Cathode for secondary batteries, secondary batteries, and electronic devices

Abstract

A cathode for a secondary battery with excellent cycle characteristics is provided. As a cathode for a secondary battery, the cathode comprises a positive current collector layer, a lower film, a positive active material layer, and a cap layer, wherein the lower film is titanium nitride, the positive active material layer is lithium cobaltate, and the cap layer is titanium oxide. By applying titanium nitride to the lower film, sufficient conductivity can be secured while suppressing oxidation of the positive current collector layer or diffusion of metal atoms. Additionally, by applying titanium oxide to the cap layer, side reactions between the positive active material layer and the electrolyte or collapse of the crystal structure of the positive active material can be suppressed, thereby improving cycle characteristics.

Description

Technology Field

[0001] One embodiment of the present invention relates to an article, a method, or a method of manufacturing. Alternatively, the present invention relates to a process, a machine, a manufacture, or a composition of matter. One embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a capacitor device, a lighting device, an electronic device, or a method of manufacturing the same.

[0002] Furthermore, in this specification, the term "electronic device" refers to any device having a capacitor, and electro-optical devices having a capacitor, information terminal devices having a capacitor, etc., are all electronic devices. Background Technology

[0003] In recent years, the development of various energy storage devices, such as lithium-ion rechargeable batteries, lithium-ion capacitors, air batteries, and all-solid-state batteries, has been actively underway. In particular, the demand for high-output, high-capacity lithium-ion rechargeable batteries has expanded rapidly alongside the development of the semiconductor industry, making them indispensable to the modern information society as a source of rechargeable energy.

[0004] In addition, with the expansion of demand, there is a demand for lithium-ion secondary batteries with higher performance. Therefore, improvements in cathode active materials are being made with the goal of increasing the capacity and improving the cycle characteristics of lithium-ion secondary batteries (e.g., Patent Document 1).

[0005] In addition, the development of all-solid-state batteries, which have higher safety among lithium-ion secondary batteries, is underway. Thin-film secondary batteries in which the positive electrode, electrolyte, and negative electrode are formed by PVD (physical vapor deposition), CVD (chemical vapor deposition), etc., are also a type of all-solid-state battery (e.g., Patent Document 2). Prior art literature

[0006] Japanese Patent Publication No. JP2018-206747, U.S. Patent Application Publication No. US2010 / 0190051

[0007] EELS analysis of cation valence states and oxygen vacuums in magnetic oxides, ZL Wang, JS Yin, YD Jiang, Micron 31(2000)571-580 The problem to be solved

[0008] There is still room for improvement in thin-film secondary batteries in various aspects, such as charge / discharge characteristics, cycle characteristics, reliability, safety, and cost. For example, regarding cycle characteristics, repeated charging and discharging can cause the crystal structure of the cathode active material to collapse, potentially leading to a decrease in charge / discharge capacity. Additionally, side reactions occurring at the interfaces between the cathode active material and the electrolyte, or between the cathode active material and the cathode current collector, can also lead to a reduction in charge / discharge capacity.

[0009] Therefore, one embodiment of the present invention has as its objective to provide a positive electrode for a secondary battery in which side reactions are unlikely to occur at the interface between the positive electrode active material and the electrolyte, or at the interface between the positive electrode active material and the positive electrode current collector, even when charging and discharging are repeated. Additionally, it has as its objective to provide a positive electrode for a secondary battery in which the crystal structure is unlikely to collapse even when charging and discharging are repeated. Alternatively, it has as its objective to provide a positive electrode for a secondary battery with excellent charge-discharge cycle characteristics. Alternatively, it has as its objective to provide a positive electrode for a secondary battery with a large charge-discharge capacity. Alternatively, it has as its objective to provide a positive electrode for a secondary battery in which the decrease in capacity during charge-discharge cycles is suppressed. Alternatively, it has as its objective to provide a secondary battery with excellent charge-discharge cycle characteristics. Alternatively, it has as its objective to provide a secondary battery with a large charge-discharge capacity. Alternatively, it has as its objective to provide a secondary battery with high safety or reliability.

[0010] Alternatively, one embodiment of the present invention has as its objective to provide a novel material, active material particles, a capacitor, or a method for manufacturing the same.

[0011] Furthermore, the description of these problems does not prevent the existence of other problems. Also, one embodiment of the present invention is not required to solve all of these problems. Additionally, problems other than these can be derived from the description of the specification, drawings, and claims. means of solving the problem

[0012] In one embodiment of the present invention, a cap layer is provided on the positive active material layer to improve cycle characteristics by making it difficult for the crystal structure to collapse or by suppressing side reactions.

[0013] One embodiment of the present invention is a positive electrode for a secondary battery having a lower film, a positive electrode active material layer, and a cap layer, wherein at least one of the lower film and the cap layer is titanium nitride, the positive electrode active material layer is lithium cobaltate, and the cap layer is a titanium compound containing oxygen.

[0014] Or, in the above, it is preferable that the crystal structure of the lower membrane and the crystal structure of the positive active material layer both have a surface in which only anions are arranged.

[0015] In addition, in the above, it is preferable that both the lower membrane and the positive active material layer have a crystal structure in which cations and anions are arranged alternately.

[0016] In addition, one embodiment of the present invention is a secondary battery having a positive electrode for the secondary battery, a solid electrolyte, and a negative electrode.

[0017] In addition, one embodiment of the present invention is an electronic device having the secondary battery.

[0018] In addition, one embodiment of the present invention is an electronic device having a lithium-ion secondary battery having the secondary battery, a positive electrode, a negative electrode, an electrolyte, and a separator. Effects of the invention

[0019] According to one embodiment of the present invention, a cathode for a secondary battery can be provided in which side reactions are unlikely to occur at the interface between the cathode active material and the electrolyte, or at the interface between the cathode active material and the cathode current collector, even when charging and discharging are repeated. A cathode for a secondary battery can be provided in which the crystal structure is unlikely to collapse even when charging and discharging is repeated. Furthermore, a cathode for a secondary battery with excellent charge-discharge cycle characteristics can be provided. Furthermore, a cathode for a secondary battery with a large charge-discharge capacity can be provided. Furthermore, a cathode for a secondary battery in which the decrease in capacity during charge-discharge cycles is suppressed can be provided. Furthermore, a secondary battery with excellent charge-discharge cycle characteristics can be provided. Furthermore, a secondary battery with a large charge-discharge capacity can be provided. Furthermore, a secondary battery with high safety or reliability can be provided.

[0020] In addition, according to one embodiment of the present invention, a novel material, an active material particle, a capacitor, or a method for manufacturing the same may be provided.

[0021] Furthermore, the description of these effects does not interfere with the existence of other effects. Also, one embodiment of the present invention is not necessarily required to possess all of these effects. Additionally, effects other than these will naturally become apparent from the description in the specification, drawings, claims, etc., and effects other than these can be derived from the description in the specification, drawings, claims, etc. Brief explanation of the drawing

[0022] Figures 1 (A) to (C) are perspective views of an anode of one embodiment of the present invention. Figures 2 (A) and (B) are diagrams illustrating the crystal structure of an anode of one form of the present invention. Figures 3 (A) to (C) are drawings illustrating a stacked structure of a secondary battery of one embodiment of the present invention. FIG. 4 (A) is a top view showing one embodiment of the present invention, and FIG. 4 (B) to (D) are cross-sectional views showing one embodiment of the present invention. FIGS. 5 (A) and (C) are top views showing one embodiment of the present invention, and FIGS. 5 (B) and (D) are cross-sectional views showing one embodiment of the present invention. FIG. 6 (A) is a top view showing one embodiment of the present invention, and FIG. 6 (B) is a cross-sectional view showing one embodiment of the present invention. FIG. 7 (A) is a top view showing one embodiment of the present invention, and FIG. 7 (B) is a cross-sectional view showing one embodiment of the present invention. FIG. 8 is a diagram illustrating the manufacturing flow of a secondary battery of one form of the present invention. Figures 9 (A) and (B) are top views illustrating one embodiment of the present invention. FIG. 10 is a cross-sectional view showing one embodiment of the present invention. FIG. 11 is a diagram illustrating the manufacturing flow of a secondary battery of one form of the present invention. Figure 12 is a schematic top view of a secondary battery manufacturing device. Figure 13 is a cross-sectional view of a part of a secondary battery manufacturing device. FIG. 14 (A) is a perspective view showing an example of a battery cell. FIG. 14 (B) is a perspective view of a circuit. FIG. 14 (C) is a perspective view of the case where the battery cell and the circuit are superimposed. FIG. 15 (A) is a perspective view showing an example of a battery cell. FIG. 15 (B) is a perspective view of a circuit. FIG. 15 (C) and (D) are perspective views of the case where the battery cell and the circuit are superimposed. Figure 16 (A) is a perspective view of a battery cell. Figure 16 (B) is a drawing showing an example of an electronic device. Figures 17 (A) to (C) are drawings showing examples of electronic devices. Figures 18 (A) to (C) are drawings showing examples of electronic devices. Figures 19 (A) to (D) are drawings showing examples of electronic devices. FIG. 20 (A) is a drawing showing a part of a system that is one embodiment of the present invention. FIG. 20 (B) is a drawing showing an example of an electronic device that is one embodiment of the present invention. FIG. 21 (A) is a schematic diagram of an electronic device that is one embodiment of the present invention. FIG. 21 (B) is a diagram showing a part of a system, and FIG. 21 (C) is an example of a perspective view of a portable data terminal used in the system. Figures 22 (A) and (B) are graphs of the charge / discharge characteristics of a secondary battery according to Example 1. Figures 23 (A) and (B) are graphs of the cycle characteristics of a secondary battery according to Example 1. Figure 24 is a cross-sectional TEM image of the anode according to Example 2. Figure 25 (A) is a cross-sectional TEM image of the positive active material layer according to Example 2. Figure 25 (B) is an ultra-fine electron diffraction image of the positive active material layer according to Example 2. Figures 26 (A) and (B) are microelectron diffraction images of the positive active material layer according to Example 2. Figure 27 is a cross-sectional TEM image of the anode according to Example 2. Figures 28 (A) and (B) are cross-sectional TEM images of the anode according to Example 2. Figure 29 is the EELS spectrum of the positive active material layer according to Example 2. Figure 30 is a cross-sectional TEM image of the anode according to Example 2. Figures 31 (A) and (B) are cross-sectional TEM images of the anode according to Example 2. Figure 32 is the EELS spectrum of the positive active material layer according to Example 2. Figure 33 (A) is a cross-sectional TEM image of the positive active material layer according to Example 2. Figure 33 (B) is an ultrafine electron diffraction image of the positive active material layer according to Example 2. Figures 34 (A) and (B) are microelectron diffraction images of the positive active material layer according to Example 2. Figure 35 (A) is a cross-sectional TEM image of the positive active material layer according to Example 2. Figure 35 (B) is an ultra-fine electron diffraction image of the positive active material layer according to Example 2. Figures 36 (A) and (B) are microelectron diffraction images of the positive active material layer according to Example 2. Figure 37 is a graph showing the charge-discharge cycle characteristics of a secondary battery according to Example 2. Figures 38 (A) and (B) are drawings illustrating the impedance measurement of a secondary battery according to Example 2. Figure 39 shows the impedance measurement results of a secondary battery according to Example 2. Figure 40 shows the impedance measurement results of a secondary battery according to Example 2. Specific details for implementing the invention

[0023] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the description below, and it will be readily understood by those skilled in the art that the form and details thereof can be varied. Furthermore, the present invention is not to be interpreted as being limited to the description of the embodiments below.

[0024] In addition, Miller indices are used to denote crystal planes and orientations in this specification and others. Individual planes representing crystal planes are indicated by (). Orientations are indicated by []. The same indices are used for reciprocal lattice points, but without parentheses. When indicating crystal planes and orientations, a bar is placed above the number in crystallography, but in this specification and others, due to constraints on application notation, a minus sign (-) is placed in front of the number instead of a bar above it.

[0025] In the present specification and other documents, the layered rock salt-type crystal structure having a composite oxide containing lithium and a transition metal refers to a crystal structure in which cations and anions are arranged alternately in a rock salt-type ionic arrangement, and the transition metal and lithium are regularly arranged to form a two-dimensional plane, thereby enabling two-dimensional diffusion of lithium. Additionally, defects such as deficiencies in cations or anions may be present. Furthermore, strictly speaking, the layered rock salt-type crystal structure may have a structure in which the lattice of the rock salt-type crystal is deformed.

[0026] In addition, the term "rock salt-type crystal structure" in this specification and others refers to a structure in which cations and anions are arranged alternately. Additionally, there may be a deficiency of cations or anions.

[0027] The anions of layered rock salt-type crystals and rock salt-type crystals take on a cubic close-packed structure (face-centered cubic lattice structure). When they come into contact, there exist crystal planes in which the orientation of the cubic close-packed structure composed of anions coincides. However, since the space group of the layered rock salt-type crystal is R-3m and is different from the space group Fm-3m of the rock salt-type crystal, the Miller indices of the crystal planes satisfying the above conditions differ between the layered rock salt-type crystal and the rock salt-type crystal. In this specification, when the cubic close-packed structure composed of anions coincides in the layered rock salt-type crystal and the rock salt-type crystal, it is sometimes stated that the crystal orientations are substantially coincide.

