KR101642871B1 - Secondary battery and Method for manufacturing the same - Google Patents

Abstract

The present invention relates to a secondary battery and a producing method thereof and, more specifically, to a secondary battery using a liquid electrolyte and a producing method thereof. The secondary battery comprises: a current collector exchanging electrons; a first electrode containing a first active material and formed on the current collector; an electrolyte layer formed on the first electrode; and a second electrode containing a second active material and formed on the electrolyte layer, wherein the electrolyte layer comprises: a plurality of supports formed by being spaced each other; and a liquid electrolyte supplied into a spaced space between the supports.

Description

[0001] The present invention relates to a secondary battery and a manufacturing method thereof,

The present invention relates to a secondary battery and a method of manufacturing the same, and more particularly, to a secondary battery using a liquid electrolyte and a method of manufacturing the same.

Power sources for portable electronic devices such as mobile phones, personal digital assistants (PDAs), and portable multimedia players (PMP); A motor drive power source for a high output hybrid vehicle, an electric car, and the like; The use of secondary batteries has been rapidly increasing as a power source for flexible displays such as electronic inks (e-ink), electronic paper (e-paper), flexible liquid crystal display devices (LCD) and flexible organic diodes (OLED) The application possibility as an integrated circuit device power source on a circuit board is also increasing.

However, when used as a power source for portable electronic devices, various packaging designs are restricted due to packaging for safety. In the case of being used as a power source for driving a motor, there is an increasing need for high output, small size and light weight. When used as a power source, it must be manufactured to be thin, light and bendable. In order to be used as a power source for an integrated circuit device, it must be precisely patterned in a certain form.

In order to meet various demands of such a secondary battery, Korean Patent Laid-Open No. 10-2010-0044087 (Apr. 29, 2010) discloses that instead of the conventional slurry coating technique, an electrode for a secondary battery is thinned uniformly and flatly In order to use a liquid electrolyte excellent in overall ionic conductivity and transport rate, a printing process is performed by one procedure. The anode and the cathode are separately formed and packaged and then the liquid electrolyte is injected. In order to prevent electrical conduction between the anode and the cathode, a thick separation membrane must be used. In addition, when the separator is used, the overall thickness of the secondary battery becomes thick, making it difficult for the secondary battery to have flexibility characteristics. In addition, there is a problem that packaging is difficult because the separator is disposed in the middle of the anode and the cathode and the liquid electrolyte is injected therebetween.

Korean Patent Publication No. 10-2010-0044087

The present invention provides a secondary battery which can easily form a liquid electrolyte therein, can prevent electrical conduction between an anode and a cathode with a simple structure, is easy to be packaged, and a method for manufacturing the same.

According to an aspect of the present invention, there is provided a secondary battery including: a collector; A first electrode containing a first active material and formed on the current collector; An electrolyte layer formed on the first electrode; And a second electrode formed on the electrolyte layer, wherein the electrolyte layer comprises: a plurality of supports separated from each other; And a liquid electrolyte provided in a spacing space between the plurality of supports.

The plurality of supports may be formed of a solid electrolyte.

The liquid electrolyte may be formed by dissolving a solid salt structure having a continuous network structure provided in the spacing space in a solvent.

The electrolyte layer may have a thickness of 1 to 200 mu m.

According to another aspect of the present invention, there is provided a method of manufacturing a secondary battery, including: forming a current collector; Forming a first electrode on the current collector; Forming an intermediate layer comprising a plurality of supports separated from each other on the first electrode and a salt structure provided in a spacing space between the plurality of supports; Forming a second electrode on the intermediate layer; And dissolving the salt structure in a solvent to form a liquid electrolyte.

The salt structure may be formed in a continuous network structure, and the plurality of supports may be formed in an isolated shape by the salt structure.

The current collector, the first electrode, the intermediate layer, and the second electrode may be formed by a printing process.

In the step of forming the intermediate layer, any one selected from the plurality of supports and the salt structure may be formed first and then the other one may be formed.

The step of forming the intermediate layer may be performed as one procedure.

In the forming the intermediate layer, the intermediate layer may be formed by a 3D printing technique using a plurality of inks including the constituent materials of the plurality of supports and the salt structure.

The plurality of supports may be formed of a solid electrolyte.

The intermediate layer may be formed to a height of 1 to 200 mu m.

The secondary battery according to an embodiment of the present invention can easily form a liquid electrolyte by forming a salt structure using a salt (for example, a lithium salt) and dissolving the salt structure with a solvent, The first electrode, the plurality of supports, the salt structure, and the second electrode can be formed all at once by 3D printing. Thus, all manufacturing processes can be performed in an in-line process, which can shorten the process time and improve productivity and process efficiency. And packaging can be made easy by packaging one stack formed at a time by 3D printing.

