WO2019017029A1

WO2019017029A1 - Secondary battery, battery pack, electric vehicle, electric power storage system, electric tool, and electronic device

Info

Publication number: WO2019017029A1
Application number: PCT/JP2018/016089
Authority: WO
Inventors: 伸之岩根; 菜津子片瀬
Original assignee: 株式会社村田製作所
Priority date: 2017-07-18
Filing date: 2018-04-19
Publication date: 2019-01-24

Abstract

This secondary battery is provided with: a battery element that includes an electrolytic solution together with a positive electrode and a negative electrode that are mutually stacked via a separator; and a film-shaped exterior member that accommodates the battery element and includes a conductive layer on the innermost side of the exterior member.

Description

Secondary battery, battery pack, electric vehicle, electric power storage system, electric tool and electronic device

The present technology relates to a secondary battery in which a battery element is housed inside a film-like exterior member, and a battery pack, an electric vehicle, an electric power storage system, an electric tool, and an electronic device using the secondary battery.

2. Description of the Related Art Various electronic devices such as mobile phones are widely used, and there is a demand for downsizing, weight reduction and long life of the electronic devices. Therefore, development of a secondary battery which is compact and lightweight and capable of obtaining high energy density is being promoted as a power source.

Secondary batteries are considered not only for electronic devices but also for other applications. For example, a battery pack detachably mounted on an electronic device or the like, an electric vehicle such as an electric vehicle, an electric power storage system such as a household electric power server, and an electric tool such as an electric drill.

A so-called laminate film secondary battery is known as a secondary battery. In this laminated film type secondary battery, the battery element is housed inside the film-like package member, and the battery element contains an electrolytic solution together with the positive electrode and the negative electrode. This is because the secondary battery has flexibility (deformability), so that the degree of freedom regarding the installation location of the secondary battery is expanded.

Since the configuration of the secondary battery greatly affects the safety, various studies have been made on the configuration of the secondary battery. Specifically, in order to prevent thermal runaway and the like, a conductive member connected to a positive electrode lead or a negative electrode lead is provided on the outer surface of the package member (see, for example, Patent Document 1). Moreover, in order to prevent ignition etc., the short circuit induction | guidance | derivation member is provided between the exterior member and the battery element (for example, refer patent document 2).

JP, 2009-064630, A JP, 2013-122910, A

Although various measures have been taken to improve the safety of secondary batteries, the measures are not sufficient. Therefore, the safety of the secondary battery still has room for improvement.

The present technology has been made in view of such problems, and an object thereof is to provide a secondary battery, a battery pack, an electric vehicle, an electric power storage system, an electric tool, and an electronic device capable of improving safety. It is in.

A secondary battery according to the present technology includes a battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on one another via a separator, and a film-like package member that houses the battery element and includes a conductive layer on the innermost side. It is

Each of the battery pack, the electric vehicle, the electric power storage system, the electric power tool, and the electronic device of the present technology includes a secondary battery, and the secondary battery has the same configuration as that of the above-described secondary battery of the present technology. .

According to the secondary battery of the present technology, since the film-like exterior member for housing the battery element includes the conductive layer on the innermost side, the safety can be improved. In addition, similar effects can be obtained in each of the battery pack, the electric vehicle, the electric power storage system, the electric tool, and the electronic device of the present technology.

In addition, the effect described here is not necessarily limited, and may be any effect described in the present technology.

It is a perspective view showing composition of a rechargeable battery of one embodiment of this art. It is a top view showing the structure of the exterior member shown in FIG. It is sectional drawing which expands and represents the structure of one part among the exterior members shown in FIG. FIG. 5 is an enlarged cross-sectional view of a configuration of a wound electrode body taken along line IV-IV shown in FIG. It is a top view for demonstrating the safe operation | movement of a secondary battery. It is a top view for demonstrating the safe operation | movement of the secondary battery following FIG. It is sectional drawing which expands and represents the structure of a part of secondary battery shown in FIG. It is sectional drawing showing the structure of the exterior member in the secondary battery of a comparative example. It is sectional drawing for demonstrating the problem of the secondary battery of a comparative example. It is sectional drawing showing the modification regarding the structure of a secondary battery. It is a top view showing the other modification regarding the composition of a rechargeable battery. It is a perspective view showing the composition of the example of application of a rechargeable battery (battery pack: single battery). It is a block diagram showing the structure of the battery pack shown in FIG. It is a block diagram showing the composition of the example of application of a rechargeable battery (battery pack: group battery). It is a block diagram showing the composition of the example of application of a rechargeable battery (electric vehicle). It is a block diagram showing the composition of the example of application of a rechargeable battery (electric power storage system). It is a block diagram showing the composition of the example of application of a rechargeable battery (electric tool).

Hereinafter, an embodiment of the present technology will be described in detail with reference to the drawings. The order to be described is as follows.

1. Secondary battery 1-1. Configuration 1-2. Operation 1-3. Manufacturing method 1-4. Action and effect 1-5. Modified example 2. Applications of Secondary Battery 2-1. Battery pack (single cell)
2-2. Battery pack (battery pack)
2-3. Electric vehicle 2-4. Power storage system 2-5. Electric tool

<1. Secondary battery>
First, a secondary battery according to an embodiment of the present technology will be described.

The secondary battery described here is, for example, a secondary battery using lithium as an electrode reactant. The "electrode reactant" is a substance involved in an electrode reaction (charge-discharge reaction).

More specifically, the secondary battery is a lithium ion secondary battery in which a battery capacity (capacity of the negative electrode) is obtained by utilizing a lithium absorption phenomenon and a lithium release phenomenon.

<1-1. Configuration>
First, the configuration of the secondary battery will be described.

FIG. 1 shows a perspective view of a secondary battery. 2 shows a plan configuration of the exterior member 20 shown in FIG. 1, and FIG. 3 is an enlarged cross-sectional configuration of a part (portion 20P1) of the exterior member 20 shown in FIG. . FIG. 4 is an enlarged cross-sectional view of the wound electrode body 10 taken along the line IV-IVI shown in FIG.

In addition, in FIG. 1, in order to make the structure of the winding electrode body 10, and the structure of the exterior member 20 intelligible, the state which the winding electrode body 10 and the exterior member 20 mutually spaced apart is shown. Moreover, in FIG. 2, in order to make the structure of the exterior member 20 legible, the state before the exterior member 20 is folded is shown.

This secondary battery is, for example, a laminate in which a wound electrode body 10 as a battery element is housed inside a flexible (or flexible) film-like package member 20 as shown in FIG. It is a film type secondary battery. The wound electrode body 10 includes, for example, a positive electrode 13, a negative electrode 14, a separator 15, and an electrolyte layer 16.

[Exterior member]
The exterior member 20 is a bag-like member that accommodates the wound electrode body 10. The exterior member 20 is, for example, a single film that can be folded in the direction of the arrow R, as shown in FIGS. 1 and 2, and the exterior member 20 includes, for example, a wound electrode body 10. A recess 20U is provided for storing the

The planar shape of the exterior member 20 is not particularly limited, and is, for example, a rectangle or the like as shown in FIG. In addition, the broken line L shown in FIG. 2 represents the position (folding line) when the exterior member 20 is folded.

In particular, as shown in FIG. 3, the exterior member 20 has a multilayer structure including the conductive layer 22 on the innermost side, and is a so-called laminate film. The “innermost” is the side closest to the wound electrode body 10 in the state where the wound electrode body 10 is enclosed in the inside of the exterior member 20.

More specifically, the exterior member 20 includes, for example, the exterior layer 21 and the conductive layer 22 in order from the outside. In addition, in FIG. 2, in order to make the exterior layer 21 and the conductive layer 22 easily distinguishable from each other, the conductive layer 22 is shaded.

(Exterior layer)
The exterior layer 21 is a layer which becomes an exterior of the secondary battery among the exterior members 20. The exterior layer 21 may be a single layer or multiple layers.

Here, the exterior layer 21 has, for example, a three-layer structure in which a surface protection layer 21A, a metal layer 21B, and a fusion layer 21A are laminated in this order from the outside.

(Surface protection layer)
The surface protective layer 21A is a layer that mainly protects the surface of the exterior member 20. The surface protective layer 21A contains, for example, one or more of insulating polymer materials such as nylon and polyethylene terephthalate. More specifically, the surface protective layer 21A contains, for example, any one or more of films including the above-described insulating polymer material. That is, the surface protective layer 21A may be a single layer or multiple layers.

The thickness of the surface protective layer 21A is not particularly limited, and is, for example, 5 μm to 25 μm.

(Metal layer)
The metal layer 21 </ b> B is a layer mainly for preventing entry of moisture and the like from the outside of the exterior member 20 into the inside. The metal layer 21B contains, for example, a metal material such as aluminum. More specifically, the metal layer 21B contains, for example, one or more of foils (metal foils) containing the above-described metal material. That is, the metal layer 21B may be a single layer or multiple layers.

The thickness of the metal layer 21B is not particularly limited, and is, for example, 10 μm to 40 μm.

(Fusing layer)
The fusion layer 21C is a layer mainly used to seal the exterior member 20 folded in the direction of the arrow R in a bag shape. In the manufacturing process of the secondary battery, for example, as described later, after the package member 20 is folded so that the fusion layers face each other via the wound electrode body 10, the outer peripheral edge portion of the fusion layer They are fused together.

The fusion layer 21C contains, for example, one or more of insulating polymer materials such as polyethylene and polypropylene. More specifically, the fusion layer 21C contains, for example, one or more of films including the above-described insulating polymer material. That is, the fusion layer 21C may be a single layer or a multilayer.

The thickness of the fusion layer 21C is not particularly limited, and is, for example, 10 μm to 40 μm.

Among them, the exterior layer 21 is an aluminum laminate film in which a nylon film (surface protective layer 21A), an aluminum foil (metal layer 21B), and a polyethylene film (fusion layer 21C) are laminated in this order from the outside. Is preferred. It is because sufficient durability, sealing performance, waterproofness and the like can be obtained.

However, the exterior layer 21 may be, for example, a laminate film having another multilayer structure. In this case, the number of layers of the exterior layer 21 is not limited to three, and may be two or four or more. Of course, the exterior layer 21 is not limited to a multilayer, and may be a single layer.

(Conductive layer)
The conductive layer 22 is a layer that forms a short circuit path (current flow path) with the wound electrode body 10 mainly by utilizing its own conductivity (electrical conductivity) at the time of breakage of the secondary battery described later. is there. This makes it difficult for the secondary battery to run away thermally even at the time of breakage, so that problems such as ignition are less likely to occur. The principle of forming a short circuit path using the conductive layer 22 will be described later (see FIG. 7).

When the exterior member 20 includes the conductive layer 22, the exterior layer 21 is reinforced by the conductive layer 22 as compared to the case where the exterior member 20 does not include the conductive layer 22. Therefore, since the physical strength of the whole exterior member 20 is improved, even if the secondary battery is repeatedly charged and discharged, the secondary battery becomes difficult to swell and to be warped.

The configuration of the conductive layer 22 is not particularly limited as long as it can form a short circuit path together with the wound electrode body 10.

Specifically, the conductive layer 22 includes, for example, one or more of conductive materials. The type of conductive material is not particularly limited, and examples thereof include carbon materials, metal materials and conductive polymer materials.

The type of carbon material is not particularly limited, and examples thereof include graphite, carbon black, acetylene black, ketjen black, needle-like carbon, carbon nanotubes, and graphene. The type of metal material is not particularly limited, and examples thereof include aluminum, copper, nickel, silver, palladium and gold. The type of conductive polymer material is not particularly limited, and examples thereof include polyacetylene and polythiophene.

Among them, the conductive material is preferably a carbon material. Since a carbon material generally has a large specific surface area, even if a gas is generated due to a decomposition reaction of an electrolytic solution or the like, the gas is adsorbed by the carbon material. As a result, even if the flexible film-like exterior member 20 is used, the secondary battery does not easily expand. In particular, when the secondary battery is used or stored in a high temperature environment, the decomposition reaction of the electrolytic solution is likely to proceed, so that the swelling of the secondary battery due to the generation of gas is effectively suppressed.

