach the conductive inner wall, The degree will decrease. However, since the porous polymer network 11 is conductive, lithium can be rapidly electrodeposited in contact with the porous conductive polymer inner wall and the porous polymer network near the conductive inner wall, so that the concentration of lithium ions can be rapidly reduced. Therefore, So that the mobility and the conductive surface area are balanced so that the reduction reaction of lithium ions can occur substantially uniformly throughout the internal space of the cavity 10_C. By this effect, the resin phase growth of lithium generated by non-uniformly depositing lithium is suppressed, and lithium (Li) can be uniformly filled in the cavity 10_C.

Alternatively, a gel solid electrolyte membrane 15 may be further provided on top of the cavity 10_C in place of or in addition to the porous polymer network 11. The gel polymer electrolyte membrane may be, for example, a combination of a plasticizer-containing polymer containing a salt, a polymer containing a filler, or a pure polymer. On the gel solid electrolyte membrane 15, a separation membrane 30 for electrically separating from the anode (not shown) may be provided.

Referring to FIG. 3B, the lithium accumulated in the cavity 11C at the time of discharging is uniformly removed from the entire region inside the cavity 10_C by the porous polymer network 11. FIG. It is possible to suppress the phenomenon that lithium ions are locally removed and oxidized only in the vicinity of the inner surface of the cavity 10_C and that the lithium ions are not oxidized in the intermediate region of the cavity 10_C. The non-desorbed lithium metal is electrically isolated in the cavity, and is no longer involved in the oxidation and reduction reaction. The dead volume in the cavity increases the irreversible capacity of the battery and shortens the lifetime.

When the porous polymer network 11 is conductive, the dead volume of lithium which causes an irreversible capacity increase can be further suppressed. A conductive path is provided from the intermediate region to the opening of the cavity 10_C by the porous polymer network 11 so that the oxidation reaction of lithium occurs uniformly over the entire range within the cavity 10_C, have.

When the porous polymer network 11 has a density distribution spatially variable inside the cavity 10_C as described above, it controls the release rate of lithium accumulated in the cavity 10_C to the cavity 10_C In the internal space. For example, in the vicinity of the inner surface of the cavity 10_C, the density of the porous polymer network 11 is high and the density of the porous polymer network 11 is low in the vicinity of the middle region or opening, The removal of lithium from the intermediate region or the opening portion becomes easier and the traveling speed of lithium ions may be larger. Therefore, the reduction reaction of lithium as a whole can be uniformly performed in the cavity 10_C based on the vicinity of the inner surface of the cavity 10_C where the oxidation of lithium can easily occur.

The cathode 10C shown in Figs. 3A and 3B has the structure of the cathode 10B disclosed with reference to Fig. 2B, but this is merely exemplary. For example, in the case of the cathode 10A disclosed with reference to FIG. 2A, the porous polymer network 11 may be formed on the side wall of the partition pattern.

4A to 4C are cross-sectional views illustrating cathodes 10D, 10E, and 10F according to other embodiments of the present invention.

Referring to Fig. 4A, the current collecting plate 10_1P of the cathode 10D may be patterned to define the cavities 10_C. Since the cavities 10_C have rectangular grooves, the cavities 10_C can be defined by forming the grooves in the depth direction from the surface of the current collecting plate 10_1P. Further, the current collecting plate 10_1P, in which the cavities 10_C are defined, may be provided by adding a first conductive layer having a cavity formed by the through holes and a second conductive layer covering the through holes.

The cavities 10_C of the current collecting plate 10_1P may have a polygonal opening such as a circle, an ellipse, a triangle, a pentagon, or a honeycomb. Further, the current collecting plate 10_1P may be patterned so as to have line-patterned grooves to have trench-shaped cathodes or to have an opening shape in which the above-described examples are combined. Further, the current collecting plate 10_1P may be patterned so as to have an irregular cavity and an opening. According to the above-described embodiments, the surface pattern itself of the current collecting plate 10_1P becomes a cavity, and as a result, both the bottom surface 10_1B and the side wall 10_1W of the cavity 10_C have conductivity.