In addition, since a plurality of supports are formed between the first electrode and the second electrode, the positive electrode and the negative electrode can be physically cut off during the 3D printing process, and the electrical conduction between the positive electrode and the negative electrode can be prevented . Since the thickness of the electrolyte layer can be made thinner to increase the ratio of the anode to the cathode per unit volume, the amount of the active material per unit volume can be increased and the energy density can be improved more than when the separator is used. In addition, the plurality of supports may be formed of a solid electrolyte so that the ions can move to a plurality of supports, thereby improving the overall ionic conductivity.

Meanwhile, in order to further improve the energy density, a unit cell of a secondary battery may be stacked, and a plurality of unit cells may be stacked by 3D printing to stack unit cells and unit cells during a continuous process. Which can increase the process efficiency, reduce the process time, and obtain a high-energy-density secondary battery.

1 is a cross-sectional view of a secondary battery according to an embodiment of the present invention.
2 is a perspective view illustrating a secondary battery manufacturing method according to another embodiment of the present invention.
3 is a perspective view illustrating a method of forming a plurality of supports and a salt structure according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. In the description, the same components are denoted by the same reference numerals, and the drawings are partially exaggerated in size to accurately describe the embodiments of the present invention, and the same reference numerals denote the same elements in the drawings.

1 is a cross-sectional view illustrating a secondary battery according to an embodiment of the present invention.

Referring to FIG. 1, a secondary battery 100 according to an embodiment of the present invention includes a current collector 110 for exchanging electrons; A first electrode (120) containing a first active material and formed on the current collector (110); An electrolyte layer 130 formed on the first electrode 120; And a second electrode 140 formed on the electrolyte layer 130 and containing a second active material.

The current collector 110 is used to exchange electrons to flow a current during charging and discharging, and a conductive substrate having a porous structure or a conductive substrate having no hole can be used. The conductive substrate (i.e., current collector) may be formed using at least one selected from copper, aluminum, stainless steel, molybdenum, tungsten, tantalum, titanium, and nickel. However, the present invention is not limited thereto. Anything that can be formed can be used. The current collector 110 preferably has a small thickness, and may be a metal foil. The thickness of the current collector 110 may be 1 nm to 30 占 퐉, preferably 10 占 퐉 to 30 占 퐉. If the thickness is less than 10 占 퐉, not only the strength as an electrode can not be obtained but also the deformation introduced due to the expansion and contraction of the active material due to charging / discharging reaction can not be relaxed or the anode may be cut off. On the other hand, when the thickness exceeds 30 μm, not only the filling amount of the active material is reduced but also the flexibility of the electrode is impaired and the internal short circuit tends to occur easily. Considering tensile strength, electrochemical stability and flexibility when winding, aluminum foil is the most preferred for current collector 110, and its thickness is preferably 10 to 30 占 퐉. The current collector 110 may be formed using a printing technique, electroless plating, or electrolytic plating. On the other hand, the current collector 110 may have a concavo-convex structure or the like formed on the surface on which the electrodes are formed to control the surface roughness, and may further be subjected to UV or plasma surface treatment. When the surface energy is raised and the electrode is formed of ink having a low viscosity, the uniformity of the electrode may be higher.

The first electrode 120 may contain the first active material and may be formed on the current collector 110. The first electrode 120 may be any one of an anode and a cathode, and the first active material may be an active material of any one of the anode and the cathode, which is the same as the first electrode 120. The first electrode 120 may include a first active material and a conductive agent, and may further include a binder to bind the first active material. When the first electrode 120 is a cathode, the first active material may be a majority of the ceramic-based cathode active material used as the cathode. For example, manganese dioxide, lithium manganese composite oxide, lithium-containing nickel oxide, lithium-containing cobalt compound , Lithium-containing nickel cobalt oxide, lithium-containing iron oxide, vanadium oxide containing lithium, etc., or a chalcogenide compound such as titanium disulfide or molybdenum disulfide. Among them, lithium-containing cobalt oxide (for example, LiCoO ₂ ), lithium-containing nickel cobalt oxide (for example, LiNi _{0 .8} Co _{0 .2} O ₂ ) or lithium manganese composite oxide (for example, LiM ₂ O ₄ , LiMnO ₂ ) is used, a high voltage can be obtained. The conductive agent may be acetylene black, carbon black, graphite or the like. The binder may bind to the active material. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVdF), ethylene propylene diene copolymer (EPDM), styrene butadiene rubber (SBR), etc. The conductive agent and the binder are contained in a smaller amount than the first active material.

The electrolyte layer 130 may be formed on the first electrode 120 and may include a plurality of supports 131 separated from each other and a liquid electrolyte 132 provided in a space between the plurality of supports 131, . The plurality of supports 131 are spaced apart from each other and provide a spacing space so that the liquid electrolyte 132 can have a continuous network structure.