The type of metal material may be determined according to the configuration of the wound electrode body 10, for example. Specifically, for example, as described later, the wound electrode body 10 is formed by winding the positive electrode 13 and the negative electrode 14 laminated to each other via the separator 15, and the positive electrode 13 is at the outermost periphery. When disposed, the conductive layer 22 preferably contains, for example, the same material as the forming material of the positive electrode current collector 13A described later, specifically, aluminum or the like. It is because the conductive layer 22 becomes difficult to melt | dissolve at the time of charge / discharge as the formation material of the conductive layer 22 and the formation material of the positive electrode collector 13A are mutually the same. On the other hand, when the negative electrode 14 is arranged at the outermost periphery, the conductive layer 22 contains, for example, the same material as the forming material of the negative electrode current collector 14A described later, specifically, copper and nickel. Is preferred. It is because the conductive layer 22 becomes difficult to melt | dissolve at the time of charge / discharge as the formation material of the conductive layer 22 and the formation material of the negative electrode collector 14A are mutually identical.

Here, the form of the conductive layer 22 is not particularly limited. The “form of the conductive layer 22” is a form mainly determined based on the method of forming the conductive layer 22 or the like.

Specifically, the conductive layer 22 may be, for example, a molded body containing a conductive material. That is, the conductive layer 22 may be, for example, a molded body in which the conductive material is previously formed into a sheet, a film, or a foil. In this case, the conductive layer 22 is bonded to the exterior layer 21 through, for example, one or more of the bonding members. The type of the bonding member is not particularly limited, and examples thereof include an adhesive and an adhesive tape.

Alternatively, the conductive layer 22 may be, for example, a coating formed by applying a solution containing a conductive material or the like to the surface of the exterior layer 21 and then drying the solution. Specifically, the solution contains, for example, a plurality of particles containing a conductive material, a binder for binding the plurality of particles, a solvent and the like. The plurality of particles may be dispersed in a solution or may be dissolved in a solution. In this case, the conductive layer 22 is in close contact with the surface of the exterior layer 21 through, for example, the application step and the drying step described above.

The type of binding agent is not particularly limited, and is, for example, any one or more types of polymeric materials such as polyvinylidene fluoride. The type of solvent is not particularly limited, and is, for example, any one or more of organic solvents such as N-methyl-2-pyrrolidone. The details regarding each of the binding agent and the solvent described here are the same as in the following.

More specifically, the specific form in the case where the conductive layer 22 contains a carbon material is, for example, as follows.

The conductive layer 22 may be, for example, a molded body (carbon sheet) in which a powdery carbon material is previously molded into a sheet.

Alternatively, the conductive layer 22 may be formed, for example, by applying a solution containing a plurality of particles (carbon particles) containing a carbon material, a binder, a solvent and the like, and then drying the solution. Good. In this case, the plurality of particles are dispersed, for example, in a solution.

Moreover, the specific form in case the conductive layer 22 contains a metal material is as follows, for example.

The conductive layer 22 may be, for example, a formed body (metal foil) in which a metal material is previously formed into a foil shape.

Alternatively, the conductive layer 22 may be formed, for example, by applying a solution containing a plurality of particles (metal particles) containing a metal material, a binder, a solvent and the like, and then drying the solution. Good. In this case, the plurality of particles are dispersed, for example, in a solution.

Moreover, the specific form in case the conductive layer 22 contains a conductive polymer material is as follows, for example.

The conductive layer 22 may be, for example, a molded body (conductive polymer film or conductive polymer sheet) in which a conductive polymer material is previously formed into a film or sheet.

Alternatively, for example, after a solution containing a plurality of particles (conductive polymer particles) containing a conductive polymer material, a binder, a solvent and the like is applied, the conductive layer 22 is dried. It may be formed by In this case, the plurality of particles are dispersed or dissolved, for example, in a solution.

The formation range of the conductive layer 22 is not particularly limited. Therefore, the conductive layer 22 may be provided, for example, on the entire surface of the exterior layer 21, or may be provided on only a part of the surface of the exterior layer 21.

Here, for example, as shown in FIG. 2, the conductive layer 22 is a region of the surface of the exterior layer 21 (fusion layer 21C) excluding the fusion region 20R1 of the outer edge, ie, fusion of the outer edge It is formed in the central non-fusion area 20R2 surrounded by the area 20R1. The fused region 20R1 is a region where the fused layers are fused together after the package member 20 is folded. Even when the conductive layer 22 is provided on the surface of the exterior layer 21, the exterior member 20 can be sealed using a part of the exterior layer 21 (the fusion layer 21C in the fusion region 20R1). It is from.

The formation range of the conductive layer 22 can be arbitrarily changed within the non-fusion area 20R2 described above. That is, the formation area of the conductive layer 22 may be the same as the area of the non-fusion area 20R2, or the formation area of the conductive layer 22 may be smaller than the area of the non-fusion area 20R2. However, as described later, in order to facilitate formation of a short circuit path using conductive layer 22 even if the secondary battery is broken at any position, conductive layer 22 is the entire non-fusion area 20R2. Preferably, it is formed in

The electrical resistance of the conductive layer 22 is not particularly limited, but is preferably as low as possible. This is because the conductive layer 22 is used to facilitate formation of a short circuit path, and current can easily flow in the short circuit path. Among them, the surface resistance of the conductive layer 22 is preferably 500 Ω or less. This is because the electrical resistance of the conductive layer 22 is sufficiently low, so that the short circuit path can be easily and stably formed using the conductive layer 22. When measuring the surface resistance of the conductive layer 22, for example, a simple low-resistivity meter Loresta AX MCP-T370 manufactured by Mitsubishi Chemical Analytech Co., Ltd. is used. In this case, for example, while using a probe MCP-TPAP manufactured by the same company, two cylindrical probes (diameter of each probe = 2 mm, distance between two probes = 10 mm) are pressed against the conductive layer 22 (Push weight of each probe = 240 g).

The thickness of the conductive layer 22 is not particularly limited, but is preferably a thickness that does not impair the flexibility of the film-like package member 20. When the exterior layer 21 receives an external force that causes breakage of the secondary battery, the conductive layer 22 easily deforms while following the exterior layer 21 according to the external force, so using the conductive layer 22 It is because it becomes easy to form a short circuit path. The “external force” is, for example, a force by which the cylindrical round bar 30 is pressed against the secondary battery in a crushing test, as described later (see FIGS. 5 to 7). Among them, the thickness of the conductive layer 22 is preferably 100 μm or less, and more preferably 50 μm or less. This is because the flexibility of the conductive layer 22 is secured regardless of the type of the conductive material, so the conductive layer 22 is easily deformed while following the exterior layer 21.

The adhesion of the conductive layer 22 to the exterior layer 21 is not particularly limited, but is preferably as high as possible. When the exterior layer 21 is deformed due to the above-described external force, the conductive layer 22 is less likely to peel off the exterior layer 21. Among them, the peel strength of the conductive layer 22 measured in the 180 ° peel test is preferably 10 mN / mm or more, and more preferably 30 mN / mm or more. This is because the adhesion of the conductive layer 22 to the exterior layer 21 is sufficiently large, and the state of adhesion of the conductive layer 22 to the exterior layer 21 can be stably maintained even if an external force is applied. In the case of measuring the peel strength, for example, a table-type precision universal testing machine Autograph AGS-J manufactured by Shimadzu Corporation is used. In the 180 ° peel test, for example, a double-sided adhesive tape is used to affix the exterior member 20 (width = 25 mm) so that the exterior layer 21 is on the front side to a metal plate arranged to extend in the vertical direction. After that, the exterior layer 21 is pulled upward (pulling speed = 100 mm / min). In this case, the peeling strength is measured while peeling the exterior layer 21 from the conductive layer 22 (peeling length = 65 mm), and the average value of the peeling strength is determined.

(Insulating layer)
In the case where the exterior member 20 includes the conductive layer 22 on the innermost side, the exterior member 20 preferably further includes an insulating layer on the outermost side. This is because the outer surface of the exterior member 20 is insulated without exposing the conductive layer 22 serving as the short circuit path to the outside of the exterior member 20, so that the safety of the secondary battery is ensured.

Here, the insulating layer is, for example, the surface protection layer 21A of the exterior layer 21 having the three-layer structure described above. The surface protective layer 21A contains, for example, an insulating polymer material as described above. Thereby, the insulation of the outer surface of the exterior member 20 is ensured.

[Wound electrode body]
For example, as shown in FIG. 4, the wound electrode body 10 has the positive electrode 13 and the negative electrode 14 laminated to each other via the separator 15 and the electrolyte layer 16, and then the positive electrode 13, the negative electrode 14, the separator 15 and the electrolyte The layer 16 is formed by winding. The outermost periphery of the wound electrode body 10 is protected by, for example, a protective tape 17.

[Positive electrode lead and negative electrode lead]
The positive electrode lead 11 is connected to the positive electrode 13, and the positive electrode lead 11 is drawn out from the inside of the exterior member 20 to the outside. The positive electrode lead 11 contains, for example, one or more of conductive materials such as aluminum. The shape of the positive electrode lead 11 is, for example, a thin plate or a mesh.

The negative electrode lead 12 is connected to the negative electrode 14, and the negative electrode lead 12 is drawn out from the inside of the package member 20 to the outside. The lead-out direction of the negative electrode lead 12 is, for example, the same as the lead-out direction of the positive electrode lead 11. The negative electrode lead 12 contains, for example, one or more of conductive materials such as copper, nickel and stainless steel. The shape of the negative electrode lead 12 is, for example, the same as the shape of the positive electrode lead 31.

[Adhesive film]
For example, an adhesive film 21 is inserted between the exterior member 20 and the positive electrode lead 11 in order to prevent the entry of the outside air. The adhesive film 21 contains, for example, one or more of materials having adhesiveness to the positive electrode lead 11, and more specifically, contains a polyolefin resin or the like. The polyolefin resin is, for example, any one or more of polyethylene, polypropylene, modified polyethylene and modified polypropylene.

For example, an adhesive film 22 having the same function as the adhesive film 21 is inserted between the exterior member 20 and the negative electrode lead 12. The forming material of the adhesive film 22 is, for example, the same as the forming material of the adhesive film 21.

[Positive electrode]
For example, as shown in FIG. 4, the positive electrode 13 includes a positive electrode current collector 13A and two positive electrode active material layers 13B provided on both sides of the positive electrode current collector 13A. However, only one positive electrode active material layer 13B may be provided on one side of the positive electrode current collector 13A.

(Positive current collector)
The positive electrode current collector 13A contains, for example, one or more of conductive materials. The type of conductive material is not particularly limited, and is, for example, a metal material such as aluminum, nickel and stainless steel. The positive electrode current collector 13A may be a single layer or a multilayer.

(Positive electrode active material layer)
The positive electrode active material layer 13B contains, as a positive electrode active material, any one or two or more kinds of positive electrode materials capable of inserting and extracting lithium. However, the positive electrode active material layer 13B may further contain one or more of other materials such as a positive electrode binder and a positive electrode conductive agent.

(Positive electrode active material (positive electrode material))
The positive electrode material is preferably a lithium-containing compound. This is because a high energy density can be obtained. The "lithium-containing compound" is a generic term for compounds containing lithium as a constituent element. The type of lithium-containing compound is not particularly limited, and examples thereof include lithium-containing composite oxides and lithium-containing phosphoric acid compounds.

The term "lithium-containing composite oxide" is a generic term for oxides containing lithium and one or more other elements as constituent elements, and, for example, a crystal of layered rock salt type, spinel type, etc. It has a structure. The "lithium-containing phosphoric acid compound" is a generic term for a phosphoric acid compound containing lithium and one or more other elements as constituent elements, and has, for example, a crystal structure such as an olivine type. In addition, "other elements" are elements other than lithium.

The type of the other element is not particularly limited, but among them, an element belonging to Groups 2 to 15 in the long period periodic table is preferable. Specifically, the other elements are, for example, nickel (Ni), cobalt (Co), manganese (Mn) and iron (Fe). This is because a high voltage can be obtained.

The lithium-containing composite oxide having a layered rock salt type crystal structure is, for example, a compound represented by each of the following formulas (1) to (3).

Li _a Mn _(1-bc) Ni _b M 1 _c O _(2-d) F _e (1)
(M1 is cobalt (Co), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc) At least one of (Zn), zirconium (Zr), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W), a to e is 0.8 The following conditions are satisfied: a ≦ 1.2, 0 <b <0.5, 0 ≦ c ≦ 0.5, (b + c) <1, −0.1 ≦ d ≦ 0.2 and 0 ≦ e ≦ 0.1. However, the composition of lithium varies depending on the charge and discharge state, and a is a value of a completely discharged state.)

