WO2013141481A1

WO2013141481A1 - Flexible thin film battery capable of withstanding high temperature treatment and method for fabricating same

Info

Publication number: WO2013141481A1
Application number: PCT/KR2013/000963
Authority: WO
Inventors: 박호영
Original assignee: 지에스칼텍스(주)
Priority date: 2012-03-21
Filing date: 2013-02-07
Publication date: 2013-09-26
Also published as: KR101355007B1; KR20130106965A

Abstract

The present invention relates to a thin film battery and a method for fabricating same, in which a cathode material can be thermally treated at a high temperature so that the thin film battery has an excellent unit cell capacity and output characteristics and also has flexibility due to its thin thickness. The thin film battery according to the present invention includes: a flexible film layer having a pyrolysis temperature of about 350 °C or more; a cathode current collector pattern and an anode current collector pattern which are formed on the flexible film layer to be electrically separated from each other; a cathode pattern formed on the cathode current collector pattern; an electrolyte pattern formed on the cathode pattern; and an anode pattern formed on the electrolyte pattern.

Description

Flexible thin film battery capable of high temperature heat treatment and manufacturing method thereof

The present invention relates to a thin film battery capable of heat treatment of a positive electrode material at a high temperature, exhibiting excellent unit cell capacity and output characteristics, and exhibiting flexibility by exhibiting flexibility. More specifically, a pyrolysis temperature of 350 ° C. or more is flexible. Film layer; A positive electrode current collector pattern and a negative electrode current collector pattern formed to be electrically separated from each other on the flexible film layer; An anode pattern formed on the anode current collector pattern; An electrolyte pattern formed on the anode pattern; And a cathode pattern formed on the electrolyte pattern and a method of manufacturing the same.

With the development of the electronic and information communication industries, individuals have carried various personal terminals and office devices, and as a result, the miniaturization of devices has been rapidly made in many fields such as mobile phones, portable AV devices, and portable OA devices.

As a result, according to the trend of miniaturization and portability of electronic devices, the energy density is further increased, and the development of excellent and small size lithium secondary batteries becomes a very urgent problem.

Meanwhile, the conventional commercialized lithium secondary battery has an active material, a separator, a liquid electrolyte, and a carbon cathode as a basic configuration. Such a structure is complex and has a limit in miniaturization. In addition, conventional lithium secondary batteries are not easy to manufacture a thin thickness by using a pouch (poch), there is a risk of explosion accident. In addition, liquid electrolytes have device fouling problems due to low temperature freezing, high temperature evaporation and leakage.

In order to overcome this problem, a thin film battery has been developed. The thin film battery is composed of a positive electrode, a solid electrolyte and a negative electrode, and is formed by sequentially forming the above-mentioned solid-state battery components. The thin film battery can be manufactured to a thickness of about several tens of micrometers, which makes it possible to miniaturize. In addition, unlike a conventional lithium secondary battery, the thin film battery is stable because there is no risk of explosion, and a battery having various patterns can be realized according to a mask shape. The solid electrolyte used in the thin film battery must satisfy all characteristics such as high ionic conductivity, electrochemical stability window, and low electrical conductivity. Solid electrolytes can solve low temperature freezing, high temperature evaporation, etc., which have been a problem in liquid electrolytes.

Thin-film microcells have a current density and total energy because all components are thinned. Although there is a disadvantage in that the storage density is low, it is intended to compensate for the disadvantages of the thin film battery by manufacturing a thin film battery having a trench structure that can increase the effective area per unit area [Korea Patent No. 296741]. The energy storage density of thin film cells is determined by the cathode material used.₂ , V₂O₅ , LiCoO₂ , LiMn₂O₄, LiNiO₂ Cathode materials have been known, and high current density LiMO exhibiting stable charge and discharge characteristics, especially in the 4 V region.₂ Much research has been conducted on (M = Co, Ni).

B. Wang et al. Presented a Li / LIPON / LiCoO ₂ / Pt / Si structured thin film battery prepared by crystallizing a LiCoO ₂ thin film by heat treatment in the air in the American Electrochemical Society. LiCoO _{2 as} a thin film cell has been shown [Journal of the Electrochemical Society, 143, p3203]. In addition, BJ Neudecker et al. Also fabricated a Lithium free battery by heat treating LiCoO ₂ anode thin film at 700 ° C. using Furnace heat treatment method [Journal of the Electrochemical Society, 147 (2), p517]. As shown in the above studies, when the anode thin film has a layered structure, it exhibits charge and discharge characteristics, and for this purpose, a high temperature heat treatment should be generally performed.