[0028] Whether the crystal orientations of two regions substantially match can be determined from TEM (transmission electron microscope) images, STEM (scanning transmission electron microscope) images, HAADF-STEM (high-angle annular dark field scanning transmission electron microscope) images, ABF-STEM (annular bright-field scanning transmission electron microscope) images, etc. X-ray diffraction (XRD), electron diffraction, neutron diffraction, etc., can also be used as materials for determination. If the crystal orientations substantially match, it can be observed from TEM images, etc., that the difference in the direction of the rows in which cations and anions are arranged alternately in a linear shape is 5° or less, or 2.5° or less. In addition, although light elements such as oxygen and fluorine may not be clearly observed in TEM images, etc., in such cases, the alignment of orientations can be determined by the arrangement of metal elements.

[0029] In addition, the theoretical capacity of a positive electrode active material in this specification and others refers to the amount of electricity when all the insertable and removable lithium in the positive electrode active material is removed. For example, the theoretical capacity of LiCoO2 is 274 mAh / g, the theoretical capacity of LiNiO2 is 274 mAh / g, and the theoretical capacity of LiMn2O4 is 148 mAh / g.

[0030] In addition, the depth of charge when all insertable and removable lithium in the present specification is inserted is set to 0, and the depth of charge when all insertable and removable lithium in the positive electrode active material is removed is set to 1.

[0031] In addition, in the present specification, etc., the statement that planes are parallel refers not only to cases where they are strictly mathematically parallel, but also to cases where the angle formed by the planes is 5° or less or 2.5° or less.

[0032] (Embodiment 1)

[0033] Using FIG. 1, a positive electrode for a secondary battery of one form of the present invention will be described.

[0034] FIG. 1 (A) is a perspective view of an example of an anode (100) which is one embodiment of the present invention. The anode (100) has an anode current collector (103), a lower film (104), an anode active material layer (101), and a cap layer (102).

[0035] A lower film (104) is provided between the positive current collector (103) and the positive active material layer (101). The lower film (104) has the function of increasing the conductivity between the positive current collector (103) and the positive active material layer (101). Alternatively, it has the function of suppressing side reactions such as oxidation of the positive current collector (103) due to oxygen contained in the positive active material layer (101), or diffusion of metal atoms contained in the positive current collector (103) into the positive active material layer (101). Alternatively, it has the function of stabilizing the crystal structure of the positive active material layer (101).

[0036] It is preferable to use a conductive material for the lower film (104). It is also preferable to use a material that is easy to inhibit oxidation. For example, titanium oxide, titanium nitride, titanium oxide partially substituted with nitrogen, titanium nitride partially substituted with oxygen, or titanium nitride oxide (TiO₂). x N y , 0 <x<2, 0<y<1) 등을 적용할 수 있다. 이 중에서도 질화 타이타늄은 도전성이 높으며 산화를 억제하는 기능이 높기 때문에 특히 바람직하다.

[0037] A cap layer (102) is provided on the positive active material layer (101). The cap layer (102) has the function of suppressing side reactions between the positive active material layer (101) and the electrolyte, or has the function of stabilizing the crystal structure of the positive active material layer (101).

[0038] It is preferable to use a titanium compound as the cap layer (102). For example, titanium oxide, titanium nitride, titanium oxide partially substituted with nitrogen, titanium nitride partially substituted with oxygen, or titanium nitride oxide (TiO₂). x N y , 0 <x<2, 0<y<1)을 가지는 것이 바람직하다. 타이타늄 및 산소는 고체 전해질에 포함될 수 있는 재료이다. 그러므로 산화 타이타늄은 캡층(102)으로서 특히 적합하다.

[0039] In addition, the term "electrolyte" in this specification, etc. includes not only solid electrolytes but also electrolytes in which a lithium salt is dissolved in a liquid solvent and electrolytes in which a lithium salt is dissolved in a gel-like compound.

[0040] The positive active material layer (101) has lithium, a transition metal M, and oxygen. The positive active material layer (101) may be said to have a composite oxide containing lithium and a transition metal M.

[0041] As the transition metal M of the positive active material layer (101), it is preferable to use a metal capable of forming a layered rock salt-type composite oxide belonging to space group R-3m together with lithium. As the transition metal M, for example, one or more of manganese, cobalt, and nickel may be used. That is, as the transition metal of the positive active material layer (101), only cobalt may be used, only nickel may be used, two types of cobalt and manganese may be used, two types of cobalt and nickel may be used, or three types of cobalt, manganese, and nickel may be used. That is, the positive active material layer (101) may have a composite oxide containing lithium and transition metal M, such as lithium cobaltate, lithium nickelate, lithium cobaltate in which part of the cobalt is substituted with manganese, lithium cobaltate in which part of the cobalt is substituted with nickel, nickel-manganese-lithium cobaltate, etc.

[0042] In addition, the positive active material layer (101) may have elements other than the transition metal M, such as magnesium, fluorine, and aluminum, in addition to the above. These elements may further stabilize the crystal structure of the positive active material layer (101). That is, the positive active material layer (101) may have lithium cobaltate with magnesium and fluorine added, lithium nickel-cobaltate with magnesium and fluorine added, lithium cobalt-aluminumate with magnesium and fluorine added, lithium nickel-cobalt-aluminumate with nickel-cobalt-aluminumate with magnesium and fluorine added, etc.

[0043] When the positive active material layer (101) has lithium, cobalt, nickel, aluminum, magnesium, oxygen, and fluorine, the atomic ratio of nickel when the atomic ratio of cobalt in the positive active material layer (101) is set to 100 is preferably, for example, 0.05 or more and 2 or less, more preferably 0.1 or more and 1.5 or less, and even more preferably 0.1 or more and 0.9 or less. When the atomic ratio of cobalt in the positive active material layer (101) is set to 100, the atomic ratio of aluminum when the atomic ratio of aluminum when the atomic ratio of cobalt in the positive active material layer (101) is set to 100 is preferably, for example, 0.05 or more and 2 or less, more preferably 0.1 or more and 1.5 or less, and even more preferably 0.1 or more and 0.9 or less. When the atomic ratio of cobalt in the positive active material layer (101) is set to 100, the atomic ratio of magnesium when the atomic ratio of magnesium when the atomic ratio of cobalt in the positive active material layer (101) is set to 100 is preferably, for example, 0.1 or more and 6 or less, and even more preferably 0.3 or more and 3 or less. In addition, when the atomic ratio of magnesium in the positive active material layer (101) is set to 1, the atomic ratio of fluorine is preferably, for example, 2 or more and 3.9 or less.

[0044] If nickel, aluminum, and magnesium are present in the concentrations described above, a stable crystal structure can be maintained even when charging and discharging are repeated at high voltage. Therefore, it can be made into a positive active material layer (101) with high capacity and excellent charge / discharge cycle characteristics.

[0045] The molar concentrations of cobalt, nickel, aluminum, and magnesium can be evaluated, for example, by inductively coupled plasma mass spectrometry (ICP-MS). The molar concentration of fluorine can be evaluated, for example, by glow discharge mass spectrometry (GD-MS).

[0046] First Principles of Calculation

[0047] Here, using Figure 2, the results of calculating the crystal structure of the interface between the positive active material layer (101) and the lower film (104) when lithium cobaltate is used in the positive active material layer (101) are explained.

[0048] Figure 2 (A) is a drawing of the case where titanium nitride is applied as the lower film (104). The calculation was performed assuming that titanium nitride has a rock salt-type crystal structure belonging to space group Fm-3m and lithium cobaltate has a layered rock salt-type crystal structure belonging to space group R-3m. The (111) plane of titanium nitride and the (001) plane of lithium cobaltate are stacked so that they are parallel.

[0049] Figure 2 (B) is a diagram of the case where titanium oxide is applied as the lower film (104). The calculation was performed assuming that titanium oxide has a rutile-type crystal structure belonging to space group P42 / mnm and lithium cobaltate has a layered rock salt-type crystal structure belonging to space group R-3m. The (100) plane of titanium oxide and the (001) plane of lithium cobaltate are stacked so that they are parallel.

[0050] In any drawing, the interface between the positive active material layer (101) and the lower film (104) is shown. Other calculation conditions are shown in Table 1.

[0051] [Table 1]

[0052]

[0053] In the case of FIG. 2 (A), where titanium nitride was applied as the lower film (104), the Ti-O distance was 2.03 Å, the Ti-N distance was 1.93 Å, the Co-O distance was 2.25 Å, and the Co-N distance was 2.21 Å. Also, 1 Å = 10 -10 It is m.

[0054] In the rock salt type crystal structure belonging to space group Fm-3m, the plane where only anions are arranged exists in a plane parallel to the (111) plane. In titanium nitride, only nitrogen atoms are arranged in a plane parallel to the (111) plane. In the layered rock salt type crystal structure belonging to space group R-3m, the plane where only anions are arranged exists in a plane parallel to the (001) plane. In lithium cobaltate, only oxygen atoms are arranged in a plane parallel to the (001) plane.

[0055] If the (111) plane of titanium nitride and the (001) plane of lithium cobaltate are parallel, the planes on both sides where only anions are arranged become parallel, and the crystal structure is easily stabilized.

[0056] In addition, the rock salt-type crystal structure belonging to space group Fm-3m and the layered rock salt-type crystal structure belonging to space group R-3m can both be described as crystal structures in which cations and anions are arranged alternately. Therefore, when lithium cobaltate of the layered rock salt-type crystal structure is laminated on titanium nitride of the rock salt-type crystal structure, the crystal orientation of the lower film (104) and the positive active material layer (101) is likely to substantially coincide.

[0057] Meanwhile, in the case of (B) of FIG. 2, where titanium oxide was applied as the lower film (104), the Ti-O distance was 2.15 Å and the Co-O distance was 1.91 Å. Titanium oxide with a rutile-type crystal structure does not have oxygen atoms arranged on a plane parallel to the (100) plane. Therefore, compared to titanium nitride, there is a possibility that the ability to stabilize the layered rock salt-type crystal structure is lower.

[0058] In this way, when lithium cobaltate having a layered rock salt-type crystal structure is used in the positive active material layer (101), titanium nitride is particularly suitable as the lower film (104).

[0059] FIG. 1 (B) is a perspective view of another example of a positive electrode (100) which is one embodiment of the present invention. The positive electrode (100) shown in FIG. 1 (B) has a positive electrode current collector (103), a positive electrode active material layer (101), and a cap layer (102). As such, the positive electrode (100) does not necessarily have to have a lower film (104). Even without having a lower film (104), it is possible to make it a secondary battery with sufficiently improved cycle characteristics by having a cap layer (102).

[0060] Although FIGS. 1 (A) and (B) describe an anode in which the anode current collector (103) serves as both a current collector and a substrate, the present invention is not limited thereto. FIGS. 1 (C) is a perspective view of another example of an anode (100) that is an embodiment of the present invention. As shown in FIGS. 1 (C), the anode (100) may be manufactured by forming an anode current collector (103), a lower film (104), an anode active material layer (101), and a cap layer (102) on a substrate (110).

[0061] This embodiment may be implemented in appropriate combination with other embodiments.

[0062] (Embodiment 2)

[0063] In this embodiment, using FIGS. 3 to 8, a secondary battery having a positive electrode for a secondary battery described in Embodiment 1 and a method for manufacturing the same will be explained.

[0064] [Composition of secondary batteries]

[0065] Figure 3 (A) is a drawing illustrating an example of a stacked structure of a secondary battery (200) having a positive electrode (100) for a secondary battery of one form of the present invention.

[0066] The secondary battery (200) is a thin-film battery and has a positive electrode (100) as described in the previous embodiment, a solid electrolyte layer (203) is formed on the positive electrode (100), and a negative electrode (212) is formed on the solid electrolyte layer (203). The negative electrode (212) has a negative electrode current collector (205) and a negative electrode active material layer (204). In addition, as shown in (A) of FIG. 3, it is preferable that the negative electrode (212) has a lower film (214) and a cap layer (209).

[0067] A lower film (214) is provided between the negative current collector (205) and the negative active material layer (204). The lower film (214) has the function of increasing the conductivity between the negative current collector (205) and the negative active material layer (204). Or it has the function of suppressing excessive expansion of the negative active material layer. Or it has the function of suppressing side reactions between the negative current collector (205) and the negative active material layer (204).

[0068] It is preferable to use a conductive material for the lower film (214). It is also preferable to use a material that can suppress excessive expansion of the negative active material layer. Furthermore, it is preferable to use a material that is easy to suppress side reactions. For example, titanium oxide, titanium nitride, titanium oxide partially substituted with nitrogen, titanium nitride partially substituted with oxygen, or titanium nitride oxide (TiO₂). x N y , 0 <x<2, 0<y<1)을 가지는 것이 바람직하다. 특히, 질화 타이타늄은 도전성이 높으며 부반응을 억제하는 기능이 높아 바람직하다.

[0069] A cap layer (209) is provided between the negative electrode active material layer (204) and the solid electrolyte layer (203). The cap layer (209) has the function of suppressing side reactions between the negative electrode active material layer (204) and the solid electrolyte layer (203).

