JP6742067B2 - Lithium ion battery - Google Patents

Description

The present disclosure relates to lithium-ion batteries.

In a lithium-ion battery having features such as thinness, lightness, and flexibility, a structure in which a positive electrode, a separator, and a negative electrode are wound or laminated is housed in, for example, an exterior member made of a laminated film. And is filled with electrolyte. By the way, in a lithium-ion battery, during charging and discharging, the negative electrode active material expands and contracts due to the lithium insertion-removal reaction (or alloying reaction), so the stress applied to the constituent members of the lithium-ion battery increases or decreases. There is a problem that the ion battery itself is deformed. Here, "deformation" means expansion in the stacking direction (stacking direction of the positive electrode, separator, and negative electrode) and expansion in the negative electrode surface due to expansion of the negative electrode active material, and accompanying force applied to each layer. Refers to both warpage in which the entire lithium-ion battery bends due to non-uniformity.

The problem of deformation of the lithium-ion battery is becoming more apparent because a thin and large-sized lithium-ion battery is required for various electronic devices such as smartphones and tablet terminals in recent years. The exclusive space of the battery in the electronic device is generally decided at the design stage. Therefore, it is necessary to design the volume of the lithium-ion battery to be small in advance so that the lithium-ion battery can be accommodated in its own space even if it is deformed. From the viewpoint of battery capacity, the deformation of the lithium-ion battery is a major disadvantage. Is.

JP 2006-338993 A JP, 2009-140904, A

Various means for suppressing the volume change of the negative electrode active material have been proposed. For example, in the technique disclosed in JP-A-2006-338993, the volume of the negative electrode mixture layer during charging is increased by removing the mesh after applying the negative electrode mixture layer to the negative electrode current collector foil through the mesh. Forms a buffer space to mitigate the effect of. However, since the negative electrode mixture does not exist in the buffer space, the battery capacity decreases accordingly. In the technique disclosed in Japanese Patent Laid-Open No. 2009-140904, the volume density of the electrode mixture layer is increased to increase the rigidity of the electrode, so that the lithium ion battery is deformed in the thickness direction even when a laminate film is used as the exterior member. It is said that this can be suppressed. However, even if the rigidity of the electrode is increased to suppress the expansion in the thickness direction of the lithium ion battery, the difference in the expansion amount due to the asymmetry in the thickness direction of the internal components of the lithium ion battery causes the bending moment. Therefore, the effect of preventing warpage is limited.

Therefore, an object of the present disclosure is to provide a lithium ion battery having a structure and a structure in which warpage due to a change in volume of a negative electrode active material does not easily occur without providing (adding) a special member or structure to the lithium ion battery. It is in.

A lithium ion battery according to a first aspect of the present disclosure for achieving the above object is formed by housing a structure in which a positive electrode, a separator, and a negative electrode are wound or laminated in an exterior member and filled with an electrolyte. A lithium-ion battery,
(A) The longitudinal direction of the structure is the X direction, the lateral direction of the structure is the Z direction, and the thickness direction of the structure is the Y direction.
(B) The outer surface along the XZ plane of the structure is the first surface and the second surface,
(C) The portion of the structure on the first surface side is the first portion, and the portion of the structure on the second surface side that is in contact with the first portion is the second portion,
(D) A side surface portion of the exterior member facing the first portion in the X direction is a first side surface portion, and a side surface portion of the exterior member facing the second portion in the X direction is a second side surface portion,
(E) The linear expansion amount in the X direction of the first portion during charging is ΔX ₁ , and the linear expansion amount in the X direction of the second portion during charging is ΔX ₂ .
(F) The minimum value of the gap located between the first portion and the first side surface portion is d ₁ , the maximum value of the gap located between the second portion and the second side surface portion is d ₂ , When the value of the gap located between the boundary between the first part and the second part and the part of the side surface of the exterior member facing the boundary in the X direction is d _m ,
ΔX ₁ >ΔX ₂
And, and
_{d 1 <ΔX 1 <d m} <d 2
To be satisfied.

A lithium ion battery according to a second aspect of the present disclosure for achieving the above object is formed by housing a structure in which a positive electrode, a separator, and a negative electrode are wound or laminated in an exterior member and filled with an electrolyte. A lithium-ion battery,
(A) The longitudinal direction of the structure is the X direction, the lateral direction of the structure is the Z direction, and the thickness direction of the structure is the Y direction.
(B) The outer surface along the XZ plane of the structure is the first surface and the second surface,
(C) The portion of the structure on the first surface side is the first portion, and the portion of the structure on the second surface side that is in contact with the first portion is the second portion,
(D) A side surface portion of the exterior member facing the first portion in the X direction is a first side surface portion, and a side surface portion of the exterior member facing the second portion in the X direction is a second side surface portion,
(E) When the linear expansion amount in the X direction of the first portion during charging is ΔX ₁ , and the linear expansion amount in the X direction of the second portion during charging is ΔX ₂ ,
ΔX ₁ >ΔX ₂
Further, at the time of charging, at least a part of the first portion contacts the first side surface portion of the exterior member, and the second portion does not contact the second side surface portion of the exterior member.

In the lithium ion battery according to a first aspect of the present _{disclosure, ΔX 1, ΔX 2, d} 1, d m, the relationship of the value of d ₂ is defined. Further, in the lithium-ion battery according to the second aspect of the present disclosure, the relationship between the values of ΔX ₁ and ΔX ₂ at the time of charging is defined, and at least a part of the first portion is the outer member of the exterior member. The second portion does not come into contact with the second side surface portion of the exterior member. Therefore, it is possible to provide a lithium-ion battery that is less likely to warp due to the volume change of the negative electrode active material during charging. It should be noted that the effects described in the present specification are merely examples and are not limited, and may have additional effects.

FIG. 1A is a conceptual diagram showing a cross section of a lithium ion battery of Example 1, and FIGS. 1B and 1C are conceptual diagrams showing a cross section of a modified example of the lithium ion battery of Example 1. FIG. 2 is a schematic exploded perspective view of a laminate film type lithium ion battery of Example 2. 3A is a schematic exploded perspective view of a laminate film type lithium ion battery of Example 2 in a state different from that shown in FIG. 2, and FIG. 3B is a laminate film type lithium ion of Example 2. FIG. 3B is a schematic cross-sectional view of the wound electrode body (structure) in the battery taken along the arrow AA in FIGS. 2 and 3A. FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D respectively illustrate a schematic partial cross-sectional view in which a part of the wound electrode body shown in FIG. 2 is enlarged, and a first aspect relating to the placement of an insulating material. And a schematic partial sectional view for explaining the second aspect relating to the placement of the insulating material, and a schematic partial sectional view for explaining the third aspect relating to the placement of the insulating material. FIG. FIG. 5 is a schematic sectional view of a laminate film type lithium ion battery of Example 3. FIG. 6 is a schematic exploded perspective view of an application example (battery pack: unit cell) of the lithium-ion battery of the present disclosure in Example 4. 7A is a block diagram showing a configuration of an application example (battery pack: unit cell) of the lithium ion battery of the present disclosure in Example 4 shown in FIG. 6, and FIG. 7B is a lithium ion of the present disclosure in Example 4. It is a block diagram showing the structure of an application example (battery pack: assembled battery) of a battery. 8A, 8B, and 8C are block diagrams showing the configuration of an application example (electric vehicle) of the lithium-ion battery of the present disclosure in Example 4, and an application example of the lithium-ion battery of the present disclosure in Example 4 ( FIG. 16 is a block diagram showing a configuration of a power storage system) and a block diagram showing a configuration of an application example (electric power tool) of the lithium ion battery of the present disclosure in a fourth embodiment.

Hereinafter, the present disclosure will be described based on examples with reference to the drawings, but the present disclosure is not limited to the examples, and various numerical values and materials in the examples are examples. The description will be given in the following order.
1. 1. General description of lithium-ion batteries according to first and second aspects of the present disclosure Example 1 (lithium ion battery according to first and second aspects of the present disclosure)
3. Example 2 (a modification of Example 1, which is a lithium ion battery having a structure in which a positive electrode, a separator and a negative electrode are wound)
4. Example 3 (a modification of Example 1, which is a lithium-ion battery having a structure in which a positive electrode, a separator, and a negative electrode are stacked)
5. Example 4 (Application example of the lithium-ion battery of the present disclosure)
6. Other

<Explanation of General Lithium Ion Battery According to First and Second Aspects of Present Disclosure>
In the lithium ion battery according to the first aspect of the present disclosure or the lithium ion battery according to the second aspect of the present disclosure (hereinafter, these may be collectively referred to as “lithium ion battery or the like of the present disclosure”) The Young's modulus of the exterior member is preferably 5×10 ⁸ Pa to 7×10 ⁹ Pa.

In the lithium-ion battery or the like of the present disclosure including the above-mentioned preferred forms, the exterior member has a laminated structure of a plastic material layer (fusion layer), a metal layer and a plastic material layer (surface protection layer), that is, a laminate film. It is preferable that the form is In the case of a laminate film type lithium ion battery, for example, after folding the exterior member so that the fusion layers face each other with the structure interposed therebetween, the outer peripheral edge portions of the fusion layers are fused. However, the exterior member may be one in which two laminated films are bonded together via an adhesive or the like. The fusing layer is made of, for example, a film of an olefin resin such as polyethylene, polypropylene, modified polyethylene, modified polypropylene, or a polymer thereof. The metal layer is made of, for example, aluminum foil, stainless steel foil, nickel foil, or the like. The surface protective layer is made of, for example, nylon, polyethylene terephthalate or the like. Above all, the exterior member is preferably an aluminum laminate film in which a polyethylene film, an aluminum foil, and a nylon film are laminated in this order. However, the exterior member may be a laminated film having another laminated structure, a polymer film such as polypropylene, or a metal film.

Further, in the lithium ion battery of the present disclosure including the various preferable forms described above, the electrolyte may be a gel electrolyte, but the electrolyte is not limited thereto. In the case of a lithium-ion battery using a liquid electrolyte, the negative electrode and the separator can relatively relatively slide, and the positive electrode and the separator can relatively relatively slide. There is. In such a case, the warp of the lithium ion battery due to the expansion of the negative electrode active material may be difficult to occur. On the other hand, the gel electrolyte does not require a vacuum injection process of an electrolytic solution and can adopt a continuous coating process, which is advantageous in terms of productivity when manufacturing a large-area lithium ion battery. it is conceivable that. However, in some cases, the gel electrolyte may not easily cause slippage between the negative electrode and the separator and between the separator and the positive electrode. As a result, the shape stability is improved, but the negative electrode and the positive electrode in the X direction. In some cases, the lithium ion battery may not be able to absorb the difference in strain amount and warp easily, but in the lithium ion battery and the like of the present disclosure, such a problem is unlikely to occur.

The separator separates the positive electrode and the negative electrode and prevents the short circuit of the current due to the contact between the positive electrode and the negative electrode while allowing lithium ions to pass through. In the lithium ion battery or the like of the present disclosure including the various preferable embodiments described above, the separator is, for example, a synthetic resin such as a polyolefin resin (polypropylene resin or polyethylene resin), a polyimide resin, a polytetrafluoroethylene resin, or an aromatic polyamide. A porous film made of ceramics; a glass fiber; a nonwoven fabric made of liquid crystal polyester fiber, aromatic polyamide fiber, or cellulosic fiber. Alternatively, the separator may be composed of a laminated film in which two or more kinds of porous films are laminated, or may be a separator coated with an inorganic material layer or an inorganic material-containing separator.

Examples of the shape and form of the lithium ion battery include a flat plate type laminate type (laminate film type).

In the lithium-ion battery of the present disclosure, the positive electrode active material may have a form containing lithium atoms.

In the positive electrode, a positive electrode active material layer is formed on one surface or both surfaces of the positive electrode current collector. Examples of the material forming the positive electrode current collector include conductive materials such as aluminum, nickel, and stainless steel. The positive electrode active material layer contains, as a positive electrode active material, a positive electrode material capable of inserting and extracting lithium. The positive electrode active material layer may further contain a positive electrode binder, a positive electrode conductive agent, and the like. Examples of the positive electrode material include a lithium-containing compound, and from the viewpoint of obtaining a high energy density, it is preferable to use a lithium-containing composite oxide or a lithium-containing phosphate compound. The lithium-containing composite oxide is an oxide containing lithium and one or more elements (hereinafter referred to as “other elements”, except lithium) as constituent elements, and has a layered rock salt type crystal structure or It has a spinel type crystal structure. The lithium-containing phosphate compound is a phosphate compound containing lithium and one or more elements (other elements) as constituent elements and has an olivine-type crystal structure. The positive electrode will be described in detail later.

In the negative electrode, a negative electrode active material layer is formed on one surface or both surfaces of the negative electrode current collector. Examples of the material forming the negative electrode current collector include conductive materials such as copper, nickel, and stainless steel. The negative electrode active material layer contains, as a negative electrode active material, a negative electrode material capable of inserting and extracting lithium. The negative electrode active material layer may further contain a negative electrode binder, a negative electrode conductive agent, and the like. The negative electrode binder and the negative electrode conductive agent can be the same as the positive electrode binder and the positive electrode conductive agent. The surface of the negative electrode current collector is preferably roughened from the viewpoint of improving the adhesion of the negative electrode active material layer to the negative electrode current collector based on the so-called anchor effect. In this case, at least the surface of the region of the negative electrode current collector in which the negative electrode active material layer is to be formed may be roughened. As a roughening method, for example, a method of forming fine particles by utilizing electrolytic treatment can be mentioned. The electrolytic treatment is a method of forming irregularities on the surface of the negative electrode current collector by forming fine particles on the surface of the negative electrode current collector using an electrolysis method in an electrolytic bath.

The negative electrode active material layer can be formed based on, for example, a coating method, a vapor phase method, a liquid phase method, a thermal spraying method, or a firing method (sintering method). The coating method is a method in which a negative electrode active material in the form of particles (powder) is mixed with a negative electrode binder and the like, and then the mixture is dispersed in a solvent such as an organic solvent and applied to a negative electrode current collector. The vapor phase method is a PVD method (physical vapor deposition method) such as a vacuum vapor deposition method, a sputtering method, an ion plating method, or a laser ablation method, and various CVD methods (chemical vapor deposition method) including a plasma CVD method. Is. Examples of the liquid phase method include 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 a negative electrode current collector. The firing method is, for example, a method of applying a mixture dispersed in a solvent using a coating method to a negative electrode current collector and then heat-treating the mixture at a temperature higher than the melting point of the negative electrode binder or the like, and an atmosphere firing method, A reaction firing method and a hot press firing method can be mentioned. The negative electrode will be described in detail later.

In order to prevent unintentional deposition of lithium on the negative electrode during charging, the chargeable capacity of the negative electrode material is preferably larger than the discharge capacity of the positive electrode. 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. The lithium deposited on the negative electrode is, for example, lithium metal when the electrode reactant is lithium.

When configuring a lithium ion battery of the present disclosure from the lithium ion secondary battery, as the lithium salt that constitutes the non-aqueous electrolyte suitable for use, for _{example, LiPF 6, LiClO 4, LiBF} 4, LiAsF 6, LiSbF 6, LiTaF ₆ , LiNbF ₆ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiCH ₃ SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiC(CF ₃ SO ₂ ) ₃ , LiC ₄ F ₉ SO ₃ , Li(FSO ₂ ) ₂ N , Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ ) ₃ C, LiBF ₃ (C ₂ F ₅ ), LiB(C ₂ O ₄ ) _{2 , LiB (C 6 F 5)} 4, LiPF 3 (C 2 F 5) 3, 1 / 2Li 2 B 12 F 12, Li 2 SiF 6, LiCl, LiBr, can be exemplified LiI, is limited to Not a thing. Further, as the organic solvent, cyclic carbonic acid esters such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC); chain carbonic acid such as dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), diethyl carbonate (DEC) Esters: tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1,3 dioxolane (DOL), 4-methyl-1,3 dioxolane (4-MeDOL), etc. Cyclic ether; 1,2 dimethoxyethane (DME) ), 1,2-diethoxyethane (DEE), chain ethers; γ-butyrolactone (GBL), γ-valerolactone (GVL), cyclic esters; methyl acetate, ethyl acetate, propyl acetate, methyl formate, ethyl formate, formic acid Examples thereof include chain esters such as propyl, methyl butyrate, methyl propionate, ethyl propionate, and propyl propionate. Alternatively, as the organic solvent, tetrahydropyran, 1,3 dioxane, 1,4 dioxane, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), N-methylpyrrolidinone (NMP), N- Methyl oxazolidinone (NMO), N,N'-dimethylimidazolidinone (DMI), dimethyl sulfoxide (DMSO), trimethyl phosphate (TMP), nitromethane (NM), nitroethane (NE), sulfolane (SL), acetonitrile (AN). , Glutaronitrile (GLN), adiponitrile (ADN), methoxyacetonitrile (MAN), 3-methoxypropionitrile (MPN), and diethyl ether. Alternatively, an ionic liquid can be used. As the ionic liquid, a conventionally known one can be used, and it may be selected as necessary.

In general, due to the asymmetry of the internal structure of the lithium-ion battery, the amount of expansion in the XZ plane during charging differs between the front (front) surface side and the back surface side of the lithium-ion battery. In Example 1, based on the two-dimensional stress simulation, the dimension of the outer package member made of the laminate film and the expansion of the structure due to the expansion of the negative electrode active material of the lithium ion battery caused the warp of the lithium ion battery. I verified what kind of influence it has.

A cross section of the lithium-ion battery of Example 1 is shown in the conceptual diagram of FIG. 1A. Here, the lithium-ion battery according to Example 1 is formed by housing a structure in which a positive electrode, a separator, and a negative electrode are wound or laminated in an exterior member, and is filled with an electrolyte (lithium-ion secondary battery). Is. Then, as shown in FIG. 1A, a schematic cross-sectional view along the XY plane,
(A) The longitudinal direction of the structure 10 is the X direction, the lateral direction of the structure 10 is the Z direction, and the thickness direction of the structure 10 is the Y direction.
(B) The outer surfaces of the structure 10 along the XZ plane (that is, parallel to or substantially parallel to the XZ plane) are the first surface 10A and the second surface 10B,
(C) A portion of the structure 10 on the first surface side is a first portion 11, and a portion of the structure 10 on the second surface side that is in contact with the first portion 11 is a second portion 12.
(D) The side surface portion of the exterior member 20 facing the first portion 11 in the X direction is the first side surface portion 21, and the side surface portion of the exterior member 20 facing the second portion 12 in the X direction is the second side surface portion. Part 22.

And moreover,
d ₁ : The minimum value of the gap located between the first portion 11 and the first side surface portion 21 d ₂ : The maximum value of the gap located between the second portion 12 and the second side surface portion 22 d _m : When the boundary between the first portion 11 and the second portion 12 is the boundary 13, this boundary 13
And the value of the gap located between the side surface portion 23 and the boundary 13 of the exterior member 20 facing in the X direction (that is, between the boundary 23 and the boundary 13 of the first side surface portion 21 and the second side surface portion 21). Positioned gap) value ΔX ₁ : linear expansion amount in the X direction of the first portion 11 during charging ΔX ₂ : linear expansion amount in the X direction of the second portion 12 during charging.

Here, for simplification, in the lithium-ion battery as a model, it is assumed that the first portion 11 and the second portion 12 of the structure 10 are integrated. The thickness of the first portion 11 of the structure 10 (thickness in the Y direction) is 1.0 mm, and the thickness of the second portion 12 of the structure 10 (thickness in the Y direction) is 1.0 mm. To do. It is also assumed that the first portion 11 and the second portion 12 are symmetrical with respect to the boundary 13. Furthermore, the length of the structure 10 in the longitudinal direction (X direction) is set to 20.0 mm. Further, the thickness of the exterior member 20 made of a laminated film is 0.1 mm, and the first side surface portion 21 and the second side surface portion 22 of the exterior member 20 are on the same plane. The angle θ formed with the surface 10B is 85 degrees. That is,
d ₁ <d _m <d ₂
Are satisfied. Furthermore, the expansion rates in the X and Y directions of the first portion 11 during charging are set to 1.1% and 6.0%, and the expansion rates in the X and Y directions of the second portion 12 are set to 1.0. % And 6.0% are assumed. Further, the Young's modulus of the first portion 11 and the second portion 12 is 2×10 ⁸ Pa, the Poisson's ratio is 0.3, the Young's modulus of the exterior member 20 made of a laminated film is 4×10 ⁹ Pa, and the Poisson's ratio is Set to 0.3.