Korean Patent No. 994,627 discloses a thin film lithium battery using a polyimide supporting substrate, but since it uses a polyimide supporting substrate having low heat resistance such as Kapton, heat treatment is possible only at a low temperature of about 300 ° C. There was a limit to improvement.

On the other hand, a relatively thick substrate in a thin film battery has a high weight and volume ratio, which affects the active material. That is, the ratio of the active material to the total weight and volume of the battery is lowered, thereby limiting the use of the battery.

Therefore, there is a need for a method capable of providing a thin film battery having a thin thickness in order to exhibit excellent capacity and output characteristics of the unit cell, and to exhibit flexible characteristics by enabling heat treatment of a cathode material at a high temperature.

Accordingly, the present inventors have studied and tried to manufacture a thin film battery that can be flexibly exhibited by having a thin thickness while exhibiting excellent unit cell capacity and output characteristics due to heat treatment of a cathode material at a high temperature. When the thin film battery is configured to include the mid film layer, it is possible to heat-treat the cathode material at a high temperature, thereby greatly improving the capacity and output characteristics of the unit cell, and the thickness of the thin film battery can be kept thin, thereby showing flexible characteristics. The discovery has completed the present invention.

Accordingly, it is an object of the present invention to provide a flexible thin film battery having excellent charge and discharge characteristics including a film layer exhibiting a high pyrolysis temperature and a method of manufacturing the same.

The thin film battery of the present invention for achieving the above object is a flexible film layer having a thermal decomposition temperature of 350 ℃ or more; A positive electrode current collector pattern and a negative electrode current collector pattern formed to be electrically separated from each other on the flexible film layer; An anode pattern formed on the anode current collector pattern; An electrolyte pattern formed on the anode pattern; And a cathode pattern formed on the electrolyte pattern.

In another aspect, the present invention, forming a flexible film layer having a thermal decomposition temperature of 350 ℃ or more on the base substrate; Forming an anode current collector pattern and an anode pattern on the flexible film layer and performing rapid thermal annealing (RTA); Forming an electrolyte pattern on the anode pattern; Forming a cathode current collector pattern on the flexible film layer to be electrically separated from the cathode current collector pattern; And forming a negative electrode pattern on the electrolyte pattern.

According to the present invention, a functional film including a polyimide film layer having excellent heat resistance may be applied to a thin film battery to perform heat treatment of a cathode material at a high temperature, thereby realizing a thin film battery having high capacity and high output characteristics. In addition, by separating the substrate commonly used in thin film cells to form a unit cell of a thin thickness to improve the energy density and output density due to the formation of multiple cells of the parallel stacked structure, and the advantage that the thin film transfer to the barrier film layer have.

1 to 4 are cross-sectional views of a thin film battery according to an embodiment of the present invention.

Figure 5 shows the TGA pyrolysis curve of the polyimide used in the examples.

6 compares the charge / discharge graphs (two cycles) of the thin film batteries of Examples and Comparative Examples.

[Description of the code]

100: thin film battery 110: flexible film layer

120: buffer layer 130: anode current collector pattern

131: anode pattern 140: cathode current collector pattern

141: cathode pattern 150: electrolyte pattern

160: base substrate 170: protective film layer

180: barrier film layer 190: protective pattern

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims.

Like reference numerals refer to like elements throughout.

Hereinafter, a thin film battery and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. When a portion of a layer, film, region, plate, or the like is said to be "on" or "on" another portion, this includes not only when the other portion is "directly above" but also when there is another portion in the middle. Also, when referred to as "below" or "below" another part, this also includes the case where there is another part "inside" as well as another part in the middle. On the contrary, when a part is "directly above" or "directly below" another part, there is no other part in the middle.

1 to 4 illustrate cross-sectional views of a thin film battery in which a plurality of layers are stacked according to an embodiment of the present invention.

박막전지의 구조Structure of Thin Film Battery

Referring to FIG. 1, the thin film battery 100 includes a flexible film layer 110, a buffer layer 120, a positive electrode current collector pattern 130, a positive electrode pattern 131, a negative electrode current collector pattern 140, and a negative electrode. The pattern 141 and the electrolyte pattern 150 are included.

At this time, the flexible film layer 110 is made of a flexible material that the thermal decomposition temperature is 350 ℃ or more, preferably a polyimide film layer may be used. The pyrolysis temperature of the flexible film layer is preferably at least 500 ℃, more preferably at least 600 ℃, the upper limit is not particularly limited, but may appear at 700 ℃ or less. The pyrolysis temperature means the inflection point temperature of the curve in the thermogravimetric analysis (TGA) diagram. As described above, the polyimide having excellent heat resistance may be used to heat the cathode material at a high temperature.

