JP2007128724A - Anode and battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anode improved in a cycle property and a battery using the same. <P>SOLUTION: The anode is manufactured by forming a three-dimensional structure by using a fibrous member 10 formed by arranging an activator layer 12 containing silicon as a constituent element on a fibrous conductive base material 11. It is preferable that an average fiber diameter of the conductive base material 11 is not less than 1 μm and not more than 60μm, and a ratio r/R of an average thickness of the activator layer 12 to an average fiber diameter R of the conductive base material 11 is in a range of 0.09 or higher and 1.030 or lower, or 0.3 or higher and 3.0 or lower. Further, the activator layer 12 contains oxygen as a constituent element, and it is preferable that a content of the oxygen is within a range of 5 to 40 atom number%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a negative electrode containing silicon (Si) as a constituent element and a battery using the negative electrode.

In recent years, as mobile devices have higher performance and more functions, there is a demand for higher capacities of secondary batteries serving as power sources thereof. Secondary batteries that meet this demand include lithium ion secondary batteries, but those currently in practical use use graphite for the negative electrode, so the battery capacity is in a saturated state, and there is a significant increase in capacity. difficult. Thus, it has been studied to increase the capacity by using silicon for the negative electrode (see, for example, Patent Document 1).
JP 2004-171876 A

  However, since silicon has a large expansion / contraction due to charging / discharging, there is a problem that when charging / discharging is repeated, the negative electrode active material layer falls off from the negative electrode current collector due to stress due to expansion / contraction, resulting in deterioration of cycle characteristics. .

  The present invention has been made in view of such problems, and an object thereof is to provide a negative electrode and a battery that can relieve stress due to expansion and contraction and improve characteristics.

  The negative electrode according to the present invention has a fiber member in which an active material layer containing silicon as a constituent element is provided on a fibrous conductive substrate.

  The battery according to the present invention is provided with an electrolyte together with a positive electrode and a negative electrode, and the negative electrode has a fiber member in which an active material layer containing silicon as a constituent element is provided on a fibrous conductive substrate. .

  According to the negative electrode of the present invention, since the conductive member has the fiber member provided with the active material layer containing silicon as a constituent element, the stress due to the expansion and contraction of the active material layer can be relaxed. Therefore, according to the battery of the present invention using this negative electrode, excellent cycle characteristics can be obtained.

  In particular, if the average fiber diameter of the conductive substrate is in the range of 1 μm to 60 μm, the ratio r / R of the average thickness r of the active material layer to the average fiber diameter R of the conductive substrate is also set. If it is made to be in the range of 0.09 or more and 1.030 or less or 0.3 or more and 3.0 or less, and if at least a part of the surface of the conductive substrate is roughened, it is higher. An effect can be obtained.

  Furthermore, if the active material layer contains oxygen as a constituent element and the content thereof is 5 atomic% to 40 atomic%, a higher effect can be obtained.

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

  The negative electrode according to one embodiment of the present invention has, for example, a fiber member in which an active material layer containing silicon as a constituent element is provided on a fibrous conductive substrate, and the fiber member has a three-dimensional structure. Is formed. Thereby, in this negative electrode, the stress due to the expansion and contraction of the active material layer can be relaxed. The fiber member forms, for example, a three-dimensional three-dimensional structure by being woven, knitted, or processed into a felt shape or a non-woven shape. Two or more of these may be combined. For example, a plain weave and a twill weave may be combined, a knitted structure may be provided at the end of the sushi weave, or a woven fabric and a felt may be combined.