In the conventional secondary battery, a separation membrane was required in the electrolyte layer in order to prevent the electric conduction between the anode and the cathode. Since the conventional separator is thicker by several tens of micrometers, it not only increases the thickness of the electrolyte layer but also is a porous film. Therefore, when the second electrode is laminated on the separator in a continuous lamination process using a printing process or a thin- The conductive material of the second electrode may be coated on the inside of the pores of the separator through fine pores to cause an electrical short, so that there is a limitation in manufacturing the entire secondary battery by the printing process.

However, in the present invention, the second electrode 140 is formed on the intermediate layer made of the salt structure 132 provided in the spacing space between the plurality of spacers 131 and the plurality of supports 131, Unlike the conventional separator, the intermediate layer does not include micropores. Therefore, when the second electrode is formed by a printing process, a problem that a conductive material is coated inside the micropores to cause a short circuit can be solved. Details of the intermediate layer will be described later in a secondary battery manufacturing method according to another embodiment of the present invention.

In the present invention, since the ionic conductivity can be controlled through the plurality of supports 131, it is possible to prevent the electric conduction between the anode and the cathode without the thick separation membrane in the electrolyte layer 130, The thickness of the secondary battery 100 can be reduced, and the overall thickness of the secondary battery 100 can be reduced. In addition, when the thickness of the electrolyte layer 130 is reduced, the ratio of the first electrode (or the anode) or the second electrode (or the cathode) per unit volume can be maximized, thereby increasing the amount of the active material per unit volume. The energy density can be improved in the present invention by solving the conventional problem that the energy density is low because the thickness of the electrolyte layer is thick and the amount of the active material per unit volume is small.

Conventionally, since there is no supporting structure at the upper and lower portions of the separator, it is difficult to maintain a constant distance between the anode and the cathode. However, in the present invention, the distance between the anode and the cathode can be kept constant by the plurality of supports 131. In addition, since the plurality of supports 131 can physically block the positive electrode and the negative electrode, the current collector 110, the first electrode 120, the electrolyte layer (or the plurality of supports), and the second electrode 140 are all printed And it is possible to easily and easily manufacture the secondary battery 100 by the 3D printing technique.

On the other hand, the plurality of supports 131 can be evenly distributed on the plane of the secondary battery 100 so as to uniformly distribute the liquid electrolytes 132, Since the plurality of supports 131 are provided separately from each other even when the plurality of supports 131 are made of a rigid material in order to support the laminated structure, Since flexibility is not sacrificed by the plurality of supports 131, the flexibility of the entire secondary battery 100 can be improved.

The plurality of supports 131 may be made of a solid electrolyte. When the plurality of supports 131 are made of a solid electrolyte, ions can move even to the plurality of supports 131. Therefore, ion conductivity of the secondary battery 100 can be improved more than that of forming a plurality of supports 131 using an insulating material . Although the solid electrolyte is not particularly limited in terms of the material, it is preferable to use an oxide-based or a sulfide-based one. Examples of the solid electrolyte include molybdenum oxide, titanium oxide, vanadium oxide, chromium oxide, tantalum oxide, zirconium oxide, hafnium oxide, Oxide and tungsten oxide, or a mixture of two or more thereof.

The liquid electrolyte 132 may be formed to have a continuous network structure and may be provided in a spaced space between the plurality of supports 131. Since the liquid electrolyte 132 is excellent in ion conductivity and transporting rate as compared with the solid electrolyte, the ion conductivity of the secondary battery 100 can be improved by using the liquid electrolyte 132. As the material of the liquid electrolyte 132, lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium fluoroborate (LiBF ₄ ), lithium hexafluoride (LiAsF ₆ ), lithium trifluoromethanesulfonate LiCF ₃ SO ₃ ), lithium titanate (Li ₄ Ti ₅ O ₁₂ ; LTO), lithium iron phosphate (LiFePO ₄ ; LFP), bistrifluoromethylsulfonylimide lithium [LiN (CF ₃ SO ₂ ) ₂ ] (LiBF ₄ ) can inhibit the generation of gas in the noble gases. In this case, the lithium fluoride (LiBF ₄ ) can suppress the generation of gas in the noble gases. (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), 1, 2-butanediol, 2-dimethoxyethane (DME),? -Butyrolactone (? -BL), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF) -Dimethoxypropane, and vinylene carbonate (VC), or a mixed solvent of two or more of them may be used.