Then, under the above conditions, simulations were performed in four cases shown in Table 1 below to see how the warp amount of the lithium ion battery changes. In the model described above, the amounts of expansion ΔX ₁ and ΔX _{2 in} the X direction of the first portion 11 and the second portion 12 during charging are as follows.
ΔX ₁ =20.0×1.1×10 ^-2 =0.22 mm
ΔX ₂ =20.0×1.0×10 ⁻² =0.20 mm
That is,
ΔX ₁ >ΔX ₂
Is.

The simulation results are shown in Table 2 below. In order to suppress the warpage of the entire lithium ion battery due to the binding force of the laminate film with respect to the lithium ion battery, Case 3 is most preferable. That is,
_{d 1 <ΔX 1 <d m} <d 2
When the above condition was satisfied, the warp of the lithium ion battery could be minimized. In other words, when charging, ΔX ₁ >ΔX ₂ , and at least part of the first portion 11 is in contact with the first side surface portion 21 of the exterior member 20, and the second portion 12 is of the exterior member 20. When it did not contact the second side surface portion 22, the warp of the lithium ion battery could be minimized.

[Table 1]

[Table 2]

In case 1, since ΔX ₁ >ΔX ₂ and there is no exterior member, there is no restriction on the elongation of the structure 10, and the structure 10 is largely warped to the first portion side.

In the case 2 (the length of the exterior member 20 in the X direction is 20.6 mm), the first portion 11 does not collide (interfere) with the first side surface portion 21, and the second portion 12 collides with the second side surface portion 22. Do not (interfere). That is, there is no restriction on the extension of the structure 10 in the X direction other than the contact between the first surface 10A, the second surface 10B and the exterior member 20, and the extension amount of the first portion 11 in the X direction is not limited. Since the amount of expansion in the X direction of the second portion 12 is larger, the protrusion was warped to the first portion side.

On the other hand, in the case 3 (the length of the exterior member 20 in the X direction is 20.5 mm), the first portion 11 collides (interferes) with the first side surface portion 21, but the second portion 12 has the second side surface portion 22. Do not collide (interfere) with. That is, the extension of the structure 10 in the X direction was restricted by the exterior member 20 with respect to the first portion 11, so that the structure 10 was convexly warped toward the second portion, but the amount of warpage was the smallest.

Further, in the case 4 (the length of the exterior member 20 in the X direction is 20.4 mm), the first portion 11 collides (interferes) with the first side surface portion 21, and the second portion 12 has the second side surface portion 22. Clash (interfere) with. That is, since the extension of the structure 10 in the X direction is more restricted than that of the case 3, the structure 10 was largely warped to the second portion side rather than the case 3.

By the way, attempts to suppress the warpage of the entire lithium-ion battery have not been made so far. The reason for this is that the needs for thin and large format lithium ion batteries have been recently increased, and the development of highly reliable and safe gel electrolyte has been advanced in recent years. The thinner and larger the film, the smaller the second moment of area, and therefore the lithium-ion battery is more likely to bend when trying to bend with the same force. Further, it is considered that the advantage of the gel electrolyte having high shape stability is that the adhesiveness of each layer is increased, and the difference in elongation in the X direction cannot be absorbed due to slippage, so that the gel tends to warp.

However, in the lithium ion battery of the present _{disclosure, ΔX 1, ΔX 2, d} 1, d m, to the relationship of the value of d ₂ is defined Alternatively, during charging,, [Delta] X _1, the [Delta] X ₂ A value relationship is defined, and at least a part of the first portion contacts the first side surface portion of the exterior member, and the second portion does not contact the second side surface portion of the exterior member. That is, in a lithium-ion battery, the gap (space) located between the exterior structure and the portion of the structure where the electrode stretches greatly in the X direction during charging is narrowed so that the structure does not expand much in the X direction. By widening the gap (space) between the exterior member and the exterior member interference (restraint force) to suppress the expansion of the entire structure, the front and back sides of the lithium-ion battery that cause warpage can be suppressed. Suppresses the difference in the amount of elongation. That is, by restricting the extension of the structure in the X direction by the side surface portion of the exterior member, the difference in strain amount between the front surface side and the back surface side of the structure is reduced, and the warpage of the entire lithium ion battery can be suppressed. Therefore, it is possible to provide a lithium-ion battery that is less likely to warp due to a change in the volume of the negative electrode active material during charging. Moreover, since the amount of warpage can be controlled by the shape of the exterior member and the material forming the exterior member without changing the design of the lithium-ion battery, it is possible to flexibly deal with the warpage.

In the example shown in FIG. 1A, the first side surface portion 21 and the second side surface portion 22 of the exterior member 20 are on the same plane, but the shapes of the first side surface portion 21 and the second side surface portion 22 are as follows. The shape is not limited. As shown in FIG. 1B or 1C, the cross-sectional shape of the side surface portion of the exterior member 20 may be a kind of staircase. In the example shown in FIG. 1B, d ₁ =d _m , and in the example shown in FIG. 1C, d _m =d ₂ . That is, it is a regulation of the lithium ion battery according to the first aspect of the present disclosure,
_{d 1 <ΔX 1 <d m} <d 2
Not satisfied. However, the provisions of the lithium-ion battery according to the second aspect of the present disclosure,
(Regulation-A) ΔX ₁ >ΔX ₂
And, and
(Regulation-B) At the time of charging, at least a part of the first portion contacts the first side surface portion of the exterior member, and the second portion does not contact the second side surface portion of the exterior member.
It has been found that the warpage of the entire lithium ion battery can be suppressed as long as the above conditions are satisfied. In other words, even if the cross-sectional shape of the side surface portion of the exterior member 20 includes a convex shape or a concave cross-sectional shape of the side surface portion of the exterior member 20, any of the above It has been found that the warpage of the entire lithium ion battery can be suppressed as long as -A) and (regulation -B) are satisfied.

In the case of a lithium ion battery, the structure expands during charging and contracts during discharging. Then, during charging and discharging, expansion and contraction are repeated. Therefore, the values of d ₁ , d ₂ , d _m , ΔX ₁ , and ΔX ₂ can be obtained by disassembling (disassembling) the lithium ion battery at the time of completion of charging and at the time of discharging.

The second embodiment is a modification of the first embodiment. The lithium ion battery of Example 2 is composed of a flat plate type laminate film type lithium ion battery (specifically, a lithium ion secondary battery), and a positive electrode, a separator and a negative electrode are wound. A schematic exploded perspective view of the lithium-ion battery of Example 2 is shown in FIGS. 2 and 3A, and a schematic enlargement of the wound electrode body (structure) shown in FIGS. 2 and 3A along arrow AA. A cross-sectional view (a schematic enlarged cross-sectional view along the YZ plane) is shown in FIG. 3B. Further, FIG. 4A shows a schematic partial cross-sectional view (a schematic partial cross-sectional view along the XY plane) in which a part of the wound electrode body shown in FIG. 3B is enlarged.

In the lithium-ion battery of Example 2, the wound electrode body 30 is housed inside the exterior member 40 made of a laminated film. The wound electrode body 30 can be manufactured by laminating the positive electrode 33 and the negative electrode 34 with the separator 35 and the electrolyte layer 36 in between, and then winding the laminated body. The positive electrode lead 31 is attached to the positive electrode 33, and the negative electrode lead 32 is attached to the negative electrode 34. The outermost peripheral portion of the wound electrode body 30 is protected by a protective tape 37.

In such a wound electrode body 30, the laminate is wound around the winding center. In FIG. 3B, the XZ plane passing through the winding center is indicated by CC, and the XZ plane passing through the winding center corresponds to the boundary between the first portion and the second portion in the first embodiment. Then, in FIG. 3B, the winding portion located above the XZ plane indicated by CC (corresponding to the first portion in Example 1) and the winding portion located below the XZ plane indicated by CC. The portion (corresponding to the second portion in the first embodiment) has a different number of windings (number of windings), and the attachment positions of the positive electrode lead 31 and the negative electrode lead 32 are different. That is, it is caused by the asymmetry in the thickness direction (Y direction) of the wound electrode body (structure) 30 that is a constituent member inside the lithium-ion battery (the asymmetry of the number of windings, the asymmetry of the mounting position of the lead). The difference in the amount of expansion causes a bending moment. However, even in Example _{2, ΔX 1, ΔX 2,} d 1, d m, by defining the relationship between the value of d _2, or alternatively, during charging, [Delta] X _1, the relationship between the value of [Delta] X ₂ By defining at least part of the first portion is in contact with the first side surface portion of the exterior member and the second portion is not in contact with the second side surface portion of the exterior member, the negative electrode during charging It is possible to provide a lithium-ion battery that is less likely to warp due to a change in volume of the active material.

The positive electrode lead 31 and the negative electrode lead 32 project in the same direction from the inside of the exterior member 40 to the outside. The positive electrode lead 31 is made of a conductive material such as aluminum. The negative electrode lead 32 is made of a conductive material such as copper, nickel, and stainless steel. These conductive materials have, for example, a thin plate shape or a mesh shape.

The exterior member 40 is a single film that can be folded in the direction of the arrow R shown in FIG. 2, and a recess (emboss) for accommodating the wound electrode body 30 is provided in a part of the exterior member 40. ing. The exterior member 40 is, specifically, a moisture-resistant aluminum sheet in which a nylon film (thickness 30 μm), an aluminum foil (thickness 40 μm), and an unstretched polypropylene film (thickness 30 μm) are laminated in this order from the outside. It consists of a laminated film (total thickness 100 μm).

Adhesive films 41 are inserted between the exterior member 40 and the positive electrode lead 31 and between the exterior member 40 and the negative electrode lead 32 to prevent outside air from entering. The adhesion film 41 is made of a material having adhesion to the positive electrode lead 31 and the negative electrode lead 32, for example, a polyolefin resin or the like, more specifically, a polyolefin resin such as polyethylene, polypropylene, modified polyethylene or modified polypropylene.

As shown in FIGS. 3B and 4A, the positive electrode 33 has a positive electrode active material layer 33B on one surface or both surfaces of the positive electrode current collector 33A. Further, the negative electrode 34 has a negative electrode active material layer 34B on one surface or both surfaces of the negative electrode current collector 34A.

When producing the positive electrode 33, first, 91 parts by mass of the positive electrode active material <LiCoO ₂ >, 3 parts by mass of the positive electrode binder (polyvinylidene fluoride), and 6 parts by mass of the positive electrode conductive material (graphite, graphite) are mixed. As a positive electrode mixture. Then, the positive electrode mixture is mixed with an organic solvent (N-methyl-2-pyrrolidone) to obtain a paste-like positive electrode mixture slurry. Next, the positive electrode mixture slurry is applied to both surfaces of the strip-shaped positive electrode current collector 33A (aluminum foil having a thickness of 12 μm) using a coating device, and then the positive electrode mixture slurry is dried to form the positive electrode active material layer 33B. To do. Then, the positive electrode active material layer 33B is compression-molded using a roll press.

When obtaining Li _1.15 (Mn _0.65 Ni _0.22 Co _0.13 ) _0.85 O ₂ as the positive electrode active material, first, nickel sulfate <NiSO ₄ >, cobalt sulfate <CoSO ₄ > and manganese sulfate <MnSO ₄ > are mixed. Then, the mixture is dispersed in water to prepare an aqueous solution. Next, while sufficiently stirring the aqueous solution, sodium hydroxide <NaOH> is added to the aqueous solution to obtain a coprecipitate (manganese-nickel-cobalt composite coprecipitated hydroxide). Then, the coprecipitate is washed with water and dried, and then lithium hydroxide monohydrate salt is added to the coprecipitate to obtain a precursor. Then, the above positive electrode active material can be obtained by baking the precursor in the air (800° C.×10 hours).

When LiNi _0.5 Mn _1.50 O ₄ is obtained as the positive electrode active material, first, lithium carbonate <Li ₂ CO ₃ >, manganese oxide <MnO ₂ >, and nickel oxide <NiO> are weighed and a ball mill is used. And mix the weighings. In this case, the mixing ratio (molar ratio) of the main elements is Ni:Mn=25:75. Then, the mixture is baked in the air (800° C.×10 hours) and then cooled. Next, after re-mixing the fired product using a ball mill, the fired product is re-fired (700° C.×10 hours) in the air, whereby the positive electrode active material can be obtained.

Alternatively, a compound represented by the following formula (A) or a LiNiMnO-based material can be used as the positive electrode active material.

Li _1+a (Mn _b Co _c Ni _1-bc ) _1-a M ⁰ _d O _2-e (A)
Here, “M ⁰ ”is at least one kind of elements belonging to Groups 2 to 15 in the long-periodic periodic table (excluding manganese, cobalt, and nickel), and 0<a<0.25,0 .3≦b<0.7, 0≦c<1-b, 0≦d≦1, 0≦e≦1 are satisfied. Specifically, Li _1.15 (Mn _0.65 Ni _0.22 Co _0.13 ) _0.85 O ₂ can be exemplified. Further, as the LiNiMnO-based material, specifically, LiNi _0.5 Mn _1.50 O ₄ can be exemplified.

When manufacturing the negative electrode 34, first, 97 parts by mass of the negative electrode active material (graphite, graphite) and 3 parts by mass of the negative electrode binder (polyvinylidene fluoride) are mixed to obtain a negative electrode mixture. The average particle diameter d ₅₀ of graphite is set to 20 μm. Next, the negative electrode mixture is mixed with an organic solvent (N-methyl-2-pyrrolidone) to obtain a paste-like negative electrode mixture slurry. Then, the negative electrode mixture slurry is applied to both surfaces of the strip-shaped negative electrode current collector 34A (copper foil having a thickness of 15 μm) using a coating device, and then the negative electrode mixture slurry is dried to form the negative electrode active material layer 34B. To do. Then, the negative electrode active material layer 34B is compression-molded using a roll pressing machine.

Alternatively, the negative electrode active material (silicon) and the precursor of the negative electrode binder (polyamic acid) can be mixed to form a negative electrode mixture. In this case, the mixing ratio is a dry mass ratio of silicon:polyamic acid=80:20. The average particle size d ₅₀ of silicon is 1 μm. N-methyl-2-pyrrolidone and N,N-dimethylacetamide are used as the solvent for the polyamic acid. After compression molding, the negative electrode mixture slurry is heated in a vacuum atmosphere under the condition of 400° C.×12 hours. As a result, polyimide, which is the negative electrode binder, is formed.

The separator 35 is made of a microporous polyethylene film having a thickness of 20 μm. The wound electrode body 30 is impregnated with a non-aqueous electrolyte solution which is a gel electrolyte.

The electrolyte layer 36 contains a non-aqueous electrolyte solution and a holding polymer compound, and the non-aqueous electrolyte solution is held by the holding polymer compound. The electrolyte layer 36 is a gel electrolyte, which has a high ionic conductivity (for example, 1 mS/cm or more at room temperature) and prevents leakage of the non-aqueous electrolyte solution. The electrolyte layer 36 may further include other materials such as additives.

Tables 3 and 4 below can be exemplified as the composition of the non-aqueous electrolyte solution.

[Table 3]
Organic solvent: EC/PC Mass ratio 1/1
Lithium salt constituting the non-aqueous electrolyte: LiPF ₆ 1.0 mol/organic solvent 1 kg
Other additives: Vinylene carbonate (VC) 1% by mass

[Table 4]
Organic solvent: EC/DMC/FEC
2.7/6.3/1.0 by mass ratio
Lithium salt constituting the non-aqueous electrolyte: LiPF ₆ 1.0 mol/organic solvent 1 kg

As the polymer compound for holding, specifically, polyacrylonitrile, polyvinylidene fluoride, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, polysiloxane, polyvinyl fluoride (PVF), poly Chlorotrifluoroethylene (PCTFE), perfluoroalkoxy fluororesin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoro Examples include ethylene copolymer (ECTFE), polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene, polycarbonate, polyethylene oxide, and vinyl chloride. be able to. These may be used alone or in combination. Further, the retaining polymer compound may be a copolymer. As the copolymer, specifically, a copolymer of vinylidene fluoride and hexafluoropyrene can be exemplified. Among them, from the viewpoint of electrochemical stability, polyvinylidene fluoride is a homopolymer. Is preferable, and a copolymer of vinylidene fluoride and hexafluoropyrene is preferable as the copolymer. Further, as the filler, Al ₂ O ₃ , SiO ₂ , TiO ₂ , BN (a compound having high heat resistance such as boronitride) may be contained.

When the non-aqueous electrolyte solution is prepared, the first compound, the second compound, the third compound and other materials are mixed and stirred, which will be described in detail later. As the first compound, bisfluorosulfonylimide lithium <LiFSI> or bistrifluoromethylsulfonylimide lithium <LiTFSI> is used. Further, as the second compound, acetonitrile (AN), propionitrile (PN) or butyronitrile (BN) which is a non-oxygen containing mononitrile compound, or methoxyacetonitrile (MAN) which is an oxygen containing mononitrile compound is used. Further, as the third compound, vinylene carbonate (VC), vinyl ethylene carbonate (VEC) or methylene ethylene carbonate (MEC), which are unsaturated cyclic carbonic acid esters, or 4-fluoro-1,3 which is a halogenated carbonic acid ester, is used. -Using dioxolan-2-one (FEC) or bis(fluoromethyl)carbonate (DFDMC), or succinonitrile (SN), which is a polynitrile compound. Further, as other materials, ethylene carbonate (EC) which is a cyclic carbonic acid ester, dimethyl carbonate (DMC) which is a chain carbonic acid ester, lithium hexafluorophosphate <LiPF ₆ > which is an electrolyte salt, and tetrafluoroborate. Lithium acid <LiBF ₄ > is used.

In the electrolyte layer 36 that is a gel electrolyte, the solvent of the non-aqueous electrolyte solution is a broad concept including not only liquid materials but also materials having ion conductivity capable of dissociating electrolyte salts. .. Therefore, when a polymer compound having ion conductivity is used, the polymer compound is also included in the solvent. Instead of the gel electrolyte layer 36, a non-aqueous electrolyte solution may be used as it is. In this case, the non-aqueous electrolyte solution is impregnated in the wound electrode body 30.

Specifically, when forming the electrolyte layer 36, first, a non-aqueous electrolyte solution is prepared. Then, the non-aqueous electrolyte solution, the retaining polymer compound, and the organic solvent (dimethyl carbonate) are mixed to prepare a sol-like precursor solution. As the polymer compound for holding, a copolymer of hexafluoropropylene and vinylidene fluoride (copolymerization amount of hexafluoropropylene=6.9% by mass) is used. Then, after applying the precursor solution to the positive electrode 33 and the negative electrode 34, the precursor solution is dried to form a gel electrolyte layer 36.

An insulating material may be provided in any of the regions (interactive material regions) between the positive electrode active material contained in the positive electrode 33 and the negative electrode active material contained in the negative electrode 34. The place where the insulating material is arranged is not particularly limited as long as it is in any of the regions between the active materials. That is, the insulating material may be present in the positive electrode 33 (positive electrode active material layer 33B) or the negative electrode 34 (negative electrode active material layer 34B), or the positive electrode 33 and the negative electrode 34. May exist between and. As an example, with respect to the place where the insulating material is arranged, for example, three modes can be mentioned as described below.

In the first aspect, as shown in FIG. 4B, the positive electrode active material layer 33B includes the particulate positive electrode active material 211. Then, a layer containing an insulating material (active material insulating layer 212 which is a first insulating layer) is formed on the surface of the positive electrode active material 211. The active material insulating layer 212 may cover only a part of the surface of the positive electrode active material 211 or may cover the entire surface thereof. When the active material insulating layer 212 covers a part of the surface of the positive electrode active material 211, there may be a plurality of active material insulating layers 212 separated from each other. The active material insulating layer 212 may be a single layer or a multilayer.