  FIG. 1 shows a cross-sectional structure in the longitudinal direction of the fiber member 10. The conductive substrate 11 functions as a current collector and may be any material as long as it has conductivity and can be processed into a fiber shape. For example, it can be composed of metal fibers such as copper fibers, nickel fibers, gold fibers, and stainless fibers. Moreover, you may make it comprise with the covering fiber etc. which provided the metal coating layer in the organic compound fiber. The average fiber diameter R of the conductive substrate 11 is preferably in the range of 1 μm to 60 μm, for example. This is because if the average fiber diameter R is too small, the strength decreases, and if it is too large, the stress applied by the expansion and contraction of the active material layer 12 increases, and the volume energy density decreases. It is preferable that at least a part of the surface of the conductive substrate 11 is roughened. This is because adhesion with the active material layer 12 can be improved.

  The active material layer 12 may be provided on the entire conductive base material 11 or may be provided on a part thereof. In the active material layer 12, silicon may be contained alone, as an alloy, or as a compound. Examples of constituent elements other than silicon include tin (Sn), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In), Silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), or chromium (Cr) can be used. The active material layer 12 preferably contains oxygen (O) as a constituent element. This is because the expansion and contraction of the active material layer 12 can be suppressed and stress can be relaxed. At least a part of oxygen contained in the active material layer 12 is preferably bonded to silicon, and the bonding state may be silicon monoxide, silicon dioxide, or other metastable state. The oxygen content in the active material layer 12 is preferably in the range of 5 atomic% to 40 atomic%. If it is less than this, a sufficient effect cannot be obtained, and if it is more than this, the irreversible capacity increases. Note that the active material layer 12 does not include a coating film that is formed on the surface of the active material layer 12 due to decomposition of the electrolytic solution by charge and discharge. Therefore, when the oxygen content in the active material layer 12 is calculated, oxygen contained in this film is not included.

  The average thickness r of the active material layer 12 is a ratio r / R to the average fiber diameter R of the conductive substrate 11 and is preferably in the range of 0.09 or more and 1.03 or less. If the ratio r / R is too large, the active material layer 12 tends to peel from the conductive substrate 11 due to expansion and contraction of the active material layer 12, and if the ratio r / R is too small, the constituent elements of the active material layer 12 This is because the bond with the constituent elements of the conductive substrate 11 becomes strong and the irreversible capacity becomes common.

  For example, after forming the active material layer 12 on the conductive base material 11 to form the fiber member 10, the negative electrode is subjected to processing such as weaving, knitting, or compression molding to obtain a three-dimensional structure. Can be formed. The active material layer 12 may be formed, for example, by a vapor phase method, or may be formed by forming a precursor layer such as silicon oxide on the conductive substrate 11 and then reducing it. Also good. Examples of the vapor phase method include a physical deposition method and a chemical deposition method. Specifically, a vacuum deposition method, a sputtering method, an ion plating method, a laser ablation method, a CVD (Chemical Vapor Deposition; chemical vapor deposition). ) Method. When oxygen is added to the active material layer 12, for example, oxygen is introduced into the atmosphere when the active material layer 12 is formed, or the conditions for reducing the oxide precursor layer are controlled. The content of can be adjusted.

  This negative electrode is used in, for example, the following secondary battery.

  FIG. 2 shows the configuration of the secondary battery. This secondary battery is a so-called coin-type battery, in which a negative electrode 22 accommodated in an outer cup 21 and a positive electrode 24 accommodated in an outer can 23 are stacked via a separator 25. The peripheral portions of the outer cup 21 and the outer can 23 are sealed by caulking through an insulating gasket 26. The exterior cup 21 and the exterior can 23 are made of, for example, a metal such as stainless steel or aluminum.

  The negative electrode 22 has the structure described above. However, since the active material layer 12 expands by charging, the average thickness r of the active material layer 12 in the charged state is a ratio r / R to the average fiber diameter R of the conductive substrate 11, which is 0.3 or more and 3.0. It is preferable to be within the following range.

  The positive electrode 24 includes, for example, a positive electrode current collector 24A and a positive electrode active material layer 24B provided on the positive electrode current collector 24A. The positive electrode active material layer 24B side is disposed so as to face the negative electrode 22. ing. The positive electrode current collector 24A is made of, for example, aluminum, nickel, stainless steel, or the like.

