JPWO2018110067A1 - Secondary battery, battery pack, electric vehicle, electric power storage system, electric tool and electronic device - Google Patents

Abstract

The secondary battery includes a battery element including a positive electrode, a negative electrode, and an electrolytic solution, and a film-like exterior member that houses the battery element and has a window including a non-porous molten fluorine resin.

Description

  The present technology relates to a secondary battery using 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 and personal digital assistants (PDAs) are widely used, and there is a demand for downsizing, weight reduction and long life of the electronic devices. Therefore, as a power source, development of a battery, in particular, a small and lightweight secondary battery capable of obtaining high energy density has been promoted.

  The secondary battery is not limited to the above-described electronic device, and its application to other applications is also considered. 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 laminate film type secondary battery is a secondary battery using a film-like exterior member. In the laminated film type secondary battery, the battery element is housed inside the film-like package member, and the battery element contains a positive electrode, a negative electrode, an electrolytic solution and the like.

  Since the film-like exterior member has flexibility, it has the property of being easily deformed in response to an external force. For this reason, in the laminated film type secondary battery, when gas is generated inside the secondary battery, the secondary battery tends to easily expand due to the deformation of the film-like exterior member.

  Various studies have been made to suppress the expansion of the secondary battery in this manner. Specifically, in order to release the gas generated inside the secondary battery to the outside, a safety valve or the like is provided on the film-like exterior member (see, for example, Patent Documents 1 to 4).

Japanese Patent Application Publication No. 2007-087922 JP 2007-157678 A JP 2007-265725 A Unexamined-Japanese-Patent No. 2014-211994

  Electronic devices and the like are becoming increasingly sophisticated and multifunctional. Therefore, the frequency of use of electronic devices and the like is increasing, and the use environment of electronic devices and the like is expanding. Therefore, there is still room for improvement in the battery characteristics including the swelling characteristics of the secondary battery.

  Therefore, it is desirable 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 obtaining excellent battery characteristics.

  A secondary battery according to an embodiment of the present technology includes a battery element including a positive electrode, a negative electrode, and an electrolytic solution, and a film-like package member having a battery element and a window including a non-porous molten fluorine resin. Is provided.

  Each of the battery pack, the electric vehicle, the electric power storage system, the electric power tool, and the electronic device according to the embodiment of the present technology includes a secondary battery, and the secondary battery is the secondary battery according to the embodiment of the present technology described above It has the same configuration.

  Here, the “window portion” is a part of the film-like exterior member, and is exposed to the internal environment in which the battery element is accommodated and the external environment in which the battery element is not accommodated. The internal environment is the internal environment of the film-like exterior member, and the external environment is the external environment of the film-like exterior member.

  According to the secondary battery of the embodiment of the present technology, the battery element is housed inside the film-like exterior member, and the window portion including the non-porous molten fluorocarbon resin is provided in the exterior member , Excellent battery characteristics can be obtained. The same effect can also be obtained in the battery pack, the electric vehicle, the power storage system, the electric tool, or the electronic device according to an embodiment 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 the composition (state before pasting of an exterior member) of a rechargeable battery of a 1st embodiment of this art. It is a perspective view showing the other structure (state after bonding of an exterior member) of the secondary battery shown in FIG. It is sectional drawing showing the structure of the exterior member along the AA shown in FIG. It is sectional drawing showing the structure of the winding electrode body along the BB line shown in FIG. It is a perspective view for demonstrating the 1st modification regarding the structure of a secondary battery. It is a perspective view for demonstrating the 2nd modification regarding the structure of a secondary battery. It is a perspective view for demonstrating the 3rd modification regarding the structure of a secondary battery. It is a perspective view showing the composition (state after pasting of an exterior member) of a rechargeable battery of a 2nd embodiment of this art. It is sectional drawing showing the structure of the exterior member along the C-C line shown in FIG. It is sectional drawing showing the structure of the exterior member which followed the DD line shown in FIG. 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 (first embodiment)
1-1. Lithium ion secondary battery 1-2. Lithium metal secondary battery 1-3. Modified example 2. Secondary battery (second embodiment)
2-1. Lithium ion secondary battery 2-2. Lithium metal secondary battery 2-3. Modified example 3. Applications of Secondary Battery 3-1. Battery pack (single cell)
3-2. Battery pack (battery pack)
3-3. Electric vehicle 3-4. Power storage system 3-5. Electric tool

<1. Secondary Battery (First Embodiment)>
First, the secondary battery of the first embodiment will be described.

<1-1. Lithium ion rechargeable battery>
The secondary battery described here is, for example, a lithium ion secondary battery in which the capacity of the negative electrode is obtained by insertion and extraction of lithium which is an electrode reactant.

  Each of FIG. 1 and FIG. 2 represents a perspective view of the secondary battery of the present embodiment. However, FIG. 1 shows the state before bonding of the exterior member 40, and the wound electrode body 30 and the exterior member 40 are separated from each other. In FIG. 2, the state after bonding of the exterior member 40 is shown.

  FIG. 3 shows a cross-sectional configuration of the exterior member 40 along the line AA shown in FIG. FIG. 4 shows a cross-sectional configuration of the wound electrode body 30 along the line B-B shown in FIG.

[overall structure]
The secondary battery is a laminated film secondary battery using a film-like exterior member 40. In the laminate film type secondary battery, for example, as shown in FIGS. 1 to 3, the wound electrode body 30 which is a battery element is housed inside the exterior member 40 having the window portion 42. The details of the window portion 42 will be described later.

  In the wound electrode body 30, for example, as shown in FIG. 4, after the positive electrode 33 and the negative electrode 34 are laminated via the separator 35 and the electrolyte layer 36, the positive electrode 33, the negative electrode 34, the separator 35 and the electrolyte layer 36 Is wound. That is, the wound electrode body 30 housed inside the exterior member 40 includes the positive electrode 33, the negative electrode 34, and the electrolyte layer 36, and the electrolyte layer 36 contains an electrolytic solution described later. The outermost periphery of the wound electrode body 30 is protected by, for example, a protective tape 37.

  The positive electrode lead 31 is attached to the positive electrode 33, and the positive electrode lead 31 is drawn from the inside to the outside of the exterior member 40. The positive electrode lead 31 contains, for example, one or more of conductive materials such as aluminum (Al). The shape of the conductive material is not particularly limited, and is, for example, a thin plate or a mesh.

  The negative electrode lead 32 is attached to the negative electrode 34, and the negative electrode lead 32 is drawn from the inside to the outside of the package member 40. The negative electrode lead 32 contains, for example, one or more of conductive materials such as copper (Cu), nickel (Ni), and stainless steel. The shape of the conductive material is, for example, the same as that described for the positive electrode lead 31.

  In FIG. 2, the positive electrode lead 31 and the negative electrode lead 32 are not shown. Each of the positive electrode lead 31 and the negative electrode lead 32 is derived in the same direction from the inside to the outside of the exterior member 40, as apparent from FIG. 1, for example.

[Exterior member]
The exterior member 40 accommodates the wound electrode body 30 as described above. Since the exterior member 40 is in the form of a film, it has flexibility.

  In particular, the exterior member 40 includes an exterior main body 41 provided with the window portion 42 described above, for example, as shown in FIGS. 1 to 3.

(Exterior body)
The exterior main body 41 is a main body of the exterior member 40, and is a film-like member. The configuration of the exterior body 41 is not particularly limited, but the exterior body 41 is, for example, a multilayer film (laminated film) including an adhesive layer.

  Specifically, the exterior main body 41 is, for example, a laminate film in which an adhesive layer, a metal layer, and a surface protective layer are laminated in this order from the inside. In this case, for example, the adhesive layers in the exterior main body 41 are adhered to each other through the wound electrode body 30, whereby the wound electrode body 30 is housed inside the exterior member 40.

  The adhesive layer in the case where a heat fusion method is used as an adhesion method is, for example, a fusion layer. The fusion layer is, for example, a film containing one or more of polymer compounds such as polyethylene and polypropylene. The metal layer is, for example, a metal foil containing any one or more kinds of metal materials such as aluminum. The surface protective layer is, for example, a film containing one or more of polymer compounds such as nylon and polyethylene terephthalate.

  Among them, the exterior main body 41 is preferably, for example, an aluminum laminated film in which a polyethylene film, an aluminum foil, and a nylon film are sequentially laminated in this order from the inside. This is because sufficient adhesion and sufficient air tightness can be obtained.

  The exterior main body 41 is, for example, as shown in FIGS. 1 to 3, an exterior portion 41A which is a first exterior member that covers the wound electrode body 30 from one side (here, the upper side), and the wound electrode body And an exterior portion 41B which is a second exterior member that covers 30 from the other (here, the lower side). The forming material of the exterior portion 41A and the forming material of the exterior portion 41B may be the same as or different from each other.

  In this case, for example, in a state in which the wound electrode body 30 is sandwiched between the exterior parts 41A and 41B, a part of the exterior part 41A and a part of the exterior part 41B are adhered to each other. The wound electrode body 30 is housed inside the exterior member 40. A portion of the exterior portion 41A is, for example, an outer edge portion of the exterior portion 41A, and a portion of the exterior portion 41B is, for example, an outer edge portion of the exterior portion 41B.

  Accordingly, the exterior body 41 seals the exterior member 40 and the non-adhesion region 41X in which the exterior portions 41A and 41B are not adhered to each other in order to store the wound electrode body 30 inside the exterior member 40. For this purpose, the package portions 41A and 41B include a bonding area 41Y bonded to each other. For example, as shown in FIGS. 1 and 2, the adhesion area 41Y is an outer edge area of each of the exterior parts 41A and 41B, and the non-adhesion area 41X is one of each of the exterior parts 41A and 41B. It is a region other than the outer edge region (central region surrounded by the outer edge region).

  Exterior parts 41A and 41B may be separated, for example, from each other, or may be connected (integrated) to each other. The exterior main body 41 in the case where the exterior parts 41A and 41B are separated from each other is, for example, two films. On the other hand, the exterior main body 41 in the case where the exterior parts 41A and 41B are connected to each other is, for example, a single film.