The active material insulating layer 212 is made of an inorganic insulating material such as insulating ceramics, or is made of an organic insulating material such as an insulating polymer compound, or is made of an inorganic insulating material and an organic insulating material. .. Specific examples of insulating ceramics include aluminum oxide <Al ₂ O ₃ >, silicon oxide <SiO ₂ >, magnesium oxide <MgO>, titanium oxide <TiO ₂ >, and zirconium oxide <ZrO ₂ >. Yes, LiNbO ₃ , LIPON<Li _3+y PO _4-x N _x , where 0.5≦x≦1, −0.3<y<0.3>, LISION (Lithium-Super-Ion-CONductor) ), Thio-LISICON (for example, Li _3.25 Ge _0.25 P _0.75 S ₄ ), Li ₂ S, Li ₂ S-P ₂ S ₅ , Li ₂ S-SiS ₂ , Li ₂ S-GeS ₂ , Li _{2. S-B 2 S 5, Li} 2 S-Al 2 S 5 and _{Li 2 O-Al 2 O 3} -TiO 2 -P 2 O 5 (LATP) may be exemplified. The insulating polymer compound may be similar to the material constituting the binder, but among them, a homopolymer of vinylidene fluoride (for example, polyvinylidene fluoride) or a copolymer (for example, vinylidene fluoride and A copolymer with hexafluoropropylene) is preferred. This is because it has excellent physical strength and is electrochemically stable. The monomer copolymerized with vinylidene fluoride may be a monomer other than hexafluoropropylene.

The procedure for forming the active material insulating layer 212 on the surface of the positive electrode active material 211 is as follows, for example. The case where the active material insulating layer 212 contains insulating ceramics will be described as an example. When forming the active material insulating layer 212, particles of the positive electrode active material 211 and particles of insulating ceramics are mixed. Then, the mixture is crushed and mixed by using a ball mill, a jet mill, a crusher, a fine powder crusher or the like. In this case, a dispersion medium such as water or a solvent may be added to the mixture. As a result, the insulating ceramics are deposited on the surface of the positive electrode active material 211, so that the active material insulating layer 212 is formed. Alternatively, the insulating ceramics may be deposited by using a mechanochemical treatment such as mechanofusion. In addition, insulating ceramics may be deposited on the surface of the positive electrode active material 211 based on a PVD method such as a sputtering method or a CVD method. Alternatively, a sol-gel method may be used. In this case, after the positive electrode active material 211 is immersed in an alkoxide solution containing aluminum, silicon, etc., and a precursor layer is deposited on the surface of the positive electrode active material 211. The precursor layer may be fired.

In the second aspect, as shown in FIG. 4C, a layer containing an insulating material (a negative electrode insulating layer 213 that is a second insulating layer) is provided on the surface of the negative electrode 34 (negative electrode active material layer 34B). The details of the covering state, the layer structure, the constituent materials, and the like of the negative electrode insulating layer 213 are the same as those of the above active material insulating layer 212. In this case, in particular, when the negative electrode insulating layer 213 contains the insulating polymer compound, the adhesion of the separator 35 to the negative electrode 34 is improved, so that the wound electrode body 30 is less likely to be distorted. Then, this suppresses the decomposition reaction of the non-aqueous electrolytic solution and also suppresses the leakage of the non-aqueous electrolytic solution with which the separator 35 is impregnated. Therefore, even if charging and discharging are repeated, the resistance hardly increases and the lithium-ion battery hardly swells.

The procedure for forming the negative electrode insulating layer 213 on the surface of the negative electrode active material layer 34B is as follows, for example. The case where the negative electrode insulating layer 213 contains an insulating ceramic and an insulating polymer compound will be described as an example. When forming the negative electrode insulating layer 213, particles of the insulating ceramics, the insulating polymer compound, and a solvent such as N-methyl-2-pyrrolidone are mixed to disperse the particles of the insulating ceramics in the solvent. At the same time, the insulating polymer compound is dissolved in the solvent. Then, after immersing the negative electrode 34 in the mixed liquid, the negative electrode 34 is taken out from the mixed liquid and dried. As a result, the solvent in the mixed liquid is volatilized and the insulating polymer compound is formed into a film, so that the negative electrode insulating layer 213 is formed on the surface of the negative electrode active material layer 34B. In this case, the thickness of the negative electrode insulating layer 213 may be adjusted by pressing the negative electrode 34 before drying. Instead of immersing the negative electrode 34 in the mixed liquid, the mixed liquid may be applied to the surface of the negative electrode active material layer 34B.

Alternatively, when forming the negative electrode insulating layer 213, first, 80 parts by mass of the powdery insulating ceramics and 20 parts by mass of the insulating polymer compound (polyvinylidene fluoride) are mixed, and then the mixture is dispersed in an organic solvent. Then, a treatment solution is prepared. Aluminum oxide <Al ₂ O ₃ > and silicon oxide <SiO ₂ > are used as the powdery insulating ceramics. The average particle diameter d ₅₀ of the insulating ceramics is 0.5 μm. Then, after immersing the negative electrode 34 in the treatment solution, the thickness of the treatment solution supplied to the surface of the negative electrode 34 is adjusted using a gravure roller. Then, the treatment solution is dried at 120° C. using a dryer to volatilize the organic solvent in the treatment solution. Thus, the negative electrode insulating layer 213 can be formed on the surface of the negative electrode active material layer 34B. The thickness of the negative electrode insulating layer 213 is, for example, 5 μm.

In the third aspect, as shown in FIG. 4D, a layer containing an insulating material (a separator insulating layer 214 that is a third insulating layer) is provided on the surface of the separator 35. The separator insulating layer 214 may be provided on the surface of the separator 35 facing the positive electrode 33, may be provided on the surface facing the negative electrode 34, or may be provided on both surfaces. The details of the covering state, layer structure, constituent materials, and the like of the separator insulating layer 214 are the same as those of the active material insulating layer 212 described above. In this case, in particular, when the separator insulating layer 214 contains an insulating polymer compound, the adhesion of the separator 35 to the positive electrode 33 and the negative electrode 34 is improved, so that the negative electrode insulating layer 213 contains a polymer compound. The same advantages are obtained as if they were included.

When the separator insulating layer 214 is formed, first, the treatment solution is prepared according to the same procedure as the case of preparing the negative electrode insulating layer 213. Then, the separator 35 is immersed in the treatment solution. Then, after pulling up the separator 35 from the treatment solution, the separator 35 is washed with water. Then, the treatment solution supplied to the surface of the separator 35 is dried with hot air at 80° C. to volatilize the organic solvent in the treatment solution. Thus, the separator insulating layers 214 can be formed on both surfaces of the separator 35. The thickness (total thickness) of the separator insulating layers 214 formed on both surfaces of the separator 35 is, for example, 4.5 μm.

The procedure for forming the separator insulating layer 214 on the surface of the separator 35 is the same as the procedure for forming the negative electrode insulating layer 213 described above. When the separator insulating layer 214 contains only the insulating polymer compound, the same procedure as that when the separator insulating layer 214 contains the insulating ceramics and the insulating polymer compound except that the particles of the insulating ceramics are not used. Can be used.

By disposing the insulating material in any of the regions between the active materials, it is possible to achieve both battery characteristics and safety. That is, when the insulating material is arranged in the region between the active materials, abnormalities such as thermal runaway are less likely to occur inside the lithium ion battery, so that the safety is improved. Moreover, when the non-aqueous electrolyte solution contains the first compound (described later), the surface state of the insulating material is optimized due to the reaction with the first compound, and thus the insulating property in the inter-active material region is improved. Even if the material is present, the lithium ions easily move smoothly, so that the battery characteristics are secured. Therefore, safety is improved while ensuring battery characteristics.

The mechanism by which the surface state of the insulating material is optimized is considered to be as follows, for example. That is, when the insulating material contains insulating ceramics such as aluminum oxide, lithium ions tend to be difficult to move due to the hydroxyl group <-OH> existing on the particle surface of the insulating material. However, when the first compound (described later) is contained in the non-aqueous electrolyte, the first compound reacts with the insulating material, so that the surface of the insulating material is a film that does not easily inhibit the movement of lithium ions. Is formed. In this case, for example, the first compound contains a SO ₂ -F bond, SO ₂ -F bond and because the hydroxyl group and is _{reacted, F-SO 2 -N-SO} 2 on the surface of the particles of the ceramic -O- A good film with bonds is formed. Then, by this coating, the surface state of the ceramic is modified so that it is difficult to inhibit the movement of lithium ions.

The lithium ion battery provided with the gel electrolyte layer 36 can be manufactured based on, for example, the following three types of procedures. In the following description, the procedure for forming the insulating layers 212, 213, 214 will be omitted.

In the first procedure, first, the positive electrode active material layers 33B are formed on both surfaces of the positive electrode current collector 33A, and the negative electrode active material layers 34B are formed on both surfaces of the negative electrode current collector 34A. On the other hand, a non-aqueous electrolyte solution, a holding polymer compound and an organic solvent are mixed to prepare a sol-like precursor solution. Then, after applying the precursor solution to the positive electrode 33 and the negative electrode 34, the precursor solution is dried to form the gel electrolyte layer 36. Then, the positive electrode lead 31 is attached to the positive electrode current collector 33A and the negative electrode lead 32 is attached to the negative electrode current collector 34A by using a welding method or the like. Next, the positive electrode 33 and the negative electrode 34 are laminated via a separator 35 made of a microporous prepropylene film having a thickness of 25 μm and wound to form a wound electrode body 30, and then a protective tape is provided on the outermost peripheral portion. Paste 37. After that, after folding the exterior member 40 so as to sandwich the wound electrode body 30, the outer peripheral edge portions of the exterior member 40 are adhered to each other using a heat fusion method or the like, and the wound electrode body is provided inside the exterior member 40. Enclose 30. An adhesion film (50 μm thick acid-modified propylene film) 41 is inserted between the positive electrode lead 31 and the negative electrode lead 32 and the exterior member 40.

Alternatively, in the second procedure, first, the positive electrode 33 and the negative electrode 34 are manufactured. Then, the positive electrode lead 31 is attached to the positive electrode 33, and the negative electrode lead 32 is attached to the negative electrode 34. After that, the positive electrode 33 and the negative electrode 34 are laminated via the separator 35 and wound to form a wound body that is a precursor of the wound electrode body 30, and then the protective tape 37 is provided on the outermost peripheral portion of the wound body. Paste. Next, after folding the exterior member 40 so as to sandwich the wound body, the remaining outer peripheral edge portion excluding the outer peripheral edge portion of one side of the exterior member 40 is adhered by a heat fusion method or the like to form a bag shape. The wound body is housed inside the exterior member 40. On the other hand, a composition for electrolyte is prepared by mixing a non-aqueous electrolyte solution, a monomer which is a raw material of a polymer compound, a polymerization initiator and, if necessary, other materials such as a polymerization inhibitor. Then, after injecting the composition for electrolyte into the inside of the bag-shaped exterior member 40, the exterior member 40 is sealed by a heat fusion method or the like. Then, the monomer is thermally polymerized to form a polymer compound. As a result, the gel electrolyte layer 36 is formed.

Alternatively, in the third procedure, a wound body is produced and a bag-shaped exterior member is manufactured in the same manner as in the second procedure except that the separator 35 having both surfaces coated with the polymer compound is used. Store inside 40. The polymer compound applied to the separator 35 is, for example, a polymer containing vinylidene fluoride as a component (a homopolymer, a copolymer, or a multicomponent copolymer). Specifically, polyvinylidene fluoride, a binary copolymer containing vinylidene fluoride and hexafluoropropylene as a component, and a ternary copolymer containing vinylidene fluoride, hexafluoropropylene and chlorotrifluoroethylene as a component Such as coalescing. You may use another 1 type, or 2 or more types of high molecular compounds with a polymer which uses vinylidene fluoride as a component. After that, a non-aqueous electrolyte solution is prepared and injected into the interior of the exterior member 40, and then the opening of the exterior member 40 is sealed using a heat fusion method or the like. Next, the exterior member 40 is heated while applying a load to bring the separator 35 into close contact with the positive electrode 33 and the negative electrode 34 via the polymer compound. As a result, the polymer compound is impregnated with the non-aqueous electrolytic solution, and the polymer compound is gelated to form the electrolyte layer 36.

In the third procedure, the swelling of the lithium ion battery is suppressed more than in the first procedure. Further, in the third procedure, as compared with the second procedure, the solvent and the monomer or the like as the raw material of the polymer compound hardly remain in the electrolyte layer 36, so that the polymer compound formation process is well controlled. It Therefore, the positive electrode 33, the negative electrode 34, the separator 35, and the electrolyte layer 36 are sufficiently adhered.

The lithium-ion battery of Example 2 operates as follows, for example. That is, when lithium ions are released from the positive electrode 33 during charging, the lithium ions are occluded in the negative electrode 34 via the non-aqueous electrolyte solution. On the other hand, during discharge, when lithium ions are released from the negative electrode 34, the lithium ions are occluded in the positive electrode 33 via the non-aqueous electrolyte solution. The lithium ion battery has, for example, an open circuit voltage (battery voltage) of 4.2 V to 6.0 V, preferably 4.25 V to 6.0 V, and more preferably 4.3 V to 4 V when fully charged. It is preferably designed to be 0.55 volts. In this case, compared with the case where the open circuit voltage at full charge is designed to be 4.2 V, even if the same type of positive electrode active material is used, the amount of released lithium per unit mass is large. Become. In this way, the amount of the positive electrode active material and the amount of the negative electrode active material are adjusted, and the lithium ion battery is designed so that the open circuit voltage (battery voltage) at the time of full charge becomes a predetermined voltage (upper limit voltage). Thus, a high energy density can be obtained.

The third embodiment is also a modification of the first embodiment. The lithium-ion battery of Example 3 is composed of a flat plate-type laminate film-type lithium-ion battery (specifically, a lithium-ion secondary battery), in which a positive electrode, a separator and a negative electrode are laminated. A schematic cross-sectional view (a schematic partial cross-sectional view along the XY plane) of the lithium-ion battery of Example 3 is shown in FIG.

Even in the lithium-ion battery of Example 3, the laminated electrode body 50 is housed inside the exterior member 58 made of a laminated film. The laminated electrode body 50 can be manufactured by laminating the positive electrode 53 and the negative electrode 54 via the separator 55 and the electrolyte layer (not shown). The positive electrode 53 is composed of a positive electrode current collector 53A and a positive electrode active material layer 53B, and the positive electrode active material layer 53B is formed on both surfaces of the positive electrode current collector 53A. The negative electrode 54 includes a negative electrode current collector 54A and a negative electrode active material layer 54B, and the negative electrode active material layer 54B is formed on both surfaces of the negative electrode current collector 54A. In the illustrated example, from the upper side to the lower side of the drawing, negative electrode current collector 54A/negative electrode active material layer 54B/separator 55/positive electrode active material layer 53B/positive electrode current collector 53A/positive electrode active material layer 53B/ Separator 55/negative electrode active material layer 54B/negative electrode current collector 54A/negative electrode active material layer 54B/separator 55/positive electrode active material layer 53B/positive electrode current collector 53A/positive electrode active material layer 53B/separator 55. It is stacked. In the illustrated example, six pairs of positive electrode 53/separator 55/negative electrode 54 are stacked. A positive electrode lead (not shown) is attached to each of the positive electrodes 53, and a negative electrode lead (not shown) is attached to the negative electrodes 54. The plurality of positive electrode leads are combined into one positive electrode output terminal portion (not shown). The plurality of negative electrode leads are combined into one negative electrode output terminal portion (not shown).

In such a laminated electrode body 50, an XZ plane passing through the center of the laminated electrode body 50 in the thickness direction is indicated by AA in FIG. 5, and the XZ plane passing through this lamination center is the first embodiment. Corresponds to the boundary between the first part and the second part. Then, in FIG. 5, a laminated portion located above the XZ plane indicated by AA (corresponding to the first portion in Example 1) and a laminated portion located below the XZ plane indicated by AA ( (Corresponding to the second portion in Example 1) is different in the attachment position of the positive electrode lead and the negative electrode lead. That is, a difference in expansion amount due to asymmetry in the thickness direction (asymmetry of lead attachment positions) in the laminated electrode body (structure) 50 which is a constituent member inside the lithium ion battery causes a bending moment. However, even in Example _{3, ΔX 1, ΔX 2,} d 1, d m, by defining the relationship between the value of d _2, or alternatively, during charging, [Delta] X _1, the relationship between the value of [Delta] X ₂ By defining at least part of the first portion is in contact with the first side surface portion of the exterior member and the second portion is not in contact with the second side surface portion of the exterior member, the negative electrode during charging It is possible to provide a lithium-ion battery that is less likely to warp due to a change in volume of the active material.

The lithium-ion battery of Example 3 has substantially the same configuration and structure as the lithium-ion battery of Example 2 except for the wound or laminated structure, and therefore detailed description is omitted. To do. Further, the lithium-ion battery of Example 3 can be manufactured by a method substantially similar to that of the lithium-ion battery of Example 2, so detailed description thereof will be omitted.

In Example 4, an application example of the lithium ion battery of the present disclosure will be described.

The application of the lithium-ion battery of the present disclosure is a machine in which the lithium-ion battery (specifically, a lithium-ion secondary battery) of the present disclosure can be used as a power source for driving/operating or a power storage source for power storage, It is not particularly limited as long as it is a device, an instrument, a device, and a system (a collection of a plurality of devices and the like). The lithium ion battery (specifically, a lithium ion secondary battery) used as a power source may be a main power source (power source used preferentially), or an auxiliary power source (instead of the main power source, or , A power source used by switching from the main power source). When using a lithium ion battery as an auxiliary power source, the main power source is not limited to the lithium ion battery.

Specific applications of the lithium-ion battery of the present disclosure include video cameras, camcorders, digital still cameras, mobile phones, personal computers, television receivers, various display devices, cordless phones, headphone stereos, music players, and mobile phones. Electronic equipment such as radio, electronic books such as electronic books and electronic newspapers, portable information terminals including PDAs (Personal Digital Assistants), electric equipment (including portable electronic equipment); toys; portable household appliances such as electric shavers Lighting equipment such as room lights; Medical electronic devices such as pacemakers and hearing aids; Memory devices such as memory cards; Battery packs used as removable power sources for personal computers; Electric tools such as electric drills and electric saws; Electric power storage systems such as household battery systems that store electric power in case of emergency, etc. and home energy servers (household power storage devices); power storage units and backup power supplies; electric vehicles, electric motorcycles, electric bicycles, segways (registration An electric vehicle such as a trademark); driving an electric power driving force conversion device (specifically, for example, a power motor) of an aircraft or a ship can be exemplified, but the invention is not limited to these applications.

Among them, the lithium ion battery of the present disclosure (specifically, a lithium ion secondary battery) is effectively applied to a battery pack, an electric vehicle, a power storage system, an electric tool, an electronic device, an electric device, or the like. .. Since excellent battery characteristics are required, it is possible to effectively improve the performance by using the lithium ion battery of the present disclosure. The battery pack is a power source using a lithium ion secondary battery and is a so-called assembled battery or the like. The electric vehicle is a vehicle that operates (runs) using a lithium ion secondary battery as a drive power source, and may be a vehicle (hybrid vehicle or the like) that also includes a drive source other than the secondary battery. The power storage system is a system that uses a lithium ion secondary battery as a power storage source. For example, in a household power storage system, since electric power is stored in a lithium ion secondary battery that is a power storage source, household electric appliances and the like can be used by using the electric power. The electric power tool is a tool in which a movable part (for example, a drill) is movable by using a lithium ion secondary battery as a power source for driving. Electronic devices and electric devices are devices that perform various functions using a lithium-ion secondary battery as a power supply (power supply source) for operation.

Hereinafter, some application examples of the lithium ion battery will be specifically described. The configuration of each application example described below is merely an example, and the configuration can be appropriately changed.

FIG. 6 shows a schematic perspective view of an exploded battery pack using the unit cells, and FIG. 7A shows a block diagram showing the configuration of the battery pack (unit cells). The battery pack is a simple type battery pack (so-called soft pack) that uses one lithium-ion secondary battery, and is mounted in, for example, an electronic device represented by a smartphone. The battery pack includes a power source 111 including the laminated film type lithium ion batteries of Examples 2 to 3, and a circuit board 116 connected to the power source 111. A positive electrode lead 112 and a negative electrode lead 113 are attached to the power supply 111.