[0070] It is preferable to use titanium or a titanium compound as the cap layer (209). Examples of titanium compounds include titanium oxide, titanium nitride, titanium oxide partially substituted with nitrogen, titanium nitride partially substituted with oxygen, or titanium nitride oxide (TiO₂). x N y , 0 <x<2, 0<y<1)을 가지는 것이 바람직하다. 타이타늄은 고체 전해질에 포함될 수 있는 재료이다. 그러므로 타이타늄 및 타이타늄 화합물은 캡층(209)으로서 특히 적합하다.

[0071] As the negative electrode active material layer (204), silicon, carbon, titanium oxide, vanadium oxide, indium oxide, zinc oxide, tin oxide, nickel oxide, etc., may be used. In addition, materials that alloy with lithium, such as tin, gallium, and aluminum, may be used. In addition, metal oxides that alloy with these may also be used. In addition, lithium titanium oxide (Li4Ti5O) 12 You may use materials such as LiTi2O4, and among these, materials containing silicon and oxygen (SiO₂) x A film (also referred to as a membrane) is preferred. Additionally, lithium metal may be used as the negative electrode active material layer (204). A mixture of these materials may also be used. For example, a mixture of silicon particles and carbon is suitable because it has good reliability and a relatively high energy density per unit volume.

[0072] A solid electrolyte layer (203) is provided between the anode (100) and the cathode (212). As the material of the solid electrolyte layer (203), Li0 . 35 La0 . 55 TiO3, La (2 / 3-A) Li 3A TiO3, Li3PO4, LixPO (4-B) N B , LiNb (1-A) Ta (A) WO6, Li7La3Zr2O 12 , Li (1+A) Al(A) Ti (2-A) (PO4)3, Li (1+A) Al (A) Ge (2-A) Examples include (PO4)3 and LiNbO2. Also, A > 0 and B > 0. Sputtering and deposition methods can be used as film deposition methods.

[0073] It is preferable to use a compound containing titanium for the solid electrolyte layer (203). Since the cap layer (102) of the positive electrode (100) and the cap layer (209) of the negative electrode (212) contain titanium, if a material containing titanium is also used for the solid electrolyte layer (203), a secondary battery can be easily manufactured.

[0074] Also, SiO C (0 <C≤2)도 고체 전해질층(203)으로서 사용할 수 있다. SiO C (0 <C≤2)를 고체 전해질층(203)으로서 사용하고, 또한 음극 활물질층(204)으로서 SiO C (0 <C≤2)를 사용하여도 좋다. 이 경우, SiO C It is preferable that the ratio of silicon to oxygen (O / Si) is higher in the solid electrolyte layer (203). By making the above configuration, conductive ions (especially lithium ions) are easily diffused in the solid electrolyte layer (203), and conductive ions (especially lithium ions) are easily detached or accumulated in the negative electrode active material layer (204), so a solid secondary battery with good characteristics can be produced. As described above, by using a material composed of the same components in the solid electrolyte layer (203) and the negative electrode active material layer (204), a secondary battery can be easily manufactured.

[0075] In addition, the solid electrolyte layer (203) may be formed into a stacked structure, and in the case of stacking, a material (Li3PO4) to which nitrogen has been added to lithium phosphate (Li3PO4) may be used. (4-Z) N Z : Also called LiPON) may be stacked as a single layer. Also, Z > 0.

[0076] In addition, as shown in (B) of FIG. 3, a secondary battery (200) having a negative electrode (212) in which a negative electrode active material layer (204) and a cap layer (209) are stacked in multiple layers may be used. By stacking multiple negative electrode active material layers (204) and cap layers (209), the capacity can be improved while suppressing excessive expansion of the negative electrode (212). At this time, the cap layer (209) in contact with the solid electrolyte layer (203) and the cap layer (209) fitted into the negative electrode active material layer (204) may be made of the same material or different materials. For example, titanium oxide may be used for the cap layer (209) in contact with the solid electrolyte layer (203), and titanium nitride may be used for the cap layer (209) fitted into the negative electrode active material layer (204).

[0077] In addition, as shown in (C) of FIG. 3, a secondary battery (200) having a positive electrode (100) in which a positive electrode active material layer (101) and a cap layer (102) are stacked in multiple layers may be used. By stacking multiple positive electrode active material layers (101) and cap layers (102), the capacity can be improved while suppressing the collapse of the crystal structure of the positive electrode active material layer (101). At this time, the cap layer (102) in contact with the solid electrolyte layer (203) and the cap layer (102) fitted into the positive electrode active material layer (101) may be made of the same material or different materials. For example, titanium oxide may be used for the cap layer (102) in contact with the solid electrolyte layer (203), and titanium nitride may be used for the cap layer (102) fitted into the positive electrode active material layer (101).

[0078] Figures 4 (A) and (B) show more specific examples of a secondary battery (200) of one form of the present invention. Here, a secondary battery (200) formed on a substrate (110) is described.

[0079] FIG. 4 (A) is a top view, and FIG. 4 (B) is a cross-sectional view taken along line A-A' of FIG. 4 (A). The secondary battery (200) is a thin-film battery, and as shown in FIG. 4 (B), a positive electrode (100) described in the previous embodiment is formed on a substrate (110), a solid electrolyte layer (203) is formed on the positive electrode (100), and a negative electrode (210) is formed on the solid electrolyte layer (203). The negative electrode (210) has a negative electrode current collector (205), a lower film (214), a negative electrode active material layer (204), and a cap layer (209).

[0080] Additionally, it is preferable that the secondary battery (200) has a protective layer (206) formed on the positive electrode (100), the solid electrolyte layer (203), and the negative electrode (210).

[0081] The films forming these layers can each be formed using a metal mask. The positive current collector (103), the lower film (104), the positive active material layer (101), the cap layer (102), the solid electrolyte layer (203), the cap layer (209), the negative active material layer (204), the lower film (214), and the negative current collector (205) can be selectively formed using a sputtering method. Additionally, the solid electrolyte layer (203) may be selectively formed by using a metal mask through a co-deposition method.

[0082] As shown in (A) of FIG. 4, a portion of the negative current collector (205) and the positive current collector (103) is exposed to form a negative terminal portion and a positive terminal portion. The area other than the negative terminal portion and the positive terminal portion is covered with a protective layer (206).

[0083] In addition, in FIG. 4 (A) and (B), a configuration in which a solid electrolyte layer (203), a negative active material layer (204), and a negative current collector (205) are stacked in this order on an anode (100) having an anode current collector (103), a lower film (104), an anode active material layer (101), and a cap layer (102) has been described, but one embodiment of the present invention is not limited thereto.

[0084] As shown in (C) of FIG. 4, the secondary battery (200) may have a positive electrode (100) that does not have a lower film (104) between the positive electrode current collector (103) and the positive electrode active material layer (101). It may also have a negative electrode (210) that does not have a lower film (214) and a cap layer (209).

[0085] In addition, the positive and negative electrodes of a secondary battery of one form of the present invention may both have a stacked structure of an active material layer and a cap layer. For example, as shown in (D) of FIG. 4, the secondary battery (200) may have a negative electrode (210) in which a negative active material layer (204) and a cap layer (209) are stacked in multiple layers. In addition, it may have a positive electrode (100) in which a positive active material layer (101) and a cap layer (102) are stacked in multiple layers.

[0086] In addition, as shown in FIG. 5 (A) and (B), a secondary battery of one embodiment of the present invention may be a secondary battery (201) having a negative electrode (211) that combines a negative electrode current collector layer and a negative electrode active material layer. FIG. 5 (A) is a top view of the secondary battery (201), and FIG. 5 (B) is a cross-sectional view taken along line B-B' of FIG. 5 (A). By using a negative electrode (211) that combines a negative electrode current collector layer and a negative electrode active material layer, the process can be simplified, and a secondary battery with high productivity can be produced. In addition, a secondary battery with high energy density can be produced.

[0087] In addition, as shown in FIG. 5 (C) and (D), one embodiment of the secondary battery of the present invention may be a secondary battery (202) in which a solid electrolyte layer (203) and a positive electrode (100) are stacked on a negative electrode (210). FIG. 5 (C) is a top view of the secondary battery (202), and FIG. 5 (D) is a cross-sectional view taken along line C-C' of FIG. 5 (C).

[0088] In addition, FIGS. 4 and 5 describe a secondary battery in which not only the positive electrode but also the solid electrolyte layer and the negative electrode are formed as thin films, but the present invention is not limited thereto. One embodiment of the present invention may be a secondary battery having an electrolyte. It may also be a secondary battery having an electrolyte and a negative electrode having a negative current collector layer and a negative active material layer. It may also be a secondary battery having a negative electrode manufactured by coating a powdered negative active material onto a negative current collector.

[0089] A secondary battery (230) having an electrolyte is shown in FIG. 6 (A) and (B). FIG. 6 (A) is a top view, and FIG. 6 (B) is a cross-sectional view taken along line D-D' of FIG. 6 (A).

[0090] As shown in Fig. 6 (B), the secondary battery (230) has a positive electrode (100) on a substrate (110), a negative electrode (212) on a substrate (111), a separator (220), an electrolyte (221), and an outer body (222). The negative electrode current collector (205), the negative electrode active material layer (204), and the cap layer (209) of the negative electrode (212) are formed as thin films.

[0091] Also, as shown in FIG. 6 (A), the secondary battery (230) has a lead electrode (223a) and a lead electrode (223b). The lead electrode (223a) is electrically connected to a positive current collector (103). The lead electrode (223b) is electrically connected to a negative current collector (205). A portion of the lead electrode (223a) and the lead electrode (223b) is extended out of the outer casing (222).

[0092] A secondary battery (231) having an electrolyte and a negative electrode (211) that combines a negative electrode current collector layer and a negative electrode active material layer is shown in FIG. 7 (A) and (B). FIG. 7 (A) is a top view, and FIG. 7 (B) is a cross-sectional view taken along line E-E' of FIG. 7 (A).

[0093] As shown in FIG. 7 (B), the secondary battery (231) has a positive electrode (100), a negative electrode (211) that combines a negative electrode current collector layer and a negative electrode active material layer, a separator (220), an electrolyte (221), and an outer body (222). By using a negative electrode (211) that combines a negative electrode current collector layer and a negative electrode active material layer, the process can be simplified, allowing for a secondary battery with high productivity. Additionally, it can be a secondary battery with high energy density.

[0094] [Production Method]

[0095] Next, an example of the flow of the method for manufacturing a secondary battery (200) shown in (A) and (B) of FIG. 4 will be explained using FIG. 8.

[0096] First, an anode current collector (103) is formed on a substrate (110) (S1). Sputtering, deposition, etc., may be used as the film formation method. Additionally, a conductive substrate may be used as the current collector. As the anode current collector (103), highly conductive materials such as metals like gold, platinum, aluminum, titanium, copper, magnesium, iron, cobalt, nickel, zinc, germanium, indium, silver, and palladium, and alloys thereof may be used. Additionally, aluminum with added elements that improve heat resistance, such as silicon, titanium, neodymium, scandium, and molybdenum, may be used. It may also be formed from a metal element that reacts with silicon to form a silicide. Examples of metal elements that react with silicon to form a silicide include zirconium, titanium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, cobalt, and nickel.

[0097] In addition, the substrate (110) may be a ceramic substrate, a glass substrate, a resin substrate, a silicon substrate, a metal substrate, etc. If a flexible material is used as the substrate (110), a flexible thin-film secondary battery can be manufactured.

[0098] The positive current collector (103) can perform the functions of both a substrate and a positive current collector by using a highly conductive material. In this case, it is preferable to use a metal substrate, such as titanium or copper. Additionally, if a lower film (104) is provided, the oxidation of the positive current collector (103) or the diffusion of metal atoms caused by oxygen contained in the positive active material layer (101), etc., is suppressed by the lower film (104). Therefore, even if the material is prone to oxidation or contains metal atoms that are prone to diffusion, it can be applied to the positive current collector (103).

[0099] Next, a film (104) is formed (S2). Sputtering and deposition methods can be used as methods for forming the film (104). For example, when titanium nitride is used as the film (104), titanium nitride can be formed by a reactive sputtering method using a titanium target and nitrogen gas.

[0100] Next, a positive active material layer (101) is formed (S3). The positive active material layer (101) can be formed by a sputtering method using a sputtering target having, for example, one or more oxides of lithium, manganese, cobalt, and nickel as the main components. For example, a sputtering target having lithium cobalt oxide (LiCoO2, LiCo2O4, etc.) as the main component, a sputtering target having lithium manganese oxide (LiMnO2, LiMn2O4, etc.) as the main component, or a sputtering target having lithium nickel oxide (LiNiO2, LiNi2O4, etc.) as the main component may be used. Additionally, it may be formed by a vacuum deposition method.

[0101] In addition, in the sputtering method, a film can be selectively formed by using a metal mask. Also, the positive active material layer (101) may be patterned by selectively removing it by dry etching or wet etching using a resist mask, etc.

[0102] In addition, to form a positive active material layer (101) having magnesium, fluorine, aluminum, etc., a sputtering target having magnesium, fluorine, aluminum, etc., in addition to one or more of lithium, manganese, cobalt, and nickel may be used to form the film. In addition, after forming the film using a sputtering target having an oxide having one or more of lithium, manganese, cobalt, and nickel as the main component, magnesium, fluorine, aluminum, etc., may be formed by vacuum deposition and annealed.