  Here, for example, since the exterior parts 41A and 41B are connected to each other, the exterior main body 41 is a single film. The single film may be a single film or a composite film in which two films are connected. Along with this, the exterior main body 41 is foldable, for example, in the direction of the arrow R shown in FIG. In this case, by folding the exterior main body 41, as described above, the exterior portion 41A covers the wound electrode body 30 from above and the exterior portion 41B covers the wound electrode body 30 from below, The wound electrode body 30 is housed inside the exterior member 40.

  In addition, in the exterior portion 41A, for example, a recessed portion 41P for housing the wound electrode body 30 is provided. Along with this, the exterior portion 41A partially protrudes outward, for example, at a portion where the recess portion 41P is provided. The recessed portion 41P is provided in the exterior portion 41A because the wound electrode body 30 can be easily positioned with respect to the exterior main body 41 and the wound electrode body 30 can be easily accommodated inside the exterior member 40. It is from.

  In a state in which the wound electrode body 30 is housed inside the exterior member 40, for example, an adhesive film 50 is used to seal the exterior member 40. Specifically, for example, the adhesive film 50 is inserted between the outer package main body 41 (the outer package parts 41A and 41B) and the positive electrode lead 31, and similarly, the adhesive film between the outer package main body 41 and the negative electrode lead 32 50 is inserted.

  The adhesive film 50 contains one or more of adhesive materials in order to prevent the outside air from invading the inside of the exterior member 40. The adhesion material is a material having adhesion to each of the positive electrode lead 31 and the negative electrode lead 32, and is, for example, a polyolefin resin or the like. The type of polyolefin resin is not particularly limited, and examples thereof include polyethylene, polypropylene, modified polyethylene and modified polypropylene.

(Window)
The window portion 42 mainly functions to prevent water from invading from the outside of the exterior member 40 (waterproof function) and functions to release the gas generated inside the exterior member 40 to the outside ( Perform the exhaust function). The water described here is, for example, water and steam existing outside the secondary battery. Further, the gas is, for example, carbon dioxide gas (carbon dioxide) generated due to a side reaction such as a decomposition reaction of the electrolytic solution.

  The window portion 42 is a part of the exterior member 40 as described above, and is exposed to the internal environment E1 and the external environment E2 as shown in FIG.

  The internal environment E1 is an environment in which the wound electrode body 30 is stored (the environment inside the exterior member 40). Therefore, the internal environment E1 is formed by housing the wound electrode body 30 inside the exterior member 40. On the other hand, the external environment E2 is an environment in which the wound electrode body 30 is not stored (an environment outside the exterior member 40). That is, the window part 42 discharges gas from the internal environment E1 to the external environment E2 while suppressing water from entering the internal environment E1 from the external environment E2.

  The exterior member 40 (exterior main body 41) has the window portion 42 because the waterproof function of the window portion 42 is used to suppress the deterioration of the cycle characteristics and the like caused by water. In order to suppress the swelling of the secondary battery by utilizing the exhaust function of In this case, since it is not necessary to use a machine such as a safety valve, an instrument and a device, it is possible to easily suppress the deterioration of the cycle characteristics and the like, and to easily suppress the swelling of the secondary battery.

  The number, position, and configuration of the windows 42 are not particularly limited as long as the waterproof function and the exhaust function described above can be exhibited.

  Specifically, the number of windows 42 may be only one or two or more. Here, the number of windows 42 is, for example, one.

  Moreover, the position of the window part 42 may be arbitrary. Here, the window portion 42 is provided, for example, in the hollow portion 41P of the exterior main body 41 (the exterior portion 41A). More specifically, for example, in a case where the recess 41P has one upper surface 41PT and four side surfaces 41PS, the window 42 is provided on the upper surface 41PT.

  That is, the window portion 42 is provided, for example, in the non-adhesive area 41X of the exterior main body 41.

  Further, for example, an opening 41K is provided in the exterior main body 41, and a window film 43 which is a film-like window member covers (closes) the opening 41K to form a window 42. That is, the window portion 42 includes, for example, a window film 43 which includes a window functional material (non-porous molten fluorine resin) described later and which closes the opening 41 K. In each of FIG. 1 and FIG. 2, in order to make the window film 43 easy to identify, the window 43 is shaded.

  The opening 41K is a through hole that allows the internal environment E1 and the external environment E2 to communicate with each other. The shape of the opening 41 K is not particularly limited, and may be, for example, circular, elliptical, rectangular, or any other shape. Here, the opening shape of the opening 41K is, for example, an oval. The size (area) of the opening 41K is not particularly limited, and can be set arbitrarily.

  The window film 43 is a film having each of the waterproof function and the exhaust function described above. Along with this, the window film 43 contains a window functional material. The “window function material” is a material that can suppress the entry of water from the outside of the exterior member 40 to the inside and can release the gas from the inside of the exterior member 40 to the outside. More specifically, the window function material is a material that functions as a barrier film that does not allow water to permeate sufficiently in order to secure a waterproof function, and a gas such as carbon dioxide is sufficient to secure an exhaust function. A gas permeable material that can be permeated by That is, the window functional material is a material having selective permeability with respect to water and gas.

  This window function material contains any one or more of non-porous molten fluororesins. This non-porous molten fluorocarbon resin is a generic name of fluorocarbon resin mainly having no one or two or more pores and having meltability that can be melt processed and melt molded. .

  The type of non-porous molten fluororesin is not particularly limited. For example, non-porous tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), non-porous tetrafluoroethylene / hexafluoropropylene copolymer Fluorine-based polymer compounds such as FEP) and non-porous tetrafluoroethylene / ethylene copolymer (ETFE). It is because these specific types of fluorine-based polymer compounds can sufficiently exhibit each of the waterproof function and the exhaust function described above.

  It is to be noted that non-fluorinated polymer compounds such as polyethylene terephthalate (PET) and polypropylene (PP) are too low in selective permeability for water and gas as described above compared to molten fluorine resin, so their high non-fluorinated type. Molecular compounds can not exhibit both the waterproof function and the exhaust function described above. Moreover, since porous PFA, porous FEP, porous ETFE, and the like correspond to the molten fluorine resin, they are porous and can not exhibit both the waterproof function and the exhaust function described above.

  Here, whether or not the polymer compound is nonporous can be confirmed, for example, by the following procedure. Specifically, after obtaining a film of a polymer compound, the cross section of the film is observed using an electron microscope or the like. The magnification during observation can be set arbitrarily. As a result, when one or more pores are observed inside the film, the polymer compound forming the film is porous. The state of the pores is not particularly limited, and may be, for example, a substantially circular void or a tubular path extending in a predetermined direction. On the other hand, when one or more pores are not observed inside the film, the polymer compound forming the film is non-porous.

  The planar shape of the window film 43 is not particularly limited, and may be, for example, a circular shape, an elliptical shape, a rectangular shape, or any other shape. That is, the planar shape of the window film 43 may be the same as the opening shape of the opening 41K, or may be different from the opening shape of the opening 41K. Here, the planar shape of the window film 43 is, for example, the same as the opening shape of the opening 41K. Therefore, the planar shape of the window film 43 is, for example, an elliptical shape.

  The size (area) of the window film 43 is not particularly limited as long as the window film 43 can close the opening 41K. That is, the area of the window film 43 may be the same as the opening area of the opening 41K, or may be larger than the opening area of the opening 41K.

  Among them, it is preferable that the area of the window film 43 be larger than the area of the opening 41 K, as the window film 43 contains the window functional material (non-porous molten fluorine resin). This is because in order to fix the window film 43 to the exterior main body 41, the window film 43 can be attached to the exterior main body 41 using an adhesive.

  Specifically, for example, as shown in FIG. 3, since the area of the window film 43 is larger than the area of the opening 41K, the window film 43 is an adhesive so as to close the opening 41K. It is affixed to the exterior main body 41 via 44. The window film 43 containing the non-porous molten fluorocarbon resin generally has another object (here, the exterior main body 41) due to the adhesion resistance and the like peculiar to the non-porous molten fluorocarbon resin. It is hard to be adhered to However, the window film 43 can be sufficiently adhered to the exterior main body 41 using the adhesive 44 by selecting the adhesive 44 excellent in compatibility (adhesion) with the nonporous molten fluorocarbon resin. .

  The installation position of the window film 43 is not particularly limited. For this reason, the window film 43 may be disposed on the inside (internal environment E1) of the exterior main body 41, or may be disposed on the outside (external environment E2) of the exterior main body 41.

  Among them, as shown in FIG. 3, the window film 43 is preferably disposed inside the exterior main body 41. Even if gas is generated inside the secondary battery, the window film 43 is prevented from peeling and falling off unintentionally. The window film 43 is adhered to the inner side surface of the exterior main body 41 via an adhesive 44, for example.

  Specifically, when gas is generated inside the secondary battery, the window film 43 is pushed from the internal environment E1 to the external environment E2 due to the increase in internal pressure. In this case, for example, as described later, when the window film 43 is disposed outside the exterior main body 41 (see FIG. 6), the window film 43 is initially located in the external environment E2, and the window Nothing exists on the outside of the film 43. Therefore, if the adhesive 44 peels off from one or both of the exterior main body 41 and the window film 43, the window film 43 may separate from the exterior main body 41 depending on the degree of increase in internal pressure. Moreover, when the window film 43 peels from the exterior main body 41, the window film 43 may be dropped from the secondary battery.

  On the other hand, when the window film 43 is disposed inside the exterior main body 41 (see FIG. 3), the window film 43 is located in the internal environment E1, and the exterior main body 41 is located outside the window film 43. Existing. In this case, at the place where the window film 43 and the exterior main body 41 overlap with each other, the window film 43 is pressed by the exterior main body 41 so as to stay in the internal environment E1. Therefore, the adhesive 44 is less likely to be peeled off from each of the exterior main body 41 and the window film 43, so the window film 43 is less likely to be separated from the exterior main body 41. In addition, even if the window film 43 peels off from the exterior main body 41 due to the rise in internal pressure, the window film 43 is still easily present in the internal environment E1, so the window film 43 does not easily come off from the secondary battery Become.