A pair of adhesive tapes 118 and 119 are attached to both side surfaces of the power supply 111. The circuit board 116 is provided with a protection circuit (PCM: Protection Circuit Module). The circuit board 116 is connected to the positive electrode 112 via the tab 114 and is connected to the negative electrode lead 113 via the tab 115. A lead wire 117 with a connector for external connection is connected to the circuit board 116. When the circuit board 116 is connected to the power supply 111, the circuit board 116 is protected from above and below by the label 120 and the insulating sheet 121. The circuit board 116 and the insulating sheet 121 are fixed by attaching the label 120. The circuit board 116 includes a control unit 121, a switch unit 122, a PTC 123, and a temperature detection unit 124. The power supply 111 can be connected to the outside through the positive electrode terminal 125 and the negative electrode terminal 127, and the power supply 111 is charged and discharged through the positive electrode terminal 125 and the negative electrode terminal 127. The temperature detection unit 124 can detect the temperature via a temperature detection terminal (so-called T terminal).

The control unit 121, which controls the operation of the entire battery pack (including the use state of the power supply 111), is provided with a central processing unit (CPU), a memory, and the like. When the battery voltage reaches the overcharge detection voltage, the control unit 121 disconnects the switch unit 122 to prevent the charging current from flowing in the current path of the power supply 111. Further, when a large current flows during charging, the control unit 121 disconnects the switch unit 122 and cuts off the charging current. In addition, when the battery voltage reaches the overdischarge detection voltage, the control unit 121 disconnects the switch unit 122 so that the discharge current does not flow in the current path of the power supply 111. Further, when a large current flows during discharging, the control unit 121 disconnects the switch unit 122 to cut off the discharging current.

The overcharge detection voltage of the lithium ion battery is, for example, 4.20 V±0.05 V, and the overdischarge detection voltage is, for example, 2.4 V±0.1 V.

The switch unit 122 switches the use state of the power source 111 (whether or not the power source 111 can be connected to an external device) according to an instruction from the control unit 121. The switch unit 122 includes a charge control switch, a discharge control switch, and the like. The charge control switch and the discharge control switch are, for example, semiconductor switches such as a field effect transistor (MOSFET) using a metal oxide semiconductor. The charge/discharge current is detected, for example, based on the ON resistance of the switch unit 122.

The temperature detection unit 124 including the temperature detection element 126 such as a thermistor measures the temperature of the power supply 111 and outputs the measurement result to the control unit 121. The measurement result of the temperature detection unit 124 is used for charge/discharge control by the control unit 121 when abnormal heat is generated, correction processing when the remaining capacity is calculated by the control unit 121, and the like.

The circuit board 116 may not be provided with the PTC 123, and in this case, the PTC element may be separately provided on the circuit board 116.

Next, FIG. 7B is a block diagram showing the configuration of a battery pack (battery pack) different from that shown in FIG. 7A. This 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, a switch control unit inside a housing 60 made of a plastic material or the like. 67, a memory 68, a temperature detecting element 69, a current detecting resistor 70, a positive electrode terminal 71, and a negative electrode terminal 72.

The control unit 61 controls the operation of the entire battery pack (including the usage state of the power supply 62) and includes, for example, a CPU and the like. The power supply 62 is, for example, an assembled battery including two or more lithium ion secondary batteries (not shown) described in the second to third embodiments, and the lithium ion secondary battery may be connected in series. , Parallel, or a mixed type of both. As an example, the power supply 62 includes six lithium ion secondary batteries connected so as to be in two parallels and three series.

The switch unit 63 switches the use state of the power source 62 (whether or not the power source 62 can be connected to an external device) according to 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 (none of which are shown). The charge control switch and the discharge control switch are, for example, semiconductor switches such as MOSFETs.

The current measuring unit 64 measures the current using the current detection resistor 70 and outputs the measurement result to the control unit 61. The temperature detection unit 65 measures the temperature using the temperature detection element 69 and outputs the measurement result to the control unit 61. The temperature measurement result is used, for example, for charge/discharge control by the control unit 61 during abnormal heat generation, correction processing when the remaining capacity is calculated by the control unit 61, and the like. The voltage detection unit 66 measures the voltage of the lithium-ion secondary battery in the power supply 62, converts the measured voltage from analog to digital, and supplies it to the control unit 61.

The switch control unit 67 controls the operation of the switch unit 63 according to the signals input from the current measuring unit 64 and the voltage detecting 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) and controls so that the charging current does not flow in the current path of the power supply 62. This allows the power supply 62 to only discharge through the discharging diode. Further, the switch control unit 67 cuts off the charging current, for example, when a large current flows during charging. Furthermore, the switch control unit 67 disconnects the switch unit 63 (discharge control switch) so that the discharge current does not flow in the current path of the power supply 62 when the battery voltage reaches the overdischarge detection voltage, for example. To do. This allows the power supply 62 to only be charged via the charging diode. Further, the switch control unit 67 cuts off the discharge current, for example, when a large current flows during discharge.

The overcharge detection voltage of the lithium ion secondary battery is, for example, 4.20 V±0.05 V, and the overdischarge detection voltage is, for example, 2.4 V±0.1 V.

The memory 68 is, for example, an EEPROM that is a non-volatile memory. The memory 68 stores, for example, numerical values calculated by the control unit 61, information on the lithium-ion secondary battery measured at the manufacturing process stage (for example, internal resistance in the initial state), and the like. If the full charge capacity of the lithium ion secondary battery is stored in the memory 68, the control unit 61 can grasp the information such as the remaining capacity. The temperature detection element 69 including a thermistor measures the temperature of the power supply 62 and outputs the measurement result to the control unit 61. The positive electrode terminal 71 and the negative electrode terminal 72 are terminals connected to an external device (for example, a personal computer or the like) operated by the battery pack or an external device or the like (for example, a charger) used to charge the battery pack. .. Charging/discharging of the power source 62 is performed via the positive electrode terminal 71 and the negative electrode terminal 72.

Next, FIG. 8A is a block diagram showing the configuration of an electric vehicle such as 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 device 78, a generator 79, a transmission 80 and a clutch 81, an inverter 82, inside a metal casing 73. 83 and various sensors 84. In addition, the electric vehicle includes, for example, a differential device 78, a front wheel drive shaft 85, a front wheel 86, a rear wheel drive shaft 87, and a rear wheel 88 that are connected to a transmission 80.

The electric vehicle can travel using, for example, either the engine 75 or the motor 77 as a drive source. The engine 75 is a main power source and is, for example, a gasoline engine or the like. When the engine 75 is used as the power source, the driving force (rotational force) of the engine 75 is transmitted to the front wheels 86 or the rear wheels 88 via, for example, the differential device 78 that is a drive unit, the transmission 80, and the clutch 81. The rotational force of the engine 75 is also transmitted to the generator 79, the generator 79 uses the rotational force to generate AC power, and the AC power is converted into DC power via the inverter 83 and stored in the power supply 76. .. On the other hand, when the motor 77, which is the conversion unit, is used as the power source, the electric power (DC power) supplied from the power source 76 is converted into AC power via the inverter 82, and the motor 77 is driven using the AC power. The driving force (rotational force) converted from the electric power by the motor 77 is transmitted to the front wheels 86 or the rear wheels 88 via, for example, the differential device 78 that is a drive unit, the transmission 80, and the clutch 81.

When the electric vehicle decelerates via a braking mechanism (not shown), the resistance force during deceleration may be transmitted to the motor 77 as a rotational force, and the rotational force may be used to cause the motor 77 to generate AC power. The AC power is converted into DC power via the inverter 82, and the DC regenerative power is stored in the power supply 76.

The control unit 74 controls the operation of the entire electric vehicle, and includes, for example, a CPU and the like. The power supply 76 includes one or more lithium ion secondary batteries (not shown) described in the second to third embodiments. The power supply 76 may be configured to be connected to an external power supply and receive power from the external power supply to store the power. The various sensors 84 are used, for example, to control the rotational speed of the engine 75 and to control the opening of a throttle valve (throttle opening) not shown. The various sensors 84 include, for example, a speed sensor, an acceleration sensor, an engine speed sensor, and the like.

Although the case where the electric vehicle is a hybrid vehicle has been described, 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.

Next, FIG. 8B is a block diagram showing the 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 general house or a commercial building.

The power source 91 is connected to, for example, an electric device (electronic device) 94 installed inside the house 89, and can be connected to an electric vehicle 96 stopped outside the house 89. The power source 91 is connected to, for example, a private power generator 95 installed in a house 89 via a power hub 93, and can be connected to an external centralized power system 97 via a smart meter 92 and a power hub 93. is there. The electric device (electronic device) 94 includes, for example, one or two or more home electric appliances. Examples of home electric appliances include a refrigerator, an air conditioner, a television receiver, and a water heater. The private power generator 95 is composed of, for example, a solar power generator, a wind power generator, or the like. Examples of the electric vehicle 96 include an electric vehicle, a hybrid vehicle, an electric motorcycle, an electric bicycle, and a Segway (registered trademark). Examples of the centralized power system 97 include a commercial power source, a power generator, a power grid, and a smart grid (next-generation power grid). Further, for example, a thermal power plant, a nuclear power plant, a hydroelectric power plant, a wind power plant. And the like, and as the power generation device provided in the centralized power system 97, various solar cells, fuel cells, wind power generation devices, micro hydraulic power generation devices, geothermal power generation devices, etc. can be exemplified. It is not limited to these.

The control unit 90 controls the overall operation of the power storage system (including the usage state of the power supply 91), and includes, for example, a CPU. The power supply 91 includes one or more lithium ion secondary batteries (not shown) described in the second to third embodiments. 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. Then, the smart meter 92 can efficiently and stably supply energy by controlling the balance between supply and demand in the house 89 while communicating with the outside, for example.

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

The electric power stored in the power supply 91 can be used arbitrarily. Therefore, for example, power can be stored in the power source 91 from the centralized power system 97 at midnight when the power rate is low, and the power stored in the power source 91 can be used during the day when the power rate is high.

The power storage system described above may be installed for each household (one household), or for each multiple households (multiple households).

Next, FIG. 8C is a block diagram showing the configuration of the power tool. The power tool is, for example, a power drill, and includes a control unit 99 and a power supply 100 inside a tool body 98 made of a plastic material or the like. For example, a drill unit 101 that is a movable unit is rotatably attached to the tool body 98. The control unit 99 controls the operation of the entire electric power tool (including the usage state of the power supply 100), and includes, for example, a CPU. The power supply 100 includes one or more lithium ion secondary batteries (not shown) described in the second to third embodiments. The control unit 99 supplies electric power from the power supply 100 to the drill unit 101 according to the operation of an operation switch (not shown).

Although the present disclosure has been described based on the preferred embodiments, the present disclosure is not limited to these embodiments, and various modifications can be made. The configurations and structures of the lithium-ion batteries described in the examples are examples, and can be changed as appropriate.

Hereinafter, the positive electrode, the negative electrode, the non-aqueous electrolyte solution, and the like that compose the lithium ion secondary battery described above will be described in detail.

The details of the lithium-containing composite oxide and the lithium-containing phosphoric acid compound, which are preferable materials constituting the positive electrode material, are as follows. The other elements constituting the lithium-containing composite oxide and the lithium-containing phosphate compound are not particularly limited, and any one or two or more elements belonging to Groups 2 to 15 in the long periodic table are listed. It is preferable to use nickel <Ni>, cobalt <Co>, manganese <Mn>, and iron <Fe> from the viewpoint of being able to obtain a high voltage.

Specific examples of the lithium-containing composite oxide having a layered rock salt type crystal structure include compounds represented by Formula (B), Formula (C), and Formula (D).

Li _a Mn _1-bc Ni _b M ¹¹ _c O _{2-d Fe} (B)

Here, M ¹¹ is cobalt <Co>, magnesium <Mg>, aluminum <Al>, boron <B>, titanium <Ti>, vanadium <V>, chromium <Cr>, iron <Fe>, copper <Cu>. >, zinc <Zn>, zirconium <Zr>, molybdenum <Mo>, tin <Sn>, calcium <Ca>, strontium <Sr>, and tungsten <W>, which is at least one element selected from the group consisting of , A, b, c, d, e values are
0.8≦a≦1.2
0<b<0.5
0≦c≦0.5
b+c<1
−0.1≦d≦0.2
0≦e≦0.1
To be satisfied. However, the composition differs depending on the charge/discharge state, and a is the value in the completely discharged state.

Li _a Ni _1-b M ¹² _b O _2-c F _d (C)

Here, M ¹² is cobalt <Co>, manganese <Mn>, magnesium <Mg>, aluminum <Al>, boron <B>, titanium <Ti>, vanadium <V>, chromium <Cr>, iron <Fe. >, copper <Cu>, zinc <Zn>, molybdenum <Mo>, tin <Sn>, calcium <Ca>, strontium <Sr> and tungsten <W>, at least one element selected from the group consisting of , A, b, c, d values are
0.8 ≤ a ≤ 1.2
0.005≦b≦0.5
-0.1 ≤ c ≤ 0.2
0≦d≦0.1
To be satisfied. However, the composition differs depending on the charge/discharge state, and a is the value in the completely discharged state.

Li _a Co _1-b M ¹³ _b O _2-c F _d (D)

Here, M ¹³ is nickel <Ni>, manganese <Mn>, magnesium <Mg>, aluminum <Al>, boron <B>, titanium <Ti>, vanadium <V>, chromium <Cr>, iron <Fe. >, copper <Cu>, zinc <Zn>, molybdenum <Mo>, tin <Sn>, calcium <Ca>, strontium <Sr>, and tungsten <W>, which is at least one element selected from the group consisting of , A, b, c, d are
0.8≦a≦1.2
0≦b<0.5
−0.1≦c≦0.2
0≦d≦0.1
To be satisfied. However, the composition differs depending on the charge/discharge state, and a is the value in the completely discharged state.

As the lithium-containing composite oxide having a layered rock salt type crystal structure, specifically, 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, Li 1.15 (Mn 0.65 Ni 0.22 Co 0.13) O 2 can be exemplified.

As the lithium-containing composite oxide having a spinel type crystal structure, a compound represented by the formula (E) can be exemplified.
Li _a Mn _2-b M ¹⁴ _b O _c F _d (E)

Here, M ¹⁴ is cobalt <Co>, nickel <Ni>, magnesium <Mg>, aluminum <Al>, boron <B>, titanium <Ti>, vanadium <V>, chromium <Cr>, iron <Fe. >, copper <Cu>, zinc <Zn>, molybdenum <Mo>, tin <Sn>, calcium <Ca>, strontium <Sr>, and tungsten <W>, which is at least one element selected from the group consisting of , A, b, c, d values are
0.9≦a≦1.1
0≦b≦0.6
3.7≦c≦4.1
0≦d≦0.1
To be satisfied. However, the composition differs depending on the charge/discharge state, and a is the value in the completely discharged state. Specific examples of the lithium-containing composite oxide having a spinel type crystal structure include LiMn ₂ O ₄ .

Furthermore, as the lithium-containing phosphate compound having an olivine type crystal structure, a compound represented by the formula (F) can be exemplified.
Li _a M ¹⁵ PO ₄ (F)

Here, M ¹⁵ is cobalt <Co>, manganese <Mn>, iron <Fe>, nickel <Ni>, magnesium <Mg>, aluminum <Al>, boron <B>, titanium <Ti>, vanadium <V. >, niobium <Nb>, copper <Cu>, zinc <Zn>, molybdenum <Mo>, calcium <Ca>, strontium <Sr>, tungsten <W>, and zirconium <Zr>. Is a kind of element, and the value of a is
0.9≦a≦1.1
To be satisfied. However, the composition differs depending on the charge/discharge state, and a is the value in the completely discharged state. Specific examples of the lithium-containing phosphate compound having an olivine type crystal structure include LiFePO ₄ , LiMnPO ₄ , LiFe _0.5 Mn _0.5 PO ₄ , and LiFe _0.3 Mn _0.7 PO ₄ .

Alternatively, as the lithium-containing composite oxide, the compound represented by the formula (G) can be exemplified.
(Li ₂ MnO ₃ ) _x (LiMnO ₂ ) _1-x (G)
Here, the value of x is
0≦x≦1
To be satisfied. However, the composition differs depending on the charge/discharge state, and x is the value in the completely discharged state.

The positive electrode also includes, for example, oxides such as titanium oxide, vanadium oxide, and manganese dioxide; disulfides such as titanium disulfide and molybdenum sulfide; chalcogenides such as niobium selenide; conductive polymers such as sulfur, polyaniline, and polythiophene. It may be.

Specific examples of the binder include synthetic rubbers such as styrene-butadiene rubber, fluorine rubber, and ethylene propylene diene; polymeric materials such as polyvinylidene fluoride and polyimide. Further, as the conductive agent, for example, carbon materials such as graphite, carbon black, acetylene black, and Ketjen black can be exemplified, but if the material has conductivity, a metal material, a conductive polymer, or the like is used. Can also

The details of the material forming the negative electrode are as follows.

Examples of the material forming the negative electrode include a carbon material. Since the carbon material has a very small change in the crystal structure during storage and release of lithium, a high energy density can be stably obtained. Moreover, since the carbon material also functions as a negative electrode conductive agent, the conductivity of the negative electrode active material layer is improved. Examples of carbon materials include graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), and graphite (graphite). However, the (002) plane spacing in the non-graphitizable carbon is preferably 0.37 nm or more, and the (002) plane spacing in the graphite is preferably 0.34 nm or less. More specifically, as the carbon material, for example, pyrolytic carbons; coke such as pitch coke, needle coke, petroleum coke; glassy carbon fiber; polymer compounds such as phenol resin and furan resin are fired at an appropriate temperature. Examples include organic polymer compound calcined products that can be obtained by (carbonization); activated carbon; carbon blacks. In addition, as the carbon material, low crystalline carbon that has been heat-treated at a temperature of about 1000° C. or lower can be used, or amorphous carbon can be used. The shape of the carbon material may be any of fibrous, spherical, granular, and scaly.

Alternatively, as the material forming the negative electrode, for example, a material containing one or more kinds of metal elements or metalloid elements as constituent elements (hereinafter, referred to as “metal-based material”) may be cited. It is possible to obtain a high energy density. The metal-based material may be a simple substance, an alloy, or a compound, may be a material composed of two or more of these, or may be a material having at least a part of one or more of these phases. May be The alloy includes not only a material composed of two or more kinds of metal elements but also a material containing one or more kinds of metal elements and one or more kinds of metalloid elements. Further, the alloy may contain a non-metal element. Examples of the texture of the metal-based material include a solid solution, a eutectic (eutectic mixture), an intermetallic compound, and a coexistence of two or more kinds of these.

Examples of the metal element and the metalloid element include a metal element and a metalloid element 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 <Zn>, hafnium <Hf>, zirconium <Zr>, yttrium <Y>, palladium <Pd>, platinum <Pt>. However, among them, silicon <Si> and tin <Sn> are preferable from the viewpoint that they have an excellent ability to insert and extract lithium, and that a remarkably high energy density can be obtained.

Examples of the material containing silicon as a constituent element include a simple substance of silicon, a silicon alloy and a silicon compound, and a material composed of two or more of these may be used, or one or more of these may be used. It may be a material having the phase of at least a part. As a material containing tin as a constituent element, a simple substance of tin, a tin alloy, a tin compound may be mentioned, and a material composed of two or more of these may be used, or one or more of these may be used. It may be a material having the phase of at least a part. The simple substance means a simple substance in a general sense, may contain a trace amount of impurities, and does not necessarily mean a purity of 100%.

As an element other than silicon constituting a silicon alloy or a silicon compound, tin <Sn>, nickel <Ni>, copper <Cu>, iron <Fe>, cobalt <Co>, manganese <Mn>, zinc <Zn>, indium. <In>, silver <Ag>, titanium <Ti>, germanium <Ge>, bismuth <Bi>, antimony <Sb>, chromium <Cr>, carbon <C>, oxygen <O>. You can also list them. As the silicon alloy or the silicon compound, specifically, SiB ₄ , SiB ₆ , Mg ₂ Si, Ni ₂ Si, TiSi 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, preferably 0.2<v< 1.4) and LiSiO can be illustrated.