When the liquid electrolyte 132 is formed to have a continuous network structure, a solid salt structure is formed to have a continuous network structure, and then a solvent for dissolving the salt is injected into one place, The liquid electrolyte 132 can be formed by allowing the solvent to dissolve all of the salt through the continuous network structure. Therefore, the liquid electrolyte 132 can be simply formed in the secondary battery 100, and the solvent can be injected only into one place, so that the sealing area can be reduced and the sealing process can be facilitated. In addition, when a solid-phase structure is first formed, all of the stacks (i.e., the collector, the first electrode, the plurality of supports, the salt structure, and the second electrode) can be formed by a printing technique, It is possible to easily and simply form a laminate as a base of the secondary battery 100. [ In the case of using 3D printing, lithium hexafluorophosphate which can effectively form a supporting structure (i.e., a salt structure) during a 3D printing process and can be easily dissolved when a solvent such as ethylene carbonate or diethyl carbonate is supplied, It is preferable to use a lithium salt such as lithium. Thus, the liquid electrolyte 132 may be formed by dissolving a solid-phase salt structure having a continuous network structure provided in a space between the plurality of supports 131 in a solvent.

On the other hand, the electrolyte layer 130 may have a thickness of 1 to 200 mu m. As the thickness of the electrolyte layer 130 becomes thinner than 1 탆, the ion transporting speed becomes faster and the maximum capacity increases and the output amount becomes better. In this case, when the thickness of the electrolyte layer 130 is thinner than 1 탆, Electrical shorting can occur without preventing the electric current from being applied. On the other hand, if the thickness of the electrolyte layer 130 is thicker than 200 占 퐉, the moving distance of the ions becomes too long, and the ion transmission time is long, so that the output efficiency can be reduced. When the thickness of the electrolyte layer 130 is reduced, the ratio of the first electrode (or the anode) or the second electrode (or the cathode) per unit volume can be maximized, and the amount of the active material per unit volume is increased. have.

The second electrode 140 may contain a second active material and may be formed on the electrolyte layer 130. The second electrode 140 may be a remaining electrode corresponding to the first electrode 120 of the anode and the cathode, and the second active material may be determined according to the polarity of the second electrode 140. The second electrode 140 may include a second active material and a conductive agent as well as the first electrode 120, and may further include a binder binding the second active material. When the second electrode 140 is a cathode, the second active material may be a conductive polymer such as polyacetal, polyacetylene, and polypyrrole, which can be doped with lithium ions, a coke capable of doping lithium ions, carbon fibers, graphite, (Si), tin (Sn), vanadium (V), titanium (Ti), titanium carbide, titanium carbide, titanium carbide, molybdenum disulfide, ), Germanium (Ge), oxides thereof, and two or more compounds. The carbon material may be in the form of a graphite carbon material, a carbon material in which a graphite crystal portion and a non- A carbon material having an uneven laminated structure, or the like. The conductive agent may be acetylene black, carbon black, graphite or the like. The binder may bind to the active material. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVdF), ethylene propylene diene copolymer (EPDM), styrene butadiene rubber (SBR), etc. The conductive agent and the binder are contained in a small amount compared to the second active material.

On the other hand, when the first electrode 120 is a cathode and the second electrode 140 is an anode, the first electrode 120 and the second electrode 140 can be formed in a manner opposite to the above, The active material can be selected accordingly. The current collector 110 may be formed on the second electrode 140 and may be formed on the second electrode 140 so that the basic constituent of the secondary battery 100 (i.e., the current collector, the first electrode, Can be packaged into the casing 150. In order to further improve the energy density, the unit cells of the secondary battery 100 may be stacked.

FIG. 2 is a perspective view showing a sequential method of manufacturing a secondary battery according to another embodiment of the present invention, and FIG. 3 is a perspective view illustrating a method of forming a plurality of supports and a salt structure according to another embodiment of the present invention.

Referring to FIGS. 2 and 3, a method for manufacturing a secondary battery according to another embodiment of the present invention will be described in more detail. However, the description of the secondary battery according to an embodiment of the present invention will be omitted. do.

According to another aspect of the present invention, there is provided a method of manufacturing a secondary battery, including: forming a current collector; Forming a first electrode on the current collector; Forming an intermediate layer comprising a plurality of supports separated from each other on the first electrode and a salt structure provided in a spacing space between the plurality of supports; Forming a second electrode on the intermediate layer; And dissolving the salt structure in a solvent to form a liquid electrolyte.

First, a current collector 110 is formed (FIG. 2A). The current collector 110 serves to exchange electrons for charging and discharging, and a conductive substrate having a porous structure or a conductive substrate having no hole can be used. The conductive substrate (i.e., current collector) may be formed using at least one selected from copper, aluminum, stainless steel, molybdenum, tungsten, tantalum, titanium, and nickel. However, the present invention is not limited thereto. Anything that can be formed can be used. The current collector 110 may be formed using electroless plating or electroplating as well as a printing technique (or a 3D printing technique). Meanwhile, the step of forming the concave-convex structure on the surface of the current collector 110 where the electrodes are formed and the step of UV or plasma surface treatment of the current collector 110 may be further performed in the step of forming the current collector 110 .