Li _a Ni _(1-b) M 2 _b O _(2-c) F _d (2)
(M2 is cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper) And at least one of (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W), wherein a to d is 0.8 ≦ a ≦ 1.2, 0.005 ≦ b ≦ 0.5, −0.1 ≦ c ≦ 0.2 and 0 ≦ d ≦ 0.1, provided that the composition of lithium depends on the charge and discharge state Differently, a is the value of the fully discharged state)

Li _a Co _(1-b) M3 _b O _(2-c) F _d (3)
(M3 represents nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper) And at least one of (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W), wherein a to d is 0.8 ≦ a ≦ 1.2, 0 ≦ b <0.5, −0.1 ≦ c ≦ 0.2 and 0 ≦ d ≦ 0.1, provided that the composition of lithium differs depending on the charge / discharge state, a is the value of the completely discharged state)

Specific examples of the lithium-containing composite oxide having a layered rock salt type crystal structure are LiNiO ₂ , LiCoO ₂ , LiCo _0.98 Al _0.01 Mg _0.01 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.8 Co _0.15 Al _0.05 O ₂ LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , Li _1.2 Mn _0.52 Co _0.175 Ni _0.1 O ₂ and Li _1.15 (Mn _0.65 Ni _0.22 Co _0.13 ) O ₂ and the like.

When the lithium-containing composite oxide having a layered rock salt type crystal structure contains nickel, cobalt, manganese and aluminum as constituent elements, the atomic ratio of nickel is preferably 50 atomic% or more. This is because a high energy density can be obtained.

The lithium-containing composite oxide having a spinel crystal structure is, for example, a compound represented by the following formula (4).

Li _a Mn _(2-b) M 4 _b O _c F _d (4)
(M4 is cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper) And at least one of (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W), wherein a to d are 0.9 ≦ a ≦ 1.1, 0 ≦ b ≦ 0.6, 3.7 ≦ c ≦ 4.1 and 0 ≦ d ≦ 0.1, provided that the composition of lithium varies depending on the charge / discharge state, a Is the value of the completely discharged state.)

A specific example of the lithium-containing composite oxide having a spinel type crystal structure is LiMn ₂ O ₄ or the like.

The lithium-containing phosphoric acid compound having an olivine type crystal structure is, for example, a compound represented by the following formula (5).

Li _a M5PO ₄ (5)
(M5 is cobalt (Co), manganese (Mn), iron (Fe), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), niobium) At least one of (Nb), copper (Cu), zinc (Zn), molybdenum (Mo), calcium (Ca), strontium (Sr), tungsten (W) and zirconium (Zr), a is 0.9 ≦ a ≦ 1.1, provided that the composition of lithium varies depending on the charge and discharge state, and a is a value of a completely discharged state)

Specific examples of the lithium-containing phosphoric acid compound having an olivine type crystal structure are LiFePO ₄ , LiMnPO ₄ , LiFe _0.5 Mn _0.5 PO ₄ and LiFe _0.3 Mn _0.7 PO ₄ and the like.

In addition, the compound etc. which are represented by following formula (6) may be sufficient as lithium containing complex oxide.

(Li ₂ MnO ₃ ) _x (LiMnO ₂ ) _1-x (6)
(X satisfies 0 ≦ x ≦ 1. However, the composition of lithium varies depending on the charge and discharge state, and x is a value of a completely discharged state)

(Other positive electrode materials)
The positive electrode material may be, for example, an oxide, a disulfide, a chalcogenide, a lithium-containing silicic acid compound, a lithium-containing boric acid compound, a conductive polymer, and the like. The oxides are, for example, titanium oxide, vanadium oxide and manganese dioxide. Examples of the disulfide include titanium disulfide and molybdenum sulfide. The chalcogenide is, for example, niobium selenide or the like. The lithium-containing silicate compound is, for example, Li ₂ FeSiO ₄ or the like. The lithium-containing boric acid compound is, for example, LiFeBO ₃ or the like. The conductive polymer is, for example, sulfur, polyaniline and polythiophene.

(Positive electrode binder)
The positive electrode binder contains, for example, one or more of synthetic rubber and polymer compound. The synthetic rubber is, for example, styrene butadiene rubber, fluorine rubber and ethylene propylene diene. The high molecular compounds are, for example, polyvinylidene fluoride, polyimide and polytetrafluoroethylene.

(Positive electrode conductive agent)
The positive electrode conductive agent contains, for example, one or more of conductive materials such as a carbon material. The carbon material is, for example, graphite, carbon black, acetylene black, ketjen black and carbon nanotubes. However, the positive electrode conductive agent is not limited to a carbon material as long as it is a conductive material, and may be a metal material, a conductive polymer, or the like.

[Negative electrode]
For example, as shown in FIG. 4, the negative electrode 14 includes a negative electrode current collector 14A and two negative electrode active material layers 14B provided on both sides of the negative electrode current collector 14A. However, only one negative electrode active material layer 14B may be provided on one side of the negative electrode current collector 14A.

(Negative current collector)
The negative electrode current collector 14A contains, for example, one or more of conductive materials. The type of conductive material is not particularly limited, and is, for example, a metal material such as copper, nickel and stainless steel. The negative electrode current collector 14A may be a single layer or a multilayer.

The surface of the negative electrode current collector 14A is preferably roughened. This is because the adhesion of the negative electrode active material layer 14B to the negative electrode current collector 14A is improved by utilizing the so-called anchor effect. In this case, the surface of the negative electrode current collector 14A may be roughened at least in a region facing the negative electrode active material layer 14B. The roughening method is, for example, a method of forming fine particles using electrolytic treatment. In the electrolytic treatment, since fine particles are formed on the surface of the negative electrode current collector 14A by using the electrolytic method in the electrolytic cell, unevenness is provided on the surface of the negative electrode current collector 14A. The copper foil produced by the electrolytic method is generally called an electrolytic copper foil.

(Anode active material layer)
The negative electrode active material layer 14B contains, as a negative electrode active material, any one kind or two or more kinds of negative electrode materials capable of inserting and extracting lithium. However, the negative electrode active material layer 14B may further contain one or more of other materials such as a negative electrode binder and a negative electrode conductive agent.

In order to prevent lithium metal from unintentionally depositing on the surface of the negative electrode 14 during charging, the chargeable capacity of the negative electrode material is preferably larger than the discharge capacity of the positive electrode 13. That is, the electrochemical equivalent of the negative electrode material capable of inserting and extracting lithium is preferably larger than the electrochemical equivalent of the positive electrode 13.

(Anode active material (negative electrode material))
The type of negative electrode material is not particularly limited as long as it is a material capable of inserting and extracting lithium.

(Carbon material)
The negative electrode material is, for example, a carbon material. The "carbon material" is a general term for materials containing carbon as a constituent element. This is because the crystal structure of the carbon material hardly changes significantly at the time of lithium storage and lithium release, and a high energy density can be stably obtained. In addition, since the carbon material also functions as a negative electrode conductive agent, the conductivity of the negative electrode active material layer 14B is improved.

The carbon material is, for example, graphitizable carbon, non-graphitizable carbon, graphite and the like. However, the spacing of the (002) plane relating to the non-graphitizable carbon is preferably 0.37 nm or more, and the spacing of the (002) plane relating to the graphite is preferably 0.34 nm or less. More specifically, the carbon material is, for example, pyrolytic carbons, cokes, glassy carbon fibers, organic polymer compound fired bodies, activated carbon, carbon blacks and the like. The cokes include pitch coke, needle coke and petroleum coke. The organic polymer compound fired body is a fired product obtained by firing (carbonizing) a polymer compound such as a phenol resin and furan resin at an appropriate temperature. In addition, the carbon material may be low crystalline carbon heat treated at a temperature of about 1000 ° C. or less, or may be amorphous carbon. The shape of the carbon material may be any of fibrous, spherical, granular and scaly.

(Metal-based material)
The negative electrode material is, for example, a metal-based material. The "metal-based material" is a generic name of a material containing one or more of metal elements and metalloid elements as constituent elements. This is because a high energy density can be obtained.

The metal-based material may be any one of an element, an alloy and a compound, two or more of them, or a material having at least a part of one or two or more of them. . However, in addition to the material which consists of 2 or more types of metal elements, the alloy also contains the material containing 1 or more types of metal elements, and 1 or more types of metalloid elements. The alloy may also contain nonmetallic elements. The structure of this metal-based material is, for example, a solid solution, a eutectic (eutectic mixture), an intermetallic compound, and a coexistence of two or more thereof.

Metal elements and metalloid elements are, for example, elements that can form an alloy with lithium. Specifically, the metal element and the metalloid element are, for example, magnesium (Mg), boron (B), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), Tin (Sn), lead (Pb), bismuth (Bi), cadmium (Cd), silver (Ag), zinc, hafnium (Hf), zirconium, yttrium (Y), palladium (Pd), platinum (Pt), etc. is there.

Among them, one or both of silicon and tin are preferred. Because the ability to insert and extract lithium is excellent, extremely high energy density can be obtained.

The material containing one or both of silicon and tin as a constituent element may be any of silicon alone, an alloy and a compound, or any of tin alone, an alloy and a compound, and among them Or a material having at least a part of one or two or more of them. The term "single substance" described herein means a single substance (which may contain a trace amount of impurities) in a general sense, and therefore means that the purity is necessarily 100%. is not.

The alloy of silicon is, for example, one of tin, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, chromium and the like as constituent elements other than silicon or It contains two or more types. The compound of silicon contains, for example, one or more of carbon, oxygen, and the like as a constituent element other than silicon. The compound of silicon may contain, for example, one or more of a series of elements described for the alloy of silicon as a constituent element other than silicon.

Specific examples of the alloy of silicon and the compound of silicon are SiB ₄ , SiB ₆ , Mg ₂ Si, Ni ₂ Si, TiSi ₂ , MoSi ₂ , MoSi ₂ , CoSi ₂ , NiSi ₂ , CaSi ₂ , CrSi ₂ , Cu ₅ Si, FeSi ₂ , MnSi ₂ , NbSi ₂ , TaSi ₂ , VSi ₂ , WSi ₂ , ZnSi ₂ , SiC, Si ₃ N ₄ , Si ₂ N ₂ O, SiO _v (0 <v ≦ 2), LiSiO and the like. In addition, _v in SiOv may be 0.2 <v <1.4.

The alloy of tin is, for example, one of silicon, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, chromium and the like as a constituent element other than tin or the like It contains two or more types. The compound of tin contains, for example, one or more of carbon, oxygen, and the like as a constituent element other than tin. The compound of tin may contain, for example, one or more of the series of elements described for the alloy of tin as a constituent element other than tin.

Specific examples of alloys of tin and compounds of tin are SnO _w (0 <w ≦ 2), SnSiO ₃ , LiSnO and Mg ₂ Sn.

In particular, the material containing tin as a constituent element is preferably, for example, a material (tin-containing material) containing a second constituent element and a third constituent element together with tin as the first constituent element. The second constituent element is, for example, cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium, zirconium, niobium, molybdenum, silver, indium, cesium (Ce), hafnium (Hf), It contains one or more of tantalum, tungsten, bismuth, silicon and the like. The third constituent element contains, for example, one or more of boron, carbon, aluminum, phosphorus and the like. This is because high battery capacity and excellent cycle characteristics can be obtained.

Among them, the tin-containing material is preferably a material (tin-cobalt carbon-containing material) containing tin, cobalt and carbon as constituent elements. In this tin-cobalt carbon-containing material, for example, the content of carbon is 9.9% to 29.7% by mass, and the ratio of the content of tin and cobalt (Co / (Sn + Co)) is 20% to 70% by mass is there. This is because a high energy density can be obtained.

The tin-cobalt carbon-containing material has a phase containing tin, cobalt and carbon, and the phase is preferably low crystalline or amorphous. Since this phase is a phase capable of reacting with lithium (reactive phase), excellent properties are obtained due to the presence of the reactive phase. The half-width (diffraction angle 2θ) of the diffraction peak obtained by X-ray diffraction of this reaction phase is 1 ° or more when the CuKα ray is used as the specific X-ray and the drawing speed is 1 ° / min. Is preferred. While lithium is occluded and released more smoothly, the reactivity with the electrolytic solution is reduced. In addition to the low crystalline or amorphous phase, the tin-cobalt carbon-containing material may include a phase containing a single element or a part of each constituent element.

As to whether the diffraction peak obtained by X-ray diffraction is a diffraction peak corresponding to a reaction phase capable of reacting with lithium, compare X-ray diffraction charts before and after the electrochemical reaction with lithium. It can be easily determined. For example, if the position of the diffraction peak changes before and after the electrochemical reaction with lithium, it is a diffraction peak corresponding to the reaction phase capable of reacting with lithium. In this case, for example, the diffraction peak of the low crystalline or amorphous reaction phase is detected in the range of 2θ = 20 ° to 50 °. This reaction phase contains, for example, the above-described series of constituent elements, and is considered to be low in crystallization or amorphization mainly due to the presence of carbon.