As an element other than tin that constitutes a tin alloy or a tin compound, silicon <Si>, nickel <Ni>, copper <Cu>, iron <Fe>, cobalt <Co>, manganese <Mn>, zinc <Zn>, indium. <In>, silver <Ag>, titanium <Ti>, germanium <Ge>, bismuth <Bi>, antimony <Sb>, chromium <Cr>, carbon <C>, oxygen <O>. You can also list them. Specific examples of the tin alloy or the tin compound include 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 containing a second constituent element and a third constituent element together with tin (first constituent element) (hereinafter referred to as “Sn-containing material”). As the second constituent element, for example, cobalt <Co>, iron <Fe>, magnesium <Mg>, titanium <Ti>, vanadium <V>, chromium <Cr>, manganese <Mn>, nickel <Ni>, copper <Cu>, zinc <Zn>, gallium <Ga>, zirconium <Zr>, niobium <Nb>, molybdenum <Mo>, silver <Ag>, indium <In>, cesium <Ce>, hafnium <Hf>, tantalum <Ta>, tungsten <W>, bismuth <Bi>, silicon <Si>, and as the third constituent element, for example, boron <B>, carbon <C>, aluminum <Al>, phosphorus <P. 〉. When the Sn-containing material contains the second constituent element and the third constituent element, high battery capacity and excellent cycle characteristics can be obtained.

Above all, the Sn-containing material is preferably a material containing tin <Sn>, cobalt <Co> and carbon <C> as constituent elements (referred to as “SnCoC-containing material”). In the SnCoC-containing material, for example, the carbon content is 9.9% by mass to 29.7% by mass, and the tin and cobalt content ratio {Co/(Sn+Co)} is 20% by mass to 70% by mass. Is. 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 reaction phase capable of reacting with lithium, the presence of the reaction phase provides excellent characteristics. The full width at half maximum (diffraction angle 2θ) of the diffraction peak obtained by X-ray diffraction of this reaction phase is 1 degree or more when CuKα ray is used as the specific X-ray and the insertion speed is 1 degree/minute. preferable. This is because lithium is absorbed and released more smoothly and the reactivity with the non-aqueous electrolyte solution is reduced. The SnCoC-containing material may include, in addition to the low crystalline or amorphous phase, a phase containing a simple substance or a part of each constituent element.

Whether or not the 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 the electrochemical reaction with lithium. be able to. For example, if the position of the diffraction peak changes before and after the electrochemical reaction with lithium, it corresponds to the reaction phase capable of reacting with lithium. In this case, for example, the diffraction peak of the low crystalline or amorphous reaction phase is seen between 2θ=20° and 50°. It is considered that such a reaction phase contains, for example, each of the constituent elements described above, and is mainly crystallized or amorphized 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. This is because aggregation and crystallization of tin and the like are suppressed. The bonding state of the elements can be confirmed by, for example, X-ray photoelectron spectroscopy (XPS) using Al-Kα ray or Mg-Kα ray as a soft X-ray source. When at least part of carbon is bonded to a metal element, a metalloid element, or the like, the peak of the synthetic wave of the carbon 1s orbit (C1s) appears in a region lower than 284.5 eV. It is assumed that the energy is calibrated so that the peak of the 4f orbit (Au4f) of the gold atom is obtained at 84.0 eV. At this time, since surface contaminant carbon is usually present on the surface of the substance, the C1s peak of the surface contaminant carbon is set to 284.8 eV, and the peak is used as the energy reference. In XPS measurement, the waveform of the C1s peak is obtained in a form that includes the peak of surface contamination carbon and the peak of carbon in the SnCoC-containing material. Therefore, for example, analysis may be performed using commercially available software to separate both peaks. In the analysis of the waveform, the position of the main peak existing on the lowest bound energy side is used as the energy reference (284.8 eV).

The SnCoC-containing material is not limited to the material (SnCoC) whose constituent elements are only tin, cobalt and carbon. Examples of the SnCoC-containing material include, in addition to tin, cobalt, and carbon, silicon <Si>, iron <Fe>, nickel <Ni>, chromium <Cr>, indium <In>, niobium <Nb>, germanium <Ge>. , Titanium <Ti>, molybdenum <Mo>, aluminum <Al>, phosphorus <P>, gallium <Ga>, bismuth <Bi>, etc., may be included as a constituent element.

In addition to the SnCoC-containing material, a material containing tin, cobalt, iron and carbon as constituent elements (hereinafter referred to as “SnCoFeC-containing material”) is also a preferable material. The composition of the SnCoFeC-containing material is arbitrary. As an example, when the iron content is set to be small, the carbon content is 9.9% by mass to 29.7% by mass, the iron content is 0.3% by mass to 5.9% by mass, The ratio of the contents of tin and cobalt {Co/(Sn+Co)} is 30% by mass to 70% by mass. When the iron content is set to a large amount, the carbon content is 11.9% by mass to 29.7% by mass, and the ratio of the contents of tin, cobalt and iron {(Co+Fe)/(Sn+Co+Fe)} is 26.4 mass% to 48.5 mass%, and the content ratio of cobalt and iron {Co/(Co+Fe)} is 9.9 mass% to 79.5 mass%. This is because a high energy density can be obtained in such a composition range. The physical properties (half-width, etc.) of the SnCoFeC-containing material are the same as those of the SnCoC-containing material described above.

Other examples of the material forming the negative electrode include metal oxides such as iron oxide, ruthenium oxide, and molybdenum oxide; and polymer compounds such as polyacetylene, polyaniline, and polypyrrole.

Above all, it is preferable that the material forming the negative electrode contains both the carbon material and the metal-based material for the following reason. That is, a metal-based material, in particular, a material containing at least one of silicon and tin as a constituent element has an advantage that the theoretical capacity is high, but on the other hand, it easily expands and contracts sharply during charge and discharge. On the other hand, the carbon material has a low theoretical capacity, but has an advantage that it is difficult to expand and contract during charging and discharging. Therefore, by using both the carbon material and the metal-based material, it is possible to suppress expansion/contraction during charge/discharge while obtaining a high theoretical capacity (in other words, battery capacity).

As noted above, non-aqueous electrolytes suitable for use in the lithium-ion batteries of the present disclosure include, but are not limited to:
A compound represented by the formula (1),
At least one of the compound represented by formula (2-A) and the compound represented by formula (2-B); and
At least one compound of the compounds represented by formula (3-A) to formula (3-F),
A non-aqueous electrolytic solution containing is included. The content of the compound represented by the formula (1) in the non-aqueous electrolyte is 2.5 mol/liter to 6 mol/liter, preferably 3 mol/liter to 6 mol/liter. ..

M ⁺ [(Z ¹ Y ¹ )(Z ² Y ² )N] ^- (1)
However, M is a metal element, and each of Z ¹ and Z ² is either a fluorine group <-F>, a monovalent hydrocarbon group or a monovalent fluorinated hydrocarbon group, and Z ¹ and Z ^At least one of ² is a fluorine group <-F> or a monovalent fluorinated hydrocarbon group, and each of Y ¹ and Y ² is a sulfonyl group <-S(=O) ₂ ->, carbonyl group. It is one of the groups <-C(=O)->.

R ¹ -CN (2-A)
^{R 2 -X-CN (2-} B)
However, R ¹ is a monovalent hydrocarbon group, R ² is a monovalent hydrocarbon group, and X is one or more ether bonds <-O-> and one or more divalent divalent groups. A hydrocarbon group is a group bonded in any order.

Ｒ²²−（ＣＮ）_n （３−Ｆ）

_{^{R 22 - (CN) n (}} 3-F)

Here, in the formula (3-A), each of R ³ and R ⁴ is a hydrogen group <-H> or a monovalent hydrocarbon group. In the formula (3-B), each of R ⁵ , R ⁶ , R ⁷ , and R ⁸ is a hydrogen group, a monovalent saturated hydrocarbon group, or a monovalent unsaturated hydrocarbon group, At least one of R ⁵ , R ⁶ , R ⁷ , and R ⁸ is a monovalent unsaturated hydrocarbon group. Further, in the formula (3-C), R ⁹ is a group represented by >CR ¹⁰ R ¹¹ , and each of R ¹⁰ and R ¹¹ is a hydrogen group or a monovalent hydrocarbon group. is there. Further, in the formula (3-D), each of R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ is a hydrogen group, a halogen group, a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group. And at least one of R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ is a halogen group or a monovalent halogenated hydrocarbon group. Furthermore, in the formula (3-E), each of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , and R ²¹ is a hydrogen group, a halogen group, a monovalent hydrocarbon group, or a monovalent halogenated group. It is any of hydrocarbon groups, and at least one of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , and R ²¹ is a halogen group or a monovalent halogenated hydrocarbon group. In addition, in the formula (3-F), R ²² is an n-valent (where n is an integer of 2 or more) hydrocarbon group. Incidentally, “>C” and “C<” represent that two joints extend from the carbon atom.

Specifically, the above non-aqueous electrolyte solution includes a first compound having a sulfonylimide type structure, a second compound having an acetonitrile type structure, and a third compound having a reactive group such as an unsaturated hydrocarbon group. And the compound. Here, the reason why the non-aqueous electrolyte solution has such a composition is that the following advantages can be obtained. That is, the non-aqueous electrolytic solution contains the first compound, the second compound and the third compound together, and the content of the first compound in the non-aqueous electrolytic solution is in the above range (2.5 mol/liter to 6 mol/liter), the chemical stability of the non-aqueous electrolyte is specifically improved by the synergistic action of the first compound, the second compound and the third compound, and the non-aqueous electrolysis at the time of charging/discharging. The decomposition reaction of the liquid is suppressed. Therefore, the discharge capacity is less likely to decrease even after repeated charging and discharging, and the battery characteristics of the secondary battery can be improved. In particular, whether or not the specific synergistic effect described here is obtained depends on the content of the first compound. Therefore, a specific synergistic effect can be obtained only when the content of the first compound is within the above range.

The first compound contains one kind or two or more kinds of the compound represented by the formula (1). Since the first compound is a salt containing a cation (M ⁺ ) and an anion ([(Z ¹ Y ¹ )(Z ² Y ² )N] ⁻ ), it functions as a part of the electrolyte salt in the secondary battery. obtain.

“M” in the formula (1) is not particularly limited as long as it is a metal element, and examples thereof include alkali metal elements and alkaline earth metal elements. Among them, “M” is an alkali metal element. Is preferable, and thereby a high energy density can be obtained. Examples of the alkali metal element include lithium <Li>, sodium <Na>, potassium <K>, rubidium <Rb>, and cesium <Cs>. Among them, lithium <Li> is preferable. The alkali metal element is preferably the same as the alkali metal element that constitutes the electrode reactant, whereby a high energy density can be obtained. The electrode reactive substance is a substance involved in the electrode reaction, and is, for example, lithium in a lithium ion secondary battery. Therefore, when used in a lithium ion secondary battery, “M” is preferably lithium.

Z ¹ and Z ² may be the same group or different groups. The monovalent hydrocarbon group in Z ¹ and Z ² is a generic term for a monovalent group composed of carbon <C> and hydrogen <H>, and may be linear or 1 or 2 It may be branched having the above side chains. The monovalent saturated hydrocarbon group may be a saturated hydrocarbon group containing no unsaturated bond, or an unsaturated hydrocarbon group containing one or more unsaturated bonds. Good. The unsaturated bond is one or both of a carbon-carbon double bond (>C=C<) and a carbon-carbon triple bond (-C≡C-).

Examples of the monovalent hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, and a group in which two or more of these groups are monovalently bonded. In other words, the monovalent saturated hydrocarbon group is, for example, an alkyl group, a cycloalkyl group, or a group in which two or more kinds of these groups are monovalently bonded. The monovalent unsaturated hydrocarbon group is, for example, an alkenyl group, an alkynyl group, an aryl group, a group containing at least one of these, and a group in which two or more of these are bonded so as to be monovalent. As the group in which two or more kinds of monovalent hydrocarbon groups are bonded, a group in which an alkyl group and an alkenyl group are bonded, a group in which an alkyl group and an alkynyl group are bonded, a group in which an alkenyl group and an alkynyl group are bonded, and alkyl Examples thereof include a group in which a group and a cycloalkyl group are bonded, and a group in which an alkyl group and an aryl group are bonded. Examples of the monovalent saturated hydrocarbon group in which two or more kinds are bonded include a group in which an alkyl group and a cycloalkyl group are bonded. Examples of the group in which two or more types of monovalent unsaturated hydrocarbon groups are bonded include a group in which an alkyl group and an alkenyl group are bonded, and a group in which an alkyl group and an alkenyl group are bonded.

As the alkyl group include a methyl group <-CH _3>, an ethyl group <-C ₂ H _5>, propyl <-C ₃ H _7>, n- butyl group <-C ₄ H _8>, t - it can be exemplified butyl _{<-C (CH 3) 2 -CH} 3>. Alkenyl groups, specifically, vinyl group <-CH = CH _2>, can be exemplified allyl group _{<-CH 2 -CH = CH 2>} . Specific examples of the alkynyl group include an ethynyl group <-C≡CH>. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Specific examples of the aryl group include a phenyl group and a naphthyl group. As the group in which two or more kinds are bound, specifically, a group in which a methyl group and an ethynyl group are bound, a group in which a vinyl group and an ethynyl group are bound, a group in which a methyl group and a cyclopropyl group are bound, and a methyl group Examples thereof include a group in which a phenyl group is bonded to.

The monovalent fluorinated hydrocarbon group is a group in which one or more hydrogen groups <-H> in the above monovalent hydrocarbon group are replaced by a fluorine group <-F>. As the monovalent fluorinated hydrocarbon group, specifically, a fluorinated alkyl group, a fluorinated alkenyl group, a fluorinated alkynyl group, a fluorinated cycloalkyl group, a fluorinated aryl group, and two or more of these are monovalent. Examples of the groups bonded so that

As a fluorinated alkyl group, specifically, fluoromethyl group <-CH ₂ F>, difluoromethyl group <-CHF _2>, perfluoromethyl group <-CF _3>, perfluoroethyl group <-C ₂ F ₅ >, perfluoropropyl group <-C ₃ F _7>, n- perfluorobutyl <-C ₄ F _8>, t- perfluorobutyl group <-C (CF _{3) 2} to illustrate the -CF _3> You can As fluorinated alkenyl groups, specifically, perfluorovinyl group <-CF = CF _2>, can be exemplified perfluoro allyl _{<-CF 2 -CF = CF 2>} . Specific examples of the fluorinated alkynyl group include a perfluoroethynyl group <-F≡CF>. Specific examples of the fluorinated cycloalkyl group include a perfluorocyclopropyl group, a perfluorocyclobutyl group, a perfluorocyclopentyl group, a perfluorocyclohexyl group, a perfluorocycloheptyl group, and a perfluorocyclooctyl group. it can. Specific examples of the fluorinated aryl group include a perfluorophenyl group and a perfluoronaphthyl group. Among them, the fluorinated alkyl group, fluorinated alkenyl group, fluorinated alkynyl group, fluorinated cycloalkyl group, and fluorinated aryl group are preferably perfluoro groups, and more preferably perfluoroalkyl groups. This is because they can be easily synthesized and the synergistic effect described later can be easily obtained.

The number of carbon atoms of the monovalent hydrocarbon group and the monovalent fluorinated hydrocarbon group is not particularly limited, but it is preferable that the carbon number is not too large. This is because the solubility and compatibility of the first compound are improved. Specifically, the fluorinated alkyl group preferably has 1 to 4 carbon atoms. The fluorinated alkenyl group and the fluorinated alkynyl group preferably have 2 to 4 carbon atoms. The fluorinated cycloalkyl group and the fluorinated aryl group preferably have 6 to 12 carbon atoms.

In Formula (1), one or both of Z ¹ and Z ² is a fluorine group <-F> or a monovalent fluorinated hydrocarbon group. This is because they can be easily synthesized and the synergistic effect described later can be easily obtained. Accordingly, when ^one of Z ¹ and Z ² is a monovalent hydrocarbon group, the other is either a fluorine group <-F> or a monovalent fluorinated hydrocarbon group. That is, neither Z ¹ nor Z ² is a monovalent hydrocarbon group.

In formula (1), each of Y ¹ and Y ² is not particularly limited as long as it is either a sulfonyl group or a carbonyl group. Y ¹ and Y ² may be the same group or different groups.

As the first compound, specifically, bisfluorosulfonylimide lithium <LiN(FSO ₂ ) ₂ >, bistrifluoromethylsulfonylimide lithium <LiN(CF ₃ SO ₂ ) ₂ >, fluorosulfonyltrifluoromethylsulfonylimide lithium < LiN(FSO ₂ )(CF ₃ SO ₂ )>, fluorosulfonylpentafluoroethylsulfonylimide lithium <LiN(FSO ₂ )(C ₂ F ₅ SO ₂ )>, fluorosulfonylnonafluorobutylsulfonylimide lithium <LiN(FSO _{2 ).} )(C ₄ F ₉ SO ₂ )>, fluorosulfonylphenylsulfonylimide lithium <LiN(FSO ₂ )(C ₆ H ₅ SO ₂ )>, fluorosulfonylpentafluorophenylsulfonylimide lithium <LiN(FSO ₂ )(C ₆ F ₅ SO ₂ )> and fluorosulfonylvinylsulfonylimide lithium <LiN(FSO ₂ )(C ₂ F ₃ SO ₂ )>.

The second compound described above contains either one or both of the compounds represented by formula (2-A) and formula (2-B). However, the second compound may include two or more kinds of the compounds represented by the formula (2-A) or two or more kinds of the compounds represented by the formula (2-B).

The compound represented by the formula (2-A) is a mononitrile compound having no ether bond (non-oxygen-containing mononitrile compound). R ¹ is not particularly limited as long as it is a monovalent hydrocarbon group. The details regarding the monovalent hydrocarbon group are as described above. As a non-oxygen-containing mono-nitrile compounds, specifically, acetonitrile <CH ₃ CN>, propionitrile <C ₃ H ₇ CN>, can be exemplified butyronitrile <C ₄ H ₉ CN>.

The compound represented by the formula (2-B) is a mononitrile compound containing an ether bond (oxygen-containing mononitrile compound). R ² is not particularly limited as long as it is a monovalent hydrocarbon group. The details regarding the monovalent hydrocarbon group are as described above. In “X” in the formula (2-B), the divalent hydrocarbon group is a general term for divalent groups composed of carbon and hydrogen, and may be linear, or 1 or It may be branched having two or more side chains. Specific examples of the divalent hydrocarbon group include an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group, an arylene group, and a group in which two or more kinds of these are bonded so as to be divalent. You can Specific examples of the group in which two or more types are bonded include a group in which an alkylene group and an alkenylene group are bonded, a group in which an alkyl group and an alkynylene group are bonded, a group in which an alkenylene group and an alkynylene group are bonded, and an alkylene group. Examples thereof include a group bonded to a cycloalkylene group and a group bonded to an alkylene group and an arylene group.

As the alkylene group, and specific examples include a methylene group <-CH ₂ ->, an ethylene group <-C ₂ H ₄ ->, propylene _{<-C 3 H 6 ->,} n- butylene <-C ₄ H ₈ ->, t-butylene _{<-C (CH 3) 2 -CH} 2 - can be exemplified>. As the alkenylene group include a vinylene group <-CH = CH->, can be exemplified arylene group <-CH ₂ -CH = CH->. Specific examples of the alkynylene group include an ethynylene group <-C[identical to]C->. Specific examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, and a cyclooctylene group. Specific examples of the arylene group include a phenylene group and a naphthylene group. Specific examples of the group in which two or more kinds are bonded include a group in which a methylene group and an ethynylene group are bonded, a group in which a vinylene group and an ethynylene group are bonded, a group in which a methylene group and a cyclopropylene group are bonded, and a methylene group. Examples thereof include a group in which and a phenylene group are bonded.