Next, the first electrode 120 is formed on the current collector 110 (FIG. 2B). The first electrode 120 may include an active material and a conductive agent, and the first electrode 120 may be one of an anode and a cathode. When the first electrode 120 is a cathode, most of the ceramic-based cathode active material used as an anode may be used as an active material. For example, manganese dioxide, a lithium manganese composite oxide, lithium-containing nickel oxide, lithium-containing cobalt compound, lithium Containing oxides, lithium-containing iron oxides, and lithium-containing vanadium oxides, and titanium oxides, titanium disulfide, and molybdenum disulfide. Among them, lithium-containing cobalt oxide (for example, LiCoO ₂ ), lithium-containing nickel cobalt oxide (for example, LiNi _{0 .8} Co _{0 .2} O ₂ ) or lithium manganese composite oxide (for example, LiM ₂ O ₄ , LiMnO ₂ ) is used, a high voltage can be obtained. And a binder for binding the active material. The conductive agent and the binder may be contained in a small amount as compared with the active material.

The intermediate layer 130 is formed on the first electrode 120. A plurality of supports 131 are formed spaced apart from each other and a salt structure is formed so as to be provided in the spacing space between the plurality of supports 131. [ (FIG. 2C). At this time, the salt structure 132 may be formed in a continuous network structure, and the plurality of supports 131 may be formed in an isolated shape by the salt structure 132, respectively. When the salt structure 132 is formed into a continuous network structure, since the solvent capable of dissolving the salt can be entirely moved through the continuous network structure, the solvent is injected into one place, It is possible to form a liquid electrolyte therein and to inject the solvent into only one place. Therefore, the sealing area can be reduced to simplify the sealing process, and it is possible to solve the problem that it is difficult to use the liquid electrolyte in the conventional printing technique. Since the salt can be stacked while maintaining the shape, all the stacks (i.e., the current collector, the first electrode, the plurality of supports, the salt structure, and the second electrode) Printing can easily and easily form the above-mentioned laminate which is the basis of the secondary battery. On the other hand, when 3D printing is used, the salt structure 132 may provide a supporting structure by which an upper laminate (for example, a second electrode) can be effectively stacked during a 3D printing process, (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiBF ₄ ), lithium arsenic fluoride (LiAsF ₆ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium titanate (Electrolyte) such as Li ₄ Ti ₅ O ₁₂ (LT ₄ ), lithium iron phosphate (LiFePO ₄ ; LFP), and bistrifluoromethylsulfonylimide lithium [LiN (CF ₃ SO ₂ ) ₂ ] (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), 1,2-dimethoxyethane (DME), and the like. The solvent may be one or more kinds selected from the group consisting of propylene carbonate (DME),? -Butyrolactone (? -BL), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1,3-dioxolane, 1,3-dimethoxypropane , Vinylene carbonate (VC), and the like, or a mixed solvent of two or more thereof.

The plurality of supports 131 are spaced apart or isolated from each other to provide a space for the liquid electrolyte to be formed. Conventionally, when a liquid electrolyte is used, a thick separation membrane having a thickness of several tens of micrometers is required in order to prevent the electrical conduction between the anode and the cathode. In the present invention, since the ionic conductivity can be controlled through the plurality of supports 131, It is possible to prevent the electric conduction between the positive electrode and the negative electrode without a separation membrane. The ratio of the first electrode (or the anode) or the second electrode (or the cathode) per unit volume can be increased by thinning the thickness of the intermediate layer 130, so that the amount of the active material per unit volume is increased to improve the energy density . In addition, since the plurality of supports 131 provide a supporting structure in which the upper stacked body (for example, the second electrode) can be stacked effectively during the 3D printing process together with the salt structure 132, the 3D printing technique can easily and easily Thereby making it possible to manufacture a secondary battery.

On the other hand, the plurality of supports 131 can be evenly distributed on the plane of the secondary battery 100 so as to uniformly distribute the liquid electrolyte, and can be dispersed in the spaced spaces, Even when the plurality of supports 131 are made of a rigid material in order to support the structure, since the plurality of supports 131 are provided apart from each other, the liquid electrolyte is provided in the space between the plurality of supports 131, Flexibility of the secondary battery 100 as a whole can be improved without sacrificing the flexibility by the support 131.

The plurality of supports 131 may be formed of a solid electrolyte. When the plurality of supports 131 are made of a solid electrolyte, ions can move even to the plurality of supports 131. Therefore, ion conductivity of the secondary battery 100 can be improved more than that of forming a plurality of supports 131 using an insulating material . Although the solid electrolyte is not particularly limited in terms of the material, it is preferable to use an oxide-based or a sulfide-based one. Examples of the solid electrolyte include molybdenum oxide, titanium oxide, vanadium oxide, chromium oxide, tantalum oxide, zirconium oxide, hafnium oxide, Oxide and tungsten oxide, or a mixture of two or more thereof.