[0103] Next, a cap layer (102) is formed on the positive active material layer (101) (S4). Sputtering or deposition methods can be used as the method for forming the cap layer (102). For example, when titanium oxide is used as the cap layer (102), titanium oxide can be formed by a reactive sputtering method using a titanium target and oxygen gas. In addition, it can also be formed by sputtering a titanium oxide target.

[0104] It is preferable to perform the film formation of the positive active material layer (101) and the cap layer (102) at a high temperature (500°C or higher). This allows for the production of a positive electrode (100) with better crystallinity.

[0105] Next, a solid electrolyte layer (203) is formed on the positive active material layer (101) (S5).

[0106] It is preferable to use a compound containing titanium for the solid electrolyte layer (203). Since the cap layer (102) of the anode (100) contains titanium, if a material containing titanium is also used for the solid electrolyte layer (203), a secondary battery can be easily manufactured. As a film formation method, sputtering or deposition methods can be used.

[0107] Next, a negative active material layer (204) is formed on the solid electrolyte layer (203) (S6). Sputtering, deposition, etc., can be used as the forming method.

[0108] Next, a negative current collector (205) is fabricated on the negative active material layer (204) (S7). As the material for the negative current collector (205), one or more types of conductive materials selected from aluminum, titanium, copper, gold, chromium, tungsten, molybdenum, nickel, silver, etc. may be used. As a film deposition method, a sputtering method, a deposition method, etc. may be used. In addition, in the sputtering method, a film can be selectively deposited by using a metal mask. In addition, the conductive film may be patterned by selectively removing it by dry etching or wet etching using a resist mask, etc.

[0109] In addition, when the positive current collector (103) or the negative current collector (205) is formed by sputtering, it is preferable that at least one of the positive active material layer (101) and the negative active material layer (204) be formed by sputtering. The sputtering device may perform continuous film formation within the same chamber or by using multiple chambers, and may be a multi-chamber type manufacturing device or an in-line type manufacturing device. The sputtering method uses a chamber and a sputtering target and is a manufacturing method suitable for mass production. Furthermore, the sputtering method allows for thin forming, resulting in excellent film formation characteristics.

[0110] Next, it is preferable to form a protective layer (206) on the anode (100), the solid electrolyte layer (203), and the cathode (210) (S8). As the protective layer (206), a metal oxide containing one or more types selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum, and magnesium may be used. Additionally, silicon nitride or silicon nitride may be used. The protective layer (206) may be formed using a sputtering method.

[0111] In addition, each layer described in this embodiment is not specifically limited to the sputtering method, and vapor deposition methods (vacuum deposition, thermal spraying, pulsed laser deposition (PLD), ion plating, cold spray, aerosol deposition) may also be used. Furthermore, the aerosol deposition (AD) method is a method of forming a film without heating the substrate. An aerosol refers to fine particles dispersed in a gas. Additionally, the CVD method or the ALD (Atomic Layer Deposition) method may be used.

[0112] A secondary battery (200), which is one form of the present invention, can be manufactured through the process described above.

[0113] This embodiment may be implemented in appropriate combination with other embodiments.

[0114] (Embodiment 3)

[0115] In order to increase the output voltage of the thin-film secondary battery, the secondary batteries can be connected in series. Although Example 2 showed an example of a secondary battery with a single cell, this embodiment shows an example of manufacturing a thin-film secondary battery in which multiple cells are connected in series.

[0116] FIG. 9 (A) shows a top view immediately after forming the first secondary battery, and FIG. 9 (B) shows a top view with two secondary batteries connected in series. In FIG. 9 (A) and (B), the same reference numerals are used for parts identical to FIG. 5 (A) shown in Embodiment 2.

[0117] Figure 9 (A) shows the state immediately after forming the negative current collector (205). The upper surface shape of the negative current collector (205) is different from Figure 5 (A). The negative current collector (205) shown in Figure 9 (A) partially contacts the side of the solid electrolyte layer and also contacts the insulating surface of the substrate.

[0118] Then, a second negative electrode active material layer, a second solid electrolyte layer (213), a second positive electrode active material layer, and a second positive electrode current collector (215) are formed in this order on the region of the negative electrode current collector (205) that does not overlap with the first negative electrode active material layer. Finally, a protective layer (206) is formed ((B) of FIG. 9).

[0119] Figure 9 (B) shows a configuration in which two solid secondary batteries are arranged in a planar arrangement and connected in series.

[0120] This embodiment may be implemented in appropriate combination with other embodiments.

[0121] (Embodiment 4)

[0122] In order to increase the output voltage or discharge capacity of the thin-film secondary battery, a multilayer secondary battery can be formed in which multiple positive and negative electrodes are stacked. Although an example of a secondary battery in the form of a single-layer cell was shown in Embodiment 2, an example of a thin-film battery in the form of a multilayer cell is shown in this embodiment.

[0123] FIG. 10 is an example of a cross-section of a thin-film cell of a three-layer cell. A positive current collector (103) is formed on a substrate (110), and a lower film (104), a positive active material layer (101), a cap layer (102), a solid electrolyte layer (203), a negative active material layer (204), and a negative current collector (205) are sequentially formed on the positive current collector (103) to form the first cell.

[0124] In addition, a second cell is formed by sequentially forming a second negative active material layer (204), a solid electrolyte layer, a cap layer, a positive active material layer, a lower film, and a positive current collector layer on a negative current collector (205).

[0125] In addition, a third cell is formed by sequentially forming a third layer, a positive active material layer, a cap layer, a solid electrolyte layer, a negative active material layer, and a negative current collector layer on top of a second positive current collector.

[0126] In FIG. 10, a protective layer (206) is formed at the end. The three-layer stacking shown in FIG. 10 has a configuration in which it is connected in series to increase capacity, but it can also be connected in parallel via external wiring. Additionally, series, parallel, or series-parallel connections can be selected via external wiring.

[0127] In addition, it is desirable to use the same material for the solid electrolyte layer (203), the second solid electrolyte layer, and the third solid electrolyte layer so that manufacturing costs can be reduced.

[0128] In addition, an example of a manufacturing flow for obtaining the structure illustrated in Fig. 10 is shown in Fig. 11.

[0129] In FIG. 11, in order to reduce the manufacturing process, it is preferable to use a lithium cobaltate film as the positive active material layer and a titanium film as the positive current collector and negative current collector (conductive layer). By using a titanium film as a common electrode, a three-layer stacked cell can be realized with a small configuration.

[0130] This embodiment may be implemented in appropriate combination with other embodiments.

[0131] (Embodiment 5)

[0132] In this embodiment, examples of a multi-chamber type manufacturing apparatus capable of fully automating the fabrication of the positive current collector layer to the negative current collector layer of a secondary battery are shown in FIG. 12 and FIG. 13. The above manufacturing apparatus can be suitably used for the fabrication of a thin-film secondary battery of one form of the present invention.

[0133] FIG. 12 is an example of a manufacturing apparatus for a multi-chamber having gates (880, 881, 882, 883, 884, 885, 886, 887, 888), a load lock chamber (870), a mask alignment chamber (891), a first return chamber (871), a second return chamber (872), a third return chamber (873), a plurality of film formation chambers (first film formation chamber (892), second film formation chamber (874)), a heating chamber (893), a second material supply chamber (894), a first material supply chamber (895), and a third material supply chamber (896).

[0134] The mask alignment room (891) has at least a stage (851) and a substrate transport mechanism (852).

[0135] The first return room (871) has a substrate cassette lifting mechanism, the second return room (872) has a substrate return mechanism (853), and the third return room (873) has a substrate return mechanism (854).

[0136] The first membrane room (892), the second membrane room (874), the second material supply room (894), the first material supply room (895), the third material supply room (896), the mask alignment room (891), the first return room (871), the second return room (872), and the third return room (873) are each connected to an exhaust mechanism. As for the exhaust mechanism, an appropriate exhaust device may be selected according to the intended use of each room, for example, an exhaust mechanism having a pump having an adsorption means such as a cryopump, a sputtering ion pump, or a titanium sublimation pump, or an exhaust mechanism having a cold trap in a turbo molecular pump.

[0137] As a procedure for forming a film on a substrate, a substrate (850) or a substrate cassette is installed in a load lock room (870) and transported to a mask alignment room (891) by a substrate transport mechanism (852). In the mask alignment room (891), a mask to be used is picked up from among a plurality of pre-installed masks and aligned with the substrate on a stage (851). After aligning, a gate (880) is opened, and the mask and substrate (850) are transported to a first transport room (871) by a substrate transport mechanism (852). After moving the mask and substrate (850) to the first transport room (871), a gate (881) is opened, and the substrate is transported to a second transport room (872) by a substrate transport mechanism (853).

[0138] The first film deposition chamber (892), which is provided with a gate (882) interposed in the second transfer chamber (872), is a sputtering film deposition chamber. The sputtering film deposition chamber is a mechanism capable of applying voltage to a sputtering target by switching between an RF power source and a pulsed DC power source. Additionally, two or three types of sputtering targets may be installed. In this embodiment, a single-crystal silicon target, a sputtering target with lithium cobalt oxide (LiCoO2) as the main component, and a titanium target are installed. A substrate heating mechanism may be provided in the first film deposition chamber (892), and film deposition may be performed while heated until the heater temperature reaches 700°C.

[0139] A cathode active material layer can be formed by a sputtering method using a single-crystal silicon target. In addition, SiO₂ can be formed using a reactive sputtering method with Ar gas and O2 gas. XA film formed by the above may be used as the negative electrode active material layer. A silicon nitride film formed by reactive sputtering with Ar gas and N2 gas may also be used as a sealing film. Additionally, an anode active material layer may be formed by a sputtering method using a sputtering target with lithium cobalt oxide (LiCoO2) as the main component. A conductive film serving as a current collector may be formed by a sputtering method using a titanium target. A cap layer or a lower film may also be formed by forming a titanium nitride film by reactive sputtering with Ar gas and N2 gas.

[0140] When forming an anode active material layer, the mask and the substrate are overlapped and transported from the second transport chamber (872) to the first film deposition chamber (892) by means of a substrate transport mechanism (853), the gate (882) is closed, and film deposition by sputtering is performed. After the film deposition is finished, the gate (882) and the gate (883) are opened and transported to the heating chamber (893), and after closing the gate (883), heating can be performed. For the heating treatment in the heating chamber (893), a Rapid Thermal Anneal (RTA) device, a resistance furnace, or a microwave heating device may be used. For the RTA device, a Gas Rapid Thermal Anneal (GRTA) device or a Lamp Rapid Thermal Anneal (LRTA) device may be used. The heating treatment in the heating chamber (893) may be performed under an atmosphere of nitrogen, oxygen, noble gas, or dry air. In addition, the heating time is set to be from 1 minute to 24 hours.

[0141] Then, after the film deposition or heat treatment is finished, the substrate and mask are returned to the mask alignment room (891) to align the position of the new mask. The aligned substrate and mask are returned to the first return room (871) by the substrate return mechanism (852). The substrate is returned by the lifting mechanism of the first return room (871), the gate (884) is opened, and the substrate is returned to the third return room (873) by the substrate return mechanism (854).

[0142] A film is formed by deposition in a second film formation chamber (874) connected to a third return chamber (873) through a gate (885).

[0143] An example of the cross-sectional structure of the configuration of the second film-forming chamber (874) is shown in FIG. 13. FIG. 13 is a schematic cross-sectional view taken along the dotted line of FIG. 12. The second film-forming chamber (874) is connected to the exhaust mechanism (849), and the first material supply chamber (895) is connected to the exhaust mechanism (848). The second material supply chamber (894) is connected to the exhaust mechanism (847). The second film-forming chamber (874) shown in FIG. 13 is a deposition chamber that performs deposition using a deposition source (856) moved from the first material supply chamber (895), and it is possible to move a deposition source from each of the multiple material supply chambers and simultaneously vaporize and deposit multiple materials, that is, to perform co-deposition. FIG. 13 shows a deposition source having a deposition boat (858) moved from the second material supply chamber (894).

[0144] Additionally, the second tabernacle room (874) is connected to the second material supply room (894) through the gate (886). Additionally, the second tabernacle room (874) is connected to the first material supply room (895) through the gate (888). Additionally, the second tabernacle room (874) is connected to the third material supply room (896) through the gate (887). Therefore, three-way co-deposition is possible in the second tabernacle room (874).

[0145] As a procedure for performing deposition, first, a substrate is installed in a substrate holding member (845). The substrate holding member (845) is connected to a rotating mechanism (865). Then, the first deposition material (855) is heated to a certain degree in the first material supply room (895), and when the deposition rate stabilizes, the gate (888) is opened, and the arm (862) is extended to move the deposition source (856) and stop it at a position below the substrate. The deposition source (856) consists of the first deposition material (855), a heater (857), and a container for holding the first deposition material (855). Additionally, the second deposition material is heated to a certain degree in the second material supply room (894), and when the deposition rate stabilizes, the gate (886) is opened, and the arm (861) is extended to move the deposition source and stop it at a position below the substrate.