Although the carbon number of the divalent hydrocarbon group is not particularly limited, it is preferably not extremely too large. This is because the solubility and compatibility of the second compound are improved. Specifically, the alkylene group preferably has 1 to 4 carbon atoms. The alkenylene group and alkynylene group preferably have 2 to 4 carbon atoms. The cycloalkylene group and the arylene group preferably have 6 to 12 carbon atoms.

“X” is not particularly limited as long as it is a group in which one or more ether bonds and one or more divalent hydrocarbon groups are bonded in any order. That is, the number of ether bonds contained in “X” may be 1, or 2 or more. Similarly, the number of divalent hydrocarbon groups contained in “X” may be 1, or 2 or more. When the number of divalent hydrocarbon groups is 2 or more, the 2 or more divalent hydrocarbon groups may be the same group or different groups. Part of two or more divalent hydrocarbon groups may be the same group. Since the order in which the ether bond and the divalent hydrocarbon group are bonded may be arbitrary, the ether bonds may be bonded to each other, the divalent hydrocarbon groups may be bonded to each other, or the ether bond and the ether bond may be bonded to each other. A divalent hydrocarbon group may be bonded.

Among them, “X” is preferably a group represented by —O—Y— (Y is a divalent hydrocarbon group). This is because they can be easily synthesized and the synergistic effect described later can be easily obtained. The details regarding the divalent hydrocarbon group are as described above. However, where X as described (i.e., -O-Y-) in, along with an ether bond (-O-) is bonded to R ^2, Y is bonded to a cyano group <-CN>. As "X", _{specifically, -O-CH 2 -, -} CH 2 -O -, - O-CH 2 -O -, - O-C 2 H 5 - can be exemplified.

Specific examples of the oxygen-containing mono-nitrile compounds, methoxy acetonitrile _{<CH 3 -O-CH 2 -CN} >, ethoxy acetonitrile _{<C 2 H 5 -O-CH} 2 -CN>, propoxy acetonitrile <C ₃ H ₇ -O- it can be exemplified CH ₂ -CN>.

The content of the second compound in the non-aqueous electrolyte solution is not particularly limited, but is preferably 20% by mass to 100% by mass, for example. This is because the synergistic effect described later can be easily obtained. When the second compound contains both the non-oxygen-containing mononitrile compound and the oxygen-containing mononitrile compound, the content of the second compound is the content of the non-oxygen-containing mononitrile compound and the content of the oxygen-containing mononitrile compound. Is the sum of The fact that the content means the sum is the same in the following.

The above-mentioned third compound contains one kind or two or more kinds of any of unsaturated cyclic carbonic acid ester, halogenated cyclic carbonic acid ester, and polynitrile compound. However, the third compound may contain two or more kinds of unsaturated cyclic carbonic acid esters. The fact that two or more kinds may be contained in this way is the same for the halogenated cyclic ester carbonate and the polynitrile compound.

The unsaturated cyclic carbonic acid ester contains one kind or two or more kinds of the compounds represented by the formula (3-A), the formula (3-B) and the formula (3-C). Here, the unsaturated cyclic carbonic acid ester is a cyclic carbonic acid ester containing one or more unsaturated bonds (carbon-carbon double bond).

The compound represented by the formula (3-A) is a vinylene carbonate compound. Each of R ³ and R ⁴ is not particularly limited as long as it is either a hydrogen group or a monovalent hydrocarbon group. The details regarding the monovalent hydrocarbon group are as described above. R ³ and R ⁴ may be the same group or different groups.

Specific examples of the vinylene carbonate-based compound include vinylene carbonate (1,3-dioxole-2-one), methylvinylene carbonate (4-methyl-1,3-dioxole-2-one), ethylvinylene carbonate (4-ethyl-). 1,3-dioxole-2-one), 4,5-dimethyl-1,3-dioxole-2-one, 4,5-diethyl-1,3-dioxole-2-one, 4-fluoro-1,3 Examples thereof include -dioxole-2-one and 4-trifluoromethyl-1,3-dioxole-2-one. Among them, vinylene carbonate is preferable because it can be easily synthesized.

The compound represented by the formula (3-B) is a vinyl ethylene carbonate compound. Each of R ⁵ , R ⁶ , R ⁷ and R ⁸ is not particularly limited as long as it is any one of a hydrogen group, a monovalent saturated hydrocarbon group and a monovalent unsaturated hydrocarbon group. The details regarding the monovalent saturated hydrocarbon group and the monovalent unsaturated hydrocarbon group are as described above. However, 1 or 2 or more of R ⁵ , R ⁶ , R ⁷ , and R ⁸ is a monovalent unsaturated hydrocarbon group. This is because the vinyl ethylene carbonate-based compound must contain one or more unsaturated bonds (carbon-carbon double bonds). R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same group or different groups. Part of R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same group.

As the vinyl ethylene carbonate-based compound, specifically, vinyl ethylene carbonate (4-vinyl-1,3-dioxolan-2-one), 4-methyl-4-vinyl-1,3-dioxolan-2-one, 4 -Ethyl-4-vinyl-1,3-dioxolan-2-one, 4-n-propyl-4-vinyl-1,3-dioxolan-2-one, 5-methyl-4-vinyl-1,3-dioxolane 2-one, 4,5-divinyl-1,3-dioxolan-2-one and 4,5-divinyl-1,3-dioxolan-2-one can be exemplified, but among them, can be easily synthesized. From the standpoint of that, vinyl ethylene carbonate is preferable.

The compound represented by the formula (3-C) is a methylene ethylene carbonate compound. R ⁹ is not particularly limited as long as it is a group represented by >CR ¹⁰ R ¹¹ . The details regarding the monovalent hydrocarbon group are as described above. R ¹⁰ and R ¹¹ may be the same group or different groups.

Specific examples of the methylene ethylene carbonate compound include methylene ethylene carbonate (4-methylene-1,3-dioxolan-2-one) and 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one. , 4,4-diethyl-5-methylene-1,3-dioxolan-2-one can be exemplified.

In addition, the unsaturated cyclic carbonic acid ester may be a compound containing two methylene groups, catechol carbonate containing a benzene ring (catechol carbonate), or the like. The compounds containing two methylene groups in formula (3-C),> C = instead of R ^9> together comprise a C = CH _2,> instead of CH _2> with a compound containing a C = CH ₂ is there.

The content of the unsaturated cyclic carbonic acid ester in the non-aqueous electrolytic solution is not particularly limited, but is preferably 0.01% by mass to 20% by mass with respect to the total amount excluding the unsaturated cyclic carbonic acid ester. ..

The halogenated cyclic carbonic acid ester contains one kind or two or more kinds of the compounds represented by the formula (3-D) and the formula (3-E). The halogenated carbonic acid ester is a carbonic acid ester having one or more halogen groups.

The compound represented by the formula (3-D) is a halogenated cyclic carbonic acid ester. R ^{12 to} R ¹⁵ are not particularly limited as long as they are any of a hydrogen group, a halogen group, a monovalent hydrocarbon group and a monovalent halogenated hydrocarbon group. The details regarding the monovalent hydrocarbon group are as described above. However, one or two or more of R ^{12 to} R ¹⁵ are either a halogen group or a monovalent halogenated hydrocarbon group. This is because the halogenated cyclic ester carbonate must contain one or more halogen groups. R ^{12 to} R ¹⁵ may be the same group or different groups. Part of R ^{12 to} R ¹⁵ may be the same group.

The monovalent halogenated hydrocarbon group is a group in which one or more hydrogen groups in the above monovalent hydrocarbon group are substituted with a halogen group. The halogen group is not particularly limited, but is, for example, any one of a fluorine group <-F>, a chlorine group <-Cl>, a bromine group <-Br>, an iodine group <-I>, among which a fluorine group <- F> is preferable. This is because they can be easily synthesized and the synergistic effect described later is easily obtained. The number of halogen groups is preferably 2 rather than 1, and may be 3 or more. This is because a higher effect can be obtained.

As the monovalent halogenated hydrocarbon group, specifically, a halogenated alkyl group, a halogenated alkenyl group, a halogenated alkynyl group, a halogenated cycloalkyl group, a halogenated aryl group, and two or more of these are monovalent. Examples of the groups bonded so that

Among the halogenated alkyl groups, specific examples of the fluorinated alkyl group, the fluorinated alkenyl group, the fluorinated alkynyl group, the fluorinated cycloalkyl group, and the fluorinated aryl group are as described above. Specific examples of the chlorinated alkyl group, the brominated alkyl group, and the iodinated alkyl group are compounds in which the fluorine group in the above specific examples of the fluorinated alkyl group is changed to a chlorine group, a bromine group, or an iodine group. Thus, changing a fluorine group to a chlorine group, a bromine group, or an iodine group means to change a chlorinated alkenyl group, a chlorinated alkynyl group, a chlorinated cycloalkyl group, a chlorinated aryl group, a brominated alkenyl group, or a brominated group. The same applies to the alkynyl group, brominated cycloalkyl group, brominated aryl group, iodinated alkenyl group, iodinated alkynyl group, iodinated cycloalkyl group, and iodinated aryl group.

Specific examples of the halogenated cyclic carbonic acid ester include 4-fluoro-1,3-dioxolan-2-one, 4-chloro-1,3-dioxolan-2-one and 4,5-difluoro-1,3-dioxolane-. 2-one, tetrafluoro-1,3-dioxolan-2-one, 4-chloro-5-fluoro-1,3-dioxolan-2-one, 4,5-dichloro-1,3-oxolan-2-one , Tetrachloro-1,3-dioxolan-2-one, 4,5-bistrifluoromethyl-1,3-dioxolan-2-one, 4-trifluoromethyl-1,3-dioxolan-2-one, 4, 5-difluoro-4,5-dimethyl-1,3-dioxolan-2-one, 4,4-difluoro-5-methyl-1,3-dioxolan-2-one, 4-ethyl-5,5-difluoro- 1,3-dioxolan-2-one, 4-fluoro-5-trifluoromethyl-1,3-dioxolan-2-one, 4-methyl-5-trifluoromethyl-1,3-dioxolan-2-one, 4-fluoro-4,5-dimethyl-1,3-dioxolan-2-one, 5-1,1-difluoroethyl-4,4-difluoro-1,3-dioxolan-2-one, 4,5-dichloro 4,5-Dimethyl-1,3-dioxolan-2-one, 4-ethyl-5-fluoro-1,3-dioxolan-2-one, 4-ethyl-4,5-difluoro-1,3-dioxolane 2-one, 4-ethyl-4,5,5-trifluoro-1,3-dioxolan-2-one, 4-fluoro-4-methyl-1,3-dioxolan-2-one may be exemplified. it can. Specific examples of the halogenated cyclic carbonic acid ester described here include isomers (cis isomer and trans isomer).

The compound represented by the formula (3-E) is a halogenated chain ester carbonate. R ^{16 to} R ²¹ are not particularly limited as long as they are any of a hydrogen group, a halogen group, a monovalent hydrocarbon group and a monovalent halogenated hydrocarbon group. The details regarding the monovalent hydrocarbon group and the monovalent halogenated hydrocarbon group are as described above. However, for the same reason as the above-mentioned halogenated cyclic ester carbonate, one or more of R ^{16 to} R ²¹ is a halogen group or a monovalent halogenated hydrocarbon group. R ^{16 to} R ²¹ may be the same group or different groups. Part of R ^{16 to} R ²¹ may be the same group. Specific examples of the halogenated chain ester carbonate include fluoromethyl methyl carbonate, bisfluoromethyl carbonate, and difluoromethyl methyl carbonate. The content of the halogenated cyclic ester carbonate in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass to 20% by mass with respect to the total total excluding the halogenated cyclic ester carbonate. ..

The polynitrile compound contains one kind or two or more kinds of the compounds represented by the formula (3-F). The polynitrile compound is a compound containing two or more nitrile groups, and the second compound is not included in the polynitrile compound described here. This is because the second compound does not contain two or more nitrile groups.

R ²² is not particularly limited as long as it is an n-valent hydrocarbon group. As an example, when R ²² has 1 carbon, a divalent hydrocarbon group may be —CH ₂ — and a trivalent hydrocarbon group may be >CH—. Similarly, when R ²² has 2 carbon atoms, examples of the divalent hydrocarbon group include —CH ₂ —CH ₂ —, and examples of the trivalent hydrocarbon group include >CH—CH ₂ —. Among them, R ²² is preferably a divalent hydrocarbon group. This is because the number of cyano groups <-CN> becomes 2, and thus the synergistic effect described later is easily obtained. The details regarding the divalent hydrocarbon group are as described above.

Specific examples of the polynitrile compound include malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, phthalonitrile, and tetracyanoquinodimethane. it can. The content of the polynitrile compound in the non-aqueous electrolytic solution is not particularly limited, but is preferably 0.01% by mass to 10% by mass with respect to the total total excluding the polynitrile compound.

The non-aqueous electrolyte solution may contain one kind or two or more kinds of other materials in addition to the above-mentioned first compound, second compound and third compound. As other materials, specifically, sulfonic acid ester, acid anhydride, cyclic carboxylic acid ester (lactone), dialkyl sulfoxide, chain dicarbonic acid ester (see the following formula (10)), aromatic carbonic acid ester (the following) Formula (11)), cyclic carbonate (see Formula (12) below), chain monocarbonate (see Formula (13) below), chain carboxylic acid ester (see Formula (14) below) , Phosphoric acid ester (see the following formula (15)), lithium monofluorophosphate <Li ₂ PO ₃ F>, lithium difluorophosphate <LiPO ₂ F ₂ >, or two or more thereof. You can

Here, each of R ²³ and R ²⁴ is either a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group, and R ²⁵ is a divalent hydrocarbon group or a divalent halogenated hydrocarbon group. It is one of the hydrogen groups. Further, each of R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ is a monovalent hydrocarbon group or a monovalent oxygen-containing hydrocarbon group. Monovalent nitrogen-containing hydrocarbon group, monovalent halogenated hydrocarbon group, monovalent halogenated oxygen-containing hydrocarbon group, monovalent halogenated nitrogen-containing hydrocarbon group, and two or more of these are monovalent Is one of the groups bonded so that Furthermore, each of R ³⁶ , R ³⁷ , R ³⁸ , and R ³⁹ is either a hydrogen group or a monovalent hydrocarbon group. Further, each of R ⁴⁰ and R ⁴¹ is either a hydrogen group or a monovalent hydrocarbon group. Furthermore, each of R ⁴² and R ⁴³ is a hydrogen group or a monovalent hydrocarbon group. Further, each of R ⁴⁴ , R ⁴⁵ and R ⁴⁶ is either a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group.

Specific examples of the sulfonic acid ester include monosulfonic acid ester and disulfonic acid ester. The content of the sulfonic acid ester in the non-aqueous electrolyte solution is not particularly limited, but for example, it is preferably 0.01% by mass to 10% by mass with respect to the total amount excluding the sulfonic acid ester.

The monosulfonic acid ester may be a cyclic monosulfonic acid ester or a chain monosulfonic acid ester. Specific examples of the cyclic monosulfonic acid ester include sultones such as propane sultone and propene sultone. Specific examples of the chain monosulfonic acid ester include compounds having a structure in which a cyclic monosulfonic acid ester is cleaved in the middle. As an example, CH ₃ —CH ₂ —CH ₂ —SO ₃ —CH ₃ can be exemplified as a compound in which propane sultone is cleaved on the way. _{-SO 3 - (- S (=} O) 2 -O-) orientation is not particularly limited. That is, the above CH ₃ —CH ₂ —CH ₂ —SO ₃ —CH ₃ may be CH ₃ —CH ₂ —CH ₂ —S(═O) ₂ —O—CH ₃ or CH ₃ — _{CH 2 -CH 2 -O-S (} = O) may be ₂ -CH _3.

The disulfonic acid ester may be a cyclic disulfonic acid ester or a chain disulfonic acid ester. Specific examples of the cyclic disulfonic acid ester include compounds represented by formula (16-1), formula (16-2), and formula (16-3). The chain disulfonic acid ester is a compound in which the cyclic disulfonic acid ester is cleaved on the way. Specific examples of the compound obtained by cleaving the compound represented by the formula (16-2) on the way include CH ₃ —SO ₃ —CH ₂ —CH ₂ —SO ₃ —CH ₃ . Two _{-SO 3 - (- S (=} O) 2 -O-) orientation is not particularly limited. _{That, CH 3 -SO 3 -CH 2 -CH} 2 -SO 3 -CH 3 _{above, CH 3 -S (= O)} 2 -O-CH 2 -CH 2 -S (= O) 2 -O- CH ₃ may be used, CH ₃ —O—S(═O) ₂ —CH ₂ —CH ₂ —S(═O) ₂ —O—CH ₃ , or CH ₃ —S(═O) ₂ —O. _{-CH 2 -CH 2 -O-S (} = O) may be ₂ -CH _3.

Specific examples of the acid anhydride include carboxylic acid anhydrides such as benzoic acid anhydride, succinic acid anhydride, glutaric acid anhydride, and maleic acid anhydride; disulfonic acid anhydrides such as ethanedisulfonic acid anhydride and propanedisulfonic acid anhydride. Examples thereof include carboxylic acid sulfonic acid anhydrides such as sulfobenzoic acid anhydride, sulfopropionic acid anhydride, and sulfobutyric acid anhydride. The content of the acid anhydride in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass to 10% by mass with respect to the total total excluding the acid anhydride.

Specific examples of the cyclic carboxylic acid ester include γ-butyrolactone and γ-valerolactone. The content of the cyclic carboxylic acid ester in the non-aqueous electrolytic solution is not particularly limited, but for example, it is preferably 0.01% by mass to 10% by mass with respect to the total amount excluding the cyclic carboxylic acid ester.

Specific examples of the dialkyl sulfoxide include dimethyl sulfoxide <(CH ₃ ) ₂ SO> and diethyl sulfoxide <(C ₂ H ₅ ) ₂ SO>. The content of the dialkyl sulfoxide in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass to 10% by mass with respect to the total total excluding the dialkyl sulfoxide.

The chain dicarbonic acid ester is any one kind or two or more kinds of compounds represented by the above formula (10). R ²³ and R ²⁴ are not particularly limited as long as they are monovalent hydrocarbon groups or monovalent halogenated hydrocarbon groups. R ²³ and R ²⁴ may be the same group or different groups. R ²⁵ is not particularly limited as long as it is a divalent hydrocarbon group or a divalent halogenated hydrocarbon group. The details regarding the monovalent hydrocarbon group and the monovalent halogenated hydrocarbon group are as described above. The divalent halogenated hydrocarbon group is a group in which one or more hydrogen groups of the divalent hydrocarbon group are substituted with a halogen group. The details regarding the divalent hydrocarbon group and the halogen group are as described above. Divalent halogenated hydrocarbon group, specifically, perfluoro methylene <-CF ₂ ->, perfluoro ethylene group <-C ₂ F ₄ ->, perfluoro propylene <-C ₃ F ₆ - >, n-perfluoro-butylene _{<-C 4 F 8 ->,} t- perfluorobutylene group _{<-C (CF 3) 2 -CF} 2 - can be exemplified>. Specific examples of the chain dicarbonic acid ester include ethane-1,2-diyldimethyldicarbonate, ethane-1,2-diylethylmethyldicarbonate, ethane-1,2-diyldiethyldicarbonate, dimethyloxybisethane. Examples thereof include 2,2,1-diyldicarbonate, ethylmethyloxybisethane-2,1-diyldicarbonate, and diethyloxybisethane-2,1-diyldicarbonate. The content of the chain dicarbonic acid ester in the non-aqueous electrolyte is not particularly limited, but is preferably 0.01% by mass to 10% by mass with respect to the total total excluding the chained dicarbonic acid ester. ..

The aromatic carbonate ester is any one kind or two or more kinds of compounds represented by the above formula (11). R ^{26 to} R ³⁵ are a monovalent hydrocarbon group, a monovalent oxygen-containing hydrocarbon group, a monovalent nitrogen-containing hydrocarbon group, a monovalent halogenated hydrocarbon group, a monovalent halogenated oxygen-containing hydrocarbon. There is no particular limitation as long as it is any one of a group, a monovalent halogenated nitrogen-containing hydrocarbon group, and a group in which two or more kinds of these groups are bonded so as to be monovalent. R ^{26 to} R ³⁵ may be the same group or different groups. Part of R ^{26 to} R ³⁵ may be the same group. The details regarding the monovalent hydrocarbon group and the monovalent halogenated hydrocarbon group are as described above.