The polyimide is PMDA (pyromellitic dianhydride), DSDA (diphenylsulfone tetracarboxylic dianhydride), BTDA (benzophenone tetracarboxylic dianhydride), Benzophenonetetracarboxylic dianhydride (BTDA) , 6FDA (hexafluoroisopropylidene bisphthalic dianhydride), BPDA (biphenyl tetracarboxylic dianhydride) and ODPA (Oxydiphthalic anhydride) At least one dianhydride selected from the group consisting of, ODA (oxy dianiline, Oxydianiline), MDA (methylene dianiline, Methylenedianiline), MPDA (meth-phenylene diamine, m-phenylene diamine), DAP ( 2,6-diaminopyridine, 2,6-Diaminopyridine), DABP (3,3'-diamino benzophenone, 3,3'-Diaminobenzophenone) , PPDA (para-phenylene diamine, p-phenylene diamine), DAPI (diamino phenyl indane), APB (bis (aminophenoxy) benzene, Bis (aminophenoxy) benzene) and GAPDS (bis (gamma- Aminopropyl) tetramethyl disiloxane, Bis (γ-aminopropyl) tetramethyl disiloxane may be prepared by thermosetting a polyamic acid (Polyamic acid), a condensate of at least one diamine selected from the group consisting of, preferably The polyamic acid may be prepared by thermosetting at 350 to 550 ° C.

More preferably, a condensate of BPDA (biphenyl tetracarboxylic dianhydride) and PPDA (para-phenylene diamine) or BPDA (biphenyl tetracarboxy dianhydride) as a polyamic acid which is a precursor of the polyimide. The use of condensates of PPDA (para-phenylene diamine) and ODA (oxy dianiline) is more advantageous in terms of the heat resistance of the polyimide produced. In particular, in this case, it is possible to exhibit a thermal decomposition temperature of 600 ° C. or higher, and thus, in the process of rapid thermal treatment after forming the anode current collector pattern and the anode pattern described below, for example, the rapid thermal treatment temperature may be increased to 600 ° C. More advantageous in terms of complete crystallization.

A buffer layer 120, which functions as passivation and insulation, is formed on the flexible film layer 110. The buffer layer may be formed of a material that does not cause a chemical reaction with lithium, and is preferably a single layer using lithium oxide, lithium fluoride, silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, or two or more of the above materials. It can be formed in a multi-layer structure using, more preferably it is formed in a single layer or a multi-layer structure containing magnesium oxide or aluminum oxide. On the other hand, the thickness of the buffer layer is preferably formed to 50 ~ 500 nm.

The flexible film layer 110 and the buffer layer 120 preferably has a thin thickness of several tens of micrometers or less so that the entire thin film battery exhibits flexible characteristics, and the sum of the thicknesses of the flexible film layer and the buffer layer is preferably in the range of 1 to 25 μm. It is preferable to exist as. In addition, the flexible film layer and the buffer layer may be formed in a multi-layered structure alternately stacked in a plurality of layers, in this case, the buffer layer may be located on the top.

The positive current collector pattern 130 is electrically connected to the positive electrode 131. The positive electrode current collector pattern 130 is not particularly limited as long as it has high conductivity without causing chemical change in the thin film battery 100. For example, the anode current collector pattern 130 may be used as a conductive layer such as noble metals such as platinum (Pt), gold (Au), and the like, heat resistant steel such as nickel-containing alloys, conductive oxide films such as ITO, and the like.

As the nickel-containing alloy, commercially available hastelloy, inconel, constantan and the like can be used. Before forming the cathode current collector pattern 130, titanium or chromium may be formed to increase the adhesion of the cathode active material. In addition, a metal oxide such as titanium oxide or titanium nitride, which is a diffusion barrier layer, may be selectively deposited between the conductive layer and the adhesive layer, and the thickness of the anode current collector pattern may include 50 to 500 including all of the adhesive layer, the diffusion barrier layer, and the conductive layer. It is preferable to form in nm.

The negative electrode current collector pattern 140 is electrically connected to the negative electrode 141 and is electrically separated from the positive electrode current collector pattern 130. The cathode current collector pattern 140 is not particularly limited as long as it has high conductivity without causing chemical change in the thin film battery 100. For example, precious metals such as platinum (Pt), gold (Au), nickel (Ni), such as Hastelloy, Inconnel, Constantan, etc., as the cathode current collector pattern 140. Alloys, copper (Cu), brass (Cu-Zn alloys), molybdenum (Mo) metals, and the like can be used. Fine irregularities may be formed on the surface of the negative electrode current collector pattern 140 to increase adhesion of the negative electrode active material, and the thickness of the negative electrode current collector pattern may be 50 to 500 nm.