The positive electrode active material layer 24B includes, for example, any one or more of positive electrode materials capable of inserting and extracting lithium as a positive electrode active material, and a conductive material such as a carbon material and the like as necessary. A binder such as polyvinylidene fluoride may be included. As the positive electrode material capable of inserting and extracting lithium, for example, a lithium-containing metal composite oxide represented by the general formula Li _x MIO ₂ is preferable. This is because the lithium-containing metal composite oxide can generate a high voltage and has a high density, so that the capacity of the secondary battery can be further increased. MI is one or more kinds of transition metals, and for example, at least one of cobalt and nickel is preferable. x varies depending on the charge / discharge state of the battery and is usually a value in the range of 0.05 ≦ x ≦ 1.10. Specific examples of such a lithium-containing metal composite oxide include LiCoO _{2 and} LiNiO ₂ .

  The positive electrode 24 is prepared by mixing a positive electrode active material, a conductive material, and a binder, for example, and preparing a mixture slurry by dispersing the mixture in a dispersion medium. Is applied to a positive electrode current collector 24A made of a metal foil, dried, and then compression molded to form the positive electrode active material layer 24B.

  The separator 25 separates the negative electrode 22 and the positive electrode 24 and allows lithium ions to pass through while preventing a short circuit of current due to contact between both electrodes. The separator 25 is made of, for example, polyethylene or polypropylene.

  The separator 25 is impregnated with an electrolytic solution that is a liquid electrolyte. This electrolytic solution contains, for example, a solvent and an electrolyte salt dissolved in this solvent, and may contain an additive as necessary. Examples of the solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, 1,3-dioxol-2-one, 4-vinyl-1,3-dioxolan-2-one, or a halogen atom. Non-aqueous solvents such as carbonic acid ester derivatives are included. Any one of the solvents may be used alone, or two or more of them may be mixed and used. Among them, it is preferable to use at least one of 1,3-dioxol-2-one and 4-vinyl-1,3-dioxolan-2-one because the decomposition reaction of the electrolytic solution can be suppressed. In addition, it is preferable to use a carbonic acid ester derivative having a halogen atom because the decomposition reaction of the electrolytic solution can be suppressed.

  The carbonic acid ester derivative having a halogen atom may be either a cyclic compound or a chain compound, but the cyclic compound is preferable because a higher effect can be obtained. Such cyclic compounds include 4-fluoro-1,3-dioxolan-2-one, 4-chloro-1,3-dioxolan-2-one, 4-bromo-1,3-dioxolan-2-one Or 4,5-difluoro-1,3-dioxolan-2-one, among which 4-fluoro-1,3-dioxolan-2-one is preferred. This is because a higher effect can be obtained.

Examples of the electrolyte salt include lithium salts such as LiPF ₆ , LiCF ₃ SO _{3, and} LiClO ₄ . Any one electrolyte salt may be used alone, or two or more electrolyte salts may be mixed and used.

  This secondary battery can be manufactured, for example, by laminating the negative electrode 22, the separator 25 impregnated with the electrolyte and the positive electrode 24, placing them in the outer cup 21 and the outer can 23, and caulking them. it can.

  In the secondary battery, when charged, for example, lithium ions are extracted from the positive electrode 24 and inserted in the negative electrode 22 through the electrolytic solution. When discharging is performed, for example, lithium ions are extracted from the negative electrode 22 and inserted in the positive electrode 24 through the electrolytic solution. Since the negative electrode 22 has a three-dimensional structure formed by the fiber member 10 in which the active material layer 12 is provided on the conductive base material 11, stress due to expansion and contraction of the active material layer 12 is relieved.

  The negative electrode according to the present embodiment may be used for the following secondary battery.