In the step of forming the intermediate layer, any one of the plurality of supports 131 and the salt structure 132 may be formed, and the other one of the plurality of the support 131 and the salt structure 132 may be formed. 3A, the salt structure 132 may be formed first to provide a plurality of isolation spaces in which a plurality of supports 131 are formed, and the plurality of supports 131 may be filled in a plurality of the provided isolation spaces. Can be formed. By using such a method, a plurality of supports 131 and a salt structure 132 can be formed using ink (or a printing technique), and a plurality of supports 131 and a salt structure 132 can be formed simply . Meanwhile, a method of providing a plurality of isolation spaces to the salt structure 132 includes a method of laminating only portions excluding a plurality of isolation spaces, and a method of laminating all of the planes in a plane, followed by etching a plurality of isolation spaces. However, the present invention is not limited to this, and a plurality of supports 131 may be formed first and a salt structure 132 may be formed in a spacing space between a plurality of supports 131, 131) and the salt structure 132 can be formed.

The step of forming the intermediate layer may be performed as one procedure. In this case, the intermediate layer 130 can be formed by a single process, and when the printing technique is used, the intermediate layer 130 can be formed by the shortest distance movement of the nozzles 10.

The intermediate layer 130 may be formed by a 3D printing technique using a plurality of inks including the constituent materials of the plurality of supports 131 and the salt structure 132, respectively. As shown in FIG. 3B, the intermediate layer 130 may be formed by using a 3D printing technique. The plurality of supports 131 and the salt structure 132 may be formed by a plurality of nozzles 10, And can have the thickness of the intermediate layer 130 at a time when the nozzle 10 passes. On the other hand, the nozzles 10 may be continuously stacked with a height varying in the z-axis to have the thickness of the intermediate layer 130, but there is no particular limitation on the method of forming the intermediate layer. When the intermediate layer 130 is formed by the 3D printing technique, the intermediate layer 130 can be formed easily and quickly by moving the nozzle 10 at the shortest distance. In addition, in the present invention, the intermediate layer 130 may be formed of a plurality of supports 131 and a salt structure 132 to form all the stacks as the basis of the secondary battery by 3D printing, The secondary battery can be manufactured quickly. Accordingly, all the manufacturing processes of the secondary battery can be performed in an in-line process, thereby shortening the process time and improving the productivity and process efficiency of the secondary battery.

Each of the plurality of inks is made of a powder of a constituent material of each of the plurality of the supports (131) and the salt structure (132), and each of the powders of the constituent materials is dissolved or dispersed, And an additive for improving ionic conductivity. The additive may include at least one of a binder, a conductive agent, a moisturizer, a dispersant, a thickener, and a buffer. In order to perform 3D printing, the ink should maintain a proper viscosity. By adding the additives, the ink having improved conductivity of the active material can be produced while maintaining an appropriate viscosity. The solvent includes deionized water as a main component and may be a solvent such as ethanol, methanol, butanol, propanol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, N-methyl- A solvent mixed with an alcohol system may be used.

The binder serves to bind the ink, and may be a binder. Examples of the binder include polyvinyl alcohol, an ethylene-propylene-diene terpolymer, a styrene-butadiene rubber, polyvinylidene fluoride (PVDF), polytetrafluoro Ethylene, tetrafluoroethylene-hexafluoropropylene copolymer, and carboxymethylcellulose (CMC) may be used. The conductive agent is a material for improving conductivity, and acetylene black, carbon black, graphite, carbon fiber, carbon nanotube, or the like can be used. In addition, the humectant suppresses drying of the ink to prevent clogging of the nozzle, and glycol, glycerol, pyrrolidone and the like can be used.