The positive electrode pattern 131 may use a positive electrode known in the art as an active material thin film, and the type thereof is not particularly limited. The positive electrode active material is, for example, LiCoO as a compound capable of reversibly intercalating / deintercalating lithium in a lithium battery.₂, LiMn₂O₄, LiNiO₂, LiFePO₄, LiNiVO₄, LiCoMnO₄, LiCo_1/3Ni_1/3Mn_1/3O₂, V₂O₅, MnO₂, MoO₃ Etc. may be used alone or in combination of two or more thereof, and the thickness of the anode pattern may be 0.5 to 15.0 μm.

In addition, the negative electrode pattern 141 may use a negative electrode known in the art as an active material thin film, and the type thereof is not particularly limited. The negative electrode active material is, for example, a material capable of reversibly oxidizing / reducing lithium in a lithium battery, using Li, Sn ₃ N ₄ , Si, graphite, Li-Mg, Li-Al alloy, etc. alone or in combination of two or more thereof. It may be used, the thickness of the negative electrode pattern may be formed to 0.5 ~ 10.0 ㎛.

The electrolyte pattern 150 is positioned between the anode 131 and the cathode 141, and an inorganic solid electrolyte or an organic solid electrolyte may be used. Examples of the inorganic solid electrolyte include Li ₂ OB ₂ O ₃ , Li ₂ OV ₂ O ₅ -SiO ₂ , Li ₂ SO ₄ -Li ₂ OB ₂ O ₃ , Li ₃ PO ₄ , Li ₂ OLi ₂ WO ₄ -B ₂ O ₃ , LiPON (Li _2.9 PO _3.3 N _0.46 ), LiBON (Li _3.099 BO _2.532 N _0.516 ) and the like, these may be used alone or in combination of two or more. Examples of the organic solid electrolyte include a lithium salt mixed with a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, a polyedgetion lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, or the like. These can be mentioned, These can be used individually or in combination of 2 or more types. In addition, the thickness of the electrolyte pattern may be formed to 0.7 ~ 3.0 ㎛.

Referring to FIG. 2, the base substrate 160 may be further included below the flexible film layer 110 of the thin film battery 100, and the base substrate may be separated from the flexible film layer. The substrate can be recycled again.

The base substrate 160 may include metal sheets such as nickel (Ni) and nickel-based alloys, titanium (Ti), chromium (Cr), stainless steel, tungsten (W), molybdenum (Mo), and the like; Ceramic or glass sheet such as aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), silicon oxide (SiO ₂ ), quartz, glass, mica, sapphire, etc. You can use one. The mica includes both natural mica and artificially synthesized synthetic mica. In addition, as the base substrate, a silicon wafer or a substrate on which an oxide is treated on the silicon wafer may be used.

Referring to FIG. 3, the thin film battery 100 may include a passivation layer 170 and a barrier film layer 180 on a cathode pattern.

The passivation layer 170 is formed to surround the anode pattern 131, the cathode pattern 141, and the electrolyte pattern 150 in order to prevent the thin film battery 100 from being oxidized in the air. The passivation layer 170 is to prevent oxidation of main components of the thin film battery in the air, and may be formed of an organic passivation layer, an inorganic passivation layer, or a combination of an organic passivation layer and an inorganic passivation layer. In addition, the thickness of the organic protective film may be formed of 1.0 ~ 5.0 ㎛, the thickness of the inorganic protective film may be formed of 30 ~ 200 nm.

Although it does not specifically limit as a material of the said organic protective film, For example, diazo type, azide type, acryl type, polyamide type, polyester type, epoxide type, poly which start superposition | polymerization by photopolymerization. Ether type, urethane type resin, etc. can be used individually or in combination of 2 or more types. As the material of the organic protective film, for example, polystyrenes, acrylics, ureas, isocyanates, xylene resins, etc., in which radicals are generated by heat to initiate polymerization, may be used alone or in combination of two or more thereof. have. It is possible to use a combination of a resin in which polymerization is initiated by photopolymerization and a resin in which radicals are generated by heat and polymerization is initiated.

The material of the inorganic protective film is not particularly limited, but for example, silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, zirconium oxide, magnesium oxide, titanium oxide, A stone oxide, cerium oxide, silicon oxynitride (SiON), etc. can be used individually or in combination of 2 or more types.