  FIG. 3 shows the configuration of the secondary battery. In this secondary battery, the wound electrode body 30 to which the leads 31 and 32 are attached is housed in a film-like exterior member 41, and can be reduced in size, weight, and thickness. The leads 31 and 32 are led out from the inside of the exterior member 41 to the outside, for example, in the same direction. The leads 31 and 32 are made of a metal material such as aluminum, copper, nickel, or stainless steel, respectively, and have a thin plate shape or a mesh shape, respectively.

  The exterior member 41 is made of, for example, a rectangular aluminum laminated film in which a nylon film, an aluminum foil, and a polyethylene film are bonded together in this order. The exterior member 41 is disposed, for example, so that the polyethylene film side and the electrode winding body 30 face each other, and the outer edge portions are in close contact with each other by fusion or an adhesive. An adhesion film 42 for preventing the entry of outside air is inserted between the exterior member 41 and the leads 31 and 32. The adhesion film 42 is made of a material having adhesion to the leads 31 and 32, for example, a polyolefin resin such as polyethylene, polypropylene, modified polyethylene, or modified polypropylene.

  The exterior member 41 may be made of a laminated film having another structure, a polymer film such as polypropylene, or a metal film instead of the above-described aluminum laminated film.

  FIG. 4 shows a cross-sectional structure taken along line II of the electrode winding body 30 shown in FIG. The electrode winding body 30 is obtained by laminating a negative electrode 33 and a positive electrode 34 via a separator 35 and an electrolyte layer 36 and winding them, and the outermost periphery is protected by a protective tape 37.

  The negative electrode 33 has the same configuration as the negative electrode 22 described above. The positive electrode 34 has a structure in which a positive electrode active material layer 34B is provided on both surfaces of a positive electrode current collector 34A, and is disposed so that the positive electrode active material layer 34B and the negative electrode 33 face each other. The configurations of the positive electrode current collector 34A, the positive electrode active material layer 34B, and the separator 35 are the same as those of the positive electrode current collector 24A, the positive electrode active material layer 24B, and the separator 25 described above.

  The electrolyte layer 36 is configured by a so-called gel electrolyte in which an electrolytic solution is held in a holding body made of a polymer compound. A gel electrolyte is preferable because high ion conductivity can be obtained and battery leakage can be prevented. The configuration of the electrolyte is the same as that of the secondary battery described above. An example of the polymer material is polyvinylidene fluoride.

  For example, the secondary battery can be manufactured as follows.

  First, an electrolyte layer 36 in which an electrolytic solution is held in a holding body is formed on each of the negative electrode 33 and the positive electrode 34, and leads 31 and 32 are attached. Next, the negative electrode 33 and the positive electrode 34 on which the electrolyte layer 36 is formed are stacked via the separator 35 and wound, and the protective tape 37 is adhered to the outermost peripheral portion to form the electrode winding body 30. Subsequently, for example, the electrode winding body 30 is sandwiched between the exterior members 41, the contact film 42 is inserted, and the outer edges of the exterior members 41 are brought into close contact by thermal fusion or the like and sealed. Thereby, the secondary battery shown in FIGS. 3 and 4 is obtained.

  Moreover, you may manufacture as follows. First, after attaching the leads 31 and 32 to the negative electrode 33 and the positive electrode 34, respectively, the negative electrode 33 and the positive electrode 34 are laminated and wound via a separator 35, and a protective tape 37 is adhered to the outermost peripheral portion to form an electrode. A wound body that is a precursor of the wound body 30 is formed. Next, the wound body is sandwiched between exterior members 41, and the outer peripheral edge except for one side is heat-sealed into a bag shape, and then the electrolyte, the monomer that is the raw material of the polymer compound, the polymerization initiator, An electrolyte composition containing another material such as a polymerization inhibitor is injected into the exterior member 41 as necessary. Subsequently, the opening of the exterior member 41 is heat-sealed and sealed in a vacuum atmosphere, and heat is applied to polymerize the monomer to form a polymer compound, thereby forming the gel electrolyte layer 36. Thereby, the secondary battery shown in FIGS. 3 and 4 is obtained.