The monovalent oxygen-containing hydrocarbon group is a general term for monovalent groups composed of carbon, hydrogen and oxygen, and may be linear or branched having one or more side chains. May be As the monovalent oxygen-containing hydrocarbon group, specifically, it can be exemplified an alkoxy group, the alkoxy group, specifically, methoxy group <-OCH _3>, an ethoxy group <-OC ₂ H _5> , it can be exemplified propoxy <-OC ₃ H _7>.

The monovalent nitrogen-containing hydrocarbon group is a general term for monovalent groups composed of carbon, hydrogen and nitrogen, and may be linear or branched having one or more side chains. May be As the monovalent nitrogen-containing hydrocarbon group, specifically, there can be mentioned amino group <-NH _2>.

The monovalent halogenated oxygen-containing hydrocarbon group is a group in which one or more hydrogen groups of the monovalent oxygen-containing hydrocarbon group are substituted with a halogen group. The details regarding the monovalent oxygen-containing hydrocarbon group and the halogen group are as described above. Monovalent halogenated oxygen-containing hydrocarbon group, specifically, perfluoro methoxy group <-OCF ₃ ->, perfluoroethoxy group <-OC ₂ F ₄ -> can be exemplified.

The monovalent halogenated nitrogen-containing hydrocarbon group is a group in which one or more hydrogen groups of the monovalent nitrogen-containing hydrocarbon group are substituted with a halogen group. The details regarding the monovalent nitrogen-containing hydrocarbon group and the halogen group are as described above. Monovalent halogenated nitrogen-containing hydrocarbon group, specifically, perfluoro amino group <-NF _2>, it can be exemplified perfluoro methylamino group <-CF ₂ -NF _2>.

As the group in which two or more kinds are bonded, specifically, a group in which an alkyl group and an alkoxy group are bonded so as to be monovalent (alkylalkoxy group), and a group in which an alkyl group and an amino group are bonded together are monovalent. Examples thereof include alkylamino groups. As alkylalkoxy group, specifically, it can be exemplified methyl methoxy <-CH ₂ -OCH _3>. As alkylamino group, specifically, it can be exemplified methylamino group <-CH ₂ -NH _2>.

Specific examples of the aromatic carbonic acid ester include diphenyl carbonate, bis-4-methylphenyl carbonate and bispentafluorophenyl carbonate.

The content of the aromatic carbonic acid ester in the non-aqueous electrolyte solution is not particularly limited, but for example, it is preferably 0.01% by mass to 10% by mass with respect to the total amount excluding the aromatic carbonic acid ester.

The cyclic carbonic acid ester is any one kind or two or more kinds of compounds represented by the above formula (12). R ^{36 to} R ³⁹ are not particularly limited as long as they are any of a hydrogen group and a monovalent hydrocarbon group. R ^{36 to} R ³⁹ may be the same group or different groups. Part of R ^{36 to} R ³⁹ may be the same group. The details regarding the monovalent hydrocarbon group are as described above. Specific examples of the cyclic carbonic acid ester include ethylene carbonate, propylene carbonate and butylene carbonate. The content of the cyclic ester carbonate in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass to 80% by mass.

The chain monocarbonic acid ester is any one kind or two or more kinds of compounds represented by the above formula (13). R ⁴⁰ and R ⁴¹ are not particularly limited as long as they are either a hydrogen group or a monovalent hydrocarbon group. R ⁴⁰ and R ⁴¹ may be the same group or different groups. Part of R ⁴⁰ and R ⁴¹ may be the same group. The details regarding the monovalent hydrocarbon group are as described above. Specific examples of the chain monocarbonic acid ester include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate and methyl propyl carbonate. The content of the chain monocarbonate ester in the non-aqueous electrolytic solution is not particularly limited, but is preferably 0.01% by mass to 70% by mass, for example.

The chain carboxylic acid ester is any one kind or two or more kinds of compounds represented by the above formula (14). R ⁴² and R ⁴³ are not particularly limited as long as they are either a hydrogen group or a monovalent hydrocarbon group. R ⁴² and R ⁴³ may be the same group or different groups. The details regarding the monovalent hydrocarbon group are as described above. Specific examples of the chain carboxylic acid ester include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, trimethyl methyl acetate, and trimethyl ethyl acetate. The content of the chain carboxylic acid ester in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass to 50% by mass with respect to the total amount excluding the chain carboxylic acid ester. ..

The phosphoric acid ester is any one kind or two or more kinds of compounds represented by the above formula (15). R ^{44 to} R ⁴⁶ are not particularly limited as long as they are either a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group. R ^{44 to} R ⁴⁶ may be the same group or different groups. Part of R ^{44 to} R ⁴⁶ may be the same group. The details regarding the monovalent hydrocarbon group and the monovalent halogenated hydrocarbon group are as described above. Specific examples of the phosphoric acid ester include trimethyl phosphate, triethyl phosphate, trifluoroethyl phosphate, and tripropyl phosphate. The content of the phosphoric acid ester in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass to 50% by mass with respect to the total total excluding the phosphoric acid ester.

Furthermore, as the other material, any one kind or two or more kinds of solvents such as a non-aqueous solvent (organic solvent) can be mentioned. However, other materials such as the above-mentioned sulfonates are excluded from the non-aqueous solvent described here.

Further, as the other material, for example, one kind or two or more kinds of electrolyte salts such as lithium salt can be exemplified. However, the electrolyte salt may contain a salt other than the lithium salt, for example. The salt other than the lithium salt is, for example, a light metal salt other than the lithium salt.

Hereinafter, a lithium salt will be described as a specific example of the electrolyte salt, but the lithium salt may be changed to a salt other than the lithium salt. That is, for example, lithium hexafluorophosphate described below may be changed to another light metal salt such as sodium hexafluorophosphate or potassium hexafluorophosphate.

Specific examples of the lithium salt include the various lithium salts described above, and the internal resistance can be reduced. Among them, any one of lithium hexafluorophosphate <LiPF ₆ >, lithium tetrafluoroborate <LiBF ₄ >, lithium perchlorate <LiClO ₄ >, and lithium hexafluoroarsenate <LiAsF ₆ > system or Two or more types are preferable. This is because the internal resistance becomes lower. In particular, lithium hexafluorophosphate <LiPF ₆ > and lithium tetrafluoroborate <LiBF ₄ > are more preferable, and lithium hexafluorophosphate <LiPF ₆ > is even more preferable.

The electrolyte salt may be any one kind or two or more kinds of the compounds represented by the formula (17), the formula (18) and the formula (19). R ⁵¹ and R ⁵³ may be the same group or different groups. The same applies to R ⁶¹ , R ⁶² , and R ⁶³ , and the same applies to R ⁷¹ and R ⁷² . Two of R ⁶¹ , R ⁶² and R ⁶³ may be the same group.

Here, X ⁵¹ is any one of a Group 1 element, a Group 2 element, and Al in the long periodic table. M ⁵¹ is a transition metal, or a group 13 element, a group 14 element, or a group 15 element in the long periodic table. R ⁵¹ is a halogen group. Further, Y ^{51 is, -C (= O) -R 52} -C (= O) -, - C (= O) -CR 53 2 -, - C (= O) -C (= O) - either It is. However, R ⁵² is any one of an alkylene group, a halogenated alkylene group, an arylene group and a halogenated arylene group, and R ⁵³ is any of an alkyl group, a halogenated alkyl group, an aryl group and a halogenated aryl group. is there. Further, a5 is an integer of 1 to 4, b5 is either 0, 2, or 4, and c5, d5, m5, and n5 are integers of 1 to 3.

Here, X ⁶¹ is either a Group 1 element or a Group 2 element in the long periodic table. M ⁶¹ is a transition metal, or a group 13 element, a group 14 element, or a group 15 element in the long periodic table. Y ⁶¹ is, -C (= O) - ( CR 61 2) b6 -C (= O) -, - R 63 2 C- (CR 62 2) c6 -C (= O) -, - R 63 2 C -(CR ⁶² ₂ ) _{c 6} -CR ⁶³ ₂ -, -R ⁶³ ₂ C -(CR ⁶² ₂ ) _{c 6} -S(=O) ₂ -, -S(=O) ₂ -(CR ⁶² ₂ ) _d6- S _{(= O) 2 -, -} C (= O) - (CR 62 2) d6 -S (= O) 2 - is either. However, each of R ⁶¹ and R ⁶³ is any one of a hydrogen group, an alkyl group, a halogen group, and a halogenated alkyl group. However, R ⁶¹ is either a halogen group or a halogenated alkyl group, and R ⁶³ is either a halogen group or a halogenated alkyl group. R ⁶² is any of a hydrogen group, an alkyl group, a halogen group and a halogenated alkyl group. Further, a6, e6, and n6 are integers of 1 or 2, b6 and d6 are integers of 1 to 4, c6 is an integer of 0 to 4, and f6 and m6 are integers of 1 to 3.

Here, X ⁷¹ is either a Group 1 element or a Group 2 element in the long periodic table. M ⁷¹ is a transition metal, or any one of Group 13 elements, Group 14 elements, and Group 15 elements in the long periodic table. R _f is either a fluorinated alkyl group or a fluorinated aryl group, and the carbon number of the fluorinated alkyl group or the fluorinated aryl group is 1 to 10. Y ⁷¹ is, -C (= O) - ( CR 71 2) d7 -C (= O) -, - R 72 2 C- (CR 71 2) d7 -C (= O) -, - R 72 2 C _{^{- (CR 71 2) d7 -CR}} 72 2 -, - R 72 2 C- (CR 71 2) d7 -S (= O) 2 -, - S (= O) 2 - (CR 71 2) e7 -S _{(= O) 2 -, -} C (= O) - (CR 71 2) e7 -S (= O) 2 - is either. However, R ⁷¹ is any one of a hydrogen group, an alkyl group, a halogen group and a halogenated alkyl group, and R ⁷² is any one of a hydrogen group, an alkyl group, a halogen group and a halogenated alkyl group, and R ⁷² Is either a halogen group or a halogenated alkyl group. Further, a7, f7, n7 are integers of 1 or 2, b7, c7, e7 are integers of 1 to 4, d7 is an integer of 0 to 4, g7, m7 are integers of 1 to 3. is there.

Group 1 elements are hydrogen <H>, lithium <Li>, sodium <Na>, potassium <K>, rubidium <Rb>, cesium <Cs>, and francium <Fr>. Group 2 elements are beryllium <Be>, magnesium <Mg>, calcium <Ca>, strontium <Sr>, barium <Ba>, and radium <Ra>. Group 13 elements are boron <B>, aluminum <Al>, gallium <Ga>, indium <In>, thallium <Tl>. Group 14 elements are carbon <C>, silicon <Si>, germanium <Ge>, tin <Sn>, and lead <Pb>. Group 15 elements are nitrogen <N>, phosphorus <P>, arsenic <As>, antimony <Sb>, bismuth <Bi>.

Specific examples of the compound represented by the formula (17) include compounds represented by the formulas (17-1) to (17-6). Specific examples of the compound represented by Formula (18) include compounds represented by Formula (18-1) to Formula (18-8). Specific examples of the compound represented by the formula (19) include compounds represented by the formula (19-1).

Further, as the electrolyte salt, a compound represented by the formula (20) or the formula (21) can be exemplified. p, q, and r may have the same value or different values. Two of p, q, and r may have the same value.

但し、Ｒ⁸¹は炭素数２乃至４の直鎖状又は分岐状のパーフルオロアルキレン基である。

However, R ⁸¹ is a linear or branched perfluoroalkylene group having 2 to 4 carbon atoms.

_{LiC (C p F 2p + 1} SO 2) (C q F 2q + 1 SO 2) (C r F 2r + 1 SO 2) (21)
However, p, q, and r are integers of 1 or more.

The compound represented by the formula (20) is a cyclic imide compound. Specific examples of the cyclic imide compound include compounds represented by formula (20-1) to formula (20-4).

The compound represented by formula (21) is a chain methide compound. Specific examples of the chain methide compound include lithium tristrifluoromethanesulfonylmethide <LiC(CF ₃ SO ₂ ) ₃ >.

The content of the electrolyte salt is not particularly limited, but is preferably 0.3 mol/kg to 3.0 mol/kg with respect to the solvent, from the viewpoint of obtaining high ionic conductivity. When calculating the content of the electrolyte salt, the amount of the above-mentioned first compound, lithium monofluorophosphate, and lithium difluorophosphate may be included in the amount of the electrolyte salt. In addition, the amount of the solvent, the second compound, the third compound, sulfonic acid ester, acid anhydride, cyclic carboxylic acid ester, dialkyl sulfoxide, chain dicarbonic acid ester, aromatic carbonic acid ester, cyclic carbonic acid ester, chain monocarbonic acid The amount of ester, chain carboxylic acid ester, phosphoric acid ester may be included.

Although the intrinsic viscosity of the non-aqueous electrolyte is not particularly limited, it is preferably 10 mPa/s or less at 25° C. from the viewpoint of ensuring the dissociation property of the electrolyte salt and the ion mobility.

In particular, the non-aqueous electrolyte solution is a sulfonic acid ester, an acid anhydride, a cyclic carboxylic acid ester, a dialkyl sulfoxide, a chain dicarbonic acid ester, an aromatic carbonic acid ester, a cyclic carbonic acid ester, a chain monocarbonic acid ester, a chain carboxylic acid ester. If one or more of phosphoric acid ester, lithium monofluorophosphate and lithium difluorophosphate are contained, a higher effect can be obtained.

Ｒ²²−（ＣＮ）_n （３−Ｆ）
但し、
式（１）中、Ｍは金属元素であり、Ｚ¹及びＺ²のそれぞれは、フッ素基、１価の炭化水素基、１価のフッ素化炭化水素基のいずれかであり、Ｚ¹及びＺ²の少なくとも一方は、フッ素基、１価のフッ素化炭化水素基のいずれかであり、Ｙ¹及びＹ²のそれぞれは、スルホニル基、カルボニル基のいずれかであり、
式（２−Ａ）中、Ｒ¹は１価の炭化水素基であり、
式（２−Ｂ）中、Ｒ²は１価の炭化水素基であり、Ｘは、１又は２以上のエーテル結合と１又は２以上の２価の炭化水素基とが任意の順に結合した基であり、
式（３−Ａ）中、Ｒ³及びＲ⁴のそれぞれは、水素基、１価の炭化水素基のいずれかであり、
式（３−Ｂ）中、Ｒ⁵，Ｒ⁶，Ｒ⁷，Ｒ⁸のそれぞれは、水素基、１価の飽和炭化水素基、１価の不飽和炭化水素基のいずれかであり、Ｒ⁵，Ｒ⁶，Ｒ⁷，Ｒ⁸の少なくとも１つは、１価の不飽和炭化水素基であり、
式（３−Ｃ）中、Ｒ⁹は、＞ＣＲ¹⁰Ｒ¹¹で表される基であり、Ｒ¹⁰及びＲ¹¹のそれぞれは、水素基、１価の炭化水素基のいずれかであり、
式（３−Ｄ）中、Ｒ¹²，Ｒ¹³，Ｒ¹⁴，Ｒ¹⁵のそれぞれは、水素基、ハロゲン基、１価の炭化水素基、１価のハロゲン化炭化水素基のいずれかであり、Ｒ¹²，Ｒ¹³，Ｒ¹⁴，Ｒ¹⁵の少なくとも１つは、ハロゲン基、１価のハロゲン化炭化水素基のいずれかであり、
式（３−Ｅ）中、Ｒ¹⁶，Ｒ¹⁷，Ｒ¹⁸，Ｒ¹⁹，Ｒ²⁰，Ｒ²¹のそれぞれは、水素基、ハロゲン基、１価の炭化水素基、１価のハロゲン化炭化水素基のいずれかであり、Ｒ¹⁶，Ｒ¹⁷，Ｒ¹⁸，Ｒ¹⁹，Ｒ²⁰，Ｒ²¹の少なくとも１つは、ハロゲン基、１価のハロゲン化炭化水素基のいずれかであり、
式（３−Ｆ）中、Ｒ²²はｎ価（但し、ｎは２以上の整数）の炭化水素基である。
［Ｃ０２］Ｍは、アルカリ金属元素であり、
１価の炭化水素基は、アルキル基、アルケニル基、アルキニル基、シクロアルキル基、アリール基、及び、これらの２種類以上が１価となるように結合した基のいずれかであり、
１価のフッ素化炭化水素基は、１価の炭化水素基の内の少なくとも１つの水素基がフッ素基によって置換された基であり、
２価の炭化水素基は、アルキレン基、アルケニレン基、アルキニレン基、シクロアルキレン基、アリーレン基、及び、これらの２種類以上が結合された基のいずれかであり、
１価の飽和炭化水素基は、アルキル基、シクロアルキル基、及び、これらが１価となるように結合された基のいずれかであり、
１価の不飽和炭化水素基は、アルケニル基、アルキニル基、アリール基、これらの１種類以上を含む基、及び、これらの２種類以上が１価となるように結合された基のいずれかであり、
ハロゲン基は、フッ素基、塩素基、臭素基、及び、ヨウ素基のいずれかであり、
１価のハロゲン化炭化水素基は、１価の炭化水素基の内の少なくとも１つの水素基がハロゲン基によって置換された基である［Ｃ０１］に記載のリチウムイオン電池。
［Ｃ０３］Ｍはリチウムであり、
１価のフッ素化炭化水素基は、パーフルオロアルキル基であり、
Ｘは、−Ｏ−Ｙ−（但し、Ｙは、２価の炭化水素基）で表される基である［Ｃ０１］又は［Ｃ０２］に記載のリチウムイオン電池。
［Ｃ０４］非水系電解液は、スルホン酸エステル、酸無水物、環状カルボン酸エステル、ジアルキルスルホキシド、式（１０）乃至式（１５）で表される化合物、モノフルオロリン酸リチウム、及び、ジフルオロリン酸リチウムの少なくとも１種を含む［Ｃ０１］乃至［Ｃ０３］のいずれか１項に記載のリチウムイオン電池。