When the passivation layer 170 is formed of a combination of an organic passivation layer and an inorganic passivation layer, the organic passivation layer and the inorganic passivation layer are alternately formed, for example, such as an organic passivation layer, an inorganic passivation layer, an organic passivation layer, or an inorganic passivation layer. It may be formed, or any one protective film such as an organic protective film / organic protective film / inorganic protective film may be laminated in two or more layers. Here, the protective film forming each layer may be the same or different materials.

In addition, the barrier film layer 180 is used as a film showing a flexible property, serves to primarily protect the thin film battery by blocking moisture and oxygen. In particular, when the base substrate is removed, it may serve as a support for the thin film battery, and thin film transfer to the barrier film layer is possible. As the barrier film, a composite film material (for example, an Ultra Barrier Film of Materion, 3M, or Dupont) having an organic / inorganic multilayer formed on a PET, PEN, or Fluoropolymer film substrate may be used. Film materials up to 10 ⁻⁴ g / m ² day may be used. In addition, the barrier film layer is preferably formed in a thickness of 20 ~ 300 ㎛ range.

In the thin film battery of the present invention as described above, the total thickness of the actual battery except for the barrier film is controlled to be within several tens of micrometers, thereby increasing the capacity of the thin film battery unit cell by stacking the unit cells. Because of this, the thin film battery can be used as a power source for smart cards, various tag products and MEMS, ultra-thin electronic devices, which are highly dependent on thickness and volume.

On the other hand, as shown in Figure 4, the thin film battery 100 of the present invention may include a positive current collector pattern 130 directly on the flexible film layer 110, without including a buffer layer. However, in this case, in order to prevent the cathode current collector pattern 140 and the cathode pattern 141 from directly contacting the flexible film layer 110 and being oxidized, a protection pattern 190 is additionally formed, and the protection pattern ( The cathode current collector pattern 140 and the cathode pattern 141 may be formed on the 190.

The protective pattern 190 may include silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, zirconium oxide, magnesium oxide, titanium oxide, stone oxide, cerium oxide, and silicon oxynitride. (SiON) and the like may be used, but preferably silicon oxide and aluminum oxide may be used, and most preferably Al ₂ O ₃ may be used.

박막전지의 제조방법Manufacturing Method of Thin Film Battery

The thin film battery of the present invention comprises the steps of forming a flexible film layer 110 having a thermal decomposition temperature of 350 ℃ or more on the base substrate 160; Forming a buffer layer (120) on the flexible film layer (110); Forming an anode current collector pattern 130 and an anode pattern 131 on the buffer layer 120 and performing rapid thermal annealing (RTA); Forming an electrolyte pattern 150 on the anode pattern; Forming a cathode current collector pattern 140 on the buffer layer 120 to be electrically separated from the anode current collector pattern 130; And forming a cathode pattern 141 on the electrolyte pattern.

Meanwhile, in forming the flexible film layer on the base substrate, an adhesive may be applied to prevent the flexible film layer from being peeled off in a subsequent step. More specifically, the adhesive may be applied by spin coating an aminosilane-based coupling agent. For example, 3-aminopropyl-triethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, or the like may be applied. Can be used.

However, the stacking order of each component in the manufacturing process of the thin film battery is not particularly limited. For example, the anode current collector pattern 130 / anode 131 / electrolyte pattern 150 / cathode 141 / cathode current collector pattern 140; Anode current collector pattern 130 / anode 131 / electrolyte pattern 150 / cathode current collector pattern 140 / cathode 141; An anode 131 / anode current collector pattern 130 / electrolyte pattern 150 / cathode 141 / cathode current collector pattern 140; A cathode current collector pattern 140 / a cathode 141 / electrolyte pattern 150 / a cathode 131 / a cathode current collector pattern 130; A cathode current collector pattern 140 / a cathode 141 / electrolyte pattern 150 / a cathode current collector pattern 130 / a cathode 131; A cathode 141 / cathode current collector pattern 140 / electrolyte pattern 150 / anode 131 / anode current collector pattern 130; Alternatively, the cathode 141 may be stacked in the order of the cathode current collector pattern 140, the electrolyte layer 150, the anode current collector pattern 130, and the anode 131.

In addition, the thin film battery of the present invention comprises the steps of forming a flexible film layer 110 having a thermal decomposition temperature of 350 ℃ or more on the base substrate 160; Forming an anode current collector pattern 130 and an anode pattern 131 on the flexible film layer 110 and performing rapid thermal annealing (RTA); Forming an electrolyte pattern 150 on the anode pattern; Forming a protective pattern 190 on the flexible film layer 110; Forming a cathode current collector pattern 140 on the protection pattern 190 to be electrically separated from the cathode current collector pattern 130; And forming a cathode pattern 141 on the electrolyte pattern.