  The thickness of the window film 43 is not particularly limited, but is, for example, 10 μm to 500 μm, preferably 10 μm to 200 μm. By using the window film 43 containing the window functional material (non-porous molten fluorine resin), it is possible to obtain a sufficient waterproof function and a sufficient exhaust function while securing the physical durability and the like of the window film 43. is there.

  Specifically, if the thickness of the window film 43 is smaller than 10 μm, the window film 43 is likely to release gas at the time of gas generation because the window film 43 is too thin, while the window film 43 produces water. There is a possibility that it becomes easy to pass through, and there is also a possibility that the window film 43 becomes easy to be deformed, broken and peeled off when the internal pressure rises. On the other hand, if the thickness of the window film 43 is larger than 500 μm, the window film 43 is too thick, so that the window film 43 is less likely to be deformed, broken or peeled even when the internal pressure rises. While it is difficult to allow water to pass through, the window film 43 may not easily release gas.

  The adhesive 44 contains, for example, one or more kinds of polymer compounds (adhesive materials) such as polyolefin resin, epoxy resin, urethane resin, cyanoacrylate and styrene butadiene rubber. The polyolefin resin is, for example, polypropylene (PP) or the like.

  The state of the adhesive 44 before bonding is not particularly limited, and may be powder, liquid, film, or a mixture of two or more of them. However, in order to make the thickness of the adhesive 44 uniform and to suppress the occurrence of pinholes in the adhesive 44, the state of the adhesive 44 before bonding is either liquid or film. It is preferable that it is one or both.

  When the adhesion between the adhesive 44 and the window film 43 is not sufficient, for example, in order to improve the adhesion, the surface of the window film 43 is pretreated to any one or more kinds of pretreatments. May be applied. The type of this pretreatment is not particularly limited, and examples thereof include drug treatment, corona treatment and ultraviolet irradiation (UV) treatment. Among them, drug treatment is preferred. This is because the adhesion between the window film 43 and the adhesive 44 can be easily improved without using equipment such as a heat source and a light source.

  Of course, even when the adhesion between the adhesive 44 and the exterior main body 41 is not sufficient, for example, as in the case where the adhesion between the adhesive 44 and the window film 43 is not sufficient, the adhesion is improved. The surface of the exterior main body 41 may be subjected to one or more kinds of pretreatment. Details regarding the pretreatment are, for example, as described above.

[Positive electrode]
For example, as shown in FIG. 4, the positive electrode 33 includes a positive electrode current collector 33A and a positive electrode active material layer 33B provided on both sides of the positive electrode current collector 33A. However, the positive electrode active material layer 33B may be provided only on one side of the positive electrode current collector 33A.

  The positive electrode current collector 33A 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 33A may be a single layer or a multilayer.

  The positive electrode active material layer 33B 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 33B may further contain one or more of other materials such as a positive electrode binder and a positive electrode conductive agent.

  The positive electrode material is preferably a lithium-containing compound, and more specifically, preferably any one or both of a lithium-containing composite oxide and a lithium-containing phosphoric acid compound. This is because a high energy density can be obtained.

  The lithium-containing composite oxide is an oxide containing lithium and one or more other elements (elements other than lithium) as constituent elements, and, for example, any of layered rock salt type and spinel type It has a crystal structure. The lithium-containing phosphoric acid compound is 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.

  The type of the other element is not particularly limited as long as it is any one type or two or more types of arbitrary elements. Among them, it is preferable that the other element be any one or two or more of the elements belonging to Groups 2 to 15 in the long period periodic table. More specifically, it is more preferred that the other elements contain any one or more metal elements of nickel (Ni), cobalt (Co), manganese (Mn) and iron (Fe). preferable. 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 (21) to (23).

Li _a Mn _(1-bc) Ni _b M 11 _c O _(2-d) F _e (21)
(M11 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 It is ≦ 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) M12 _b O _(2-c) F _d (22)
(M12 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) M13 _b O _(2-c) F _d (23)
(M13 is 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)

  The lithium-containing composite oxide having a layered rock salt type crystal structure may be, for example, a compound represented by the following formula (24). This compound is a lithium-nickel-containing composite oxide containing nickel as a constituent element and having a relatively large content ratio of nickel.

Li _x Co _y Ni _z M _1-yz O _ba X _e (24)
(M is boron (B), magnesium (Mg), aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), gallium (Ga), yttrium (Y), zirconium (Zr), molybdenum) (Mo), strontium (Sr), cesium (Cs), barium (Ba), indium (In) and antimony (Sb), at least one of which X is a halogen element x, y, z , A and b satisfy 0.8 <x ≦ 1.2, 0 ≦ y ≦ 1.0, 0.5 ≦ z ≦ 1.0, 0 ≦ a ≦ 1.0, 1.8 ≦ b ≦ 2. Satisfy 2 and y <z)

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 (25).

Li _a Mn _(2-b) M14 _b O _c F _d (25)
(M14 is cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper) 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 (26).

Li _a M 15 PO ₄ (26)
(M15 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.

  The lithium-containing composite oxide may be a compound represented by the following formula (27).

(Li ₂ MnO ₃ ) _x (LiMnO ₂ ) _1-x (27)
(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)

  In addition, the positive electrode material may be, for example, one or more of an oxide, a disulfide, a chalcogenide, and a conductive polymer. 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 conductive polymer is, for example, sulfur, polyaniline and polythiophene. However, the positive electrode material may be another material other than the above.

  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 and polyimide.

  The positive electrode conductive agent contains, for example, one or more of carbon materials and the like. This carbon material is, for example, graphite, carbon black, acetylene black and ketjen black. However, the positive electrode conductive agent may be a metal material, a conductive polymer, or the like as long as the material has conductivity.

[Negative electrode]
For example, as shown in FIG. 4, the negative electrode 22 includes a negative electrode current collector 34A and a negative electrode active material layer 34B provided on both sides of the negative electrode current collector 34A. However, the negative electrode active material layer 34B may be provided only on one side of the negative electrode current collector 34A.

  The negative electrode current collector 34A contains, for example, one or more of conductive materials. The type of conductive material is not particularly limited, but is, for example, metal materials such as copper, aluminum, nickel and stainless steel. The negative electrode current collector 34A may be a single layer or a multilayer.

  The surface of the negative electrode current collector 34A is preferably roughened. This is because adhesion of the negative electrode active material layer 34B to the negative electrode current collector 34A is improved by the so-called anchor effect. In this case, the surface of the negative electrode current collector 34A may be roughened at least in a region facing the negative electrode active material layer 34B. 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 34A by the electrolytic method in the electrolytic cell, irregularities are provided on the surface of the negative electrode current collector 34A. The copper foil produced by the electrolytic method is generally called an electrolytic copper foil.

  The negative electrode active material layer 34B contains, as a negative electrode active material, one or more of negative electrode materials capable of inserting and extracting lithium. However, the negative electrode active material layer 34B 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 negative electrode 34 during charging, the chargeable capacity of the negative electrode material is preferably larger than the discharge capacity of the positive electrode 33. 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 33.

  The negative electrode material is, for example, one or more of carbon materials. This is because a high energy density can be stably obtained since the change in crystal structure at the time of lithium storage and release is very small. In addition, since the carbon material also functions as a negative electrode conductive agent, the conductivity of the negative electrode active material layer 34B is improved.

  The carbon material is, for example, graphitizable carbon, non-graphitizable carbon, and graphite. However, the spacing of the (002) plane in non-graphitizable carbon is preferably 0.37 nm or more, and the spacing of the (002) plane in 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 obtained by firing (carbonizing) a polymer compound such as a phenol resin and a 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.

  The negative electrode material is, for example, a material (metal-based 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.

  The above-described metal element and metalloid element are, for example, any one or more of metal elements and metalloid elements capable of forming an alloy with lithium. Specifically, 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) and platinum (Pt).

  Among them, one or both of silicon and tin are preferred. This is because the ability to insert and extract lithium is excellent, so that 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" as used herein means a single substance (which may contain a trace amount of impurities) in a general sense, and does not necessarily mean 100% purity.

  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 (Sn-containing material) containing a second constituent element and a third constituent element together with tin which is a 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. When the Sn-containing material contains the second and third constituent elements, high battery capacity and excellent cycle characteristics can be obtained.

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

  The SnCoC-containing material has a phase containing tin, cobalt and carbon, and the phase is preferably low crystalline or amorphous. Since this phase is a reactive phase capable of reacting with lithium, excellent properties are obtained based on 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. This is because lithium is absorbed and released more smoothly, and the reactivity with the electrolytic solution is reduced. In addition to the low crystalline or amorphous phase, the SnCoC-containing material may include a phase containing a single element or a part of each constituent element.

  Whether or not a diffraction peak obtained by X-ray diffraction corresponds to a reaction phase capable of reacting with lithium can be easily determined by comparing X-ray diffraction charts before and after an electrochemical reaction with lithium. For example, if the position of the diffraction peak changes before and after the electrochemical reaction with lithium, it corresponds to a reaction phase capable of reacting with lithium. In this case, for example, the diffraction peak of the low crystalline or amorphous reaction phase is observed between 2θ = 20 ° and 50 °. Such a reaction phase contains, for example, the above-described constituent elements, and is considered to be low in crystallization or amorphization mainly due to the presence of carbon.

  In the SnCoC-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-K alpha rays or Mg-K alpha 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 a region lower than 284.5 eV. Note that the peak of the 4f orbital (Au 4 f) of the gold atom is energy-calibrated to be obtained at 84.0 eV. Under the present circumstances, since surface contamination carbon exists in the substance surface normally, the peak of C1s of 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 surface contaminating carbon peak and the carbon peak in the SnCoC-containing material. Therefore, for example, the two peaks are separated by analysis using commercially available software. 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 SnCoC-containing material is not limited to a material (SnCoC) whose constituent elements are only tin, cobalt and carbon. This SnCoC-containing material is, for example, in addition to tin, cobalt and carbon, any one of silicon, iron, nickel, chromium, indium, niobium, germanium, titanium, molybdenum, aluminum, phosphorus, gallium and bismuth etc. A kind or two or more kinds may be contained as a constituent element.