[0146] After that, the shutter (868) and the deposition source shutter (869) are opened, and co-deposition is performed. During deposition, the rotation mechanism (865) is rotated to increase the uniformity of the film thickness. The substrate, after the deposition is finished, is returned to the mask alignment room (891) via the same path. When removing the substrate from the manufacturing device, the substrate is returned from the mask alignment room (891) to the load lock room (870) and then removed.

[0147] Additionally, FIG. 13 illustrates an example in which a substrate (850) and a mask are held in a substrate holding portion (845). By rotating the substrate (850) (and the mask) using a substrate rotation mechanism, the uniformity of the film formation can be improved. The substrate rotation mechanism may also serve as a substrate transport mechanism.

[0148] Additionally, the second membrane chamber (874) may have an imaging means (863), such as a CCD camera. By having an imaging means (863), the position of the substrate (850) can be confirmed.

[0149] In addition, in the second film-forming chamber (874), the thickness of the film formed on the substrate surface can be predicted from the measurement result of the film thickness measuring instrument (867). As for the film thickness measuring instrument (867), for example, a crystal oscillator may be used.

[0150] Additionally, to control the deposition of the vaporized deposition material, a shutter (868) that overlaps with the substrate until the vaporization rate of the deposition material stabilizes, or a deposition source shutter (869) that overlaps with the deposition source (856) or the deposition boat (858) is provided.

[0151] Although an example of a resistance heating method was shown for the deposition source (856), an EB (Electron Beam) deposition method may also be used. Additionally, although an example of a crucible was shown as the container for the deposition source (856), a deposition boat may also be used. An organic material is placed in the crucible heated by the heater (857) as the first deposition material (855). Furthermore, when pellets or particulate SiO are used as the deposition material, a deposition boat (858) is used. The deposition boat (858) consists of three parts, and a member having a concave surface, an inner cover with two holes, and an upper cover with one hole are superimposed. Additionally, the inner cover may be removed to perform deposition. The deposition boat (858) acts as a resistor when current is applied, and the deposition boat itself is heated by a mechanism.

[0152] In addition, although the present embodiment shows an example of a multi-chamber type, it is not particularly limited and may be an in-line type manufacturing device.

[0153] This embodiment may be implemented in appropriate combination with other embodiments.

[0154] (Embodiment 6)

[0155] In this embodiment, an example of a thin-film secondary battery having a battery control circuit, etc., will be described.

[0156] Figure 14 (A) is an external view of a thin-film secondary battery. The secondary battery (913) has terminals (951) and (952). Terminal (951) is electrically connected to the positive electrode, and terminal (952) is electrically connected to the negative electrode. A secondary battery of one form of the present invention has excellent cycle characteristics. In addition, since it can be made into a solid-state secondary battery, it also has excellent safety. Therefore, a secondary battery of one form of the present invention can be suitably used as a secondary battery (913).

[0157] FIG. 14 (B) is an external view of a battery control circuit. The battery control circuit shown in FIG. 14 (B) has a substrate (900) and a layer (916). A circuit (912) and an antenna (914) are provided on the substrate (900). The antenna (914) is electrically connected to the circuit (912). Terminals (971) and (972) are electrically connected to the circuit (912). The circuit (912) is electrically connected to terminal (911).

[0158] The terminal (911) is connected to a device to which power is supplied, for example, by a thin-film solid secondary battery. For example, it is connected to a display device, a sensor, etc.

[0159] The layer (916) has the function of shielding an electromagnetic field, for example, from a secondary battery (913). For example, a magnetic material can be used as the layer (916).

[0160] Figure 14 (C) shows an example in which the battery control circuit shown in Figure 14 (B) is placed on a secondary battery (913). Terminal (971) is electrically connected to terminal (951), and terminal (972) is electrically connected to terminal (952). Layer (916) is placed between the substrate (900) and the secondary battery (913).

[0161] It is preferable to use a flexible substrate as the substrate (900).

[0162] By using a flexible substrate as the substrate (900), a thin battery control circuit can be realized. Additionally, as shown in (D) of FIG. 15 described later, the battery control circuit can be wound onto a secondary battery.

[0163] Using FIGS. 15 (A) to (D), another example of a thin-film secondary battery having a battery control circuit, etc. is described. FIGS. 15 (A) is an external view of a thin-film solid secondary battery. The battery control circuit shown in FIGS. 15 (B) has a substrate (900) and a layer (916).

[0164] As shown in (C) of FIG. 15, the substrate (900) is bent to fit the shape of the secondary battery (913), and the battery control circuit is placed around the secondary battery, so that the battery control circuit can be wound around the secondary battery as shown in (D) of FIG. 15. By making the secondary battery with such a configuration, it is possible to make the secondary battery smaller.

[0165] This embodiment may be implemented in appropriate combination with other embodiments.

[0166] (Embodiment 7)

[0167] In this embodiment, examples of electronic devices using thin-film secondary batteries are described using FIGS. 16 (A), (B) and FIGS. 17 (A) to (C). One embodiment of the secondary battery of the present invention has high discharge capacity and cycle characteristics, and high safety. Therefore, the electronic device has high safety and can be used for a long time.

[0168] Figure 16 (A) is an external perspective view of a thin-film secondary battery (3001) according to the present invention. A positive lead electrode (513) electrically connected to the positive electrode of a solid secondary battery and a negative lead electrode (511) electrically connected to the negative electrode are sealed with a laminate film or insulating material so as to protrude.

[0169] Figure 16 (B) is an IC card, which is an example of an application device using a thin-film secondary battery according to the present invention. Power obtained by supplying power from radio waves (3005) can be charged into the thin-film secondary battery (3001). An antenna and an IC (3004) or a thin-film secondary battery (3001) are arranged inside the IC card (3000). The ID (3002) and photograph (3003) of a worker wearing a management badge are displayed on the IC card (3000). A signal such as an authentication signal can be transmitted from the antenna using the power charged in the thin-film secondary battery (3001).

[0170] An active matrix display device may be provided for displaying ID (3002) and photos (3003). Examples of active matrix display devices include reflective liquid crystal displays, organic EL displays, and electronic paper. An image (video or still image) or time may be displayed on the active matrix display device. Power for the active matrix display device may be supplied from a thin-film secondary battery (3001).

[0171] Since plastic substrates are used in IC cards, an organic EL display device using a flexible substrate is preferred.

[0172] In addition, a solar cell may be provided instead of a photograph (3003). It can generate power by absorbing light through irradiation with external light, and charge the thin-film secondary battery (3001) with that power.

[0173] In addition, thin-film secondary batteries are not limited to IC cards and can be used as power sources for wireless sensors used in vehicles and as secondary batteries for MEMS devices.

[0174] Figure 17 (A) shows an example of a wearable device. Wearable devices may use a secondary battery as a power source. In addition, to improve splash resistance, water resistance, or dust resistance when used by a user in daily life or outdoors, there is a demand for a wearable device capable of wireless charging as well as wired charging with an exposed connector part.

[0175] For example, a secondary battery, which is one form of the present invention, can be mounted in a glasses-type device (400) as shown in (A) of FIG. 17. The glasses-type device (400) has a frame (400a) and a display part (400b). By mounting a secondary battery in the temple part of the frame (400a) which has a curve, the glasses-type device (400) can be made lightweight, have good weight balance, and have a long continuous usage time. By including a secondary battery, which is one form of the present invention, a configuration that can save space by miniaturizing the housing can be realized.

[0176] Additionally, a secondary battery, which is one form of the present invention, can be mounted in the headset-type device (401). The headset-type device (401) has at least a microphone part (401a), a flexible pipe (401b), and an earphone part (401c). A secondary battery can be provided within the flexible pipe (401b) or within the earphone part (401c). By including a secondary battery, which is one form of the present invention, a configuration that can save space due to the miniaturization of the housing can be realized.

[0177] In addition, a secondary battery, which is one form of the present invention, can be mounted on a device (402) that can be directly attached to the body. A secondary battery (402b) can be provided within a thin housing (402a) of the device (402). By including a secondary battery, which is one form of the present invention, a configuration that can save space by miniaturizing the housing can be realized.

[0178] Additionally, a secondary battery, which is one form of the present invention, can be mounted on a device (403) that can be attached to clothing. A secondary battery (403b) can be provided within a thin housing (403a) of the device (403). By including a secondary battery, which is one form of the present invention, a configuration that can save space by miniaturizing the housing can be realized.

[0179] Additionally, a secondary battery, which is one form of the present invention, can be mounted on the belt-type device (406). The belt-type device (406) has a belt section (406a) and a wireless power supply / receiving section (406b), and a secondary battery can be mounted inside the belt section (406a). By including a secondary battery, which is one form of the present invention, a configuration that can save space due to the miniaturization of the housing can be realized.

[0180] Additionally, a secondary battery, which is one form of the present invention, can be mounted on the wristwatch-type device (405). The wristwatch-type device (405) has a display unit (405a) and a belt unit (405b), and a secondary battery can be provided to the display unit (405a) or the belt unit (405b). By including a secondary battery, which is one form of the present invention, a configuration that can save space due to the miniaturization of the housing can be realized.

[0181] The display unit (405a) can display not only the time but also various information such as incoming mail or phone calls.

[0182] In addition, since the wristwatch-type device (405) is a wearable device that is worn directly on the arm, it may be equipped with a sensor that measures the user's pulse and blood pressure. It can manage health by accumulating data regarding the user's exercise amount and health.

[0183] In Fig. 17 (B), a perspective view of a wristwatch-type device (405) removed from the arm is shown.

[0184] Additionally, a side view of the wristwatch-type device (405) is shown in (C) of FIG. 17. FIG. 17 (C) shows a state in which a secondary battery (913) is built inside. The secondary battery (913) is the secondary battery shown in Embodiment 5. The secondary battery (913) is provided in a position overlapping with the display part (405a), and is small and lightweight.

[0185] This embodiment may be implemented in appropriate combination with other embodiments.

[0186] (Embodiment 8)

[0187] In this embodiment, an electronic device using a secondary battery having a positive electrode of one form of the present invention is described using FIGS. 18 (A) to (C), FIGS. 19 (A) to (D), and FIGS. 20 (A) and (B). A secondary battery having a positive electrode of one form of the present invention has high discharge capacity and cycle characteristics, and thus high safety. Therefore, it can be suitably used in the electronic device described below. In particular, it can be suitably used in electronic devices requiring durability.

[0188] A perspective view of a wristwatch-type portable information terminal (also called a smartwatch) (700) is shown in (A) of FIG. 18. The portable information terminal (700) has a housing (701), a display panel (702), a buckle (703), a band (705A, 705B), and operation buttons (711, 712).

[0189] A display panel (702) mounted on a housing (701) that also serves as a bezel has a rectangular display area. Additionally, the display area forms a curved surface. It is preferable that the display panel (702) be flexible. Additionally, the display area may be non-rectangular.

[0190] Band (705A) and band (705B) are connected to the housing (701). Buckle (703) is connected to band (705A). Band (705A) and the housing (701) are connected so that the connection can be rotated, for example, through a pin. The same applies to the connection between band (705B) and the housing (701), and between band (705A) and the buckle (703).

[0191] A perspective view of a band (705A) and a secondary battery (750) is shown in FIG. 18 (B) and (C), respectively. The band (705A) has a secondary battery (750). For example, the secondary battery described in the previous embodiment may be used for the secondary battery (750). The secondary battery (750) is embedded inside the band (705A), and a portion of the positive lead (751) and negative lead (752) each protrude from the band (705A) (see FIG. 18 (B)). The positive lead (751) and negative lead (752) are electrically connected to a display panel (702). Additionally, the surface of the secondary battery (750) is covered with an outer body (753) (see FIG. 18 (C)). Furthermore, the pin may function as an electrode. Specifically, the positive lead (751) and the display panel (702), and the negative lead (752) and the display panel (702) may be electrically connected through a pin connecting the band (705A) and the housing (701), respectively. By doing so, the configuration at the connection portion of the band (705A) and the housing (701) can be simplified.

[0192] The secondary battery (750) is flexible. Therefore, the band (705A) can be manufactured by forming it integrally with the secondary battery (750). For example, the band (705A) shown in (B) of FIG. 18 can be manufactured by fixing the secondary battery (750) to a mold corresponding to the shape of the band (705A), pouring the material of the band (705A) into the mold, and curing the material.

[0193] When a rubber material is used as the material for the band (705A), the rubber is cured by heat treatment. For example, when fluorine rubber is used as the rubber material, it is cured by heat treatment at 170°C for 10 minutes. Also, when silicone rubber is used as the rubber material, it is cured by heat treatment at 150°C for 10 minutes.

[0194] Materials used for the band (705A) include fluorine rubber, silicone rubber, fluorosilicone rubber, and urethane rubber.

[0195] In addition, the portable information terminal (700) illustrated in (A) of FIG. 18 may have various functions. For example, it may have a function to display various information (still images, video, text images, etc.) in a display area, a touch panel function, a function to display a calendar, date, or time, a function to control processing by various software (programs), a wireless communication function, a function to connect to various computer networks using the wireless communication function, a function to transmit or receive various data using the wireless communication function, and a function to read a program or data stored on a recording medium and display it in a display area.