  The operation of this secondary battery is the same as that of the coin-type secondary battery shown in FIG.

  As described above, according to the present embodiment, since the conductive substrate 11 has the fiber member 10 provided with the active material layer 12 containing silicon as a constituent element, the stress due to the expansion and contraction of the active material layer 12 is obtained. Can be relaxed, and excellent cycle characteristics can be obtained.

  In particular, if the average fiber diameter of the conductive substrate 11 is in the range of 1 μm to 60 μm, the ratio r of the average thickness r of the active material layer 12 to the average fiber diameter R of the conductive substrate 11 If / R is in the range of 0.09 or more and 1.030 or less or 0.3 or more and 3.0 or less, at least a part of the surface of the conductive substrate 11 is roughened. Therefore, a higher effect can be obtained.

  Furthermore, if the active material layer 12 contains oxygen as a constituent element and the content thereof is 5 atomic% to 40 atomic%, a higher effect can be obtained.

  Further, specific embodiments of the present invention will be described in detail with reference to the drawings.

(Examples 1-1 to 1-3)
The fiber member 10 shown in FIG. 1 was produced. In Example 1-1, first, copper fibers having an average fiber diameter R of 15 μm are prepared as the conductive base material 11, and a film of a solution containing perhydropolysilazane is formed on the surface of the conductive base material 11. It was fired at 450 ° C. to form a silicon dioxide precursor layer on the surface of the conductive substrate 11. Next, this precursor layer was reduced using coke, and an active material layer 12 containing silicon was formed on the conductive substrate 11. In Examples 1-2 and 1-3, the active material layer 12 was formed by depositing silicon on the same conductive base material 11 of Example 1-1 by the CVD method or the electron beam evaporation method.

  When the cross sections of the produced fiber members 10 of Examples 1-1 to 1-3 were observed with a scanning electron microscope (SEM), the average thickness r of the active material layer 12 was 8 μm. Moreover, when the oxygen content in the active material layer 12 was measured by an energy dispersive X-ray fluorescence spectrometer (EDX), all were about 7 atomic%.

Subsequently, a coin-type test battery as shown in FIG. 2 was produced using the produced fiber member 10. The negative electrode was formed by plain weaving the produced fiber member 10. A lithium metal plate is used for the counter electrode, a porous polypropylene film is used for the separator, and LiPF ₆ is mixed with a solvent in which ethylene carbonate and diethyl carbonate are mixed at a mass ratio of ethylene carbonate: diethyl carbonate = 3: 7 for the electrolyte. Was dissolved at a concentration of 1 mol / l.

  Moreover, as Comparative Example 1-1 with respect to Examples 1-1 to 1-3, a negative electrode was formed by depositing silicon on a rolled copper foil having a thickness of 15 μm by an electron beam evaporation method to form an active material layer having a thickness of 8 μm. Except for this, a test battery was fabricated in the same manner as in Example 1-1.

The manufactured test batteries of Examples 1-1 to 1-3 and Comparative Example 1-1 were charged and discharged at a current density of 1 mA / cm ² for 50 cycles, and the ratio of the discharge capacity at the 50th cycle to the first cycle was determined. It calculated | required as a discharge capacity maintenance factor. The results are shown in Table 1.

  As shown in Table 1, according to Examples 1-1 to 1-3 using the fiber member 10, compared with Comparative Example 1-1 in which an active material layer was formed on a copper foil, the discharge capacity retention rate was higher. We were able to greatly improve. That is, it was found that the cycle characteristics can be improved by using the fiber member 10 in which the active material layer 12 is provided on the conductive substrate 11.