The thin film battery may be manufactured by a conventionally known dry process, wet process, or a combination of dry and wet methods. Examples of the dry process include thermal evaporation, e-beam evaporation, sputtering, chemical vapor deposition (CVD), and the like, and spin coating and sol-gel methods. , Dip coating, casting, printing, spraying, and the like.

In particular, when a positive current collector pattern and a positive electrode pattern are formed on the flexible film layer 110 and rapid thermal annealing (RTA) is performed, 400 to 700 ° C., for complete crystallization of the positive electrode material, is preferable. It is good to proceed the heat treatment at a high temperature of 500 ~ 600 ℃.

In addition, the manufacturing method may further include forming a passivation layer 170 surrounding the anode pattern, the electrolyte pattern, and the cathode pattern, and forming the barrier film layer 180 on the passivation layer.

The passivation layer 170 is encapsulated to surround the anode pattern 131, the cathode pattern 141, and the electrolyte pattern 150 to protect the pattern, and a barrier film on the passivation layer 170. Layer 180 may be formed.

After the barrier film layer 180 is formed, the base substrate 160 may be separated from the flexible film layer 110. The base substrate 160 may be separated by a lift-off or a wet lift-off by a laser. Through this, the total thickness of the entire thin film battery may be thinned to maintain flexible characteristics. In this case, the barrier film layer 180 may serve as a support for the thin film battery instead of the separated base substrate 160. In addition, the separated base substrate can be recycled.

Hereinafter, the thin film battery of the present invention will be described in detail with reference to preferred embodiments of the present invention.

The following examples are only for illustrating the present invention, but the scope of the present invention is not limited to the following examples.

실시예Example

[Measurement of Heat Resistance of Flexible Film Layer]

As shown in Formula 1 below, polyamic acid (PAA) prepared by reacting BPDA (biphenyl tetracarboxylic dianhydride) and PPDA (para-phenylene diamine) was used as a precursor of polyimide. Ube's U-varnish series was used.

[Revision 18.02.2013 under Rule 26]
Formula 1

At this time, the polyamic acid (PAA) (Ube's U-varnish series) was coated on a glass substrate to measure heat resistance, and then cured at 550 ° C. to form a polyimide film, which was then peeled off to a 2.5 mg sample. TGA (TGA 2050 / TA instruments Inc) analysis was performed, and the results are shown in FIG. 5.

As shown in FIG. 5, the polyimide was pyrolyzed at about 600 ° C., and the inflection point of the TGA curve was measured at 653.76 ° C. FIG.

[Manufacture of thin film battery]

Using a glass having a thickness of 0.7mm as the base substrate 160, and spin-coated a 10% by weight ethanol dilution of 3-aminopropyl-triethoxysilane on the base substrate 160, and then Polyamic acid (PAA) (U-varnish series, manufactured by Ube) was spin coated and cured at 550 ° C. to form a 15 μm polyimide film layer 110.

Next, magnesium oxide (MgO) was deposited at 300 nm on the polyimide film layer 110 to form a buffer layer 120.

In addition, platinum sputtered with a thickness of 10 nm on the upper portion of the buffer layer 120 using the anode current collector pattern 130, and titanium and inconel were added to increase adhesion with the buffer layer 120. 150 nm and 120 nm in thickness were deposited between the platinum (Pt) and the buffer layer 120, respectively. Subsequently, a cathode pattern 131 was formed by applying magnetron sputtering by applying a DC / RF hybridization power source having a thickness of 2 μm in an argon or argon / oxygen mixed gas atmosphere of 10 to 20 mTorr using a LiCoO ₂ target as a cathode active material. The effective area of the LiCoO ₂ active material thin film electrode was formed to be 2.4 cm ² through a mask pattern. In order to crystallize the anode, a rapid heat treatment was performed at 600 ° C. under an atmosphere of Ar / O ₂ mixed gas. Subsequently, the solid electrolyte layer thin film 150 was sputtered with RF magnetron in a pure nitrogen atmosphere using a Li ₃ PO ₄ target to deposit a 1.5 μm thick LiPON electrolyte layer in which oxygen in Li ₃ PO ₄ was replaced with some nitrogen. . Subsequently, a 350 nm thick Cu—Zn alloy was deposited as a cathode current collector pattern 140. Subsequently, a metal lithium thin film was deposited to have a thickness of 2 μm by vacuum thermal evaporation to form a cathode pattern 141.