In the tin-cobalt carbon-containing material, it is preferable that at least a part of carbon which is a constituent element is bonded to a metal element or a metalloid element which is another constituent element. This is because aggregation or crystallization of tin or the like is suppressed. The bonding state of elements can be confirmed using, for example, X-ray photoelectron spectroscopy (XPS). In a commercially available apparatus, for example, Al-Kα rays or Mg-Kα rays are used as soft X-rays. When at least a part of carbon is bonded to a metal element or a metalloid element or the like, a peak of a synthetic wave of carbon 1s orbital (C1s) appears in an energy region lower than 284.5 eV. In addition, it is assumed that the energy calibration is performed so that the peak of 4f orbit (Au4f) of gold atom is obtained at 84.0 eV. Under the present circumstances, since surface contamination carbon exists in the surface of a substance normally, the peak of C1s resulting from the surface contamination carbon is made into 284.8 eV, and the peak is used as an energy standard. In XPS measurement, the waveform of the C1s peak is obtained in a form including the peak attributed to surface contamination carbon and the peak attributed to carbon in the tin-cobalt carbon-containing material. Therefore, for example, by analyzing the peaks including both peaks using commercially available software, the both peaks are separated. In the analysis of the waveform, the position of the main peak present on the lowest binding energy side is used as the energy reference (284.8 eV).

The tin-cobalt carbon-containing material is not limited to a material whose constituent elements are only tin, cobalt and carbon. The tin-cobalt-carbon-containing material may be, for example, in addition to tin, cobalt and carbon, any of silicon, iron, nickel, chromium, indium, niobium, germanium, titanium, molybdenum, aluminum, phosphorus, gallium and bismuth etc. You may contain 1 type or 2 types or more as a constitutent element.

Besides tin-cobalt carbon-containing materials, materials containing tin, cobalt, iron and carbon as constituent elements (tin-cobalt-iron-carbon-containing materials) are also preferable. The composition of this tin-cobalt-iron-carbon-containing material is optional. For example, when the content of iron is set to be small, the content of carbon is 9.9% by mass to 29.7% by mass, and the content of iron is 0.3% by mass to 5.9% by mass The content ratio of tin and cobalt (Co / (Sn + Co)) is 30% by mass to 70% by mass. In addition, when the content of iron is set to be large, the content of carbon is 11.9 mass% to 29.7 mass%, and the content ratio of tin, cobalt and iron ((Co + Fe) / (Sn + Co + Fe)) Is 26.4% by mass to 48.5% by mass, and the ratio of the content of cobalt and iron (Co / (Co + Fe)) is 9.9% by mass to 79.5% by mass. In such a composition range, high energy density can be obtained. The physical properties (such as half width) of the tin-cobalt-iron-carbon-containing material are the same as the physical properties of the above-mentioned tin-cobalt-carbon-containing material.

(Combined use of carbon material and metal material)
Among them, the negative electrode material preferably contains both a carbon material and a metal-based material for the following reasons.

Metal-based materials, in particular, materials containing one or both of silicon and tin as constituent elements have the advantage of high theoretical capacity, but have the concern that they tend to undergo extensive expansion and contraction during charge and discharge. On the other hand, carbon materials have the concern that the theoretical capacity is low, but they have the advantage of being difficult to expand and contract during charge and discharge. Therefore, by using the carbon material and the metal-based material in combination, expansion and contraction at the time of charge and discharge are suppressed while securing a high theoretical capacity (that is, battery capacity).

(Other negative electrode materials)
The negative electrode material may be, for example, a metal oxide and a polymer compound. The metal oxide is, for example, iron oxide, ruthenium oxide and molybdenum oxide. The polymer compounds are, for example, polyacetylene, polyaniline and polypyrrole.

(Negative electrode binder and negative electrode conductive agent)
The details of the negative electrode binder are, for example, the same as the details of the positive electrode binder described above. Further, details of the negative electrode conductive agent are, for example, the same as the details of the negative electrode conductive agent described above.

In the secondary battery, as described above, in order to prevent lithium metal from being unintentionally deposited on the surface of the negative electrode 14 during charging, electricity of the negative electrode material capable of inserting and extracting lithium The chemical equivalent is preferably larger than the electrochemical equivalent of the positive electrode. Moreover, compared with the case where it is 4.20V, the open circuit voltage (namely, battery voltage) at the time of complete charge is the discharge amount of lithium per unit mass using the same positive electrode active material compared with the case where it is 4.20V. Preferably, the amount of the positive electrode active material and the amount of the negative electrode active material are mutually adjusted in consideration of the fact that This gives a high energy density.

[Separator]
For example, as shown in FIG. 4, the separator 15 is disposed between the positive electrode 13 and the negative electrode 14, and allows lithium ions to pass while preventing a short circuit of the current caused by the contact of the both electrodes.

The separator 15 contains, for example, one or more types of porous films such as synthetic resin and ceramic, and may be a laminated film of two or more types of porous films. Synthetic resins are, for example, polytetrafluoroethylene, polypropylene and polyethylene.

In particular, the separator 15 may include, for example, the above-described porous membrane (base layer) and a polymer compound layer provided on one side or both sides of the base layer. This is because the adhesion of the separator 15 to each of the positive electrode 13 and the negative electrode 14 is improved, so distortion of the wound electrode body 10 is suppressed. Thereby, the decomposition reaction of the electrolytic solution is suppressed, and the leakage of the electrolytic solution impregnated in the base material layer is also suppressed. Therefore, even if charge and discharge are repeated, the electric resistance is hardly increased and the secondary battery is Is less likely to swell.

The polymer compound layer contains, for example, a polymer compound such as polyvinylidene fluoride. It is because it is excellent in physical strength and electrochemically stable. However, the polymer compound may be other than polyvinylidene fluoride. In the case of forming the polymer compound layer, for example, a solution in which the polymer compound is dissolved in an organic solvent or the like is applied to the base material layer, and then the base material layer is dried. In addition, after a base material layer is immersed in a solution, the base material layer may be dried.

The polymer compound layer may contain, for example, one or more of insulating particles such as inorganic particles. The types of inorganic particles are, for example, aluminum oxide and aluminum nitride.

[Electrolyte layer]
The electrolyte layer 16 contains an electrolytic solution and a polymer compound. However, the electrolyte layer 16 may further contain any one or more of other materials such as additives.

Since the electrolyte layer 16 described here is a so-called gel electrolyte, in the electrolyte layer 16, the electrolytic solution is held by the polymer compound. This is because high ionic conductivity (for example, 1 mS / cm or more at room temperature) can be obtained, and leakage of the electrolytic solution can be prevented.

For example, as shown in FIG. 4, the electrolyte layer 16 is disposed between the positive electrode 13 and the separator 15 and disposed between the negative electrode 14 and the separator 15. However, the electrolyte layer 16 may be disposed, for example, only between the positive electrode 13 and the separator 15, or may be disposed only between the negative electrode 14 and the separator 15.

(Electrolyte solution)
The electrolyte contains a solvent and an electrolyte salt. However, the electrolytic solution may further contain any one or more of other materials such as additives.

(solvent)
The solvent contains any one or more kinds of non-aqueous solvents such as organic solvents. The electrolyte containing a non-aqueous solvent is a so-called non-aqueous electrolyte.

Nonaqueous solvents are, for example, cyclic carbonates, linear carbonates, lactones, linear carboxylic esters and mononitrile compounds. This is because excellent battery capacity, cycle characteristics and storage characteristics can be obtained.

Cyclic carbonates are, for example, ethylene carbonate, propylene carbonate and butylene carbonate. Examples of chain carbonates include dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dibutyl carbonate and methyl propyl carbonate. Lactones are, for example, γ-butyrolactone and γ-valerolactone. The chain carboxylic acid ester is, for example, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethylacetate, methyl trimethylacetate and the like. The mononitrile compounds are, for example, acetonitrile, methoxyacetonitrile, 3-methoxypropionitrile and the like.

Other non-aqueous solvents are, for example, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1 And 4-dioxane, N, N-dimethylformamide, N-methyl pyrrolidinone, N-methyl oxazolidinone, N, N'-dimethyl imidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate and dimethyl sulfoxide and the like. It is because the same advantage is obtained.

Among them, the non-aqueous solvent preferably contains one or more selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. This is because high battery capacity, excellent cycle characteristics and excellent storage characteristics can be obtained. In this case, high viscosity (high dielectric constant) solvents such as ethylene carbonate and propylene carbonate (for example, relative permittivity ε ≧ 30) and low viscosity solvents such as dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate (for example, viscosity The combination with ≦ 1 mPa · s) is more preferable. This is because the dissociative nature of the electrolyte salt and the mobility of the ions are improved.

Moreover, the non-aqueous solvent includes, for example, unsaturated cyclic carbonate, halogenated carbonate, sulfonic acid ester, acid anhydride, dicyano compound (dinitrile compound), diisocyanate compound, phosphoric acid ester, carbon-carbon triple bond chain compound, etc. It is. This is because the chemical stability of the electrolytic solution is improved.

An unsaturated cyclic carbonate is a cyclic carbonate having one or more unsaturated bonds (carbon-carbon double bonds). The unsaturated cyclic carbonate is, for example, vinylene carbonate, vinyl ethylene carbonate and methylene ethylene carbonate. The content of the unsaturated cyclic carbonate in the non-aqueous solvent is not particularly limited, and is, for example, 0.01% by weight to 10% by weight.

The halogenated carbonate is a cyclic or chain carbonate containing one or more halogen elements as a constituent element. When the halogenated carbonate ester contains two or more halogens as constituent elements, the number of kinds of two or more halogens may be only one or two or more. Cyclic halogenated carbonates are, for example, 4-fluoro-1,3-dioxolan-2-one and 4,5-difluoro-1,3-dioxolan-2-one. The chain halogenated carbonates are, for example, fluoromethyl methyl carbonate, bis (fluoromethyl) carbonate and difluoromethyl methyl carbonate. The content of the halogenated carbonate in the non-aqueous solvent is not particularly limited, and is, for example, 0.01% by weight to 50% by weight.

Sulfonic acid esters are, for example, monosulfonic acid esters and disulfonic acid esters. The content of sulfonic acid ester in the non-aqueous solvent is not particularly limited, and is, for example, 0.01% by weight to 10% by weight.

The monosulfonic acid ester may be a cyclic monosulfonic acid ester or a linear monosulfonic acid ester. Cyclic monosulfonic acid esters are, for example, sultones such as 1,3-propane sultone and 1,3-propene sultone. The linear monosulfonic acid ester is, for example, a compound in which a cyclic monosulfonic acid ester is cleaved halfway. The disulfonic acid ester may be a cyclic disulfonic acid ester or a linear disulfonic acid ester.

The acid anhydride is, for example, carboxylic acid anhydride, disulfonic acid anhydride and carboxylic acid sulfonic acid anhydride. Carboxylic anhydrides are, for example, succinic anhydride, glutaric anhydride and maleic anhydride. Examples of disulfonic anhydride include anhydrous ethanedisulfonic acid and anhydrous propanedisulfonic acid. Carboxylic acid sulfonic acid anhydrides are, for example, sulfobenzoic anhydride, sulfopropionic anhydride and sulfobutyric anhydride. The content of the acid anhydride in the non-aqueous solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

The dinitrile compound is, for example, a compound represented by NC-R1-CN (R1 is any of an alkylene group and an arylene group). The dinitrile compounds are, for example, succinonitrile _{_{(NC-C 2 H 4 -CN}} ), glutaronitrile _{_{(NC-C 3 H 6 -CN}} ), adiponitrile _{_{(NC-C 4 H 8 -CN}} ) and phthalonitrile ( NC-C ₆ H ₄ -CN) and the like. The content of the dinitrile compound in the non-aqueous solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

The diisocyanate compound is, for example, a compound represented by OCN-R2-NCO (R2 is any of an alkylene group and an arylene group). The diisocyanate compound is, for example, hexamethylene diisocyanate (OCN-C ₆ H ₁₂ -NCO). The content of the diisocyanate compound in the non-aqueous solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

The phosphoric acid ester is, for example, trimethyl phosphate and triethyl phosphate. The content of phosphoric acid ester in the non-aqueous solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

A carbon-carbon triple bond chain compound is a chain compound having one or more carbon-carbon triple bonds. Examples of such a carbon-carbon triple bond chain compound include propargyl methyl carbonate (CH≡C-CH ₂ —O—C ((O) —O—CH ₃ ) and propargyl methyl sulfonate (CH≡C—CH ₂ —O -S (= O) ₂ -CH ₃ ) and the like. The content of the chain compound having a carbon-carbon triple bond in the non-aqueous solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

(Electrolyte salt)
The electrolyte salt contains, for example, any one or more of salts such as lithium salts. However, the electrolyte salt may include, for example, other salts than the lithium salt. Other salts are, for example, salts of light metals other than lithium.