The dispersing agent serves to disperse the active material and the conductive agent evenly. The dispersant may be at least one selected from the group consisting of fatty acid salts, alkyldicarboxylic acid salts, alkylsulfuric acid ester salts, polyvalent sulfuric ester alcohol salts, alkylnaphthalene sulfate, alkylbenzenesulfuric acid salts, alkylnaphthalene sulfuric acid ester salts, Sulfonic acid salts, naphthenic acid salts, alkyl ether carboxylic acid salts, acylated peptide, alpha olefin sulfate, N-acylmethyltaurine salt, alkyl ether sulfate, secondary alcohol alcohol ethoxy sulfate, polyoxyethylene alkylperme ether sulfate, Alkyl ether phosphates, alkyl amine salts, alkyl pyridinium salts, alkyl imidazolium salts, fluorinated or silicone-acrylic acid polymers, polyoxyethylene alkyl ethers, polyoxyethylene sterol ethers, poly Lanolin derivatives of oxyethylene, polyoxyethylene / polyoxypropylene copolymers, polyoxyethylene sorbitan A water-soluble polyester, a fatty acid ester, a monoglyceride fatty acid ester, a sucrose fatty acid ester, an alkanolamide fatty acid, a polyoxyethylene fatty acid amide, polyoxyethylene alkylamine, polyvinyl alcohol, polyvinylpyridone, polyacrylamide, , A hydroxyl group-containing cellulose resin, an acrylic resin, a butadiene resin, an acrylic acid resin, a styrene acrylic resin, a polyester resin, a polyamide resin, a polyurethane resin, an alkyl betaine resin, an alkylamine oxide resin and a phosphatidylcholine resin. . The thickener serves to enhance the viscosity, and ethylene-vinyl alcohol copolymer, cellulose derivative (for example, carboxymethyl cellulose, methyl cellulose) and the like can be used. The buffer may be at least one amine compound selected from the group consisting of trimethylamine, triethanolamine, diethanolamine, ethanolamine, sodium hydroxide, and ammonium hydroxide to maintain the stability of the ink and to control the pH of the ink.

On the other hand, in the case of forming all of the laminated materials which are the basis of the secondary battery by the 3D printing technique, the laminated material is formed by using each ink of the laminated material, And a solvent that dissolves or disperses the respective constituent material powder. The printer for 3D printing may be a printer capable of controlling three axes of x, y, and z, and a micronozzle and a bulk nozzle may be used. A pneumatic controller capable of controlling the ejection speed of the ink may also be used.

The plurality of supports 131 and the salt structure 132 may be formed to a height of 1 to 200 탆. The plurality of support bodies 131 and the salt structure body 132 constitute the intermediate layer 130 because the salt structure body 132 is dissolved in a solvent to form a liquid electrolyte. The thinner the intermediate layer 130, The ion transfer rate is increased and the maximum capacity is increased, so that the yield is improved. However, if the thickness of the intermediate layer 130 becomes too thin to be thinner than 1 占 퐉, electrical conduction between the anode and the cathode can not be prevented and a short may occur. On the other hand, if the thickness of the intermediate layer 130 is thicker than 200 占 퐉, the movement distance of the ions becomes too long, and the ion delivery time is long, so that the output efficiency can be reduced. When the thickness of the intermediate layer 130 is reduced, the ratio of the first electrode (or the anode) or the second electrode (or the cathode) per unit volume can be maximized, and the amount of the active material per unit volume is increased, .

The second electrode 140 is formed on the intermediate layer 130 (FIG. 2D). The second electrode 140 may include an active material and a conductive agent and the second electrode 140 may be a remaining electrode corresponding to the first electrode 120 of the anode and the cathode. When the second electrode 140 is a cathode, a conductive polymer such as polyacetal, polyacetylene, and polypyrrole that can be doped with lithium ions as an active material, a coke capable of doping lithium ions, a carbon fiber, a graphite, (Si), tin (Sn), vanadium (V), titanium (Ti), and vanadium (V), carbon materials such as silicon carbide, carbonaceous material, pyrolytic carbon material, Germanium (Ge), oxides thereof, or two or more compounds. The carbon material may be in the form of a carbon black material, a carbon material in which a graphite crystal portion and a non-crystal material are mixed, A carbon material having a structured laminated structure, or the like. And a binder (or a binder) for binding the active material. The conductive agent and the binder may be contained in a smaller amount than the active material. On the other hand, when the first electrode 120 is a cathode and the second electrode 140 is an anode, the first electrode 120 and the second electrode 140 can be formed in a manner opposite to the above, The active material can be selected accordingly.

The current collector 110, the first electrode 120, the intermediate layer 130, and the second electrode 140 may all be formed by a printing process. In the present invention, the intermediate layer 130 is formed of a plurality of supports 131 and a salt structure 132, and the current collector 110, the first electrode 120, the intermediate layer 130, The second electrode 140 can be formed. Thus, the secondary battery can be manufactured easily and quickly by the 3D printing technique. Accordingly, all the manufacturing processes of the secondary battery can be performed in an in-line process, thereby shortening the process time and improving the productivity and process efficiency of the secondary battery.

Next, the salt structure 132 is dissolved in a solvent to form a liquid electrolyte. As shown in FIG. 2E, the laminate as a base of the secondary battery may be packaged with the casing 150, and a liquid electrolyte may be formed by injecting a solvent for dissolving the salt structure 132 into the salt structure 132 have. In this case, after the solvent is injected, the injection port used for injecting the liquid electrolyte is sealed so that the liquid electrolyte does not leak.