Next, the protective film layer 170 was formed by alternately depositing an inorganic protective film (Al ₂ O ₃ ) having a thickness of 50 nm and an organic protective film (Polyurea) having a thickness of 1 μm. 3M Ultra Barrier Film was formed on the passivation layer 170 as a barrier film layer 180 by lamination.

Finally, the base substrate 160 is separated from the polyimide film layer 110 by lift-off using an excimer laser, thereby manufacturing a final thin film battery in which the base substrate is separated.

비교예Comparative example

A 75 μm thick Kapton (Dupont) film was used as the base substrate, and platinum (Pt) was DC sputtered to a thickness of 10 nm using a positive current collector pattern on the base substrate to increase adhesion to the base substrate. Titanium (Ti) Inconel was deposited between platinum (Pt) and the base substrate to a thickness of 150 nm and 120 nm, respectively. Subsequently, a cathode pattern was formed by applying magnetron sputtering by applying a DC / RF hybridization power source having a thickness of 2 μm in an argon or argon / oxygen mixed gas atmosphere of 10 to 20 mTorr using a LiCoO ₂ target as a cathode active material. The effective area of the LiCoO ₂ active material thin film electrode was formed to be 2.4 cm ² through a mask pattern. In order to crystallize the anode, a rapid heat treatment was performed at 350 ° C. under an atmosphere of Ar / O ₂ mixed gas. Subsequently, the solid electrolyte layer thin film was RF magnetron sputtered in a pure nitrogen atmosphere using a Li ₃ PO ₄ target to deposit a 1.5 μm thick LiPON electrolyte layer in which oxygen in Li ₃ PO ₄ was replaced with some nitrogen. Next, as a cathode current collector pattern, a 350 nm thick Cu—Zn alloy was deposited by thin film. Subsequently, a metal lithium thin film was deposited to a thickness of 2 μm by vacuum thermal evaporation to form a cathode pattern.

Next, an inorganic protective film (Al) having a thickness of 50 nm as a protective film layer.₂O₃) And thickness 1 μm The final thin film battery was manufactured by alternately depositing an organic protective film (Polyurea).

실험예 : 방전용량의 측정 Experimental Example: Measurement of Discharge Capacity

Discharge capacities were measured according to charge and discharge cycles of the thin film batteries of Examples and Comparative Examples, and the results are shown in Table 1 and FIG. 6.

Table 1

Number of cycles	Discharge Capacity (μAh)
Number of cycles	Example	Comparative example
2	237	210
4	234	175
6	231	138
8	228	110
10	227	87

As shown in Table 1, the thin film battery of Example showed more than 13% discharge capacity in the initial charge / discharge cycle compared to the thin film battery of the comparative example which performed the rapid heat treatment at 350 ° C., and the discharge capacity decreased with cycles. (capacity fade) also did not appear much.

In addition, as shown in the charge / discharge graph of FIG. 6, the comparative example shows the LiCoO ₂ electrode characteristics of the low-temperature phase (LT-phase) and the discharge characteristics of the LiCoO ₂ electrode of the typical high-temperature phase (HT-phase). Compared with not showing a constant flat voltage, the average discharge voltage was also low.

Although the above description has been made with reference to the embodiments of the present invention, this is only an example, and those skilled in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true technical protection scope of the present invention should be judged by the claims described below.

Claims

Pyrolysis temperature is 350 ℃ or more flexible film layer;

A positive electrode current collector pattern and a negative electrode current collector pattern formed to be electrically separated from each other on the flexible film layer;

An anode pattern formed on the anode current collector pattern;

An electrolyte pattern formed on the anode pattern; And

Cathode pattern formed on the electrolyte pattern

Thin film battery comprising a.
The method of claim 1,

The flexible film layer is a thin film battery, characterized in that the polyimide film layer.
The method according to claim 1 or 2,

The flexible film layer is a thin film battery, characterized in that having a thermal decomposition temperature of 500 ℃ or more.
The method according to claim 1 or 2,