The lithium salt is, for example, lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), lithium hexafluoride arsenate (LiAsF ₆ ), tetraphenyl Lithium borate (LiB (C ₆ H ₅ ) ₄ ), lithium methanesulfonate (LiCH ₃ SO ₃ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium tetrachloroaluminate (LiAlCl ₄ ), hexafluoride Dilithium silicate (Li ₂ SiF ₆ ), lithium chloride (LiCl), bis (fluorosulfonyl) imide lithium (LiN (SO ₂ F) ₂ ), bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ ) and lithium bromide (LiBr). This is because excellent battery capacity, cycle characteristics and storage characteristics can be obtained.

Among them, one or two or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate and lithium hexafluoroarsenate are preferable, and lithium hexafluorophosphate is more preferable. . It is because internal resistance falls.

The content of the electrolyte salt is not particularly limited, but preferably 0.3 mol / kg to 3.0 mol / kg with respect to the solvent. It is because high ion conductivity is obtained.

(Polymer compound)
The polymer compound contains one or more of homopolymers and copolymers.

Examples of homopolymers include polyacrylonitrile, polyvinylidene fluoride, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, polysiloxane, polyvinyl fluoride, polyvinyl acetate, polyvinyl alcohol, and polymethacryl. Acid methyl acrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene and polycarbonate.

The copolymer is, for example, a copolymer of vinylidene fluoride and another monomer. The “other monomer” is a monomer other than vinylidene fluoride, and is, for example, one or more of hexafluoropropylene, monomethyl maleate, trifluoroethylene, chlorotrifluoroethylene and the like. . The copolymerization amount (% by weight) of the other monomer in the copolymer is not particularly limited and can be arbitrarily set.

Among them, the homopolymer is preferably polyvinylidene fluoride, and the copolymer is preferably a copolymer of vinylidene fluoride and hexafluoropropylene. This is because the physical strength of the electrolyte layer 16 is improved and the electrolyte layer 16 is electrochemically stabilized.

Here, in the electrolyte layer 16 which is a gel electrolyte, the “solvent” contained in the electrolytic solution is not only a liquid material (the non-aqueous solvent described above) but also ion conduction capable of dissociating the electrolyte salt. It is a broad concept that includes even materials with sex. For this reason, when the polymer compound has ion conductivity, the polymer compound is also included in the solvent described herein.

(Additive)
The type of additive is not particularly limited. Specifically, the additive is, for example, a plurality of insulating particles. Since the short circuit between the positive electrode 13 and the negative electrode 14 is suppressed by the separator 15 being less likely to be oxidized during charge and discharge of the secondary battery, the safety of the secondary battery is improved.

The plurality of insulating particles contain, for example, one or more of inorganic compounds. The type of inorganic compound is not particularly limited. For example, aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), magnesium oxide (MgO), aluminum nitride (AlN), boron nitride (BN) and zeolites.

<1-2. Operation>
The secondary battery operates, for example, as follows. Hereinafter, after describing the charge and discharge operation, the safe operation will be described.

[Charge and discharge operation]
At the time of charging, lithium ions are released from the positive electrode 13 and the lithium ions are occluded by the negative electrode 14 through the electrolyte layer 16. On the other hand, at the time of discharge, lithium ions are released from the negative electrode 14, and the lithium ions are occluded by the positive electrode 13 via the electrolyte layer 16.

[Safe operation]
Each of FIG. 5 and FIG. 6 schematically shows the configuration of the secondary battery in order to explain the safe operation of the secondary battery. FIG. 7 is an enlarged sectional view of a part (portion 20P2) of the secondary battery shown in FIG.

5 to 7 show the procedure of the crushing test described later, for example, in order to explain the operation (safety operation) of the secondary battery at the time of breakage. However, in FIG. 7, the electrolyte layer 16 is omitted to simplify the illustration.

In the crushing test, for example, as illustrated in FIG. 5, the secondary battery in which the wound electrode body 10 is enclosed in the exterior member 20 and the positive electrode lead 11 and the negative electrode lead 12 are connected to the wound electrode body 10. On the other hand, cylindrical round bars 30 are disposed to face each other. The round bar 30 is, for example, a metal bar containing one or more of metal materials such as iron, chromium and nickel. The position of the round bar 30 is not particularly limited, but is, for example, a position facing near the center of the secondary battery.

After this, by pressing the round bar 30 against the secondary battery, for example, as shown in FIG. 6, a part of the secondary battery is crushed by the round bar 30, so that the round bar 30 bites into the wound electrode body 10 through the exterior member 20. The force pressing the round bar 30 against the secondary battery can be set arbitrarily.

In this case, since a part of each of the positive electrode 13, the negative electrode 14 and the separator 15 is broken by the round bar 30, the broken surface 13 M is exposed at the place where the positive electrode 13 is broken and the negative electrode 14 is broken. The fractured surface 14M is exposed at the portion.

On the other hand, since the exterior member 20 (the exterior layer 21 and the conductive layer 22) has flexibility, the exterior member 20 is not broken even if it is pushed by the round bar 30, and via the round bar 30. It is pressed against each of the positive electrode 13 and the negative electrode 14. Thereby, the fractured surface 13M contacts the conductive layer 22, and the fractured surface 14M contacts the conductive layer 22.

In this case, particularly, when the package member 20 is sufficiently pressed against each of the positive electrode 13 and the negative electrode 14 through the round bar 30, the conductive layer 22 covers the fracture surfaces 13M and 14M. As a result, the contact area between the fracture surface 13M and the conductive layer 22 becomes sufficiently large, and the contact area between the fracture surface 14M and the conductive layer 22 becomes sufficiently large. 7 shows the case where the positive electrode active material layer 13B contacts the conductive layer 22 after breakage of the positive electrode 13 and the negative electrode active material layer 14B contacts the conductive layer 22 after breakage of the negative electrode 14.

Thus, for example, a short circuit path D extending from the negative electrode 14 (negative electrode active material layer 14B) to the positive electrode 13 (positive electrode active material layer 13B) via the conductive layer 22 is formed. In this case, of course, if the positive electrode 13 is broken at a plurality of locations and the negative electrode 14 is broken at a plurality of locations, a plurality of short circuit paths D are formed. The short circuit path D is a current flow path having a low resistance.

Thus, even if the secondary battery is broken due to an external force (here, for example, a force by which the round bar is pressed against the secondary battery), the positive electrode 13 and the negative electrode 14 come in contact with each other. Not only current flows in the short circuit path formed, but also current flows in the short circuit path D having the above-described low resistance. That is, when the current flows in the short circuit path D having a low resistance, the current does not easily concentrate in the short circuit path formed due to the positive electrode 13 and the negative electrode 14 coming into contact with each other. The current is distributed in As a result, the amount of heat generation is unlikely to increase, and the temperature of the secondary battery is unlikely to rise excessively. In this case, in particular, if the plurality of short circuit paths D are formed as described above, the heat generation parts are dispersed in a plurality of places, so that the temperature of the secondary battery becomes more difficult to rise.

From these things, since it becomes difficult to carry out thermal runaway of the winding electrode body 10 at the time of the failure | damage of a secondary battery, the winding electrode body 10 becomes difficult to ignite.

<1-3. Manufacturing method>
The secondary battery provided with the gel electrolyte layer 16 is manufactured, for example, by the following three types of procedures. In addition, since the configuration of the exterior member 20 has already been described in detail, the description thereof will be omitted below.

[First step]
In the case of producing the positive electrode 13, first, a positive electrode active material, and if necessary, a positive electrode binder, a positive electrode conductive agent, and the like are mixed to form a positive electrode mixture. Subsequently, the positive electrode mixture is dispersed in an organic solvent or the like to prepare a paste-like positive electrode mixture slurry. Finally, the positive electrode mixture slurry is applied to both surfaces of the positive electrode current collector 13A, and then the positive electrode mixture slurry is dried to form the positive electrode active material layer 13B. After that, the positive electrode active material layer 13B may be compression molded using a roll press machine or the like, as necessary. In this case, the positive electrode active material layer 13B may be heated or compression molding may be repeated multiple times.

When manufacturing the negative electrode 14, the negative electrode active material layer 14B is formed on both surfaces of the negative electrode current collector 14A by the same procedure as the manufacturing procedure of the positive electrode 13 described above. Specifically, the negative electrode active material is mixed with a negative electrode binder and a negative electrode conductive agent to form a negative electrode mixture, and then the negative electrode mixture is dispersed in an organic solvent or the like to form a paste. A negative mix slurry is prepared. Subsequently, the negative electrode mixture slurry is applied to both surfaces of the negative electrode current collector 14A, and then the negative electrode mixture slurry is dried to form the negative electrode active material layer 14B. Thereafter, the negative electrode active material layer 14B may be compression molded using a roll press or the like, as necessary.

The method of forming the negative electrode active material layer 14B is not particularly limited. For example, any one or two or more of a coating method, a gas phase method, a liquid phase method, a thermal spraying method and a firing method (sintering method) It is. The coating method is, for example, a method of preparing a solution in which particles (powder) of a negative electrode active material and a negative electrode binder or the like are dissolved or dispersed by an organic solvent or the like, and then coating the solution on the negative electrode current collector 14A. It is. The vapor phase method is, for example, physical deposition method and chemical deposition method, and more specifically, vacuum deposition method, sputtering method, ion plating method, laser ablation method, thermal chemical vapor deposition, chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition. The liquid phase method is, for example, an electrolytic plating method and an electroless plating method. The thermal spraying method is a method of spraying a molten or semi-molten negative electrode active material onto the negative electrode current collector 14A. The baking method is, for example, a method of applying the above-described solution to the negative electrode current collector 14A using a coating method, and then heat treating the solution at a temperature higher than the melting point of the negative electrode binder and the like. The firing method is, for example, an atmosphere firing method, a reaction firing method, a hot press firing method, or the like.

In the case of forming the electrolyte layer 16, an electrolytic solution, a polymer compound, an organic solvent and the like are mixed, and then the mixture is stirred to prepare a precursor solution. The precursor solution is applied to the positive electrode 13, and then dried to form the electrolyte layer 16. The precursor solution is applied to the negative electrode 14, and then the precursor solution is dried to form the electrolyte layer 16. Form

When assembling the secondary battery, first, the positive electrode lead 11 is connected to the positive electrode current collector 13A using a welding method or the like, and the negative electrode lead 12 is connected to the negative electrode current collector 14A using a welding method or the like. . Subsequently, the positive electrode 13 on which the electrolyte layer 16 is formed and the negative electrode 14 on which the electrolyte layer 16 is formed are wound around each other through the separator 15, and then the positive electrode 13, the negative electrode 14, the separator 15, and the electrolyte layer 16. The wound electrode body 10 is formed by winding. After this, the protective tape 17 is attached to the outermost periphery of the wound electrode body 10. Subsequently, in a state in which the wound electrode body 10 is housed in the recess 20U, the exterior member 20 is folded so as to sandwich the wound electrode body 10. Finally, the outer peripheral edge portions of the exterior member 20 are adhered to each other using a heat fusion method or the like, so that the wound electrode body 10 is sealed inside the exterior member 20. In this case, the adhesive film 21 is inserted between the positive electrode lead 11 and the package member 20, and the adhesive film 22 is inserted between the negative electrode lead 12 and the package member 20.

As a result, the wound electrode body 10 is enclosed in the exterior member 20, and thus the secondary battery is completed.

[Second step]
First, each of the positive electrode 13 and the negative electrode 14 is fabricated by the same procedure as the first procedure described above, and then the positive electrode lead 11 is connected to the positive electrode 13 using a welding method etc. The negative electrode lead 12 is connected to 14. Subsequently, the positive electrode 13 and the negative electrode 14 are stacked on each other through the separator 15, and then the positive electrode 13, the negative electrode 14 and the separator 31 are wound to form a wound body which is a precursor of the wound electrode body 10. Make. After this, the protective tape 37 is attached to the outermost periphery of the wound body.