(Examples 2-1-1 to 2-7-4)
Except that the average fiber diameter R of the conductive substrate 11 and the average thickness r of the active material layer 12 were changed as shown in Table 2, the fiber member 10 and the test battery were the same as in Example 1-1 except that they were changed. Was made. For the produced test batteries of Examples 2-1-1 to 2-7-4, the discharge capacity retention ratio was determined in the same manner as in Example 1-1. Moreover, after repeating 50 cycles charge / discharge about the test battery of Example 2-1-1 to 2-7-4, it charged again, the thing of the charged state was disassembled, and the fiber member 10 was observed by SEM. The average thickness r of the active material layer 12 was examined. The obtained results are shown in Table 2.

  As shown in Table 2, as the average fiber diameter R of the conductive base material 11 was increased, the discharge capacity retention rate tended to decrease after being improved. Further, as the ratio r / R of the average thickness r of the active material layer 12 to the average fiber diameter R of the conductive base material 11 was increased, the discharge capacity retention rate tended to decrease after being improved.

  That is, it has been found that higher effects can be obtained if the average fiber diameter R of the conductive substrate 11 is in the range of 1 μm to 60 μm. In addition, the average thickness r of the active material layer 12 is a ratio r / R to the average fiber diameter R of the conductive base material 11 within a range of 0.09 or more and 1.03 or less, or 0.3 or more and 3.0. It was found that a higher effect can be obtained by making it within the following range.

(Examples 3-1 to 3-3)
A fiber member 10 and a test battery were produced in the same manner as in Example 1-1 except that the type of the conductive substrate 11 was changed as shown in Table 3. For the produced test batteries of Examples 3-1 to 3-19, the discharge capacity retention ratio was determined in the same manner as in Example 1-1. The obtained results are shown in Table 3 together with the results of Example 1-1.

  As shown in Table 3, all were able to obtain a high discharge capacity retention rate as in Example 1-1. That is, it was found that an excellent effect can be obtained by using any conductive substrate 11.

(Example 4-1)
A fiber member 10 and a test electrode were produced in the same manner as in Example 1-1 except that the surface of the conductive substrate 11 was roughened by wet etching. For the produced test battery of Example 4-1, the discharge capacity retention rate was determined in the same manner as in Example 1-1. The obtained results are shown in Table 4 together with the results of Example 1-1.

  As shown in Table 4, according to Example 4-1, the discharge capacity retention rate could be further improved as compared with Example 1-1. That is, it was found that a higher effect can be obtained if the surface of the conductive substrate 11 is roughened.

(Examples 5-1 to 5-5)
A fiber member 10 and a test electrode were produced in the same manner as in Example 1-1 except that the oxygen content in the active material layer 12 was changed as shown in Table 7. The oxygen content was adjusted by changing the conditions for reducing the precursor layer. For the produced test batteries of Examples 5-1 to 5-5, the discharge capacity retention ratio was determined in the same manner as in Example 1-1. The obtained results are shown in Table 5 together with the results of Example 1-1.

  As shown in Table 5, when the oxygen content was increased, the discharge capacity retention rate tended to decrease after being improved. That is, it has been found that higher effects can be obtained if the oxygen content in the active material layer 12 is in the range of 5 atomic% to 40 atomic%.

(Example 6-1)
A test battery was fabricated in the same manner as in Example 1-1 except that an electrolytic solution in which 4-fluoro-1,3-dioxolan-2-one was mixed instead of ethylene carbonate was used. For the manufactured test battery of Example 6-1 as well, the discharge capacity retention rate was determined in the same manner as in Example 1-1. The obtained results are shown in Table 6 together with the results of Example 1-1.

  As shown in Table 6, according to Example 6-1, the discharge capacity retention rate could be further improved as compared with Example 1-1. That is, it was found that the cycle characteristics can be further improved by using 4-fluoro-1,3-dioxolan-2-one as the electrolytic solution.

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the above embodiments and examples, and various modifications can be made. For example, in the above-described embodiments and examples, the case where an electrolytic solution which is a liquid electrolyte or a so-called gel electrolyte is used has been described, but another electrolyte may be used. Examples of other electrolytes include solid electrolytes having ionic conductivity, a mixture of a solid electrolyte and an electrolyte solution, and a mixture of a solid electrolyte and a gel electrolyte.