  Besides SnCoC-containing materials, materials containing tin, cobalt, iron and carbon as constituent elements (SnCoFeC-containing materials) are also preferable. The composition of this SnCoFeC containing material is arbitrary. 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 ratio of the content 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 SnCoFeC-containing material are the same as the physical properties of the above-described SnCoC-containing material.

  In addition, the negative electrode material may be, for example, one or more of metal oxides and polymer compounds. The metal oxide is, for example, iron oxide, ruthenium oxide and molybdenum oxide. The polymer compounds are, for example, polyacetylene, polyaniline and polypyrrole.

  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 both the carbon material and the metal-based material, expansion and contraction during charge and discharge can be suppressed while obtaining high theoretical capacity (in other words, battery capacity).

  The negative electrode active material layer 34B is formed, for example, by any one or two or more methods of a coating method, a vapor phase method, a liquid phase method, a thermal spraying method and a firing method (sintering method). The coating method is, for example, a method of mixing particles (powder) of the negative electrode active material with a negative electrode binder or the like, dispersing the mixture in an organic solvent or the like, and then applying the mixture to the negative electrode current collector 34A. The gas phase method is, for example, physical deposition method and chemical deposition method. More specifically, for example, vacuum deposition, sputtering, ion plating, laser ablation, thermal chemical vapor deposition, chemical vapor deposition (CVD), plasma chemical vapor deposition, and the like. 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 34A. The firing method is, for example, a method of applying a mixture dispersed in an organic solvent or the like to the negative electrode current collector 34A using a coating method, and then heat treating at a temperature higher than the melting point of the negative electrode binder. As the firing method, for example, an atmosphere firing method, a reaction firing method, a hot press firing method and the like can be used.

  In this secondary battery, as described above, in order to prevent lithium from being unintentionally deposited on the negative electrode 34 during charging, the electrochemical equivalent of the negative electrode material capable of inserting and extracting lithium is And the electrochemical equivalent of the positive electrode. In addition, when the open circuit voltage at the full charge (ie, the battery voltage) is 4.25 V or more, the same positive electrode active material is used as compared to the case where the open circuit voltage at the full charge is 4.20 V. Since the amount of release of lithium per unit mass also increases, the amounts of the positive electrode active material and the negative electrode active material are adjusted accordingly. This gives a high energy density.

  The open circuit voltage (charge termination voltage) at the time of full charge is not particularly limited, but as described above, is preferably 4.2 V or more. Among them, the open circuit voltage at the time of full charge is preferably 4.25 V or more, more preferably 4.35 V or more. Even if the open circuit voltage at the time of full charge is extremely high, an advantage based on the optimization of the mixing ratio of the electrolyte salt and ethylene carbonate described above can be obtained, so that excellent battery characteristics can be obtained. Although the discharge end voltage is not particularly limited, it is, for example, 3.0 V or less.

[Separator]
For example, as shown in FIG. 4, the separator 35 is disposed between the positive electrode 33 and the negative electrode 34. Thereby, the separator 35 mainly isolates the positive electrode 33 and the negative electrode 34, and passes lithium ions while preventing a short circuit of current caused by the contact of the both electrodes.

  The separator 35 is, for example, any one or two 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 35 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 35 to each of the positive electrode 33 and the negative electrode 34 is improved, so that distortion of the wound electrode body 30 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, the resistance is less likely to increase even if charge and discharge are repeated, and Bulge is suppressed.

  The polymer compound layer contains, for example, one or more of polymer compounds such as polyvinylidene fluoride. It is because it is excellent in physical strength and electrochemically stable. However, the polymer compound is not limited to 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, in the case of forming the polymer compound layer, for example, after the base material layer is dipped 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, aluminum nitride, boehmite and talc.

[Electrolyte layer]
The electrolyte layer 36 contains an electrolytic solution and a polymer compound. The electrolyte layer 36 described here is a so-called gel electrolyte, and in the electrolyte layer 36, an electrolytic solution is held by a 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. The electrolyte layer 36 may further contain one or more of other materials such as additives.

  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 non-aqueous solvents such as an organic solvent. The electrolyte containing a non-aqueous solvent is a so-called non-aqueous electrolyte.

  Nonaqueous solvents are, for example, cyclic carbonates, chain carbonates, lactones, chain carboxylic esters and nitriles (mononitriles). 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. The chain carbonate is, for example, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and methyl propyl carbonate. The lactone is, for example, γ-butyrolactone and γ-valerolactone. The chain carboxylic acid ester is, for example, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethylacetate and ethyl trimethylacetate. Nitriles are, for example, acetonitrile, methoxyacetonitrile and 3-methoxypropionitrile.

  In addition, 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 , 4-dioxane, N, N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N, N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethyl sulfoxide and the like. It is because the same advantage is obtained.

  Among them, the solvent preferably contains one or more of 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 比 30) and low viscosity solvents such as dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate (for example, viscosity ≦ 1 mPa The combination with s) is more preferable. This is because the dissociative nature of the electrolyte salt and the mobility of the ions are improved.

  In particular, the solvent is selected from unsaturated cyclic carbonates, halogenated carbonates, sulfonic esters, acid anhydrides, dicyano compounds (dinitrile compounds), diisocyanate compounds, phosphoric esters, and chain compounds having a carbon-carbon triple bond. Or one or more of them may be included. This is because the chemical stability of the electrolytic solution is improved.

  An unsaturated cyclic carbonate is a cyclic carbonate containing one or more unsaturated bonds (carbon double bond or carbon double bond). The unsaturated cyclic carbonate is, for example, vinylene carbonate, vinyl ethylene carbonate and methylene ethylene carbonate. The content of unsaturated cyclic carbonate in the 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 halogens as a constituent element. When the halogenated carbonate ester contains two or more halogens as constituent elements, the kind of two or more halogens may be only one kind or two or more kinds. Examples of cyclic halogenated carbonates include 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 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 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 solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

Dinitrile compounds, for _{example, NC-C m H 2m -CN} (m is 1 or more is an integer.) Is a compound represented by the. 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 solvent is not particularly limited, and is, for example, 0.5% by weight to 5% by weight.

Diisocyanate compound, for _{example, OCN-C n H 2n -NCO} (n is 1 or more is an integer.) Is a compound represented by the. The diisocyanate compounds such as hexamethylene diisocyanate _{(OCN-C 6 H 12 -NCO} ) and the like. Although content of the diisocyanate compound in a solvent is not specifically limited, For example, it is 0.5 weight%-5 weight%.

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

The chain compound having a carbon-carbon triple bond is a chain compound having one or more carbon-carbon triple bonds (—C≡C—). Examples of the chain compound having a carbon-carbon triple bond include propargyl methyl carbonate (CH≡C—CH ₂ —O—C (= O) —O—CH ₃ ) and propargyl methyl sulfonate (CH≡C—CH _2). -OS (= O) ₂ -CH ₃ ) and the like. The content of the chain compound having a carbon-carbon triple bond in the 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 contain, for example, a salt other than a lithium salt. The salt other than lithium is, for example, a salt of a light metal 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 These include dilithium silicate (Li ₂ SiF ₆ ), lithium chloride (LiCl) 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. . This is because a higher effect can be obtained because the internal resistance is reduced.

  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.

  However, in the electrolyte layer 36 which is a gel electrolyte, the solvent contained in the electrolytic solution is a broad concept including not only a liquid material but also a material having ion conductivity capable of dissociating the electrolyte salt. . Thus, when using a polymer compound having ion conductivity, the polymer compound is also included in the non-aqueous solvent.

  The polymer compound is, for example, polyacrylonitrile, polyvinylidene fluoride, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, polysiloxane, polyvinyl fluoride, polyvinyl acetate, polyvinyl alcohol, polymethacryl And / or polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene, polycarbonate and the like. Besides, the polymer compound may be a copolymer. The copolymer is, for example, a copolymer of vinylidene fluoride and hexafluoropyrene. Among them, polyvinylidene fluoride is preferable as a homopolymer, and a copolymer of vinylidene fluoride and hexafluoropyrene is preferable as a copolymer. It is because it is electrochemically stable.

  Instead of the electrolyte layer 36, an electrolytic solution may be used as it is. In this case, the electrolytic solution is impregnated into the wound electrode body 30.

[Operation]
The secondary battery operates, for example, as follows.

  At the time of charging, lithium ions are released from the positive electrode 33, and the lithium ions are occluded in the negative electrode 34 via the electrolyte layer 36. On the other hand, at the time of discharge, lithium ions are released from the negative electrode 34, and the lithium ions are stored in the positive electrode 33 via the electrolyte layer 36.

[Production method]
The secondary battery provided with the gel electrolyte layer 36 is manufactured, for example, by the following three types of procedures.

(First step)
In the case of producing the positive electrode 33, 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 form a paste-like positive electrode mixture slurry. Subsequently, the positive electrode mixture slurry is applied to both surfaces of the positive electrode current collector 33A, and then the positive electrode mixture slurry is dried to form the positive electrode active material layer 33B. Finally, while heating the positive electrode active material layer 33B as necessary, the positive electrode active material layer 33B is compression molded using a roll press machine or the like. In this case, compression molding may be repeated multiple times.

  When manufacturing the negative electrode 34, the negative electrode active material layer 34B is formed on both surfaces of the negative electrode current collector 34A by the same procedure as the above-described positive electrode 33. Specifically, first, the negative electrode active material is mixed with a negative electrode binder, a negative electrode conductive agent, and the like to form a negative electrode mixture, and then the negative electrode mixture is dispersed in an organic solvent or the like. A paste-like negative electrode mixture slurry is obtained. Subsequently, the negative electrode mixture slurry is applied to both surfaces of the negative electrode current collector 34A, and then the negative electrode mixture slurry is dried to form the negative electrode active material layer 34B. Finally, the negative electrode active material layer 34B is compression molded using a roll press machine or the like.

  In the case of forming the gel electrolyte layer 36, first, a precursor solution is prepared by mixing an electrolytic solution, a polymer compound, an organic solvent, and the like. Subsequently, after applying a precursor solution to the positive electrode 33, the precursor solution is dried to form a gel electrolyte layer 36. Further, after applying a precursor solution to the negative electrode 34, the precursor solution is dried to form a gel electrolyte layer 36.