Subsequently, the exterior member 20 is folded so as to sandwich the wound body, and the remaining outer peripheral edge excluding one outer peripheral edge of the exterior member 20 is adhered using a heat fusion method or the like. The wound body is housed inside the bag-like exterior member 20.

Then, after mixing the electrolyte solution, the monomer which is a raw material of a high molecular compound, a polymerization initiator, and other materials such as a polymerization inhibitor according to need, the mixture is stirred to prepare an electrolyte. The composition is prepared. Subsequently, after the composition for electrolyte is injected into the inside of the bag-like exterior member 20, the exterior member 20 is sealed using a heat fusion method or the like.

Finally, a polymer compound is formed by thermally polymerizing the monomers in the composition for electrolyte. As a result, the electrolytic solution is held by the polymer compound, whereby the electrolyte layer 16 is formed. Thus, the wound electrode body 10 is sealed inside the exterior member 20.

[Third step]
First, a wound body is produced by the same procedure as the above-described second procedure except that a separator 15 in which two polymer compound layers are formed on both surfaces of a porous membrane (base material layer) is used. . Subsequently, the wound body is housed inside the bag-like exterior member 20. Subsequently, an electrolytic solution is injected into the inside of the exterior member 20, and then the opening of the exterior member 20 is sealed using a heat fusion method or the like. Finally, by heating the package member 20 while applying weight to the package member 20, the separator 15 is adhered to the positive electrode 13 via the polymer compound layer, and the separator 14 is placed on the negative electrode 14 via the polymer compound layer. Attach the 15 together. As a result, the electrolytic solution is impregnated into the polymer compound layer and the polymer compound layer is gelated, so that the electrolyte layer 16 is formed. Thus, the wound electrode body 10 is sealed inside the exterior member 20.

In this third procedure, the secondary battery is less likely to swell than in the first procedure. Further, in the third procedure, compared to the second procedure, the solvent and the monomer (raw material of the polymer compound) and the like are less likely to remain in the electrolyte layer 16, so the step of forming the polymer compound is well controlled. . Thereby, each of the positive electrode 13, the negative electrode 14, and the separator 15 is sufficiently in close contact with the electrolyte layer 16.

<1-4. Action and effect>
According to this secondary battery, the wound electrode body 10 is accommodated inside the film-like exterior member 20, and the exterior member 20 includes the conductive layer 22 on the innermost side, so the reason described below will be described. Safety can be improved.

FIG. 8 shows the configuration of the exterior member 40 in the secondary battery of the comparative example, and shows a cross-sectional configuration corresponding to FIG. FIG. 9 shows a cross-sectional configuration corresponding to FIG. 7 in order to explain the problems regarding the safety of the secondary battery of the comparative example.

The secondary battery of the comparative example is, for example, the same as the secondary battery of the present technology (see FIG. 3) except that an exterior member 40 is provided instead of the exterior member 20 as shown in FIG. It has a configuration. Since the exterior member 40 does not include, for example, the conductive layer 22, the configuration is the same as that of the exterior member 20 except that it is composed only of the exterior layer 21 (surface protective layer 21 A, metal layer 21 B, fusion layer 21 C). have.

In the secondary battery of the comparative example, as shown in FIG. 9, when a part of each of the positive electrode 13, the negative electrode 14 and the separator 15 is broken by the round bar 30 in the above-described crushing test (see FIGS. 5 and 6). While the fractured surface 13M contacts the fusion layer 21C, the fractured surface 14M contacts the fusion layer 21C.

However, since the fusion layer 21C contains the insulating polymer material such as polyethylene as described above, even if each of the fracture surfaces 13M and 14M contacts the fusion layer 21C, the short circuit path D (see FIG. 7) is not formed.

In this case, when the secondary battery is broken due to the external force, current concentrates in the short circuit path formed due to the positive electrode 13 and the negative electrode 14 coming into contact with each other. As a result, the calorific value tends to increase in the entire secondary battery, and the temperature of the secondary battery tends to rise excessively. Therefore, since the wound electrode body 10 is easily thermally runaway, the wound electrode body 10 is easily ignited. This makes it difficult to improve the safety of the secondary battery.

On the other hand, in the secondary battery of the present technology, as described with reference to FIGS. 5 to 7, since the exterior member 20 includes the conductive layer 22 on the innermost side, the round bar 30 is used in the crushing test. When a part of each of the positive electrode 13, the negative electrode 14 and the separator 15 is broken, each of the

broken surfaces

13 M and 14 M contacts the conductive layer 22 to form a short circuit path D.

In this case, as described above, even if the secondary battery is broken due to external force, the current flows in the short circuit path D having low resistance, so the positive electrode 13 and the negative electrode 14 come in contact with each other It becomes difficult for current to concentrate in the short circuit path formed. As a result, the amount of heat generation is unlikely to increase in the entire secondary battery, and the temperature of the secondary battery is unlikely to rise excessively. Thus, the wound electrode body 10 is less likely to cause thermal runaway, and hence the wound electrode body 10 is less likely to be ignited. Thereby, the safety of the secondary battery can be improved.

In particular, in the secondary battery of the present technology, the same effect can be obtained not only when the above-described crushing test is performed but also when the nailing test and the like are performed, and therefore the same effect can be obtained. Of course, the secondary battery was unintentionally broken (each of the positive electrode 13 and the negative electrode 14 was broken) due to some factor, not only when the intentional breakage test such as the crushing test and the nail penetration test was performed. Even in the case, the same effect can be obtained because the same effect can be obtained.

In addition, if the conductive layer 22 is formed over the entire non-fused region 20R2, the short circuit path D is easily formed utilizing the conductive layer 22 regardless of the position of breakage of the secondary battery. You can get higher effects.

In addition, when the conductive layer 22 contains one or more of carbon material, metal material and conductive polymer material as the conductive material, the short circuit path D is easily formed and the short circuit is generated. Since a sufficient amount of current easily flows in the path D, higher effects can be obtained.

In this case, if the conductive layer 22 is a molded body containing a conductive material, or if the conductive layer 22 contains a plurality of particles containing a conductive material and a binder, the conductive layer 22 is easy and It is formed stably. Therefore, since the short circuit path D is easily and stably formed, a higher effect can be obtained.

In addition, when the conductive layer 22 includes the insulating layer (surface protective layer 21A) on the outermost side, the outer surface of the exterior member 20 is insulated, so that the safety of the secondary battery can be further improved.

<1-5. Modified example>
The configuration of the secondary battery of the present technology can be changed as appropriate.

[Modification 1]
Specifically, as shown in FIG. 2, after the package member 20 is folded, the fusion layers 21C are fused to each other to seal the package member 20, so that the non-fusion region 20R2 is electrically conductive. Layer 22 was formed.

However, for example, the conductive layer 22 may be formed on both the fused region 20R1 and the non-fused region 20R2. In this case, for example, as described above, after the package member 20 is folded, the package member 20 can be sealed by adhering the conductive layers 22 to each other through an adhesive or the like. Also in this case, the same effect can be obtained.

However, in order to improve the sealability by utilizing the fusion layer 21C, as shown in FIG. 2, by forming the conductive layer 22 in the non-fusion area 20R2, the fusion layers 21C can be It is preferable to seal the exterior member 20 by fusing them together.

[Modification 2]
As shown in FIG. 2, by using one exterior member 20, one exterior member 20 is folded in order to accommodate the wound electrode assembly 10.

However, for example, by using two exterior members 20, the fusion layer 21C of one exterior member 20 and the fusion layer 21C of the other exterior member 20 may be fused to each other. Also in this case, since the wound electrode body 10 is enclosed in the exterior member 20, the same effect can be obtained.

[Modification 3]
For example, as shown in FIG. 10 corresponding to FIG. 3, by forming a plurality of projections 22 T on the surface of the conductive layer 22, unevenness may be provided on the surface of the conductive layer 22.

In this case, the surface area of the conductive layer 22 is increased as compared with the case where no unevenness is provided on the surface of the conductive layer 22 (FIG. 3). Thus, when the secondary battery is broken (FIG. 7), the contact area between the fracture surface 13M and the conductive layer 22 is likely to increase, and the contact area between the fracture surface 14M and the conductive layer 22 is likely to increase. Therefore, the short circuit path D is more easily formed, and the heat is more easily dispersed using the short circuit path D, so that a higher effect can be obtained.

[Modification 4]
For example, as shown in FIG. 11 corresponding to FIG. 2, by forming a plurality of openings 22 K in the conductive layer 22, the conductive layer 22 may be meshed.

In this case, the surface area of the conductive layer 22 is increased as compared with the case where the conductive layer 22 is not in the form of a mesh (FIG. 2). Therefore, for the same reason as in the third modification described above, the short circuit path D is more easily formed, and heat is more easily dispersed by using the short circuit path D, so that a higher effect can be obtained.

[Modification 5]
As shown in FIG. 4, an electrolyte layer 16 which is a gel electrolyte in which an electrolytic solution is held by a polymer compound was used.

However, instead of the electrolyte layer 16, an electrolytic solution that is a liquid electrolyte may be used. In this case, instead of forming the electrolyte layer 16 on the surface of each of the positive electrode 13 and the negative electrode 14, for example, the electrolytic solution is impregnated in each of the positive electrode 13, the negative electrode 14, and the separator 15. Also in this case, the same effect can be obtained.

[Modification 6]
Of course, any two or more of the series of modifications 1 to 5 may be combined with each other.

<2. Applications of Secondary Battery>
Next, application examples of the above-described secondary battery will be described.

Applications of secondary batteries include machines, devices, instruments, devices and systems (aggregates of multiple devices) where secondary batteries can be used as a power source for driving or a power storage source for storing electric power, etc. For example, it is not particularly limited. The secondary battery used as a power source may be a main power source or an auxiliary power source. The main power supply is a power supply that is preferentially used regardless of the presence or absence of other power supplies. The auxiliary power source may be, for example, a power source used instead of the main power source, or a power source switched from the main power source as needed. When a secondary battery is used as an auxiliary power supply, the type of main power supply is not limited to the secondary battery.

The application of the secondary battery is, for example, as follows. They are electronic devices (including portable electronic devices) such as video cameras, digital still cameras, mobile phones, laptop computers, cordless phones, headphone stereos, portable radios, portable TVs, and portable information terminals. It is a portable household appliance such as an electric shaver. Storage devices such as backup power supplies and memory cards. It is a power tool such as a power drill and a power saw. It is a battery pack installed in a notebook computer as a removable power supply. Medical electronics such as pacemakers and hearing aids. It is an electric vehicle such as an electric car (including a hybrid car). It is a power storage system such as a household battery system for storing power in preparation for an emergency or the like. Of course, applications of the secondary battery may be applications other than the above.

Among them, it is effective that the secondary battery is applied to a battery pack, an electric vehicle, an electric power storage system, an electric tool, an electronic device, and the like. Since excellent battery characteristics are required in these applications, it is possible to effectively improve the performance by using the secondary battery of the present technology. The battery pack is a power supply using a secondary battery. The battery pack may use a single cell or an assembled battery as described later. The electric vehicle is a vehicle that operates (travels) using a secondary battery as a driving power source, and as described above, may be a car (such as a hybrid car) equipped with a driving source other than the secondary battery. The power storage system is a system using a secondary battery as a power storage source. For example, in a household power storage system, since power is stored in a secondary battery which is a power storage source, it is possible to use the power to use household electrical appliances and the like. The electric power tool is a tool in which a movable portion (for example, a drill or the like) moves using a secondary battery as a power source for driving. The electronic device is a device that exhibits various functions as a power source (power supply source) for driving a secondary battery.

Here, some application examples of the secondary battery will be specifically described. The configuration of the application example described below is merely an example, and the configuration of the application example can be changed as appropriate.

<2-1. Battery pack (single cell)>
FIG. 12 shows a perspective view of a battery pack using single cells. FIG. 13 shows a block configuration of the battery pack shown in FIG. FIG. 12 shows the battery pack in a disassembled state.

The battery pack described here is a simple battery pack (so-called soft pack) using one secondary battery, and is mounted, for example, on an electronic device represented by a smartphone. For example, as shown in FIG. 12, the battery pack includes a power supply 111 which is a laminated film secondary battery and a circuit board 116 connected to the power supply 111. The positive electrode lead 112 and the negative electrode lead 113 are attached to the power source 111.