[0196] Additionally, the housing (701) may have a speaker, a sensor (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, longitude, electric field, current, voltage, power, radiation, flow rate, humidity, inclination, vibration, smell, or infrared), a microphone, etc., inside. Additionally, the portable information terminal (700) may be manufactured by using a light-emitting element in its display panel (702).

[0197] Additionally, in FIG. 18 (A), an example is shown in which a secondary battery (750) is included in band (705A), but the secondary battery (750) may also be included in band (705B). For band (705B), the same material as band (705A) can be used.

[0198] Figure 19 (A) illustrates an example of a robot vacuum cleaner. The robot vacuum cleaner (6300) has a display unit (6302) placed on the upper surface of a housing (6301), a plurality of cameras (6303) placed on the side, a brush (6304), an operation button (6305), various sensors, etc. Although not illustrated, the robot vacuum cleaner (6300) is provided with tires, a suction port, etc. The robot vacuum cleaner (6300) can drive autonomously, detect dust (6310), and suck up dust from a suction port provided on the lower surface.

[0199] For example, the robot vacuum cleaner (6300) can determine the presence or absence of obstacles such as walls, furniture, or steps by interpreting an image captured by a camera (6303). Additionally, if an object prone to getting tangled in the brush (6304), such as wiring, is detected by image interpretation, the rotation of the brush (6304) can be stopped. The robot vacuum cleaner (6300) has a secondary battery according to one embodiment of the present invention and a semiconductor device or electronic component inside. By using a secondary battery according to one embodiment of the present invention in the robot vacuum cleaner (6300), the robot vacuum cleaner (6300) can be made into an electronic device with a long operating time and high reliability.

[0200] Figure 19 (B) illustrates an example of a robot. The robot (6400) illustrated in Figure 19 (B) has a secondary battery (6409), an illuminance sensor (6401), a microphone (6402), an upper camera (6403), a speaker (6404), a display unit (6405), a lower camera (6406), an obstacle sensor (6407), a moving mechanism (6408), a computing device, etc.

[0201] The microphone (6402) has the function of detecting the user's voice and environmental sounds. Additionally, the speaker (6404) has the function of outputting voice. The robot (6400) can communicate with the user by using the microphone (6402) and the speaker (6404).

[0202] The display unit (6405) has the function of displaying various information. The robot (6400) can display information desired by the user on the display unit (6405). The display unit (6405) may be equipped with a touch panel. Additionally, the display unit (6405) may be a detachable information terminal and can be charged and exchange data by being installed at a fixed position on the robot (6400).

[0203] The upper camera (6403) and the lower camera (6406) have the function of capturing images of the surroundings of the robot (6400). Additionally, the obstacle sensor (6407) can detect the presence or absence of obstacles in the direction of travel when the robot (6400) moves forward using the moving mechanism (6408). The robot (6400) can move safely by recognizing the surrounding environment using the upper camera (6403), the lower camera (6406), and the obstacle sensor (6407).

[0204] The robot (6400) has a secondary battery (6409) according to one embodiment of the present invention and a semiconductor device or electronic component inside. By using the secondary battery according to one embodiment of the present invention in the robot (6400), the robot (6400) can be made into an electronic device with a long operating time and high reliability.

[0205] Figure 19 (C) illustrates an example of an aircraft. The aircraft (6500) shown in Figure 19 (C) has a propeller (6501), a camera (6502), and a secondary battery (6503), and has the ability to fly autonomously.

[0206] For example, image data captured by a camera (6502) is stored in an electronic component (6504). The electronic component (6504) can interpret the image data to detect the presence or absence of obstacles when moving. Additionally, the remaining battery capacity can be estimated from the change in the storage capacity of the secondary battery (6503) by the electronic component (6504). The aircraft (6500) has a secondary battery (6503) according to one embodiment of the present invention inside. By using a secondary battery according to one embodiment of the present invention in the aircraft (6500), the aircraft (6500) can be made into an electronic device with a long operating time and high reliability.

[0207] Figure 19 (D) illustrates an example of a vehicle. The vehicle (7160) has a secondary battery (7161), an engine, tires, brakes, a steering device, a camera, etc. Additionally, it is desirable to have a system (1000) described later. The vehicle (7160) has a secondary battery (7161) according to one embodiment of the present invention inside. By using a secondary battery according to one embodiment of the present invention in the vehicle (7160), the vehicle (7160) can be made into a vehicle with a long driving range, high safety, and high reliability.

[0208] In addition, one embodiment of the present invention may be an electronic device or system having a thin-film battery as described in the preceding embodiment and another secondary battery. The other secondary battery is not particularly limited, but, for example, a lithium-ion secondary battery having a positive electrode, a negative electrode, an electrolyte, and a separator, or a bulk all-solid-state secondary battery may be used. Furthermore, in this specification and other contexts, the term "system" refers to a system in which each of the elements is combined. One of the elements is a secondary battery.

[0209] Figure 20 (A) shows a system (1000) having a thin-film battery (1001) described in the previous embodiment and a lithium-ion secondary battery (1002) having a positive electrode, a negative electrode, an electrolyte, and a separator. By making such an electronic device or system, the advantages of both a secondary battery having a larger discharge capacity and a thin-film battery described in the previous embodiment, which is easy to make thin and light, can be utilized. It is preferable that the system (1000) has a wireless power supply device. If a wireless power supply device is provided, power can be easily supplied from the lithium-ion secondary battery (1002) to the thin-film battery (1001).

[0210] Figure 20 (B) shows the interior of a vehicle (7160) having a system (1000). The vehicle (7160) has a secondary battery for driving, a wireless power supply device (7162), and a key (7163). By placing the key (7163) on the wireless power supply device (7162), power can be supplied from the secondary battery (7161) to the key (7163). Additionally, Figure 20 (B) shows an example where the wireless power supply device (7162) is installed on the dashboard, but it is not limited thereto. A storage location for the key (7163) may be provided in another location around the driver's seat, and the wireless power supply device (7162) may be provided in said storage location.

[0211] At this time, if the key (7163) has the thin film battery described in the previous embodiment, it is desirable to have a thinner and lighter key. In addition, for the secondary battery for driving the vehicle (7160), it is desirable to use a secondary battery that is easy to obtain a larger discharge capacity, such as a lithium-ion secondary battery having a positive electrode, a negative electrode, an electrolyte, and a separator, or a bulk all-solid-state secondary battery.

[0212] This embodiment may be implemented in appropriate combination with other embodiments.

[0213] (Embodiment 9)

[0214] The device described in this embodiment comprises at least a biosensor and a solid-state secondary battery that supplies power to the biosensor, and can acquire various biometric information using infrared light and visible light and store it in memory. Such biometric information can be used for both personal authentication of a user and for healthcare purposes. A secondary battery of one form of the present invention has high discharge capacity and cycle characteristics, and also has high safety. Therefore, the device has high safety and can be used for a long time.

[0215] A biosensor is a sensor that acquires biological information, and it obtains biological information that can be used for healthcare purposes. Examples of biological information include pulse waves, blood glucose levels, oxygen saturation, and triglyceride concentrations. The data is stored in memory.

[0216] In addition, it is desirable to provide the device described in this embodiment with means for acquiring other biometric information. For example, in addition to internal biometric information such as electrocardiogram, blood pressure, and body temperature, there is superficial biometric information such as facial expression, complexion, and pupils. Furthermore, information regarding steps taken, exercise intensity, elevation difference during movement, and diet (calorie intake, nutrients, etc.) is also important information for healthcare. By utilizing multiple types of biometric information, comprehensive health management becomes possible, leading not only to daily health management but also to the early detection of diseases.

[0217] For example, blood pressure can be calculated from the difference in timing between the two beats of the electrocardiogram and the pulse wave (the length of the pulse wave propagation time). If blood pressure is high, the pulse wave propagation time is short, and conversely, if blood pressure is low, the pulse wave propagation time is long. Furthermore, the user's physical condition can be estimated from the relationship between heart rate and blood pressure calculated from the electrocardiogram and pulse wave. For instance, if both heart rate and blood pressure are high, it can be estimated that the user is in a state of tension or excitement, whereas if both heart rate and blood pressure are low, it can be estimated that the user is in a relaxed state. Additionally, if a state of low blood pressure and a high heart rate persists, there is a possibility of heart disease.

[0218] Users can frequently check biometric information measured by electronic devices or their physical condition estimated based on such information, thereby improving their health awareness. As a result, this may serve as an opportunity to reflect on their daily habits, such as avoiding binge drinking and eating, engaging in moderate exercise, or managing their health, or to seek medical attention at a medical institution if necessary.

[0219] Each data may be shared among multiple biosensors. FIG. 21 (A) is an example in which a biosensor (80a) is implanted in the user's body and a biosensor (80b) is mounted on the wrist. FIG. 21 (A) is a device having a biosensor (80a) capable of measuring an electrocardiogram, for example, and a biosensor (80b) capable of performing heart rate measurement, such as optically monitoring the pulse of the user's wrist. In addition, the wristwatch-type or wristband-type mountable device shown in FIG. 21 (A) is not limited to heart rate measurement and can use various biosensors.

[0220] The embedded device shown in FIG. 21 (A) is predicated on being small, having almost no heat generation, and not causing allergic reactions when in contact with the skin. The secondary battery used in one embodiment of the device of the present invention is suitable because it is small, has almost no heat generation, and does not cause allergic reactions. In addition, it is preferable for the embedded device to have an antenna built in to enable wireless charging.

[0221] The device shown in (A) of FIG. 21, which is embedded within the body, is not limited to a biosensor capable of measuring an electrocardiogram, but can use a biosensor capable of acquiring other biological data.

[0222] A biosensor (80b) embedded in a device may have the function of storing acquired data in a temporary memory embedded in the device. Alternatively, each data acquired by the biosensor may be transmitted wirelessly or via a wire to a portable data terminal (85) of (B) in FIG. 21, and the portable data terminal (85) may have the function of detecting waveforms. The portable data terminal (85) may be a smartphone, etc., and may detect whether problems such as arrhythmia occur from the data acquired by each biosensor. When transmitting data acquired by multiple biosensors via a wire to the portable data terminal (85), it is preferable to transmit the acquired data all at once until a wired connection is established. Additionally, each detected data may be automatically assigned a date, stored in the memory of the portable data terminal (85), and managed privately. Alternatively, as shown in (B) of FIG. 21, it may be transmitted to a medical institution (87), such as a hospital, via a network (including the Internet). The above data is managed on a hospital data server and can be used as examination data during treatment. Since medical data can be massive, high-speed communication may be performed using Bluetooth (registered trademark) or a network including frequency bands from 2.4 GHz to 2.4835 GHz from the biosensor (80b) to the mobile data terminal (85), and using a 5th generation wireless method from the mobile data terminal (85) to the mobile data terminal (85). The 5th generation wireless method uses frequencies in the 3.7 GHz band, 4.5 GHz band, and 28 GHz band. By using the 5th generation wireless method, data acquisition and transmission to a medical institution (87) are possible not only at home but also when going out, allowing for accurate acquisition of data when there is an abnormality in the user's physical condition and subsequent use for processing or treatment.Additionally, as a mobile data terminal (85), the configuration shown in (C) of FIG. 21 can be used.

[0223] Figure 21 (C) shows another example of a portable data terminal. The portable data terminal (89) has a speaker, a pair of electrodes (83), a camera (84), and a microphone (86) in addition to a secondary battery.

[0224] A pair of electrodes (83) are provided with a display portion (81a) fitted into a part of the housing (82). The display portion (81b) is a curved area. The electrodes (83) function as electrodes for acquiring biological information.

[0225] As shown in (C) of FIG. 21, by arranging a pair of electrodes (83) in the longitudinal direction of the housing (82), the acquisition of biometric information can be performed without the user being aware of it when using the portable data terminal (89) with a horizontally long screen.

[0226] An example of the usage state of the portable data terminal (89) is shown. The display unit (81a) can display information such as electrocardiogram data (88a) and heart rate data (88b) obtained with a pair of electrodes (83).

[0227] As shown in (A) of FIG. 21, this function may be unnecessary when the biosensor (80a) is implanted in the user's body, but when it is not implanted, the user can obtain an electrocardiogram by holding a pair of electrodes (83) with both hands. Even when the biosensor (80a) is implanted in the user's body, the portable data terminal (89) shown in (C) of FIG. 21 can be used to check whether the biosensor (80a) is functioning normally. Additionally, the portable data terminal (89) shown in (C) of FIG. 21 can be used when comparing electrocardiogram data among multiple users.

[0228] The camera (84) can capture images of the user's face, etc. Biometric information such as facial expressions, pupils, and complexion can be obtained from the image of the user's face.

[0229] The microphone (86) can acquire the user's voice. Voice information that can be used for voice authentication can be obtained from the acquired voice information. Additionally, by regularly acquiring voice information and monitoring changes in the quality of the voice, it can also be used for health management. Of course, video calls with a doctor at a medical institution (87) are also possible using the microphone (86), camera (84), and speaker.

[0230] By using the device shown in (A) of FIG. 21 and the portable data terminal (89) shown in (C) of FIG. 21, a remote medical support system can be realized, such as transmitting information to a doctor at a hospital from a remote location to receive medical treatment from the doctor.

[0231] This embodiment may be implemented in appropriate combination with other embodiments.