  When assembling the secondary battery, first, the positive electrode lead 31 is attached to the positive electrode current collector 33A using a welding method or the like, and the negative electrode lead 32 is attached to the negative electrode current collector 34A using a welding method or the like. Subsequently, the positive electrode 33 and the negative electrode 34 are stacked via the separator 35, and then the positive electrode 33, the negative electrode 34, and the separator 35 are wound to form the wound electrode body 30. Subsequently, the protective tape 37 is attached to the outermost periphery of the wound electrode body 30. Finally, using the exterior member 40 provided with the window portion 42, the exterior member 40 is folded so as to sandwich the wound electrode body 30, and then the outer edges of the exterior member 40 are joined together using a heat fusion method or the like. By bonding, the wound electrode body 30 is enclosed in the inside of the exterior member 40. In this case, the adhesive film 50 is inserted between the positive electrode lead 31 and the package member 40, and the adhesive film 50 is inserted between the negative electrode lead 32 and the package member 40.

  Thereby, a laminate film type secondary battery provided with the gel electrolyte layer 36 is completed.

(Second step)
After fabricating each of the positive electrode 33 and the negative electrode 34 according to the same procedure as the first procedure, when assembling the secondary battery, first attach the positive electrode lead 31 to the positive electrode 33 and attach the negative electrode lead 32 to the negative electrode 34 .

  Subsequently, the positive electrode 33 and the negative electrode 34 are stacked via the separator 35 and then wound to produce a wound body which is a precursor of the wound electrode body 30, and then the outermost periphery of the wound body Affix the protective tape 37 to the part. Subsequently, using the exterior member 40 provided with the window portion 42, the exterior member 40 is folded so as to sandwich the wound electrode body 30, and then one side of the exterior member 40 is heat fused or the like. The wound outer body is accommodated inside the bag-like exterior member 40 by pasting the remaining outer edges except the outer edge.

  Then, the composition for electrolytes is prepared by mixing an 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, as needed. Subsequently, after the composition for electrolyte is injected into the inside of the bag-like exterior member 40, the exterior member 40 is sealed using a heat fusion method or the like. Finally, the monomer is thermally polymerized to form a polymer compound. Since the electrolytic solution is held by the polymer compound, the gel electrolyte layer 36 is formed. Thus, a laminate film type secondary battery is completed.

(Third step)
When a secondary battery is assembled, first, a wound body is manufactured according to the same procedure as the above-described second procedure except that the separator 35 in which the polymer compound layer is formed is used, and then the window portion is formed. The wound body is accommodated in the inside of the bag-like exterior member 40 provided with the numeral 42.

  Subsequently, an electrolytic solution is injected into the inside of the exterior member 40, and then the exterior member 40 is sealed using a heat fusion method or the like. Subsequently, the exterior member 40 is heated while being weighted, so that the separator 35 is in close contact with the positive electrode 33 through the polymer compound layer and the separator 35 is in close contact with the negative electrode 34 through the polymer compound layer. As a result, the electrolytic solution is impregnated into each of the polymer compound layers, and each of the polymer compound layers is gelled, whereby the electrolyte layer 36 is formed. Thus, a laminate film type secondary battery is completed.

  In the third procedure, swelling of the secondary battery is suppressed as compared to the first procedure. Further, in the third procedure, compared to the second procedure, since the solvent and the monomer (raw material of the polymer compound) and the like are less likely to remain in the electrolyte layer 36, the step of forming the polymer compound is well controlled. . For this reason, each of the positive electrode 33, the negative electrode 34, and the separator 35 and the electrolyte layer 36 easily adhere to each other.

[Action and effect]
According to this laminate film type lithium ion secondary battery, the wound electrode body 30 is housed inside the film-like exterior member 40, and the window portion including the window function material (non-porous molten fluorine resin) 42 (window film 43) is provided on the exterior member 40 (exterior main body 41). Therefore, excellent battery characteristics can be obtained for the reasons described below.

  When the window member 42 is not provided in the exterior member 40, if a gas such as carbon dioxide is generated inside the secondary battery due to a side reaction such as decomposition reaction of the electrolyte, there is no escape place for the gas Therefore, gas is accumulated inside the secondary battery. In this case, since the exterior member 40 is deformed so as to protrude from the internal environment E1 toward the external environment E2 in accordance with the increase in the internal pressure, the secondary battery is expanded.

  On the other hand, in the case where the exterior member 40 is provided with the window portion 42, as described above, even if gas is generated inside the secondary battery, the gas is utilized using the exhaust function of the window portion 42. Is released to the outside, so the swelling of the secondary battery is suppressed. Moreover, when the opening 41K is provided in the exterior member (the exterior main body 41), there is a concern that water may enter the inside of the secondary battery through the opening 41K, but the waterproof function of the window 42 is used Since the infiltration of water is suppressed, the deterioration of cycle characteristics and the like caused by the water is also suppressed. As a result, the swelling of the secondary battery is suppressed using the window portion 42 and the deterioration of the cycle characteristics and the like is suppressed without using equipment such as a safety valve or the like, equipment, and devices, so that excellent battery characteristics are obtained. Is obtained.

  In particular, if the window functional material (nonporous molten fluorocarbon resin) contains one or more of nonporous PFA, nonporous FEP, nonporous ETFE, etc., the window 42 Since it is easier to suppress the entry of water and the window portion 42 is more likely to release the gas, higher effects can be obtained.

  Further, if the window main body 41 is provided with the opening 41K and the window film 43 including the window function material covers the opening 41K, the window 42 is formed, the opening 41K (window film 43 Because the gas is sufficiently released through the above, higher effects can be obtained.

  In this case, if the window film 43 has an area larger than the area of the opening 41 K and the window film 43 is attached to the exterior main body 41 via the adhesive 44, the exterior main body 41 The window film 43 is firmly fixed to the As a result, the waterproof function and the exhaust function of the window portion 42 are stably exhibited, so that a higher effect can be obtained.

  In addition, if the thickness of the window film 43 is 10 μm to 500 μm, a sufficient waterproof function and a sufficient exhaust function can be obtained while securing the physical durability and the like of the window film 43, so that a higher effect can be obtained. Can.

<1-2. Lithium metal rechargeable battery>
The secondary battery described here is a laminated film type lithium metal secondary battery in which the capacity of the negative electrode 34 can be obtained by deposition and dissolution of lithium metal. This secondary battery has the same configuration as the above-described laminate film type lithium ion secondary battery except that the negative electrode active material layer 34B is formed of lithium metal, and by the same procedure. Manufactured.

  In this secondary battery, since lithium metal is used as the negative electrode active material, high energy density can be obtained. The negative electrode active material layer 34B may already exist from the time of assembly, but may not be present at the time of assembly, and may be formed of lithium metal deposited during charging. In addition, by using the negative electrode active material layer 34B as a current collector, the negative electrode current collector 34A may be omitted.

  The secondary battery operates, for example, as follows. At the time of charging, lithium ions are released from the positive electrode 33, and the lithium ions are deposited as lithium metal on the surface of the negative electrode current collector 34A through the electrolyte layer 36. On the other hand, at the time of discharge, lithium metal becomes lithium ions from the negative electrode active material layer 34 B and is eluted into the electrolyte layer 36, and the lithium ions are occluded by the positive electrode 21 through the electrolyte layer 36.

  According to this laminate film type lithium metal secondary battery, the wound electrode body 30 is housed inside the film-like exterior member 40, and the window portion 42 (window film 43) containing the window function material is the exterior member 40 (outer body 41). Therefore, excellent battery characteristics can be obtained for the same reason as the above-described lithium ion secondary battery. Other operations and effects of the lithium metal secondary battery are similar to those of the lithium ion secondary battery.

<1-3. Modified example>
The configuration of the secondary battery of the present embodiment can be changed as appropriate.

(Modification 1)
Specifically, the window film 43 may be bonded to the exterior main body 41 using any one type or two or more types of methods in which the adhesive 44 is not used, for example. The method which does not use this adhesive 44 is, for example, a heat fusion method and an ultrasonic welding method. Also in this case, since the window film 43 is fixed to the exterior main body 41, the same effect can be obtained.

(Modification 2)
For example, as shown in Drawing 5 corresponding to Drawing 2, window part 42 may be provided in side 41PS instead of upper surface 41PT of hollow parts 41P. The opening shape and the opening area of the opening 41 K can be set arbitrarily, and the plane shape and the area of the window film 43 can be set arbitrarily. Here, for example, each of the opening shape of the opening 41K and the planar shape of the window film 43 is substantially rectangular (a rectangle in which the four corners are rounded), and the area of the window film 43 is the opening of the opening 41K. It is larger than the area. Also in this case, the same effect can be obtained by the window portion 24 exhibiting a waterproof function and an exhaust function.

(Modification 3)
Further, for example, as shown in FIG. 6 corresponding to FIG. 3, the window film 43 is disposed outside the exterior main body 41 (external environment E2) instead of the inside (internal environment E1) of the exterior main body 41 May be The window film 43 is adhered to the outer surface of the exterior main body 41 via an adhesive 44, for example. Also in this case, the same effect can be obtained by the window portion 24 exhibiting a waterproof function and an exhaust function.

  However, as described above, when the window film 43 is disposed outside the exterior main body 41, there is a possibility that the window film 43 may be peeled off due to the generation of gas (increase in internal pressure), and the window film 43 may drop out of the secondary battery. Therefore, in order to suppress that the window film 43 peels off and falls off, it is preferable that the window film 43 is arrange | positioned inside the exterior main body 41 (internal environment E1).

(Modification 4)
Further, for example, as shown in FIG. 7 corresponding to FIG. 3, a protective layer 46 may be provided on the window film 43. The “on the window film 43” means the outside of the window film 43.