  As the solid electrolyte, for example, a polymer solid electrolyte in which an electrolyte salt is dispersed in a polymer compound having ion conductivity, or an inorganic solid electrolyte made of ion conductive glass or ionic crystals can be used. Examples of the polymer compound of the solid polymer electrolyte include, for example, an ether polymer compound such as polyethylene oxide or a crosslinked product containing polyethylene oxide, an ester polymer compound such as polymethacrylate, and an acrylate polymer compound. Or can be copolymerized. In addition, as the inorganic solid electrolyte, one containing lithium nitride or lithium phosphate can be used.

  In the above embodiments and examples, a coin type or wound laminate type secondary battery has been described. However, the present invention is not limited to a cylindrical type, a square type, a button type, a thin type, a large size, or a laminated laminate type. The present invention can be similarly applied to a secondary battery having the shape. In addition, the present invention can be applied not only to secondary batteries but also to primary batteries.

It is sectional drawing showing the structure of the fiber member contained in the negative electrode which concerns on one embodiment of this invention. It is sectional drawing showing the structure of the secondary battery using the negative electrode which concerns on one embodiment of this invention. It is a disassembled perspective view showing the structure of the other secondary battery using the negative electrode which concerns on one embodiment of this invention. It is sectional drawing showing the structure along the II line of the secondary battery shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fiber member, 11 ... Conductive base material, 12 ... Active material layer, 21 ... Exterior cup, 22, 33 ... Negative electrode, 23 ... Exterior can, 24, 34 ... Positive electrode, 24A, 34A ... Positive electrode collector, 24B , 34B ... positive electrode active material layer, 25, 35 ... separator, 26 ... gasket, 31, 32 ... lead, 30 ... electrode winding body, 36 ... electrolyte layer, 37 ... protective tape, 41 ... exterior member, 42 ... adhesive film

Claims (15)

  A negative electrode comprising a fibrous member in which an active material layer containing silicon as a constituent element is provided on a fibrous conductive substrate.   The negative electrode according to claim 1, wherein the fiber member forms a three-dimensional structure.   2. The negative electrode according to claim 1, wherein an average fiber diameter of the conductive substrate is in a range of 1 μm to 60 μm.   2. The negative electrode according to claim 1, wherein a ratio r / R of an average thickness r of the active material layer to an average fiber diameter R of the conductive substrate is in a range of 0.09 to 1.030. .   2. The negative electrode according to claim 1, wherein at least a part of the conductive substrate is composed of metal fibers or coated fibers in which a metal coating layer is provided on organic compound fibers.   The negative electrode according to claim 1, wherein a surface of at least a part of the conductive substrate is roughened.   The negative electrode according to claim 1, wherein the active material layer contains oxygen as a constituent element, and the content thereof is 5 atomic% to 40 atomic%. A battery comprising an electrolyte together with a positive electrode and a negative electrode,
The negative electrode has a fiber member in which an active material layer containing silicon as a constituent element is provided on a fibrous conductive substrate.   The battery according to claim 8, wherein the fiber member forms a three-dimensional structure.   The battery according to claim 8, wherein an average fiber diameter of the conductive substrate is in a range of 1 µm to 60 µm.   9. The battery according to claim 8, wherein a ratio r / R of an average thickness r of the active material layer to an average fiber diameter R of the conductive substrate is in a range of 0.3 to 3.0. .   9. The battery according to claim 8, wherein at least a part of the conductive substrate is composed of metal fibers or coated fibers obtained by providing a metal coating layer on organic compound fibers.   The battery according to claim 8, wherein a surface of at least a part of the conductive substrate is roughened.   The battery according to claim 8, wherein the active material layer contains oxygen as a constituent element, and the content thereof is 5 atomic% to 40 atomic%. The battery according to claim 8, wherein the electrolyte contains a carbonic acid ester derivative having a halogen atom.

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