[0232] (Example 1)

[0233] In this embodiment, a secondary battery having a lower film and a cap layer, which is one form of the present invention, and a secondary battery without a lower film or a cap layer, as a comparative example, were fabricated, and charge / discharge characteristics and cycle characteristics were evaluated.

[0234] Production of secondary batteries

[0235] Sample 1, which is one embodiment of the present invention, was prepared as follows. First, a titanium sheet was used as a substrate and a positive current collector layer. The titanium sheet was a rolled foil with a thickness of 0.1 mm, a purity of 99.5%, and was etched and non-mirror-surfaced, and was processed to 12 mmφ for use.

[0236] A 20 nm titanium nitride (TiN) film was deposited as a substrate on a titanium sheet by sputtering. The sputtering conditions were as follows.

[0237] Target: Titanium target, 100mm diameter

[0238] Sputtering Power Supply, Output: DC Power, 500W

[0239] Atmosphere: Argon flow rate 12.0 sccm, Nitrogen flow rate 28 sccm, Pressure 0.4 Pa

[0240] Tabernacle time: 8 minutes

[0241] Tabernacle temperature: Set to 600℃

[0242] Film formation rate: 2.5 nm / min

[0243] Next, a 1000 nm lithium cobaltate (LiCoO2) film was deposited as the positive active material layer by sputtering. The sputtering conditions were as follows.

[0244] Target: Lithium cobaltate target, diameter 100mm

[0245] Sputtering Power Supply, Output: RF Power, 500W

[0246] Atmosphere: Argon flow rate 40 sccm, Oxygen flow rate 10 sccm, Pressure 0.4 Pa

[0247] Tabernacle time: 461 minutes

[0248] Tabernacle temperature: Set to 600℃

[0249] Film formation rate: 2.2 nm / min

[0250] Next, as a cap layer, titanium oxide (TiO₂) of approximately 20 nm is used. x The ) was formed by the sputtering method. The sputtering conditions were as follows.

[0251] Target: Titanium target, 100mm diameter

[0252] Sputtering Power Supply, Output: DC Power, 500W

[0253] Atmosphere: Argon flow rate 24 sccm, Oxygen flow rate 16 sccm, Pressure 0.4 Pa

[0254] Tabernacle time: 27.7 minutes

[0255] Film deposition temperature: Set to 600℃ (actual substrate temperature is approximately 400℃)

[0256] Film formation rate: 0.72 nm / min

[0257] Also, Sample 2 without a backing film and titanium oxide (TiO₂) as the backing film. x Sample 3 was made with the tabernacle. Except for the diaphragm, it was made in the same way as Sample 1.

[0258] In addition, as a comparative example, samples 4 to 6 without a cap layer were prepared. These were prepared in the same manner as samples 1 to 3, except that a cap layer was not formed.

[0259] The production conditions for each sample are shown in Table 2.

[0260] [Table 2]

[0261]

[0262] Production of battery cells

[0263] Next, a CR2032 type (diameter 20 mm, height 3.2 mm) coin cell was fabricated using each sample as the positive electrode.

[0264] Lithium metal was used for the counter electrode.

[0265] For the electrolyte, 1 mol / L of lithium hexafluoride phosphate (LiPF6) was used, and for the electrolyte, a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) in an EC:DEC ratio of 3:7 (volume ratio) was used. In addition, for the secondary battery for which charge / discharge efficiency was evaluated, 2 wt% of vinylene carbonate (VC) was added to the electrolyte.

[0266] Polypropylene with a thickness of 25 μm was used for the separator.

[0267] The positive and negative cans were made of stainless steel (SUS).

[0268] Measurement of Charge / Discharge Efficiency

[0269] Initial characteristics were measured by charging at CCCV, 0.2C, 4.2V, and a cutoff current of 0.1C. Discharging was performed at CC, 0.2C, and a cutoff voltage of 2.5V. In addition, 1C was defined as a current value of 137 mA / g per weight of positive active material. The measurement temperature was set to 25℃. The results of the initial characteristics measurements are shown in Table 3 and Figures 22 (A) and (B). Figure 22 (A) is a graph of samples 1 to 3, and Figure 22 (B) is a graph of samples 4 to 6.

[0270] [Table 3]

[0271]

[0272] From Table 3 and Figures 22 (A) and (B), it was found that all samples exhibited good charge / discharge characteristics.

[0273] Charge / Discharge Cycle Characteristics

[0274] Next, the charge-discharge cycle characteristics of these battery cells were evaluated. The charge-discharge in the measurement of cycle characteristics was performed in the same manner as the measurement of initial characteristics. The results of the cycle characteristics are shown in Figures 23 (A) and (B). Figure 23 (A) is a graph of samples 1 to 3, and Figure 23 (B) is a graph of samples 4 to 6.

[0275] From Figures 23 (A) and (B), samples 1 to 3 having a cap layer exhibited significantly better cycle characteristics than samples 4 to 6 not having a cap layer. Sample 1, having titanium nitride as the underlayer, exhibited the best characteristics, with a discharge capacity of 115 mAh / g and a discharge capacity retention rate of 93% after 25 cycles. Sample 3, having titanium oxide as the underlayer, exhibited the next best characteristics after Sample 1, with a discharge capacity of 113 mAh / g and a discharge capacity retention rate of 93% after 25 cycles. Sample 2, not having a underlayer, had a discharge capacity of 111 mAh / g and a discharge capacity retention rate of 92% after 25 cycles.

[0276] Therefore, it was found that a secondary battery with good charge-discharge cycle characteristics can be fabricated by providing a cap layer. Furthermore, it was found that charge-discharge cycle characteristics are better when a bottom layer is present than when there is no bottom layer, and that titanium nitride is particularly desirable.

[0277] (Example 2)

[0278] In this embodiment, a secondary battery having a cap layer, which is one form of the present invention, and a secondary battery without a cap layer, as a comparative example, were fabricated, and the characteristics were analyzed by TEM, electron energy loss spectroscopy (EELS), microelectron diffraction, impedance measurement, etc., and the cycle characteristics were evaluated.

[0279] Production of secondary batteries

[0280] Sample 11, which is one embodiment of the present invention, was prepared as follows. First, a 100 μm titanium sheet was used to serve as both a substrate and an anode current collector layer.

[0281] A 20 nm titanium nitride (TiN) film was deposited as a substrate on a titanium sheet by sputtering. The sputtering conditions were as follows.

[0282] Target: Titanium target, 2-inch diameter

[0283] Sputtering Power Supply, Output: RF Power, 100W

[0284] Atmosphere: Argon flow rate 3.0 sccm, Nitrogen flow rate 7 sccm, Pressure 0.5 Pa

[0285] Tabernacle time: 15 minutes

[0286] Tabernacle temperature: Set to 600℃

[0287] Target-Board Distance: 75mm

[0288] Next, a 900 nm lithium cobaltate (LiCoO2) film was deposited as the positive active material layer by sputtering. The sputtering conditions were as follows.

[0289] Target: Lithium cobaltate target, 2-inch diameter

[0290] Sputtering Power Supply, Output: RF Power, 200W

[0291] Atmosphere: Argon, flow rate 10 sccm, pressure 0.5 Pa

[0292] Tabernacle time: 109 minutes

[0293] Tabernacle temperature: Set to 600℃

[0294] Target-Board Distance: 75mm

[0295] Film formation rate: 9.2 nm / min

[0296] Next, a 20 nm titanium oxide (TiO2) film was deposited as a cap layer by sputtering. The sputtering conditions were as follows.

[0297] Target: Titanium target, 100mm diameter

[0298] Sputtering Power Supply, Output: DC Power, 500W

[0299] Atmosphere: Argon flow rate 24 sccm, Oxygen flow rate 16 sccm, Pressure 0.4 Pa

[0300] Tabernacle time: 27.7 minutes

[0301] Film deposition temperature: Set to 600℃ (actual substrate temperature is approximately 400℃)

[0302] Film formation rate: 0.72 nm / min

[0303] In addition, Sample 12, which does not have a cap layer, was prepared as a comparative example. Sample 12 was prepared in the same way as Sample 11 except for the cap layer.

[0304] The production conditions for each sample are shown in Table 4.

[0305] [Table 4]

[0306]

[0307] <tem>

[0308] The shooting conditions for the TEM images were as follows.

[0309] Sample Pretreatment: Fragmentation by FIB (μ-sampling method)

[0310] Transmission Electron Microscope: JEM-ARM200F manufactured by JEOL Ltd.

[0311] Observation Condition Acceleration Voltage: 200kV

[0312] Magnification accuracy: ±3%

[0313] FIG. 24 shows a cross-sectional TEM image of sample 11 before charging and discharging. A titanium oxide cap layer (1102) was observed on the surface layer. FIG. 27 shows a cross-sectional TEM image of sample 11 after charging and discharging. A titanium oxide cap layer (1102) was observed on the surface layer. FIG. 30 shows a cross-sectional TEM image of sample 12 after charging and discharging. In both samples, it was observed that the positive active material layer (1101) of lithium cobaltate was polycrystalline and that the crystallites were in the shape of vertically elongated pillars.

[0314] <eels>

[0315] Next, for the samples after charging and discharging, the electronic state of cobalt was analyzed using EELS, and the valence was calculated from the L3 / L2 ratio by referring to Non-Patent Literature 1. The measurement conditions for EELS were as follows.

[0316] Elemental analysis (point analysis)

[0317] Scanning Transmission Electron Microscope: JEM-ARM200F manufactured by JEOL Ltd.

[0318] Acceleration voltage: 200kV

[0319] Beam diameter: approx. 0.1 nmφ

[0320] Elemental analyzer: Gatan-manufactured Quantum ER

[0321] Electron Spectrometer: MOS Detector Array

[0322] Taking time: 30 seconds

[0323] The EELS analysis portions of Sample 11 after charging and discharging are indicated as *1 and *2 in Fig. 28 (A) and *3, *4, and *5 in Fig. 28 (B). *1 and *2 are at a depth of about 100 nm from the outermost surface of the lithium cobaltate layer toward the substrate. *3 to *5 are likewise at a depth of about 30 nm. All analysis portions are at the grain boundary and its vicinity, but *2, *4, and *5 are inside the grain than *1 and *3. Also, Fig. 28 (B) is an enlarged image of the portion of photo.3-14 enclosed by white lines in Fig. 27.

[0324] The EELS spectra of the portions marked *1 to *5 of Sample 11 are shown in Fig. 29. The Background subtracted EEL spectrum, calculated from the binding energy side lower than the Co-L3 edge, and the Co-L2,3 continuum subtracted spectrum, calculated from the energy band between the Co-L3 edge and the Co-L2 edge, with the background further subtracted, are shown in the figure. Additionally, the Background subtracted EEL spectrum was obtained by subtracting the background from the original data by fitting a power law model. Furthermore, the Co-L2,3 continuum subtracted spectrum was calculated by further subtracting the data from which the background had been removed by the power law fitting, using a model of the scattering cross-section of cobalt (Hartree-slater cross-section model) as the background function. In addition, the area intensity ratio of L3 / L2 and the calculated valence of cobalt are shown in Table 5.

[0325] [Table 5]

[0326]

[0327] Figures 31 (A) and (B) are cross-sectional TEM images of sample 12 after charging and discharging. The EELS analysis portions are indicated as *1 and *2 in Figure 31 (A) and *3, *4, and *5 in Figure 18 (B). All analysis portions are at the grain boundaries and their vicinity, but *2, *4, and *5 are inside the grains, more so than *1 and *3. Also, Figure 31 (B) is an enlarged image of the portion of photo.2-16 enclosed by white lines in Figure 30.

[0328] The EELS spectra of parts *1 to *5 of sample 12 after charging and discharging are also shown in FIG. 32. The area intensity ratio of L3 / L2 and the calculated valence of cobalt are shown in Table 6.

[0329] [Table 6]

[0330]

[0331] From Tables 5 and 6, it was found that sample 11, which has a cap layer, tends to have the reduction of cobalt within the crystal grains more suppressed. Therefore, it was suggested that providing a cap layer can suppress the deterioration of the layered rock salt-type crystal structure.

[0332] Microscopic electron diffraction

[0333] Next, the crystal structure of the grain boundaries and their vicinity of lithium cobaltate was analyzed using microelectron diffraction.

[0334] Figure 25 (A) is a cross-sectional TEM image of sample 11 before charging and discharging. The areas analyzed for microelectron diffraction are indicated as *point1-1, *point1-2, and *point1-3 in Figure 25 (A). Also, Figure 25 (A) is an enlarged image of the area of ​​photo.1-7 enclosed by the black line in Figure 24.

[0335] Figure 25 (B) shows an ultrafine electron beam diffraction image of the *point1-1 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point1-1 section, the plane spacing of 1 was calculated to be 0.137 nm, the plane spacing of 2 to be 0.143 nm, and the plane spacing of 3 to be 0.464 nm. In addition, the plane angles were ∠1O2=17°, ∠1O3=107°, and ∠2O3=90°. At this time, the electron beam incident direction is

[0120] , and from the plane spacing and plane angles, it was thought that 1 is -213 of a layered rock salt type crystal, 2 is likewise -210, and 3 is likewise 00-3, and has a layered rock salt type crystal structure. As a result of calculating the lattice constants of the *point1-1 part from these d values, a=2.86(Å) and c=13.9(Å).