The current collecting plate 10_1P is formed so that the electric insulating pattern 10P that electrically passivates between the openings OP of the cavities 10_C and separates the openings OP is aligned with the cavities 10_C of the collecting plate 10_1P. Lt; / RTI > In terms of manufacturing, an insulating layer can be formed first on a flat collector plate before patterning. Then, the insulating layer may be patterned by photolithography, imprinting, or laser processing so as to have a groove pattern exposing the upper surface of the collector plate of the base to define the openings of the cavities. Thereafter, the patterned insulating layer is used as an etching mask to etch the surface of the current collecting plate exposed at the bottom by a predetermined depth to form cavities 10_C of the current collecting plate 10_1P by wet or dry etching, The aligned cathode 10D may be provided.

4B, alternatively, a solid electrolyte 15 such as an intrinsic solid electrolyte membrane or a gel electrolyte membrane may be further provided on the upper portion of the cavity 10_C. At least a part of the solid electrolyte film 15 is incorporated into the cavity 10_C to stabilize lithium Li in the cavity 10_C and suppress its dendritic growth. The solid electrolyte 15 may be provided as a double layer replaced or stacked with the separator 30 shown in Fig.

Referring to FIG. 4C, a porous polymer network 11 may be further provided inside the cavity 10_C of the cathode 10F, as described above with reference to FIG. 3A. The porous polymer network 11 is fixed in the cavities 10_C by bonding one end 11F of the polymer chain to the inner surfaces of the cavities. The porous polymer network 11 may be formed of a non-conductive polymer, but is preferably formed of a conductive polymer. The conductive polymer may be, for example, a single polymer or two or more different polymers, and the polymer may be a positive charge carrier or a negative charge carrier, but the present invention is not limited thereto.

5 is a cross-sectional view for explaining a cathode 10G according to still another embodiment of the present invention.

Referring to Fig. 5, the cavities 10_C of the cathode 10G have an inner sidewall having a non-conductive surface and a bottom surface having a conductive surface. For example, the cavities 10_C can be obtained by the barrier formation described with reference to Fig. 2A. In other embodiments, the inner sidewalls of the cavities 10_C may also have a conductive surface.

A glass fiber layer 15 'may be formed on top of the cavities 10_C. The glass fiber layer 15 'provides pores for the movement of lithium and inhibits the growth of resinous phase of lithium (Li) out of the cavity 10_C. A separation membrane (see 30 in FIG. 3A) may be formed on the glass fiber layer 10 '. Optionally, the glass fiber layer 10 'may replace the separator. Further, the glass fiber layer 10 'may form a double layer together with the gel polymer electrolyte 15 disclosed with reference to Fig. 3A.

6A and 6B are cross-sectional views illustrating cathodes according to still another embodiment of the present invention.

Referring to FIG. 6A, a negative collector plate 10_1P is patterned to define cavities 10_C. Gradually narrows from the inside of the cavities 10_C toward the opening OP, and has a generally spherical shape. Such a spherical cavity can be obtained by isotropic etching such as wet etching using the electric insulating pattern 10P or another masking member as an etching mask. The spherical cavities 10_C are exemplary only, and the present invention is not limited thereto. For example, the cavities 10_C may have a taper shape gradually becoming narrow toward the upper surface of the current collecting plate 10_1P.

Referring to FIG. 6B, the cavities 10_C according to another embodiment may have a channel shape of irregular shape having no repeated pattern in comparison with adjacent cavities. Although not shown, the irregular channels may be connected to each other. The openings OP of the indefinite channels are spaced apart from each other by the electrically insulating pattern 10P and electrically passivated therebetween.

The features disclosed with reference to Figs. 1A to 6B can be implemented in combination with each other unless they are contradictory. For example, a porous polymer network may be formed in cavities having an irregular channel shape, or a gel polymer electrolyte and / or a glass fiber layer may be formed on the cavity.

7 is an exploded perspective view showing a battery 1000 including a cathode 10 according to an embodiment of the present invention.

Referring to FIG. 7, the battery 1000 may be a cylindrical battery. The electrode assembly 100 may have a jelly roll structure in which the cathode 10 and the anode 20 according to the above embodiment are stacked with the separator 30 interposed therebetween. The cathode 10 may include two cathode layers 10_2 coupled to both main surfaces of the current collector plate 10_1. The cathode layers 10_2 face the anode 20_2 with the separator 30 therebetween to form a battery chemical reaction zone.