A pair of

adhesive tapes

118 and 119 is attached to both sides of the power supply 111. On the circuit board 116, a protection circuit (PCM: Protection Circuit) is formed. The circuit board 116 is connected to the positive electrode 112 through the tab 114 and connected to the negative electrode lead 113 through the tab 115. Further, the circuit board 116 is connected to the connector-attached lead wire 117 for external connection. When the circuit board 116 is connected to the power supply 111, the circuit board 116 is protected by the label 120 and the insulating sheet 121. By attaching the label 120, the circuit board 116, the insulating sheet 121, and the like are fixed.

In addition, the battery pack includes, for example, a power supply 111 and a circuit board 116 as shown in FIG. The circuit board 116 includes, for example, a control unit 121, a switch unit 122, a PTC element 123, and a temperature detection unit 124. The power source 111 can be connected to the outside through the positive electrode terminal 125 and the negative electrode terminal 127, so the power source 111 is charged and discharged through the positive electrode terminal 125 and the negative electrode terminal 127. The temperature detection unit 124 detects a temperature using a temperature detection terminal (so-called T terminal) 126.

The control unit 121 controls the operation of the entire battery pack (including the usage state of the power supply 111). The control unit 121 includes, for example, a central processing unit (CPU) and a memory.

For example, when the battery voltage reaches the overcharge detection voltage, the control unit 121 disconnects the switch unit 122 so that the charging current does not flow in the current path of the power supply 111. Further, for example, when a large current flows during charging, the control unit 121 cuts off the charging current by disconnecting the switch unit 122.

On the other hand, for example, when the battery voltage reaches the overdischarge detection voltage, the control unit 121 disconnects the switch unit 122 to prevent the discharge current from flowing in the current path of the power supply 111. Further, for example, when a large current flows at the time of discharge, the control unit 121 cuts off the discharge current by disconnecting the switch unit 122.

The overcharge detection voltage is not particularly limited, but is, for example, 4.2V ± 0.05V, and the overdischarge detection voltage is not particularly limited, but is, for example, 2.4V ± 0.1 V.

The switch unit 122 switches the use state of the power supply 111, that is, the presence or absence of connection between the power supply 111 and an external device, in accordance with an instruction from the control unit 121. The switch unit 122 includes, for example, a charge control switch and a discharge control switch. Each of the charge control switch and the discharge control switch is, for example, a semiconductor switch such as a field effect transistor (MOSFET) using a metal oxide semiconductor. The charge and discharge current is detected based on, for example, the ON resistance of the switch unit 122.

The temperature detection unit 124 measures the temperature of the power supply 111 and outputs the measurement result of the temperature to the control unit 121. The temperature detection unit 124 includes, for example, a temperature detection element such as a thermistor. The measurement result of the temperature measured by the temperature detection unit 124 is used, for example, when the control unit 121 performs charge / discharge control during abnormal heat generation, or when the control unit 121 performs correction processing when calculating the remaining capacity. .

The circuit board 116 may not have the PTC element 123. In this case, the circuit board 116 may be additionally provided with a PTC element.

<2-2. Battery pack (battery pack)>
FIG. 14 shows a block configuration of a battery pack using a battery pack.

The battery pack includes, for example, a control unit 61, a power supply 62, a switch unit 63, a current measurement unit 64, a temperature detection unit 65, a voltage detection unit 66, and a switch control unit 67 in a housing 60. , A memory 68, a temperature detection element 69, a current detection resistor 70, and a positive electrode terminal 71 and a negative electrode terminal 72. The housing 60 contains, for example, a plastic material or the like.

The control unit 61 controls the operation of the entire battery pack (including the usage state of the power supply 62). The control unit 61 includes, for example, a CPU. The power source 62 is a battery pack including two or more secondary batteries, and the connection form of the two or more secondary batteries may be in series, in parallel, or a combination of both. As one example, the power supply 62 includes six secondary batteries connected in two parallel three series.

The switch unit 63 switches the use state of the power supply 62, that is, the presence or absence of connection between the power supply 62 and an external device, in accordance with an instruction from the control unit 61. The switch unit 63 includes, for example, a charge control switch, a discharge control switch, a charging diode, and a discharging diode. Each of the charge control switch and the discharge control switch is, for example, a semiconductor switch such as a field effect transistor (MOSFET) using a metal oxide semiconductor.

The current measuring unit 64 measures the current using the current detection resistor 70, and outputs the measurement result of the current to the control unit 61. The temperature detection unit 65 measures the temperature using the temperature detection element 69, and outputs the measurement result of the temperature to the control unit 61. The measurement result of the temperature is used, for example, when the control unit 61 performs charge / discharge control during abnormal heat generation, or when the control unit 61 performs correction processing when calculating the remaining capacity. The voltage detection unit 66 measures the voltage of the secondary battery in the power supply 62, and supplies the control unit 61 with the measurement result of the analog-digital converted voltage.

The switch control unit 67 controls the operation of the switch unit 63 in accordance with the signals input from each of the current measurement unit 64 and the voltage detection unit 66.

For example, when the battery voltage reaches the overcharge detection voltage, the switch control unit 67 disconnects the switch unit 63 (charge control switch) to prevent the charging current from flowing in the current path of the power supply 62. Thus, the power supply 62 can only discharge via the discharge diode. Note that, for example, when a large current flows during charging, the switch control unit 67 cuts off the charging current.

Further, for example, when the battery voltage reaches the overdischarge detection voltage, the switch control unit 67 disconnects the switch unit 63 (discharge control switch) to prevent the discharge current from flowing in the current path of the power supply 62. Thus, the power source 62 can only charge via the charging diode. The switch control unit 67 cuts off the discharge current, for example, when a large current flows during discharge.

The memory 68 includes, for example, an EEPROM which is a non-volatile memory. In the memory 68, for example, numerical values calculated by the control unit 61, information of the secondary battery measured in the manufacturing process stage (for example, internal resistance in an initial state) and the like are stored. If the full charge capacity of the secondary battery is stored in the memory 68, the control unit 61 can grasp information such as the remaining capacity.

The temperature detection element 69 measures the temperature of the power supply 62, and outputs the measurement result of the temperature to the control unit 61. The temperature detection element 69 includes, for example, a thermistor.

Each of the positive electrode terminal 71 and the negative electrode terminal 72 is used for an external device (for example, a laptop personal computer) operated by using a battery pack, an external device (for example, a charger or the like) used for charging the battery pack, It is a terminal to be connected. The power source 62 is charged and discharged via the positive electrode terminal 71 and the negative electrode terminal 72.

<2-3. Electric vehicles>
FIG. 15 shows a block configuration of a hybrid vehicle which is an example of the electric vehicle.

The electric vehicle includes, for example, a control unit 74, an engine 75, a power supply 76, a driving motor 77, a differential gear 78, a generator 79, and a transmission 80 in a metal casing 73. And a clutch 81,

inverters

82 and 83, and various sensors 84. In addition, the electric-powered vehicle includes, for example, a front wheel drive shaft 85 and a front wheel 86 connected to the differential 78 and the transmission 80, and a rear wheel drive shaft 87 and a rear wheel 88.

The electrically powered vehicle can travel, for example, using one of the engine 75 and the motor 77 as a drive source. The engine 75 is a main power source, such as a gasoline engine. When the engine 75 is used as a power source, for example, the driving force (rotational force) of the engine 75 is transmitted to the front wheels 86 and the rear wheels 88 via the differential 78 as a driving unit, the transmission 80 and the clutch 81. Ru. Since the rotational power of engine 75 is transmitted to generator 79, generator 79 generates AC power using the rotational power, and the AC power is converted to DC power through inverter 83. Therefore, the DC power is stored in the power supply 76. On the other hand, in the case where the motor 77 which is a conversion unit is used as a power source, the electric power (DC power) supplied from the power source 76 is converted into AC power via the inverter 82. 77 drives. The driving force (rotational force) converted from the electric power by the motor 77 is transmitted to the front wheel 86 and the rear wheel 88 via, for example, the differential 78 as a driving unit, the transmission 80 and the clutch 81.

When the electric vehicle decelerates via the braking mechanism, the resistance at the time of deceleration is transmitted to the motor 77 as a rotational force, so that the motor 77 generates alternating current power using the rotational force. Good. Since this AC power is converted to DC power via inverter 82, it is preferable that the DC regenerative power be stored in power supply 76.

Control unit 74 controls the operation of the entire electric vehicle. The control unit 74 includes, for example, a CPU. The power source 76 includes one or more secondary batteries. The power supply 76 may be connected to an external power supply and may store power by receiving power supply from the external power supply. The various sensors 84 are used, for example, to control the rotational speed of the engine 75 and to control the opening degree of the throttle valve (throttle opening degree). The various sensors 84 include, for example, one or more of a speed sensor, an acceleration sensor, an engine speed sensor, and the like.

Although the case where the electric vehicle is a hybrid vehicle is exemplified, the electric vehicle may be a vehicle (electric vehicle) that operates using only the power supply 76 and the motor 77 without using the engine 75.

<2-4. Power storage system>
FIG. 16 shows a block configuration of the power storage system.

The power storage system includes, for example, a control unit 90, a power supply 91, a smart meter 92, and a power hub 93 inside a house 89 such as a home or a commercial building.

Here, the power supply 91 can be connected to, for example, the electric device 94 installed inside the house 89 and to the electric vehicle 96 stopped outside the house 89. Also, the power supply 91 is connected to, for example, a private generator 95 installed in a house 89 via a power hub 93, and is connected to an external centralized power system 97 via a smart meter 92 and the power hub 93. It is possible.

The electric device 94 includes, for example, one or more types of home appliances, and the home appliances are, for example, a refrigerator, an air conditioner, a television, a water heater, and the like. The in-house generator 95 includes, for example, one or more of a solar power generator, a wind power generator, and the like. The electric vehicle 96 includes, for example, any one or more of an electric car, an electric bike, a hybrid car and the like. The centralized power system 97 includes, for example, any one or two or more of a thermal power plant, a nuclear power plant, a hydroelectric power plant, a wind power plant and the like.

The control unit 90 controls the operation of the entire power storage system (including the usage state of the power supply 91). The control unit 90 includes, for example, a CPU. The power supply 91 includes one or more secondary batteries. The smart meter 92 is, for example, a network compatible power meter installed in the house 89 on the power demand side, and can communicate with the power supply side. Along with this, the smart meter 92 enables highly efficient and stable energy supply by controlling the balance between the demand and supply of power in the house 89 while communicating with the outside, for example.

In this power storage system, for example, power is stored in the power supply 91 from the centralized power system 97 which is an external power supply via the smart meter 92 and the power hub 93, and from a private generator 95 which is an independent power supply via the power hub 93. Thus, power is stored in the power supply 91. The electric power stored in the power supply 91 is supplied to the electric device 94 and the electric vehicle 96 according to the instruction of the control unit 90, so that the electric device 94 can be operated and the electric vehicle 96 can be charged. Become. That is, the power storage system is a system that enables storage and supply of power in the house 89 using the power supply 91.

The power stored in the power supply 91 can be used as needed. For this reason, for example, it is possible to store the power from the centralized power system 97 in the power supply 91 at midnight, when the electricity charge is low, and use the power accumulated in the power supply 91 during the day when the electricity charge is high. it can.

In addition, the above-mentioned electric power storage system may be installed for every one house (one household), and may be installed for every two or more houses (plural households).

<2-5. Power tool>
FIG. 17 shows a block configuration of the power tool.

The power tool described here is, for example, a power drill. The power tool includes, for example, a control unit 99 and a power supply 100 inside a tool body 98. For example, a drill portion 101 which is a movable portion is attached to the tool body 98 so as to be operable (rotatable).

The tool body 98 contains, for example, a plastic material or the like. The control unit 99 controls the operation of the entire power tool (including the usage state of the power supply 100). The control unit 99 includes, for example, a CPU. The power supply 100 includes one or more secondary batteries. The control unit 99 supplies power from the power supply 100 to the drill unit 101 in response to the operation of the operation switch.

Hereinafter, embodiments of the present technology will be described.

(Experimental examples 1 to 4)
The laminated film type secondary battery (lithium ion secondary battery) shown in FIGS. 1 to 4 was manufactured by the following procedure, and the safety of the secondary battery was examined.

[Preparation of secondary battery]
When producing the positive electrode 13, first, 90 parts by mass of a positive electrode active material (lithium cobaltate (LiCoO ₂ )), 5 parts by mass of a positive electrode binder (polyvinylidene fluoride), and a positive electrode conductive agent (carbon black) It was set as the positive mix by mixing with 5 mass parts. Subsequently, the positive electrode mixture was charged into an organic solvent (N-methyl-2-pyrrolidone), and then the organic solvent was stirred to prepare a paste-like positive electrode mixture slurry. Subsequently, a positive electrode mixture slurry is applied on both sides of the positive electrode current collector 13A (strip-like aluminum foil, thickness = 15 μm) using a coating apparatus, and then the positive electrode mixture slurry is dried to obtain a positive electrode active material. Layer 13B was formed. Finally, the positive electrode active material layer 13B was compression molded using a roll press. Thus, the positive electrode 13 including the positive electrode current collector 13A and the positive electrode active material layer 13B was obtained.