  The protective layer 46 mainly functions to physically protect the surface of the window film 43. The protective layer 46 contains, for example, any one or more of breathable materials. The type of material having air permeability is not particularly limited, and examples thereof include porous resins, ceramic and mesh filters. The type of porous resin is not particularly limited. For example, porous polytetrafluoroethylene (PTFE), nylon, polypropylene (PP), polyethylene (PE), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC) And zeolites. The thickness of the protective layer 46 is not particularly limited, and can be arbitrarily set.

  If the protective layer 46 can protect the window film 43, the size (area) of the protective layer 46 is not particularly limited. That is, the area of the protective layer 46 may be the same as the exposed area of the window film 43 (the area of the window film 43 exposed to the opening 41 K) or may be larger than the exposed area of the window film 43.

  Here, the protective layer 46 has, for example, an area larger than the exposed area of the window film 43, and is adhered to the exterior main body 41 via the adhesive 45. The adhesive 45 is preferably provided so as not to block the opening 41 K, for example, in order to ensure air permeability using the window film 43. FIG. 7 shows, for example, the case where the protective layer 46 is not adhered to the window film 43 via the adhesive 45. Details regarding the adhesive 45 are similar to the details regarding the adhesive 44, for example.

  In this case, since the window film 43 is physically protected by the protective layer 46, the deformation, breakage and peeling of the window film 43 due to external force are suppressed. Moreover, since the material having air permeability has the property of easily passing gas, even if the protective layer 46 is provided on the window film 43, the gas is released to the outside via the protective layer 46. Be done. Therefore, since the physical durability of the window film 43 is improved while the exhaust function of the window portion 42 is secured, a higher effect can be obtained.

  Although not specifically shown here, for example, as shown in FIG. 6, in the case where the window film 43 is disposed outside the exterior main body 41, the protective layer 46 is provided on the window film 43. May be The protective layer 46 is adhered to the exterior main body 41 or the like through an adhesive 45, for example. Also in this case, the same effect can be obtained.

<2. Secondary Battery (Second Embodiment)>
Next, the secondary battery of the second embodiment will be described. Below, the component of the secondary battery of 1st Embodiment is quoted at any time.

<2-1. Lithium ion rechargeable battery>
The secondary battery described here is a lithium ion secondary battery. The secondary battery according to the second embodiment of the present invention is different from the secondary battery of the first embodiment except that the exterior main body 41 is not provided with the opening 41K, and the exterior member 40 has a window 47 instead of the window 42. It has the same configuration as the battery and is manufactured by the same procedure.

[Constitution]
FIG. 8 shows a perspective view configuration (state after bonding) of the secondary battery of the present embodiment, and corresponds to each of FIG. 1 and FIG. However, in FIG. 8, as in FIG. 2, the positive electrode lead 31 and the negative electrode lead 32 are not shown.

  FIG. 9 shows a cross-sectional configuration of the exterior member 40 along the line C-C shown in FIG. FIG. 10 shows a cross-sectional configuration of the exterior member 40 along the line D-D shown in FIG.

  The window portion 47 mainly performs the same function (water proof function and exhaust function) as the window portion 42. For example, as shown in FIG. 8, the window portion 47 is provided in the adhesion region 41 Y instead of the non-adhesion region 41 X of the exterior main body 41, and includes the window film 48 instead of the window film 43. There is.

  Specifically, for example, in a state where the window film 48 is sandwiched between the exterior parts 41A and 41B, the window parts 47 are formed by bonding the exterior parts 41A and 41B to each other. That is, the window portion 47 includes, for example, a window function material (non-porous molten fluorine resin) and a window film 48 interposed between the exterior portions 41A and 41B. In FIG. 8, in order to make the window 47 (window film 48) easy to identify, the window 47 is shaded.

  The window portion 47 is exposed to the internal environment E1 and the external environment E2, as shown in FIGS. 9 and 10. The window portion 47 is provided in the exterior member 40 for the same reason as the case where the window portion 42 is provided in the exterior member 40. That is, by using the waterproof function and the exhaust function of the window portion 47, the deterioration of the cycle characteristics and the like is suppressed and the swelling of the secondary battery is suppressed without using the equipment such as the safety valve and the like. Be done.

  The number, position, and configuration of the windows 47 are not particularly limited as long as the waterproof function and the exhaust function described above can be exhibited.

  The number of windows 47 may be only one or two or more. Here, the number of windows 47 is, for example, one.

  Further, the position of the window portion 47 may be any position as long as it is any position in the bonding area 41Y. Here, the window portion 47 is provided, for example, in a part of the bonding region 41Y on the side where the positive electrode lead 31 and the negative electrode lead 32 are introduced from the inside to the outside of the exterior member 40.

  The window film 48 includes, for example, any one or more of the window function materials similarly to the window film 43. The planar shape of the window film 48 is not particularly limited, and may be, for example, a circular shape, an elliptical shape, a rectangular shape, or any other shape. Here, the planar shape of the window film 48 is, for example, rectangular.

  For example, the window film 48 is adhered to the exterior main body 41 (exterior portion 41A) via the adhesive 49, and is similarly adhered to the exterior main body 41 (exterior portion 41B) via the adhesive 49. . Details regarding the adhesive 49 are, for example, similar to the details regarding the adhesive 44.

  In the region where the window film 48 is not present, as described above, the adhesive layer of the exterior portion 41A and the adhesive layer of the outer layer portion 41B are adhered to each other. Thereby, the exterior member 40 is sealed.

  The thickness of the window film 48 is not particularly limited, and is, for example, 10 μm to 500 μm, preferably 10 μm to 200 μm. Similar to the case where the thickness of the window film 43 is specified, a sufficient waterproof function and a sufficient exhaust function can be obtained while securing the physical durability of the window film 48 and the like.

  When the adhesion between the adhesive 49 and the window film 48 is not sufficient, for example, as in the case where the adhesion between the adhesive 44 and the window film 43 is not sufficient, the adhesion is improved. The surface of the window film 48 may be subjected to any one or more of the pretreatments. Details regarding the pretreatment are, for example, as described above.

  Of course, when the adhesion between the adhesive 49 and the exterior main body 41 is not sufficient, for example, as in the case where the adhesion between the adhesive 44 and the exterior main body 41 is not sufficient, the adhesion is improved. In addition, any one type or two or more types of pretreatment may be applied to the surface of the exterior main body 41.

[Production method]
In this secondary battery, for example, the window film 48 is attached to the exterior main body 41 (the exterior parts 41A and 41B) using the adhesive 49, except that the exterior member 40 provided with the window 48 is used. , It manufactures by the procedure similar to the secondary battery of 1st Embodiment.

[Action and effect]
According to this laminate film type lithium ion secondary battery, the wound electrode body 30 is housed inside the film-like exterior member 40, and the window portion 47 (window film 48) containing the window function material is the exterior member 40 is provided. In this case, for the same reason as the secondary battery of the first embodiment, the waterproof function of the window film 48 is utilized to suppress the deterioration of the cycle characteristics and the like due to water, and By using the exhaust function, swelling of the secondary battery is suppressed. Therefore, excellent battery characteristics can be obtained.

  In particular, if the window portion 48 is formed by bonding the exterior portions 41A and 41B to each other through the window film 48 containing the window functional material, the window portion 48 is not provided in the exterior main body 41 or the like. Can be obtained, so that higher effects can be obtained.

  In addition, if the thickness of the window film 48 is 10 μm to 500 μm, a sufficient waterproof function and a sufficient exhaust function can be obtained while securing the physical durability and the like of the window film 48, so that a higher effect can be obtained. Can.

  The other actions and effects of the secondary battery of the present embodiment are the same as the actions and effects of the secondary battery of the first embodiment.

2-2. Lithium metal rechargeable battery>
The secondary battery described here is a laminated film type lithium metal secondary battery. This secondary battery has the same structure as the above-described laminate film type lithium ion secondary battery except that lithium metal is used as the negative electrode active material, and is manufactured by the same procedure. Ru.

  According to this laminate film type lithium metal secondary battery, the wound electrode body 30 is housed inside the film-like exterior member 40, and the window portion 47 (window film 48) containing the window function material is the exterior member 40 is provided. Therefore, excellent battery characteristics can be obtained for the same reason as the above-described lithium ion secondary battery. Other operations and effects of the lithium metal secondary battery are similar to those of the lithium ion secondary battery.

<2-3. Modified example>
The configuration of the secondary battery of the present embodiment can be changed as appropriate. Specifically, even if the window film 48 is attached to the exterior main body 41 using any one type or two or more types of methods which do not use the adhesive 49 as in the window film 43, for example, Good. The details of the method not using the adhesive 49 are, for example, as described above. Also in this case, since the window film 48 is fixed to the exterior main body 41, the same effect can be obtained.

<3. 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 the secondary battery can be used as a driving power source or a power storage source for storing electric power, etc. If it is, it will not be limited in particular. 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.

<3-1. Battery pack (single cell)>
FIG. 11 shows a perspective view of a battery pack using single cells. FIG. 12 shows a block configuration of the battery pack shown in FIG. FIG. 11 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 of the present technology, and is mounted on, for example, an electronic device represented by a smartphone. For example, as shown in FIG. 11, the battery pack includes a power supply 111 which is a laminated film type 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, for example, 4.2V ± 0.05V, and the overdischarge detection voltage is, for example, 2.4V ± 0.1V.

  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.

<3-2. Battery pack (battery pack)>
FIG. 13 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 supply 62 is a battery assembly including two or more types of secondary batteries of the present technology, and the connection type of the two or more types of 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 measurement result of the voltage that has been analog-digital converted to the control unit 61.

  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 overcharge detection voltage is, for example, 4.2V ± 0.05V, and the overdischarge detection voltage is, for example, 2.4V ± 0.1V.

  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, and the like. 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.

<3-3. Electric vehicles>
FIG. 14 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 supply 76 includes one or more secondary batteries of the present technology. 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.

<3-4. Power storage system>
FIG. 15 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 electrical 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 types of secondary batteries of the present technology. 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).

<3-5. Power tool>
FIG. 16 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 types of secondary batteries of the present technology. 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.

  An embodiment of the present technology will be described.

(Experimental example 1-1 to 1-15)
By providing the window 42 (the opening 41 K and the window film 43) in the non-adhesion region 41X of the exterior main body 41 according to the following procedure, lithium ion of the laminate film type shown in FIGS. A secondary battery was produced.