The jellyroll structure shown in Fig. 7 is exemplary, and the electrode assembly 100 can be packaged in the housing 200 of the battery 1000 in various ways by bending, folding, winding, stacking, or a combination thereof. In addition, the battery 1000 is not limited to a cylindrical battery, but may be made of other coin type batteries, prismatic type batteries, or flexible batteries of various shapes using fibers.

Battery tabs or leads (Tb_A, Tb_B) may be formed on the sides of the cathode and the anodes (10, 20). The number of battery taps or leads TA may be formed at regular intervals to reduce internal resistance and may be bound together to form a common terminal. The battery tab or the lead TA can be electrically coupled to the current-collecting layers 10_1 and 20_1 by fusion or soldering. The tab or the lead TA may be internally connected to the cathode 300 and the anode 400 of the battery 1000 in the housing 500, respectively.

The separator 30 between the cathode 10 and the anode 20 is easy to change in shape and has excellent mechanical strength so that it is not torn or cracked even by deformation of the electrodes 10 and 20, A material having excellent ion conductivity can be selected. Further, as described above with reference to FIG. 3A, a separate gel solid separator 15 may be inserted between the separator 30 and the cathode 10.

The separation membrane 30 may be a single layer film or a multilayer film, and the multilayer film may be a laminate of the same single layer film or a laminate of a single layer film formed of different materials. For example, the laminate may have a structure including a ceramic coating film on the surface of a polymer electrolyte membrane such as polyolefin. For example, the separation membrane 30 may be a polymer-based microporous membrane, a woven fabric, a nonwoven fabric, a ceramic, an intrinsic solid polymer electrolyte membrane, a gel polymer electrolyte membrane, or a combination thereof.

The intrinsic solid electrolyte membrane may be formed of a material selected from the group consisting of polyethylene, polypropylene, polyimide, polysulfone, polyurethane, polyvinyl chloride, polystyrene, polyethylene oxide, polypropylene oxide, polybutadiene, cellulose, carboxymethylcellulose, Acrylonitrile, polyvinylidene fluoride, polytetrafluoroethylene, copolymers of vinylidene fluoride and hexafluoropropylene, copolymers of vinylidene fluoride and trifluoroethylene, copolymers of vinylidene fluoride and tetrafluoro A copolymer of propylene, ethylene, a copolymer of propylene and ethylene, a copolymer of polymethylacrylate, polyethylacrylate, polyethylacrylate, polymethylmethacrylate, polyethylmethacrylate, polybutyl acrylate, polybutylmethacrylate, polyvinyl acetate, Alcohol, or a combination thereof. Luer binary may comprise a polymer matrix, additives and the electrolyte.

The battery 1000 may be a non-aqueous electrolyte such as ethylene carbonate, propylene carbonate, dimethyl carbonate or diethyl carbonate containing a lithium salt such as LiClO ₄ or LiPF ₆ , but the present invention is not limited thereto. Further, although not shown, a suitable cooling device or battery managing system for controlling stability and / or power supply characteristics during use of the battery 1000 may additionally be combined.

The secondary battery according to the embodiment of the present invention not only improves the capacity of the negative electrode due to the enlargement of the current collecting area and the reaction area of lithium but also provides an output voltage close to the theoretical value due to the reduction potential of lithium, Charge and discharge of high output and high efficiency can be ensured and can be applied as a power source for an automobile or as a medium to large-sized battery for electric power storage. Further, according to the embodiment of the present invention, a lithium metal battery in which the resin phase growth of lithium is suppressed and the lifetime is improved can be provided.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be clear to those who have knowledge.

Claims (30)