[0336] Figure 26 (A) shows the microscopic electron beam diffraction image of the *point1-2 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point1-2 section, the plane spacing of 1 was calculated to be 0.137 nm, the plane spacing of 2 to be 0.143 nm, and the plane spacing of 3 to be 0.464 nm. In addition, the plane angles were ∠1O2=17°, ∠1O3=107°, and ∠2O3=90°. At this time, the electron beam incident direction is

[0120] , and from the plane spacing and plane angles, it was thought that 1 is -213 of a layered rock salt type crystal, 2 is likewise -210, and 3 is likewise 00-3, and has a layered rock salt type crystal structure. As a result of calculating the lattice constants of *point1-2 from these d values, a=2.86(Å) and c=13.9(Å).

[0337] Figure 26 (B) shows the microscopic electron beam diffraction image of the *point1-3 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point1-3 section, the plane spacing of 1 was calculated to be 0.146 nm, the plane spacing of 2 to be 0.139 nm, and the plane spacing of 3 to be 0.463 nm. In addition, the plane angles were ∠1O2=17°, ∠1O3=90°, and ∠2O3=72°. At this time, the electron beam incident direction is

[0120] , and from the plane spacing and plane angles, it was thought that 1 is -210 of a layered rock salt type crystal, 2 is likewise -21-3, and 3 is likewise 00-3, and that it has a layered rock salt type crystal structure. As a result of calculating the lattice constants for *point1-3 from these d values, a=2.92(Å) and c=13.9(Å).

[0338] Figure 33 (A) is a cross-sectional TEM image of sample 11 after charging and discharging. The analysis portions of the ultrafine electron diffraction are indicated as *point3-1, *point3-2, and *point3-3 in Figure 33 (A).

[0339] Figure 33 (B) shows an ultrafine electron beam diffraction image of the *point3-1 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point3-1 section, the plane spacing of 1 was calculated to be 0.227 nm, the plane spacing of 2 to be 0.183 nm, and the plane spacing of 3 to be 0.475 nm. In addition, the plane angles were ∠1O2=21°, ∠1O3=71°, and ∠2O3=50°. At this time, the electron beam incident direction is [0-10], and from the plane spacing and plane angles, it was thought that 1 is 10-2 of a layered rock salt type crystal, 2 is 10-5, and 3 is 00-3, and that it has a layered rock salt type crystal structure. As a result of calculating the lattice constants of *point3-1 from these d values, a=2.76(Å) and c=14.2(Å).

[0340] Figure 34 (A) shows the microelectron diffraction image of the *point3-2 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point3-2 section, the plane spacing of 1 was calculated to be 0.226 nm, the plane spacing of 2 to be 0.181 nm, and the plane spacing of 3 to be 0.468 nm. In addition, the plane angles were ∠1O2=22°, ∠1O3=71°, and ∠2O3=49°. At this time, the electron beam incident direction is [0-10], 1 is -102 of the layered rock salt type crystal, 2 is likewise -105, and 3 is likewise 003, and it was thought to have a layered rock salt type crystal structure. From these d values, the lattice constants of the *point3-2 part were calculated as a=2.74(Å) and c=14.1(Å).

[0341] Figure 34 (B) shows the microelectron diffraction image of the *point3-3 section. The transmitted light is represented as O, and a portion of the diffraction spot is represented as 1, as shown in the figure. As a result of analyzing the *point3-3 section, the plane spacing of 1 was calculated to be 0.470 nm. At this time, the electron beam incident direction is

[0003] , and 1 is the 003 of a layered rock salt type crystal, and it was thought to have a layered rock salt type crystal structure. From this d value, the lattice constant of the *point3-3 section was calculated to be c=14.0 (Å). The a-axis was not calculated as there was no corresponding d value.

[0342] Figure 35 (A) is a cross-sectional TEM image of sample 12 after charging and discharging. The analysis portions of the ultrafine electron diffraction are indicated as *point2-1, *point2-2, and *point2-3 in Figure 35 (A).

[0343] Figure 35 (B) shows the microscopic electron beam diffraction image of the *point2-1 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point2-1 section, the plane spacing of 1 was calculated to be 0.125 nm, the plane spacing of 2 to be 0.115 nm, and the plane spacing of 3 to be 0.234 nm. In addition, the plane angles were ∠1O2=29°, ∠1O3=96°, and ∠2O3=66°. At this time, the electron beam incident direction is

[0010] , and 1 is 20-1 of the layered rock salt type crystal, 2 is 205 likewise, and 3 is 006 likewise, and it was thought to have a layered rock salt type crystal structure. As a result of calculating the lattice constants of *point2-1 from these d values, a=2.91(Å) and c=14.1(Å).

[0344] Figure 36 (A) shows the microscopic electron beam diffraction image of the *point2-2 section. The transmitted light is O, and parts of the diffraction spots are designated as 1, 2, and 3, as shown in the figure. As a result of analyzing the *point2-2 section, the plane spacing of 1 was calculated to be 0.126 nm, the plane spacing of 2 to be 0.115 nm, and the plane spacing of 3 to be 0.234 nm. In addition, the plane angles were ∠1O2=29°, ∠1O3=95°, and ∠2O3=66°. At this time, the electron beam incident direction is

[0010] , and 1 is 20-1 of the layered rock salt type crystal, 2 is 205 likewise, and 3 is 006 likewise, and it was thought to have a layered rock salt type crystal structure. As a result of calculating the lattice constants of the *point2-2 part from these d values, a=2.91(Å) and c=14.1(Å).

[0345] Figure 36 (B) shows the microelectron diffraction image of the *point2-3 section. The transmitted light is represented as O, and a portion of the diffraction spot is represented as 1, as shown in the figure. As a result of the analysis of the *point2-3 section, the plane spacing of 1 was calculated to be 0.474 nm. At this time, the electron beam incident direction is

[0003] , and 1 is the 003 of the layered rock salt type crystal, and it was thought to have a layered rock salt type crystal structure. From this d value, the lattice constant of the *point2-3 section was calculated to be c = 14.21 (Å). The a-axis was not calculated as there was no corresponding d value.

[0346] As described above, the lattice constant of sample 11 without a cap layer after charging and discharging tended to be larger than the lattice constant of lithium cobaltate before charging and discharging. This is presumed to be due to the reduction of cobalt.

[0347] Meanwhile, in sample 12 having a cap layer, the a-axis tended to be small on average even after charging and discharging. This suggests that the reduction of cobalt is suppressed because the valence of cobalt is high.

[0348] Charge / Discharge Cycles

[0349] Next, secondary batteries using samples 11 and 12 were fabricated, and charge / discharge cycle characteristics were evaluated.

[0350] A CR2032 type coin cell (diameter 20 mm, height 3.2 mm) was fabricated using Sample 11 and Sample 12 as the positive electrode and lithium metal as the counter electrode.

[0351] For the electrolyte, 1 mol / L of lithium hexafluoride phosphate (LiPF6) was used, and for the electrolyte, ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in an EC:DEC ratio of 3:7 (volume ratio), and 2 wt% of vinylene carbonate (VC) was added as an additive.

[0352] Polypropylene with a thickness of 25 μm was used for the separator.

[0353] The positive and negative cans were made of stainless steel (SUS).

[0354] The cycle test was performed under the following conditions. The charging voltage was set to 4.2V. The measurement temperature was set to 25℃. Charging was performed at CC / CV (0.2C, 0.1C cut), and discharging was performed at CC (0.1C, 2.5V cut), with a rest period of 10 minutes before the next charge. In addition, in this example, 1C was set to 137mA / g.

[0355] Figure 37 shows the results of the charge-discharge cycle test. Compared to sample 12 without a cap layer, the anode of sample 11 with a cap layer showed very good charge-discharge cycle characteristics.

[0356] Impedance

[0357] The impedance of the secondary battery was measured during the above charge-discharge cycle test.

[0358] In this embodiment, the electrochemical phenomenon occurring in a secondary battery of one form of the present invention is interpreted by substituting it into an equivalent circuit such as (A) of FIG. 38.

[0359] Here, Rs represents the electrical resistance of the electrode and the resistance of the electrolyte. Here, the electrical resistance of the electrode is defined as including all simple electrical resistance contained within the coin cell. Additionally, the resistance of the electrolyte refers to the ion diffusion resistance in the solution.

[0360] R1 is sometimes denoted as Rf or Rsurface and is the high-frequency component of the secondary battery's impedance. R1 includes the resistance to lithium ion diffusion at the interface between the positive electrode and the electrolyte.

[0361] CPE1 (constant phase element, electric double layer capacitance) is a capacitance that replicates the behavior of a porous electrode.

[0362] R2 is sometimes denoted as Rct and is a low-frequency component. R2 includes the resistance of the charge transfer process in which Li ions deinsert from the positive active material layer (LiCoO2 in this embodiment).

[0363] Ws1 is the resistance due to lithium diffusion in the solid.

[0364] Impedance is typically represented by a graph as shown in (B) of Fig. 38. The range in which each component affects is indicated in the figure.

[0365] The impedance of Sample 11 is shown in FIG. 39, and the impedance of Sample 12 is shown in FIG. 40. The graphs for the 2nd and 50th cycles, respectively, are shown. The measurement device used was a CELLTEST multi-channel electrochemical measurement system manufactured by Solartron, and an AC voltage of 10 mV was quenched from 0.001 Hz to 1 MHz. The measurement temperature was set to 25°C. Before measuring the impedance, the samples were charged to 4.2 V at 0.2 C and left for 2 hours. At this time, the OCV for Sample 11 was 4.1308 V after 2 cycles and 4.0607 V after 50 cycles, respectively. For Sample 12, it was 4.1162 V after 2 cycles and 4.0005 V after 50 cycles.

[0366] As shown in Fig. 40, when comparing the impedance of the 2nd cycle and the 50th cycle in Sample 12, R1 (high frequency component) is particularly increased. Therefore, it is presumed that deterioration occurs in the lithium diffusion path, for example, at the interface between the positive active material layer and the electrolyte, and at some grain boundaries, and that this is the cause of the deterioration of charge / discharge cycle characteristics as shown in Fig. 37.

[0367] Meanwhile, as shown in Fig. 39, in Sample 11, the increase in R1 is relatively small when comparing the impedance at the 2nd and 50th cycles. Therefore, it is presumed that the formation of the film is suppressed due to the effect of the cap layer. In addition, R2 (low frequency component) has increased significantly. Therefore, it is presumed that deterioration has occurred in the crystal structure of LiCoO2. Explanation of the symbols

[0368] 100: Positive electrode, 101: Positive electrode active material layer, 102: Cap layer, 103: Positive electrode current collector, 104: Underlay film, 110: Substrate, 111: Substrate, 200: Secondary battery, 201: Secondary battery, 202: Secondary battery, 203: Solid electrolyte layer, 204: Negative electrode active material layer, 205: Negative electrode current collector, 206: Protective layer, 209: Cap layer, 210: Negative electrode, 211: Negative electrode, 212: Negative electrode, 213: Solid electrolyte layer, 214: Underlay film, 215: Positive electrode current collector, 220: Separator, 221: Electrolyte, 222: Cap body, 223a: Lead electrode, 223b: Lead electrode, 230: Secondary battery, 231: Secondary battery< / eels> < / tem>

Claims

Claim 1 A positive electrode for a secondary battery, comprising a lower film, a positive electrode active material layer, and a cap layer, wherein at least one of the lower film and the cap layer comprises titanium nitride, and the positive electrode active material layer comprises lithium cobaltate. Claim 2 A positive electrode for a secondary battery according to claim 1, wherein the crystal structure included in the lower film and the crystal structure included in the positive electrode active material layer each have a surface in which only anions are arranged. Claim 3 A positive electrode for a secondary battery according to claim 1 or 2, wherein the lower film and the positive electrode active material layer each have a crystal structure in which cations and anions are alternately arranged. Claim 4 A secondary battery comprising: a positive electrode for a secondary battery according to claim 1 or 2; a solid electrolyte; and a negative electrode. Claim 5 An electronic device comprising a secondary battery according to claim 4. Claim 6 A system comprising: a secondary battery according to claim 4; and a lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and a separator. Claim 7 A positive electrode for a secondary battery comprising a positive electrode current collector, a lower film, a positive electrode active material layer, and a cap layer, wherein the lower film is on the positive electrode current collector, the positive electrode active material layer is on the lower film, the cap layer is on the positive electrode active material layer, the lower film comprises titanium, oxygen, and nitrogen, the cap layer comprises titanium, oxygen, and nitrogen, and the positive electrode active material layer comprises lithium cobaltate. Claim 8 delete Claim 9 In claim 7, the cap layer comprises TiOxNy, and 0 <x<2 및 0<y<1인, 이차 전지용 양극. Claim 10 A positive electrode for a secondary battery according to claim 7, wherein the crystal structure included in the lower film and the crystal structure included in the positive electrode active material layer each have a surface in which only anions are arranged. Claim 11 In claim 2 or claim 10, the crystal structure comprising the lower membrane having the A positive electrode for a secondary battery, wherein the plane in which only anions are arranged is parallel to the plane in which only anions are arranged having the crystal structure included in the positive electrode active material layer.

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