The method may further include forming a current collector 110 on the second electrode 140 and may stack the unit cells of the secondary battery 100 to further improve energy density. Step < / RTI > The outer casing 150 may be formed by 3D printing. Alternatively, a plurality of unit cells may be formed by 3D printing and stacked. In this case, since unit cells and unit cells can be stacked during the continuous process, the process efficiency can be enhanced and the process time can be shortened. In the case where the casing material 150 is formed by 3D printing, After forming the casing member 150, an opening for injecting a solvent for dissolving the salt structure 132 may be formed by drilling a hole, or the casing 150 may be formed so as to form an injection port for dissolving the salt structure 132 have. At this time, the injection port is also sealed. When the unit cells of the secondary battery 100 are stacked, the second electrode of one unit cell and the first electrode of the other unit cell may be stacked so as to be in contact with each other. The second electrode and the first electrode of another unit cell may be connected to each other. There is no particular limitation on the method of connecting the second electrode of one unit cell to the first electrode of another unit cell.

As described above, the secondary battery according to an embodiment of the present invention can easily form a liquid electrolyte by forming a salt structure using a salt (for example, a lithium salt) and dissolving the salt structure with a solvent, Since the salt structure can be formed by the printing method, the current collector, the first electrode, the plurality of supports, the salt structure, and the second electrode can be formed all at once by 3D printing. Thus, all manufacturing processes can be performed in an in-line process, which can shorten the process time and improve productivity and process efficiency. And packaging can be made easy by packaging one stack formed at a time by 3D printing. In addition, since a plurality of supports are formed between the first electrode and the second electrode, the positive electrode and the negative electrode can be physically cut off during the 3D printing process, and the electrical conduction between the positive electrode and the negative electrode can be prevented . Since the thickness of the electrolyte layer can be made thinner to increase the ratio of the anode to the cathode per unit volume, the amount of the active material per unit volume can be increased and the energy density can be improved more than when the separator is used. In addition, the plurality of supports may be formed of a solid electrolyte so that the ions can move to a plurality of supports, thereby improving the overall ionic conductivity. Meanwhile, in order to further improve the energy density, a unit cell of a secondary battery may be stacked, and a plurality of unit cells may be stacked by 3D printing to stack unit cells and unit cells during a continuous process. It is possible to obtain a high-energy-density fuel cell, which can increase the process efficiency and reduce the process time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Those skilled in the art will appreciate that various modifications and equivalent embodiments may be possible. Accordingly, the technical scope of the present invention should be defined by the following claims.

10: Nozzle 100: Secondary battery
110: collector 120: first electrode
130: electrolyte layer or intermediate layer 131: plural supports
132: liquid electrolyte or salt structure 140: second electrode
150: Outer material

Claims (12)

A whole house for exchanging electrons;
A first electrode containing a first active material and formed on the current collector;
An electrolyte layer formed on the first electrode; And
A second electrode containing a second active material and formed on the electrolyte layer,
Wherein the electrolyte layer comprises:
A plurality of spacers which are spaced apart from each other and isolated from each other, and which maintain a gap between the first electrode and the second electrode; And
And a liquid electrolyte provided in a spaced-apart space between the plurality of supports and having a continuous network structure,
The liquid electrolyte is obtained by dissolving a solid salt structure in a solvent provided along the continuous network structure,
Wherein the current collector, the first electrode, the second electrode, the plurality of supports, and the solid salt structure are formed by a printing process.
The method according to claim 1,
Wherein the plurality of supports comprises a solid electrolyte.
delete The method according to claim 1,
Wherein the electrolyte layer has a thickness of 1 to 200 mu m.
Forming a current collector;
Forming a first electrode on the current collector;
Forming an intermediate layer comprising a plurality of supports isolated from each other on the first electrode and a salt structure provided in a space between the plurality of supports and having a continuous network structure;
Forming a second electrode on the intermediate layer; And
And dissolving the salt structure in a solvent to form a liquid electrolyte,
In the step of forming the liquid electrolyte, the salt structure may be dissolved in the solvent provided along the continuous network structure to form the liquid electrolyte of the continuous network structure,
Wherein the plurality of supports maintains a gap between the first electrode and the second electrode,
Wherein the current collector, the first electrode, the intermediate layer, and the second electrode are formed by a printing process.
delete delete The method of claim 5,
Wherein the forming of the intermediate layer comprises forming one of the plurality of supports and the salt structure first and then forming the remaining one.
The method of claim 5,
Wherein the step of forming the intermediate layer is performed as one procedure.
The method of claim 5,
Wherein the intermediate layer is formed by a 3D printing technique using a plurality of inks including a constituent material of the plurality of supports and a constituent material of the salt structure.
The method of claim 5,
Wherein the plurality of supports are formed of a solid electrolyte.
The method of claim 5,
Wherein the intermediate layer has a height of 1 to 200 mu m.

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