When producing the positive electrode 33, first, 97 parts by mass of a positive electrode active material (LiNi _0.5 Co _0.2 Mn _0.3 O ₂ ), ₂ parts by mass of a positive electrode binder (polyvinylidene fluoride), and a positive electrode conductive agent (carbon black) The mixture was mixed with 1 part by mass to obtain a positive electrode mixture. Subsequently, after the positive electrode mixture was charged into an organic solvent (N-methyl-2-pyrrolidone), the organic solvent was stirred to obtain a paste-like positive electrode mixture slurry. Subsequently, the positive electrode mixture slurry is applied on both sides of the positive electrode current collector 33A (12 μm thick strip-like aluminum foil) using a coating apparatus, and then the positive electrode mixture slurry is dried to form the positive electrode active material layer 33B. It formed. Finally, the positive electrode active material layer 33B was compression molded using a roll press.

  When producing the negative electrode 34, first, 95 parts by weight of a negative electrode active material (granular graphite powder, median diameter D50 = 20 μm), and a negative electrode binder (acrylic modified product of styrene butadiene rubber copolymer) 1.5 The negative electrode mixture and the negative electrode binder (microparticles polyvinylidene fluoride, median diameter D50 = 0.3 μm) 2 parts by mass, and a thickener (carboxymethyl cellulose) 1.5 parts by mixing did. Subsequently, the negative electrode mixture was charged into pure water, and then the pure water was stirred to obtain a paste-like negative electrode mixture slurry. Subsequently, the negative electrode mixture slurry is applied on both sides of the negative electrode current collector 34A (15 μm thick strip-shaped copper foil) using a coating apparatus, and then the negative electrode mixture slurry is dried to form the negative electrode active material layer 34B. It formed. Finally, the negative electrode active material layer 34B was compression molded using a roll press.

When preparing an electrolytic solution, an electrolyte salt (LiPF ₆ ) is added to a solvent (ethylene carbonate, ethyl methyl carbonate and vinylene carbonate) and then the solvent is stirred to dissolve the electrolyte salt in the solvent. The In this case, the mixing ratio (mass ratio) of the solvents was ethylene carbonate: ethyl methyl carbonate: vinylene carbonate = 30: 69: 1. In addition, the content of the electrolyte salt was 1 mol / dm ³ (= 1 mol / l) with respect to the solvent.

  When assembling the secondary battery, first, the positive electrode lead 31 made of aluminum was welded to the positive electrode current collector 33A, and the negative electrode lead 32 made of copper was welded to the negative electrode current collector 34A.

  Subsequently, a polymer compound (polyvinylidene fluoride) is dissolved in an organic solvent (N-methyl-2-pyrrolidone) to obtain a solution in which the polymer compound is dissolved in the organic solvent, and then a base material layer The solution was applied to both sides of a (12 μm thick microporous polyethylene film). Subsequently, the solution was phase-separated by immersing the substrate layer in a water bath, and then the substrate layer was dried with warm air. As a result, the polymer compound layers were formed on both sides of the base material layer, so that the separator 35 was obtained.

  Subsequently, the positive electrode 33 and the negative electrode 34 are stacked via the separator 35 to obtain a stacked body. Subsequently, the laminate was wound in the longitudinal direction, and then a protective tape 37 was attached to the outermost periphery of the laminate to produce a wound electrode body 30.

  Subsequently, the film-like exterior member 40 was folded so as to sandwich the wound electrode body 30, and the outer peripheral edge portions of three sides of the exterior member 40 were heat-sealed. The exterior member 40 is an aluminum laminated film in which a 25 μm thick nylon film, a 40 μm thick aluminum foil, and a 30 μm thick polypropylene film are laminated in this order from the outside. In the case of heat-sealing the package member 40, the adhesive film 50 was inserted between the positive electrode lead 31 and the package member 40, and the adhesive film 50 was inserted between the negative electrode lead 32 and the package member 40.

  In this case, the window film 43 including the window functional material is attached to the exterior main body 41 via the adhesive 44 so as to cover the opening 41K provided in the non-adhesion region 41X of the exterior main body 41. Thus, the exterior member 40 provided with the window portion 42 was used. Further, the protective layer 46 was attached to the window film 43 via the adhesive 46, whereby the exterior member 40 provided with the protective layer 46 was used.

  In addition, the exterior member 40 in which the window part 42 was not provided was used for the comparison. Moreover, the exterior member 40 in which the window film 43 contains materials other than a window functional material was used for comparison.

  The presence or absence of the window portion 42, the configuration (position and dimension (cm × cm)) of the opening 41K, the configuration (material and thickness (μm)) of the window film 43, and the configuration (presence and absence and material) of the protective layer 46 As shown in 1.

  The material of the window film 43 is as follows. Non-porous PFA, non-porous FEP and non-porous ETFE were used as the window functional material (non-porous molten fluorocarbon resin). As materials other than the window function material, porous PFA, polypropylene (PP) and polyethylene terephthalate (PET) were used.

  As a forming material (porous resin) of the protective layer 46, porous polytetrafluoroethylene (PTFE) was used.

  In the case where the window film 43 including the window functional material is attached to the exterior main body 41 via the adhesive 44, first, the surface of the window film 43 is pretreated. In this case, the surface of the window film 43 is reformed (so-called fluorobonder treatment) by spraying a pretreatment agent (fluororesin surface treatment agent fluorobonder E manufactured by Technos Co., Ltd.) on the surface of the window film 43. did. Subsequently, the surface of the exterior main body 41 was subjected to pretreatment. In this case, a primer (PPX primer manufactured by Cemedine Co., Ltd.) was applied to the surface of the exterior main body 41. Finally, the pretreatment surface of the window film 43 and the pretreatment surface of the exterior main body 41 were adhered via the adhesive 44 (PPX manufactured by Cemedine Co., Ltd.).

  When the window film 43 containing a material other than the window functional material is attached to the exterior main body 41 via the adhesive 44, the window film 43 containing the window functional material is attached to the exterior main body 41 via the adhesive 44. The same procedure was used as in the case.

  Finally, the electrolytic solution is impregnated into the separator 35 by injecting the electrolytic solution into the inside of the exterior member 40, and then the outer peripheral edge portions of the remaining one side of the exterior member 40 are heat-sealed in the reduced pressure environment. did. As a result, since the wound electrode body 30 was enclosed in the inside of the exterior member 40, a laminate film type lithium ion secondary battery (battery size = 80 mm × 60 mm × 40 mm, battery capacity = 3000 mAh) was completed.

  In order to evaluate the battery characteristics of the secondary battery, the capacity retention characteristics, the blister characteristics, the physical durability characteristics and the adhesive characteristics of the secondary battery were examined. The results shown in Table 1 were obtained.

  In the case of examining the capacity maintenance characteristics, first, the secondary battery was stored (storage period = 7 days) in a high temperature environment (temperature = 60 ° C., humidity = 90%) using a thermostat. Then, after taking out the secondary battery from the thermostat, the discharge capacity (mAh) was measured by charging and discharging the secondary battery. Finally, capacity retention rate (%) = (discharge capacity / battery capacity (= 3000 mAr)) × 100 was calculated.

  During charging, constant current charging was performed until the voltage reached 4.2 V at a current of 0.2 A. During discharge, constant current discharge was performed until the voltage reached 2.5 V at a current of 0.6 A.

  When investigating the swelling characteristics, first, after charging the secondary battery in a normal temperature environment (temperature = 23 ° C.), using a micrometer, the thickness of the charged secondary battery (thickness before storage) Was measured. Subsequently, the secondary battery in a charged state is stored (storage period = 7 days) in a high temperature environment (temperature = 60 ° C., humidity = 90%) in a thermostatic chamber, and then a secondary state of charge is stored using a micrometer. The thickness of the battery (thickness after storage) was measured. Finally, the rate of change in thickness (%) = [(thickness after storage−thickness before storage) / thickness before storage] × 100 was calculated.

  During charging, constant current charging was performed until the voltage reached 4.2 V at a current of 1 A.

  In the case of examining the physical durability characteristics, a scratching test in accordance with JIS K5400-5-4 was conducted to visually confirm the scratching state of the outermost surface of the window portion 42. As a result, "A" occurred when no scratch occurred on the outermost surface of the window 42, "B" occurred when a scratch occurred on the outermost surface of the window 42, and a scratch occurred on the outermost surface of the window 42 Not only that, the case where the window part 42 was damaged was evaluated as "C", respectively. The outermost surface of the window portion 42 is the surface of the window film 43 when the protective layer 46 is not provided, and is the surface of the protective layer 46 when the protective layer 46 is provided.

  In the case of examining the adhesion characteristics, the adhesion strength of the window film 43 was confirmed by conducting an adhesion test in accordance with JIS K7127: 1999. As a result, the case where the window film 43 did not peel off was evaluated as “A”, and the case where the window film 43 peeled off was evaluated as “C”.

  When the window portion 42 was not provided (Experimental Example 1-12), although a high capacity retention rate was obtained, the thickness change rate increased. This result indicates that the secondary battery was expanded in response to the rise of the internal pressure because a gas resulting from the decomposition reaction of the electrolytic solution was generated inside the secondary battery. Below, let the result when not providing the window part 42 be a comparison reference.

  On the other hand, when the window part 42 was provided, each of a capacity | capacitance maintenance factor and thickness change rate fluctuated large according to the material of the window film 43. As shown in FIG.

  In detail, when materials (porous PFA and PP) other than the window functional material were used as the forming material of the window film 43 (Experimental Examples 1-13 and 1-14), the thickness change rate was significantly reduced However, the capacity retention rate also decreased significantly. Moreover, when material (PET) other than a window function material was used (Experimental example 1-15), although the high capacity | capacitance maintenance factor was maintained, thickness change rate was substantially equivalent.