House front plate;
A plurality of cavities each electrically coupled to the current collector plate and each including a conductive inner surface providing an electrochemical reaction site by electrodeposition and desorption of lithium ions and an opening exposing the conductive inner surface;
An electrically insulative pattern surrounding and electrically passivating and spacing the openings between adjacent ones of the plurality of cavities; And
And a polymer chain layer having pores inside the plurality of cavities,
And one end of the polymer chain of the polymer chain layer is bonded to the inner surface of the plurality of cavities. The method according to claim 1,
Wherein at least a portion of the conductive inner surface of the plurality of cavities comprises a surface of the current collector plate. The method according to claim 1,
Wherein some of the inner surfaces of the plurality of cavities comprise a material that is non-conductive. The method according to claim 1,
And an electrically insulating pattern layer on which the plurality of cavities are formed, on the current collecting plate,
Wherein the electrically insulative pattern layer is provided by the upper surface of the electrically insulative pattern layer. 5. The method of claim 4,
Wherein the electrically insulating pattern layer includes a barrier rib pattern defining the plurality of cavities,
And the surface of the current collector plate is exposed at the bottom of the plurality of cavities. 5. The method of claim 4,
Further comprising a conductive liner electrically connected to the current collecting plate on inner side walls of the plurality of cavities. The method according to claim 6,
Wherein the conductive liner comprises a metal layer or a conductive polymer layer. 8. The method of claim 7,
The metal layer may be formed of at least one of copper, titanium, stainless steel, nickel, platinum, gold, silver, ruthenium, tantalum, niobium, hafnium, zirconium, vanadium, indium, cobalt, tungsten, tin, beryllium, molybdenum, And a cathode. The method according to claim 1,
Wherein the current collecting plate is patterned in a depth direction to define the plurality of cavities,
And the openings of the electrically insulating pattern are formed on the current collecting plate so as to be aligned with the plurality of cavities. delete The method according to claim 1,
Wherein the polymer chain layer comprises a conductive polymer. 12. The method of claim 11,
The conductive polymer may be at least one selected from the group consisting of polyaniline, polyoxyphenylene, polyphenylene sulfide, polythiophene, polyfuran, polypyrrole, polymethylpyrrole, ), Polystyrene, and derivatives or copolymers thereof. delete The method according to claim 1,
Further comprising a gel electrolyte film stacked on top of the plurality of cavities. The method according to claim 1,
Further comprising a glass fiber layer provided on top of the plurality of cavities. The method according to claim 1,
Wherein the plurality of cavities are arranged in an array of circular, elliptical, polygonal, and trench-like shapes. The method according to claim 1,
Wherein the plurality of cavities have an irregular cavity and an opening. The method according to claim 1,
Wherein the current collector plate comprises a metal, a conductive oxide, a conductive polymer or a carbon-based electrode material, or a combination thereof. The method according to claim 1,
Wherein the electrically insulating pattern is a polymeric material selected from the group consisting of polyethylene, polystyrene, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin and phenol resin or a mixture thereof; Insulating inorganic material; Or a combination thereof. Providing a collector plate;
Forming an insulating layer on the current collecting plate;
Wherein a plurality of cavities having a conductive inner surface for providing an electrochemical reaction site by electrodeposition and desorption of lithium ions are formed on one of the current collector plate and the insulating layer, Patterning the current collector plate or the insulating layer to electrically passivate between adjacent openings and to separate the openings; And
And forming a polymer chain layer having pores inside the plurality of cavities,
And one end of the polymer chain of the polymer chain layer is bonded to the inner surface of the plurality of cavities. 21. The method of claim 20,
And forming the plurality of cavities in the insulating layer,
Wherein a surface of the current collector plate is exposed through a bottom of the plurality of cavities. 22. The method of claim 21,
And forming a conductive liner electrically connected to a surface of the current collector plate on inner side walls of the plurality of cavities. 21. The method of claim 20,
Forming a groove pattern exposing an upper surface of the current collecting plate to define an opening of the plurality of cavities in the insulating layer; And
And patterning the current collecting plate to form the plurality of cavities by etching the current collecting plate exposed through the groove pattern in a depth direction using the insulating layer as a mask film. delete 21. The method of claim 20,
Wherein the polymer chain layer comprises a conductive polymer. 26. The method of claim 25,
The conductive polymer may be at least one selected from the group consisting of polyaniline, polyoxyphenylene, polyphenylene sulfide, polythiophene, polyfuran, polypyrrole, polymethylpyrrole, ), Polystyrene, and derivatives or copolymers thereof. delete 21. The method of claim 20,
Further comprising the step of forming a gel electrolyte film on the plurality of cavities so that at least part of the cavities are embedded in the plurality of cavities. A negative electrode according to claim 1;
A positive electrode facing the negative electrode; And
And a separator between the negative electrode and the positive electrode. 30. The method of claim 29,
Wherein the secondary battery is a lithium metal battery.

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