When producing the negative electrode 14, first, 96 parts by weight of a negative electrode active material (artificial graphite), 1 part by weight of a negative electrode binder (acrylic acid-modified styrene-butadiene rubber copolymer), and negative electrode binding By mixing 2 parts by mass of the agent (polyvinylidene fluoride) and 1 part by mass of a thickener (carboxymethyl cellulose), a negative electrode mixture was obtained. Subsequently, the negative electrode mixture was charged into an organic solvent (N-methyl-2-pyrrolidone), and then the organic solvent was stirred to prepare a paste-like negative electrode mixture slurry. Subsequently, a negative electrode mixture slurry is applied on both sides of the negative electrode current collector 14A (strip-shaped copper foil, thickness = 15 μm) using a coating apparatus, and then the negative electrode mixture slurry is dried to obtain a negative electrode active material. Layer 14B was formed. Finally, the negative electrode active material layer 14B was compression molded using a roll press. Thus, the negative electrode 14 including the negative electrode current collector 14A and the negative electrode active material layer 14B was obtained.

In the case of forming the electrolyte layer 16, first, an electrolyte salt (lithium hexafluorophosphate) is added to a solvent (ethylene carbonate, propylene carbonate and diethyl carbonate), and then the solvent is stirred to obtain an electrolytic solution. Was prepared. In this case, the mixing ratio (weight ratio) of the solvent was ethylene carbonate: propylene carbonate: diethyl carbonate = 15: 15: 70, and the concentration of the electrolyte salt was 1 mol / kg with respect to the solvent.

Subsequently, mixing is carried out by mixing 90 parts by mass of the electrolytic solution and 10 parts by mass of a polymer compound (copolymer of vinylidene fluoride and hexafluoropropylene, copolymerized amount of hexafluoropropylene = 15% by weight). A solution was obtained. Subsequently, the polymer solution was uniformly dispersed in the electrolytic solution by treating the mixed solution using a homogenizer. Subsequently, the mixed solution was stirred while heating (heating temperature = 75 ° C.), and the mixed solution was further stirred (stirring time = 1 hour) to prepare a sol-like precursor solution.

Finally, the precursor solution is applied to the surface of the positive electrode 13 and then dried to form the gel electrolyte layer 16, and the precursor solution is applied to the surface of the negative electrode 14, and then the precursor solution is applied. The gel electrolyte layer 16 was formed by drying.

When assembling the secondary battery, first, the positive electrode lead 11 made of aluminum was welded to the positive electrode current collector 13A, and the negative electrode lead 12 made of copper was welded to the negative electrode current collector 14A. Subsequently, a laminate is obtained by laminating the positive electrode 13 on which the electrolyte layer 16 is formed and the negative electrode 14 on which the electrolyte layer 16 is formed via the separator 15 (microporous polyethylene film, thickness = 7 μm). I got Subsequently, the laminate was wound in the longitudinal direction, and then the protective tape 17 was attached to the outermost periphery of the laminate to produce a wound electrode body 10. Finally, the package member 20 (the package layer 21 and the conductive layer 22) was folded so as to sandwich the wound electrode body 10, and the outer peripheral edge portions of three sides of the package member 20 were heat-sealed. In this case, the adhesive film 21 (polypropylene film, thickness = 60 μm) is inserted between the positive electrode lead 11 and the package member 20, and the adhesive film 22 (polypropylene film) is formed between the negative electrode lead 12 and the package member 20. , Thickness = 60 μm).

As the exterior layer 21, a surface protective layer 21A (nylon film, thickness = 25 μm), a metal layer 21 B (aluminum foil, thickness = 40 μm), and a fusion layer 21 C (polypropylene film, thickness = 30 μm) An aluminum laminated film laminated in this order from the outside was used.

The details of the forming material (conductive material), the forming method, and the form of the conductive layer 22 are as shown in Table 1. Here, a carbon material (carbon black) and a metal material (aluminum) were used as the conductive material.

When a carbon material was used as the conductive material, a coating method was used as a method of forming the conductive layer 22. In this case, first, 50 parts by mass of a plurality of particles (powdery carbon black which is a plurality of carbon particles) containing a conductive material and 50 parts by mass of a binder (polyvinylidene fluoride) were mixed. Subsequently, the mixture was charged into an organic solvent (N-methyl-2-pyrrolidone), and then the organic solvent was stirred to prepare a paste-like slurry. Subsequently, a slurry was applied to the non-fusion area 20R2 of the exterior layer 21 (fusion layer 21C), and then the slurry was dried to form a conductive layer 22 (thickness = 10 μm).

When a metal material is used as the conductive material, a sticking method is used as a method of forming the conductive layer 22. In this case, a molded body of a conductive material (aluminum foil which is a metal foil, thickness ==) is used in the non-fusion area 20R2 of the exterior layer 21 (fusion layer 21C) using an acrylic adhesive. 10 μm) was attached.

When a metal material is used as the conductive material, a coating method is used as a method of forming the conductive layer 22. In this case, first, 50 parts by mass of a plurality of particles (powdered aluminum which is a plurality of metal particles) containing a conductive material and 50 parts by mass of a binder (polyvinylidene fluoride) were mixed. Subsequently, the mixture was charged into an organic solvent (N-methyl-2-pyrrolidone), and then the organic solvent was stirred to prepare a paste-like slurry. Subsequently, a slurry was applied to the non-fusion area 20R2 of the exterior layer 21 (fusion layer 21C), and then the slurry was dried to form a conductive layer 22 (thickness = 10 μm).

In addition, the exterior member 20 (exterior layer 21) in which the conductive layer 22 is not formed was used for comparison. The presence or absence of the conductive layer 22 is as shown in Table 1.

As a result, since the wound electrode body 10 was sealed inside the exterior member 20, a laminate film type secondary battery (battery capacity = 3000 mAh) was completed.

[Evaluation of battery characteristics]
When the crushing test was performed using the secondary battery to evaluate the safety of the secondary battery, the results shown in Table 1 were obtained.

When carrying out the crushing test, first, after overcharging the secondary battery, as described with reference to FIG. 5 and FIG. The secondary battery was partially crushed by pressing 16.5 mm). In this case, constant current charging was performed until the voltage reached 4.7 V at a current of 1500 mA, and then constant voltage charging was performed until the current reached 30 mA at a voltage of 4.7 V. Moreover, the weight given to the secondary battery via the round bar 30 was 50 kN.

Subsequently, the state of the secondary battery was visually observed to determine whether the secondary battery was ignited. In this case, the case where the secondary battery did not ignite was judged as “pass”, and the case where the secondary battery ignited was judged as “fail”.

Finally, by repeating the above determination procedure using 20 secondary batteries (number of tests = 20), the number of passed = the number of passed secondary batteries / the number of secondary batteries used in the crushing test (= 20 pieces were examined.

When the conductive layer 22 was not used (Experimental Example 4), the number of passes became extremely low. The pass rate in this case was 25%. On the other hand, in the case where the conductive layer 22 was used (Experimental Examples 1 to 3), the pass rate was extremely high regardless of the type, formation method and form of the conductive material. The pass rate in this case was 90% at the maximum.

From the results shown in Table 1, when the wound electrode body 10 is accommodated inside the film-like exterior member 20 and the exterior member 20 includes the conductive layer 22 at the innermost side, the secondary battery is ignited It became difficult to do. Therefore, the safety of the secondary battery is improved.

Although the present technology has been described above by citing embodiments and examples, the present technology is not limited to the aspects described in the embodiments and examples, and various modifications are possible.

Specifically, for example, although the case where the battery element has a wound structure has been described, the present invention is not limited thereto. For example, the battery element may have another structure such as a laminated structure.

In addition, although the lithium ion secondary battery in which the capacity of the negative electrode is obtained by utilizing the lithium storage phenomenon and the lithium release phenomenon has been described, the invention is not limited thereto. For example, it may be a lithium ion secondary battery in which the capacity of the negative electrode is obtained by utilizing the precipitation phenomenon of lithium and the dissolution phenomenon of lithium. Also, for example, by setting the capacity of the negative electrode active material capable of inserting and extracting lithium to be smaller than the capacity of the positive electrode, the capacity resulting from the lithium absorption phenomenon and the lithium release phenomenon and the lithium It may be a secondary battery in which the capacity of the negative electrode is obtained based on the sum of the capacity resulting from the deposition phenomenon and the dissolution phenomenon of lithium.

Moreover, although demonstrated regarding the secondary battery which used lithium as an electrode reaction substance, it is not restricted to this. For example, sodium and potassium may be any other Group 1 element in any long period periodic table, or may be elements of Group 2 in the long periodic table such as magnesium and calcium, or other light metals such as aluminum.

In addition, the effect described in this specification is an illustration to the last, is not limited, and may have other effects.

The present technology can also be configured as follows.
(1)
A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
And a film-like package member including the conductive layer on the inner side thereof.
(2)
The conductive layer comprises a conductive material,
The conductive material includes at least one of a carbon material, a metal material, and a conductive polymer material.
The secondary battery as described in said (1).
(3)
The conductive layer is a molded body including the conductive material.
The secondary battery as described in said (2).
(4)
The conductive layer is
A plurality of particles comprising the conductive material;
The secondary battery according to (2), including a binder for binding the plurality of particles.
(5)
The exterior member further includes an insulating layer on the outermost side.
The secondary battery according to any one of the above (1) to (4).
(6)
Being a lithium ion secondary battery,
The secondary battery according to any one of the above (1) to (5).
(7)
The secondary battery according to any one of (1) to (6) above,
A control unit that controls the operation of the secondary battery;
A switch unit that switches the operation of the secondary battery according to an instruction of the control unit.
(8)
The secondary battery according to any one of (1) to (6) above,
A converter for converting the power supplied from the secondary battery into a driving power;
A driving unit driven according to the driving force;
And a control unit that controls the operation of the secondary battery.
(9)
The secondary battery according to any one of (1) to (6) above,
One or more electric devices supplied with power from the secondary battery,
And a controller configured to control power supply from the secondary battery to the electric device.
(10)
The secondary battery according to any one of (1) to (6) above,
A movable part to which power is supplied from the secondary battery;
(11)
The electronic device provided with the secondary battery in any one of said (1) thru | or (6) as an electric power supply source.

Claims

A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
And a film-like package member including the conductive layer on the inner side thereof.
The conductive layer comprises a conductive material,
The conductive material includes at least one of a carbon material, a metal material, and a conductive polymer material.
The secondary battery according to claim 1.
The conductive layer is a molded body including the conductive material.
The secondary battery according to claim 2.
The conductive layer is
A plurality of particles comprising the conductive material;
The secondary battery according to claim 2, further comprising: a binder that binds the plurality of particles.
The exterior member further includes an insulating layer on the outermost side.
The secondary battery according to claim 1.
Being a lithium ion secondary battery,
The secondary battery according to claim 1.
With a secondary battery,
A control unit that controls the operation of the secondary battery;
A switch unit that switches the operation of the secondary battery in accordance with an instruction from the control unit;
The secondary battery is
A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
A battery pack comprising: a film-like package member that houses the battery element and includes a conductive layer on the innermost side.
With a secondary battery,
A converter for converting the power supplied from the secondary battery into a driving power;
A driving unit driven according to the driving force;
A control unit that controls the operation of the secondary battery;
The secondary battery is
A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
An electric vehicle, comprising: a film-like exterior member that houses the battery element and includes a conductive layer on the innermost side.
With a secondary battery,
One or more electric devices supplied with power from the secondary battery,
A control unit that controls power supply from the secondary battery to the electric device;
The secondary battery is
A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
And a film-like exterior member that houses the battery element and includes a conductive layer on the innermost side.
With a secondary battery,
A movable part supplied with power from the secondary battery;
The secondary battery is
A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
And a film-like exterior member that houses the battery element and includes a conductive layer on the innermost side.
Equipped with a secondary battery as a power supply source,
The secondary battery is
A battery element including an electrolytic solution together with a positive electrode and a negative electrode stacked on each other via a separator;
An electronic apparatus comprising: a film-like package member that houses the battery element and includes a conductive layer on the innermost side.