The flexible film layer is PMDA (pyromellitic dianhydride), DSDA (diphenylsulfone tetracarboxylic dianhydride), diphenylsulfone tetracarboxylic dianhydride), BTDA (benzophenone tetracarboxylic dianhydride, Benzophenonetetracarboxylic dianhydride) ), 6FDA (hexafluoroisopropylidene-bisphthalic dianhydride, Hexafluoroisopropylidene bisphthalic dianhydride), BPDA (biphenyl tetracarboxylic dianhydride) and ODPA (Oxydiphthalic anhydride) At least one dianhydride selected from the group consisting of), ODA (oxy dianiline, Oxydianiline), MDA (methylene dianiline, Methylenedianiline), MPDA (meth-phenylene diamine, m-phenylene diamine), DAP (2,6-diaminopyridine, 2,6-Diaminopyridine), DABP (3,3'-diamino benzophenone, 3,3'-Diaminobenzop henone), PPDA (para-phenylene diamine, p-phenylene diamine), DAPI (diamino phenyl indane, Diamino phenyl indane), APB (bis (aminophenoxy) benzene, Bis (aminophenoxy) benzene) and GAPDS (bis Thin film battery, characterized in that the polyimide film layer made from a condensate of at least one diamine selected from the group consisting of gamma-aminopropyl) tetramethyl disiloxane, Bis (γ-aminopropyl) tetramethyl disiloxane).
The method of claim 1,

A buffer layer is formed on the flexible film layer,

The thin film battery, characterized in that the positive electrode current collector pattern and the negative electrode current collector pattern formed on the buffer layer to be electrically separated from each other.
The method of claim 5,

The buffer layer is a thin film battery comprising one or two or more compounds selected from lithium oxide, lithium fluoride, silicon oxide, silicon nitride, magnesium oxide and aluminum oxide.
The method of claim 1,

A protective pattern is formed on the flexible film layer,

The thin film battery, characterized in that the negative current collector pattern is formed on the protective pattern.
The method according to claim 1 or 2,

The thin film battery, characterized in that the flexible film layer further comprises a base substrate at the bottom.
The method according to claim 1 or 2,

The thin film battery further comprises a protective film layer and a barrier film layer on the cathode pattern.
The method of claim 9,

The barrier film layer is a thin film battery, characterized in that the water transmittance is 10 -4 g / m 2 day or less.
The method of claim 5,

Thin film battery, characterized in that the sum of the thickness of the flexible film layer and the buffer layer is in the range of 1 ~ 25 ㎛.
Forming a flexible film layer having a pyrolysis temperature of 350 ° C. or higher on the base substrate;

Forming an anode current collector pattern and an anode pattern on the flexible film layer and performing rapid heat treatment;

Forming an electrolyte pattern on the anode pattern;

Forming a cathode current collector pattern on the flexible film layer to be electrically separated from the cathode current collector pattern; And

And forming a cathode pattern on the electrolyte pattern.
The method of claim 12,

Forming a buffer layer on the flexible film layer, and forming a cathode current collector pattern and an anode pattern on the buffer layer.
The method of claim 12,

Forming a protection pattern on the flexible film layer and forming a cathode current collector pattern on the protection pattern so as to be electrically separated from the cathode current collector pattern.
The method of claim 12,

The flexible film layer is PMDA (pyromellitic dianhydride), DSDA (diphenylsulfone tetracarboxylic dianhydride), diphenylsulfone tetracarboxylic dianhydride), BTDA (benzophenone tetracarboxylic dianhydride, Benzophenonetetracarboxylic dianhydride) ), 6FDA (hexafluoroisopropylidene-bisphthalic dianhydride, Hexafluoroisopropylidene bisphthalic dianhydride), BPDA (biphenyl tetracarboxylic dianhydride) and ODPA (Oxydiphthalic anhydride) At least one dianhydride selected from the group consisting of), ODA (oxy dianiline, Oxydianiline), MDA (methylene dianiline, Methylenedianiline), MPDA (meth-phenylene diamine, m-phenylene diamine), DAP (2,6-diaminopyridine, 2,6-Diaminopyridine), DABP (3,3'-diamino benzophenone, 3,3'-Diaminobenzop henone), PPDA (para-phenylene diamine, p-phenylene diamine), DAPI (diamino phenyl indane, Diamino phenyl indane), APB (bis (aminophenoxy) benzene, Bis (aminophenoxy) benzene) and GAPDS (bis A method of manufacturing a thin film battery, characterized in that the condensate of at least one diamine selected from the group consisting of gamma-aminopropyl) tetramethyl disiloxane and Bis (γ-aminopropyl) tetramethyl disiloxane) is formed by thermosetting.
The method of claim 12,

The rapid heat treatment is a manufacturing method of a thin film battery, characterized in that made at 400 ~ 700 ℃.
The method of claim 12,

Forming a protective layer surrounding the anode pattern, the electrolyte pattern, and the cathode pattern; And

The method of claim 1, further comprising forming a barrier film layer on the passivation layer.
The method of claim 17,

After the formation of the barrier film layer, the method of manufacturing a thin film battery, further comprising the step of separating the base substrate from the flexible film layer.