  However, when window function materials (non-porous PFA, non-porous FEP and non-porous ETFE) are used as the material for forming the window film 43 (Experimental Examples 1-1 to 1-11), the openings 41 K are used. Regardless of the position, the type of window functional material, the thickness of the window film 43, etc., the thickness change rate is significantly reduced while the capacity retention rate is substantially maintained. As a result, when the window 42 (the window film 43 including the window functional material) is used, the gas generated inside the secondary battery is released to the outside, so that the secondary battery becomes difficult to expand and the secondary Since water is less likely to enter the inside of the battery, the discharge capacity is less likely to be reduced.

  Moreover, in the case where a window functional material is used (Experimental Examples 1-1 to 1-11), the same degree of rubbing as in the case where a material other than the window functional material is used (Experimental Examples 1-13 to 1-15) While the state was obtained, the same adhesive strength was obtained. That is, even when using a window functional material as a forming material of the window film 43, each of the scratched state and the adhesive strength did not deteriorate.

  In particular, in the case of using a window function material (Experimental Examples 1-1 to 1-11), the following tendency was obtained. First, when the thickness of the window film 43 is 10 μm to 500 μm, the thickness change rate is sufficiently reduced. In this case, when the thickness of the window film 43 is 200 μm or less, the thickness change rate is further reduced. Second, when the protective layer 46 is used, the scratching condition of the outermost surface of the window portion 42 is significantly improved.

(Experimental example 2-1 to 2-4)
As shown in Table 2, except for that the window portion 47 (window film 48) is provided in the bonding area 41Y instead of the non-bonding area 41X of the exterior main body 41, Experimental Examples 1-1 to 1-15 The laminated film type lithium ion secondary battery shown in FIGS. 8 to 10 was manufactured by the same procedure as in the above, and the battery characteristics of the secondary battery were evaluated.

  In the case where the window film 48 including the window functional material is attached to the exterior main body 41 (the exterior parts 41A and 41B) via the adhesive 49, first, both surfaces of the window film 48 are subjected to pretreatment. In this case, both surfaces of the window film 48 were subjected to modification treatment (fluoro bonder treatment) by spraying a pretreatment agent (fluororesin surface treatment agent fluorobonder E manufactured by Technos Co., Ltd.) on both surfaces of the window film 48. . Subsequently, pretreatment was applied to the surface of the exterior portion 41A and the surface of the exterior portion 41B. In this case, an undercoating agent (PPX primer manufactured by Cemedine Co., Ltd.) was applied to the surface of the exterior portion 41A, and a similar undercoating agent was applied to the surface of the exterior portion 41B. Finally, the pretreatment surface of the window film 48 and the pretreatment surface of the exterior portion 41A are adhered to each other through the adhesive 49 (PPX manufactured by Cemedine Co., Ltd.), and the window film through the similar adhesive 49. The pretreatment surface of 48 and the pretreatment surface of the exterior portion 41B were adhered to each other.

  Also in the case where the window portion 47 is provided in the bonded region 41Y (Table 2), the same result as in the case where the window portion 42 is provided in the non-bonded region 41X (Table 1) is obtained. That is, when the window portion 47 is provided and the window functional material is used as the forming material of the window film 48 (Experimental example 2-1 to 2-41), the window portion 47 is not provided (Experimental example 1) As compared with the case where a material other than the window function material is used as the forming material of the window film 48 and the window film 48 (Experimental examples 1-13 to 1-15), a high capacity retention rate can be obtained and the thickness change rate Decreased significantly. Of course, in the case where the window portion 47 is provided and the window functional material is used (Experimental example 2-1 to 2-4), the window portion 47 is not provided (Experimental example 1-12) and other than the window functional material The abrasion state and the adhesive strength equivalent to each of the cases (Experimental Examples 1-13 to 1-15) were also obtained.

  From the results shown in Tables 1 and 2, the wound electrode body is housed inside the film-like exterior member, and the exterior member contains the window portion including the window functional material (non-porous molten fluorine resin). When provided, the capacity retention characteristics and the swelling characteristics of the secondary battery were improved while securing the physical durability and adhesion characteristics of the exterior member. Therefore, excellent battery characteristics were obtained in the secondary battery.

  Although the present technology has been described above with reference to some 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 structure of the battery element in the secondary battery of the present technology is not particularly limited. Specifically, the battery element may have another structure such as, for example, a laminated structure.

  The secondary battery (lithium ion secondary battery) in which the capacity of the negative electrode can be obtained by lithium absorption and release and the secondary battery (lithium metal secondary battery) in which the capacity of the negative electrode is obtained by precipitation and dissolution of lithium have been described. The principle by which the capacity of the negative electrode is obtained in the secondary battery of the present technology is not particularly limited. Specifically, for example, by making the capacity of the negative electrode material capable of inserting and extracting lithium smaller than the capacity of the positive electrode, the secondary battery can be calculated by the sum of the capacity by insertion and extraction of lithium and the capacity by precipitation and dissolution of lithium. It may be a secondary battery or the like in which the capacity of the negative electrode can be obtained.

  Moreover, although demonstrated about the case where lithium is used as an electrode reactant, it is not restricted to this. The electrode reactant may be, for example, another group 1 element in the long period periodic table such as sodium (Na) and potassium (K), or a long period periodic table such as magnesium (Mg) and calcium (Ca). And may be other light metals such as aluminum (Al). In addition, the electrode reactant may be an alloy containing one or more of any of the series of elements described above.

  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 a positive electrode, a negative electrode, and an electrolytic solution;
A secondary battery comprising: a film-like exterior member for housing the battery element and having a window portion containing a non-porous molten fluorine resin.
(2)
The non-porous molten fluorine resin includes non-porous tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), non-porous tetrafluoroethylene / hexafluoropropylene copolymer (FEP) and non-porous tetrafluoroethylene. At least one of ethylene and ethylene copolymer (ETFE),
The secondary battery as described in said (1).
(3)
The exterior member has an opening,
The window portion is formed by covering at least the opening portion with a film-like window member containing the non-porous molten fluorine resin.
The secondary battery as described in said (1) or (2).
(4)
The window member has an area larger than the area of the opening, and is attached to the exterior member via an adhesive.
The secondary battery as described in said (3).
(5)
A protective layer including a breathable material is provided on the window member.
The secondary battery as described in said (3) or (4).
(6)
The thickness of the window member is 10 μm or more and 500 μm or less.
The secondary battery according to any one of the above (3) to (5).
(7)
The exterior member is
A first exterior member covering the battery element from one side;
A second exterior member that covers the battery element from the other side;
The window portion is formed by bonding a part of the first exterior member and a part of the second exterior member to each other through the film-like window member containing the non-porous molten fluorine resin. Being
The secondary battery as described in said (1) or (2).
(8)
The window member is attached to each of the first exterior member and the second exterior member via an adhesive.
The secondary battery as described in said (7).
(9)
The thickness of the window member is 10 μm or more and 500 μm or less.
The secondary battery as described in said (7) or (8).
(10)
Being a lithium ion secondary battery,
The secondary battery according to any one of the above (1) to (9).
(11)
The secondary battery according to any one of the above (1) to (10);
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.
(12)
The secondary battery according to any one of the above (1) to (10);
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.
(13)
The secondary battery according to any one of the above (1) to (10);
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.
(14)
The secondary battery according to any one of the above (1) to (10);
A movable part to which power is supplied from the secondary battery;
(15)
The electronic device provided with the secondary battery in any one of said (1) thru | or (10) as an electric power supply source.

  This application claims priority based on Japanese Patent Application No. 2016-244512 filed on Dec. 16, 2016 in the Japanese Patent Office, and the entire contents of this application are referred to this application by reference. In the

  Various modifications, combinations, subcombinations, and modifications will occur to those skilled in the art depending on the design requirements and other factors, which are within the spirit of the appended claims and the scope of equivalents thereof. It is understood that it is included in.

Claims (15)

A battery element including a positive electrode, a negative electrode, and an electrolytic solution;
A secondary battery comprising: a film-like exterior member for housing the battery element and having a window portion containing a non-porous molten fluorine resin. The non-porous molten fluorine resin includes non-porous tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), non-porous tetrafluoroethylene / hexafluoropropylene copolymer (FEP) and non-porous tetrafluoroethylene. At least one of ethylene and ethylene copolymer (ETFE),
The secondary battery according to claim 1. The exterior member has an opening,
The window portion is formed by covering at least the opening portion with a film-like window member containing the non-porous molten fluorine resin.
The secondary battery according to claim 1. The window member has an area larger than the area of the opening, and is attached to the exterior member via an adhesive.
The secondary battery according to claim 3. A protective layer including a breathable material is provided on the window member.
The secondary battery according to claim 3. The thickness of the window member is 10 μm or more and 500 μm or less.
The secondary battery according to claim 3. The exterior member is
A first exterior member covering the battery element from one side;
A second exterior member that covers the battery element from the other side;
The window portion is formed by bonding a part of the first exterior member and a part of the second exterior member to each other through the film-like window member containing the non-porous molten fluorine resin. Being
The secondary battery according to claim 1. The window member is attached to each of the first exterior member and the second exterior member via an adhesive.
The secondary battery according to claim 7. The thickness of the window member is 10 μm or more and 500 μm or less.
The secondary battery according to claim 7. 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 a positive electrode, a negative electrode, and an electrolytic solution;
A battery pack comprising: a film-like exterior member for housing the battery element and having a window including a non-porous molten fluorine resin. 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 a positive electrode, a negative electrode, and an electrolytic solution;
An electric vehicle comprising: a film-like exterior member for housing the battery element and having a window portion containing a non-porous molten fluorine resin. 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 a positive electrode, a negative electrode, and an electrolytic solution;
And a film-like exterior member for housing the battery element and having a window portion containing a non-porous molten fluorine resin. With a secondary battery,
A movable part supplied with power from the secondary battery;
The secondary battery is
A battery element including a positive electrode, a negative electrode, and an electrolytic solution;
A power tool comprising: a film-like exterior member for housing the battery element and having a window including a non-porous molten fluorine resin. Equipped with a secondary battery as a power supply source,
The secondary battery is
A battery element including a positive electrode, a negative electrode, and an electrolytic solution;
An electronic apparatus comprising: a film-like exterior member for housing the battery element and having a window including a non-porous molten fluorine resin.

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