但し、
Ｒ²³及びＲ²⁴のそれぞれは、１価の炭化水素基、１価のハロゲン化炭化水素基のいずれかであり、
Ｒ²⁵は、２価の炭化水素基、２価のハロゲン化炭化水素基のいずれかであり、
Ｒ²⁶，Ｒ²⁷，Ｒ²⁸，Ｒ²⁹，Ｒ³⁰，Ｒ³¹，Ｒ³²，Ｒ³³，Ｒ³⁴，Ｒ³⁵のそれぞれは、１価の炭化水素基、１価の酸素含有炭化水素基、１価の窒素含有炭化水素基、１価のハロゲン化炭化水素基、１価のハロゲン化酸素含有炭化水素基、１価のハロゲン化窒素含有炭化水素基、これらの２種類以上が１価となるように結合した基のいずれかであり、
Ｒ³⁶，Ｒ³⁷，Ｒ³⁸，Ｒ³⁹のそれぞれは、水素基、１価の炭化水素基のいずれかであり、
Ｒ⁴⁰及びＲ⁴¹のそれぞれは、水素基、１価の炭化水素基のいずれかであり、
Ｒ⁴²及びＲ⁴³のそれぞれは、水素基、１価の炭化水素基のいずれかであり、
Ｒ⁴⁴，Ｒ⁴⁵，Ｒ⁴⁶のそれぞれは、１価の炭化水素基、１価のハロゲン化炭化水素基のいずれかである。
［Ｃ０５］２価のハロゲン化炭化水素基は、２価の炭化水素基の内の少なくとも１つの水素基がハロゲン基によって置換された基であり、
ハロゲン基は、フッ素基、塩素基、臭素基及びヨウ素基のいずれかであり、
１価の酸素含有炭化水素基は、アルコキシ基であり、
１価の窒素含有炭化水素基は、アルキルアミノ基であり、
１価のハロゲン化酸素含有炭化水素基は、１価の酸素含有炭化水素基の内の少なくとも１つの水素基がハロゲン基によって置換された基であり、
１価のハロゲン化窒素含有炭化水素基は、１価の窒素含有炭化水素基の内の少なくとも１つの水素基がハロゲン基によって置換された基である［Ｃ０４］に記載のリチウムイオン電池。
［Ｃ０６］非水系電解液は、六フッ化リン酸リチウム及び四フッ化ホウ酸リチウムの内の少なくとも一方を含む［Ｃ０１］乃至［Ｃ０５］のいずれか１項に記載のリチウムイオン電池。
［Ｃ０７］正極は、電極反応物質を吸蔵・放出可能である正極活物質を含み、
負極は、電極反応物質を吸蔵・放出可能である負極活物質を含み、
正極活物質と負極活物質との間に絶縁性材料を備え、
絶縁性材料は、絶縁性セラミックス及び絶縁性高分子化合物の少なくとも一方を含む［Ｃ０１］乃至［Ｃ０６］のいずれか１項に記載のリチウムイオン電池。
［Ｃ０８］絶縁性セラミックスは、酸化アルミニウム、酸化ケイ素、酸化マグネシウム、酸化チタン、及び、酸化ジルコニウムの少なくとも１種を含み、
絶縁性高分子化合物は、フッ化ビニリデンの単独重合体及び共重合体の少なくとも一方を含む［Ｃ０７］に記載のリチウムイオン電池。
［Ｃ０９］正極活物質の表面に、絶縁性材料を含む第１絶縁層が設けられている［Ｃ０７］又は［Ｃ０８］に記載のリチウムイオン電池。
［Ｃ１０］負極の表面に、絶縁性材料を含む第２絶縁層が設けられている［Ｃ０７］又は［Ｃ０８］に記載のリチウムイオン電池。
［Ｃ１１］セパレータの表面に、絶縁性材料を含む第３絶縁層が設けられている［Ｃ０７］又は［Ｃ０８］に記載のリチウムイオン電池。
［Ｄ０１］《電池パック》
［Ａ０１］乃至［Ｃ１１］のいずれか１項に記載のリチウムイオン電池、
リチウムイオン電池の動作を制御する制御部、及び、
制御部の指示に応じてリチウムイオン電池の動作を切り換えるスイッチ部、
を備えている電池パック。
［Ｄ０２］《電動車両》
［Ａ０１］乃至［Ｃ１１］のいずれか１項に記載のリチウムイオン電池、
リチウムイオン電池から供給された電力を駆動力に変換する変換部、
駆動力に応じて駆動する駆動部、及び、
リチウムイオン電池の動作を制御する制御部、
を備えている電動車両。
［Ｄ０３］《電力貯蔵システム》
［Ａ０１］乃至［Ｃ１１］のいずれか１項に記載のリチウムイオン電池、
リチウムイオン電池から電力を供給される１又は２以上の電気機器、及び、
リチウムイオン電池からの電気機器に対する電力供給を制御する制御部、
を備えている電力貯蔵システム。
［Ｄ０４］《電動工具》
［Ａ０１］乃至［Ｃ１１］のいずれか１項に記載のリチウムイオン電池、及び、
リチウムイオン電池から電力を供給される可動部、
を備えている電動工具。
［Ｄ０５］《電子機器》
［Ａ０１］乃至［Ｃ１１］のいずれか１項に記載のリチウムイオン電池を電力供給源として備えている電子機器。 Note that the present disclosure can also take the following configurations.
[A01] <<Lithium Ion Battery: First Mode>>
A lithium ion battery in which a structure in which a positive electrode, a separator and a negative electrode are wound or laminated is housed in an exterior member and which is filled with an electrolyte,
The longitudinal direction of the structure is the X direction, the lateral direction of the structure is the Z direction, and the thickness direction of the structure is the Y direction.
The outer surface along the XZ plane of the structure is the first surface and the second surface,
The portion of the structure on the first surface side is the first portion, the portion of the structure on the second surface side that is in contact with the first portion is the second portion,
A side surface portion of the exterior member facing the first portion in the X direction is a first side surface portion, and a side surface portion of the exterior member facing the second portion in the X direction is a second side surface portion,
The linear expansion amount in the X direction of the first portion during charging is ΔX ₁ , and the linear expansion amount in the X direction of the second portion during charging is ΔX ₂ .
The minimum value of the gap located between the first part and the first side surface part is d ₁ , the maximum value of the gap located between the second part and the second side surface part is d ₂ , the first part And the second portion, and the value of the gap located between the side surface portion of the exterior member facing the boundary in the X direction is d _m ,
ΔX ₁ >ΔX ₂
And, and
_{d 1 <ΔX 1 <d m} <d 2
A lithium-ion battery that satisfies the requirements.
[A02] The lithium ion battery according to [A01], wherein the exterior member has a Young's modulus of 5×10 ⁸ Pa to 7×10 ⁹ Pa.
[A03] The lithium ion battery according to [A01] or [A02], in which the exterior member has a laminated structure of a plastic material layer, a metal layer, and a plastic material layer.
The lithium-ion battery according to any one of [A01] to [A03], in which the [A04] electrolyte is a gel electrolyte.
[A05] The lithium-ion battery according to any one of [A01] to [A04], in which the material forming the separator is polypropylene resin, polyethylene resin, or polyimide resin.
[B01] <<Lithium-ion Battery: Second Mode>>
A lithium ion battery in which a structure in which a positive electrode, a separator and a negative electrode are wound or laminated is housed in an exterior member and which is filled with an electrolyte,
The longitudinal direction of the structure is the X direction, the lateral direction of the structure is the Z direction, and the thickness direction of the structure is the Y direction.
The outer surface along the XZ plane of the structure is the first surface and the second surface,
The portion of the structure on the first surface side is the first portion, the portion of the structure on the second surface side that is in contact with the first portion is the second portion,
A side surface portion of the exterior member facing the first portion in the X direction is a first side surface portion, and a side surface portion of the exterior member facing the second portion in the X direction is a second side surface portion,
When the linear expansion amount in the X direction of the first portion during charging is ΔX ₁ , and the linear expansion amount in the X direction of the second portion during charging is ΔX ₂ ,
ΔX ₁ >ΔX ₂
In addition, the lithium ion battery in which at least a part of the first portion is in contact with the first side surface portion of the exterior member and the second portion is not in contact with the second side surface portion of the exterior member during charging.
[B02] The lithium ion battery according to [B01], wherein the exterior member has a Young's modulus of 5×10 ⁸ Pa to 7×10 ⁹ Pa.
[B03] The lithium ion battery according to [B01] or [B02], in which the exterior member has a laminated structure of a plastic material layer, a metal layer, and a plastic material layer.
The lithium ion battery according to any one of [B01] to [B03], in which the [B04] electrolyte is a gel electrolyte.
[B05] The lithium ion battery according to any one of [B01] to [B04], in which the material forming the separator is polypropylene resin, polyethylene resin, or polyimide resin.
The [C01] electrolyte is composed of a non-aqueous electrolyte solution,
The non-aqueous electrolyte is
A compound represented by the formula (1),
At least one of the compound represented by formula (2-A) and the compound represented by formula (2-B); and
At least one compound of the compounds represented by formula (3-A) to formula (3-F),
And the content of the compound represented by the formula (1) is 2.5 mol/liter to 6 mol/liter, preferably 3 mol/liter to 6 mol/liter of [A01] to [B05]. The lithium-ion battery according to any one of items.
M ⁺ [(Z ¹ Y ¹ )(Z ² Y ² )N] ^- (1)
R ¹ -CN (2-A)
^{R 2 -X-CN (2-} B)

_{^{R 22 - (CN) n (}} 3-F)
However,
In the formula (1), M is a metal element, and each of Z ¹ and Z ² is a fluorine group, a monovalent hydrocarbon group or a monovalent fluorinated hydrocarbon group, and Z ¹ and Z ^At least one of ² is a fluorine group or a monovalent fluorinated hydrocarbon group, and each of Y ¹ and Y ² is a sulfonyl group or a carbonyl group,
In formula (2-A), R ¹ is a monovalent hydrocarbon group,
In formula (2-B), R ² is a monovalent hydrocarbon group, and X is a group in which a 1 or 2 or more ether bond and a 1 or 2 or more divalent hydrocarbon group are bonded in any order. And
In formula (3-A), each of R ³ and R ⁴ is a hydrogen group or a monovalent hydrocarbon group,
In formula (3-B), each of R ⁵ , R ⁶ , R ⁷ , and R ⁸ is a hydrogen group, a monovalent saturated hydrocarbon group, or a monovalent unsaturated hydrocarbon group, and R ⁵ , R ⁶ , R ⁷ , and R ⁸ are at least one monovalent unsaturated hydrocarbon group,
In formula (3-C), R ⁹ is a group represented by >CR ¹⁰ R ¹¹ , and each of R ¹⁰ and R ¹¹ is a hydrogen group or a monovalent hydrocarbon group,
In formula (3-D), each of R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ is a hydrogen group, a halogen group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, At least one of R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ is any one of a halogen group and a monovalent halogenated hydrocarbon group,
In formula (3-E), each of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , and R ²¹ is a hydrogen group, a halogen group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group. At least one of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , and R ²¹ is a halogen group or a monovalent halogenated hydrocarbon group,
In the formula (3-F), R ²² is an n-valent (where n is an integer of 2 or more) hydrocarbon group.
[C02]M is an alkali metal element,
The monovalent hydrocarbon group is any of an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, and a group in which two or more kinds of these groups are monovalently bonded,
The monovalent fluorinated hydrocarbon group is a group in which at least one hydrogen group in the monovalent hydrocarbon group is substituted with a fluorine group,
The divalent hydrocarbon group is any of an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group, an arylene group, and a group in which two or more of these are bonded,
The monovalent saturated hydrocarbon group is any of an alkyl group, a cycloalkyl group, and a group in which these are monovalently bonded,
The monovalent unsaturated hydrocarbon group is either an alkenyl group, an alkynyl group, an aryl group, a group containing at least one of these, or a group in which two or more of these groups are monovalently bonded. Yes,
The halogen group is any one of a fluorine group, a chlorine group, a bromine group, and an iodine group,
The lithium ion battery according to [C01], wherein the monovalent halogenated hydrocarbon group is a group in which at least one hydrogen group in the monovalent hydrocarbon group is substituted with a halogen group.
[C03]M is lithium,
The monovalent fluorinated hydrocarbon group is a perfluoroalkyl group,
The lithium ion battery according to [C01] or [C02], wherein X is a group represented by -O-Y- (where Y is a divalent hydrocarbon group).
[C04] The non-aqueous electrolyte solution is a sulfonic acid ester, an acid anhydride, a cyclic carboxylic acid ester, a dialkyl sulfoxide, a compound represented by the formula (10) to the formula (15), lithium monofluorophosphate, and difluorophosphorus. The lithium ion battery according to any one of [C01] to [C03], which contains at least one kind of lithium acid.

However,
R ²³ and R ²⁴ are each a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group,
R ²⁵ is either a divalent hydrocarbon group or a divalent halogenated hydrocarbon group,
Each of R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ is a monovalent hydrocarbon group, a monovalent oxygen-containing hydrocarbon group, 1 Valent nitrogen-containing hydrocarbon group, monovalent halogenated hydrocarbon group, monovalent halogenated oxygen-containing hydrocarbon group, monovalent halogenated nitrogen-containing hydrocarbon group, such that two or more of these are monovalent Is one of the groups bonded to
R ³⁶ , R ³⁷ , R ³⁸ , and R ³⁹ are each a hydrogen group or a monovalent hydrocarbon group,
R ⁴⁰ and R ⁴¹ are each a hydrogen group or a monovalent hydrocarbon group,
R ⁴² and R ⁴³ are each a hydrogen group or a monovalent hydrocarbon group,
Each of R ⁴⁴ , R ⁴⁵ and R ⁴⁶ is either a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group.
The [C05] divalent halogenated hydrocarbon group is a group in which at least one hydrogen group in the divalent hydrocarbon group is substituted with a halogen group,
The halogen group is any one of a fluorine group, a chlorine group, a bromine group and an iodine group,
The monovalent oxygen-containing hydrocarbon group is an alkoxy group,
The monovalent nitrogen-containing hydrocarbon group is an alkylamino group,
The monovalent halogenated oxygen-containing hydrocarbon group is a group in which at least one hydrogen group in the monovalent oxygen-containing hydrocarbon group is substituted with a halogen group,
The lithium ion battery according to [C04], wherein the monovalent halogenated nitrogen-containing hydrocarbon group is a group in which at least one hydrogen group in the monovalent nitrogen-containing hydrocarbon group is substituted with a halogen group.
[C06] The lithium-ion battery according to any one of [C01] to [C05], wherein the non-aqueous electrolyte solution contains at least one of lithium hexafluorophosphate and lithium tetrafluoroborate.
[C07] The positive electrode contains a positive electrode active material capable of inserting and extracting an electrode reactant,
The negative electrode contains a negative electrode active material capable of inserting and extracting an electrode reactant,
An insulating material is provided between the positive electrode active material and the negative electrode active material,
The lithium ion battery according to any one of [C01] to [C06], wherein the insulating material contains at least one of an insulating ceramic and an insulating polymer compound.
The [C08] insulating ceramic contains at least one of aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, and zirconium oxide,
The lithium ion battery according to [C07], wherein the insulating polymer compound contains at least one of a vinylidene fluoride homopolymer and a copolymer.
[C09] The lithium ion battery according to [C07] or [C08], in which a first insulating layer containing an insulating material is provided on the surface of the positive electrode active material.
[C10] The lithium ion battery according to [C07] or [C08], in which a second insulating layer containing an insulating material is provided on the surface of the negative electrode.
[C11] The lithium ion battery according to [C07] or [C08], in which a third insulating layer containing an insulating material is provided on the surface of the separator.
[D01] <<Battery pack>>
The lithium ion battery according to any one of [A01] to [C11],
A control unit for controlling the operation of the lithium-ion battery, and
A switch unit that switches the operation of the lithium-ion battery according to the instruction of the control unit,
Battery pack equipped with.
[D02] <<Electric vehicle>>
The lithium ion battery according to any one of [A01] to [C11],
A converter that converts the electric power supplied from the lithium-ion battery into driving force,
A drive unit that drives according to the drive force, and
A control unit that controls the operation of the lithium-ion battery,
An electric vehicle equipped with.
[D03] <<Power storage system>>
The lithium ion battery according to any one of [A01] to [C11],
One or more electric devices supplied with power from a lithium-ion battery, and
A control unit that controls the power supply from the lithium-ion battery to the electric device,
Power storage system comprising.
[D04] <<Electric power tool>>
The lithium ion battery according to any one of [A01] to [C11], and
Moving parts powered by lithium-ion batteries,
Power tool equipped with.
[D05] <<Electronic equipment>>
An electronic device comprising the lithium ion battery according to any one of [A01] to [C11] as a power supply source.

10... Structure, 10A... First surface which is the outer surface of the structure, 10B... Second surface which is the outer surface of the structure, 11... Part of the structure on the first surface side 1st part, 12... 2nd part which is a part of the structure by the side of a 2nd surface, 13... boundary of 1st part and 2nd part, 20... exterior member, 21 ...First side surface portion that is a side surface portion of the exterior member that faces the first portion in the X direction, 22...Second side portion that is a side surface portion of the exterior member that faces the second portion in the X direction Side portion, 23... Side portion of the exterior member facing the boundary in the X direction, 30... Winding electrode body (structure), 31... Positive electrode lead, 32... Negative electrode lead, 33. ....Positive electrode, 33A... Positive electrode current collector, 33B... Positive electrode active material layer, 34... Negative electrode, 34A... Negative electrode current collector, 34B... Negative electrode active material layer, 35... Separator, 36... Electrolyte layer, 37... Protective tape, 40... Exterior member, 41... Adhesive film, 50... Laminated electrode body (structure), 53... Positive electrode, 53A. .. Positive electrode current collector, 53B... Positive electrode active material layer, 54... Negative electrode, 54A... Negative electrode current collector, 54B... Negative electrode active material layer, 55... Separator, 58... Exterior member, 211... Positive electrode active material, 212... Active material insulating layer, 213... Negative electrode insulating layer, 214... Separator insulating layer, 60... Casing, 61... Control section, 62... Power source, 63... Switch section, 64... Current measuring section, 65... Temperature detecting section, 66... Voltage detecting section, 67... Switch control section, 68... Memory , 69... Temperature detecting element, 70... Current detecting resistor, 71... Positive terminal, 72... Negative terminal, 73... Casing, 74... Control section, 75... Engine , 76... Power source, 77... Motor, 78... Differential device, 79... Generator, 80... Transmission, 81... Clutch, 82, 83... Inverter, 84... ..Various sensors, 85... front wheel drive shaft, 86... front wheel, 87... rear wheel drive shaft, 88... rear wheel, 89... house, 90... control unit, 91... Power source, 92... Smart meter, 93... Power hub, 94... Electric equipment (electronic equipment), 95... Private generator, 96... Electric vehicle, 97... Concentrated Mold power system, 98... Tool body, 99... Control part, 100... Power supply, 101... Drill part, 111... Power supply, 116... Circuit board, 112... Positive electrode lead 113, negative electrode lead, 118, 119... adhesive tape, 114... tab, 115... tab, 117... lead wire with connector, 120... label, 121... insulation Sheet, 121... Control unit, 122... Switch unit, 123... PTC, 124... Temperature detection unit, 125... Positive electrode terminal, 126... Temperature detection element, 127... Negative electrode Terminal

Claims (6)

A lithium ion battery in which a structure in which a positive electrode, a separator and a negative electrode are wound or laminated is housed in an exterior member and which is filled with an electrolyte,
The longitudinal direction of the structure is the X direction, the lateral direction of the structure is the Z direction, and the thickness direction of the structure is the Y direction.
The outer surface along the XZ plane of the structure is the first surface and the second surface,
The portion of the structure on the first surface side is the first portion, the portion of the structure on the second surface side that is in contact with the first portion is the second portion,
A side surface portion of the exterior member facing the first portion in the X direction is a first side surface portion, and a side surface portion of the exterior member facing the second portion in the X direction is a second side surface portion,
The linear expansion amount in the X direction of the first portion during charging is ΔX ₁ , and the linear expansion amount in the X direction of the second portion during charging is ΔX ₂ .
The minimum value of the gap located between the first portion and the first side surface portion is d ₁ , the maximum value of the gap located between the second portion and the second side surface portion is d ₂ , the first portion when the boundary between the second portion, and, when the value of the gap located between the side portion of the outer member opposite the boundary and X direction is d _m,
ΔX ₁ >ΔX ₂
And, and
_{d 1 <ΔX 1 <d m} <d 2
Satisfied ,
The boundary between the first portion and the second portion passes through the winding center of the wound structure and is in the middle of the thickness direction in the XZ plane, or the boundary between the first portion and the second portion is the thickness of the laminated structure. Ri XZ plane der in the thickness direction of the intermediate passing through the center of the direction, and
A lithium ion battery in which the Young's modulus of the exterior member is higher than the Young's modulus of the first portion and the Young's modulus of the second portion . The lithium ion battery according to claim 1, wherein the Young's modulus of the exterior member is 5×10 ⁸ Pa to 7×10 ⁹ Pa. The lithium ion battery according to claim 1, wherein the exterior member has a laminated structure of a plastic material layer, a metal layer, and a plastic material layer. The lithium ion battery according to claim 1, wherein the electrolyte is a gel electrolyte. The lithium ion battery according to claim 1, wherein the material forming the separator is polypropylene resin, polyethylene resin, or polyimide resin. A lithium ion battery in which a structure in which a positive electrode, a separator and a negative electrode are wound or laminated is housed in an exterior member and which is filled with an electrolyte,
The longitudinal direction of the structure is the X direction, the lateral direction of the structure is the Z direction, and the thickness direction of the structure is the Y direction.
The outer surface along the XZ plane of the structure is the first surface and the second surface,
The portion of the structure on the first surface side is the first portion, the portion of the structure on the second surface side that is in contact with the first portion is the second portion,
A side surface portion of the exterior member facing the first portion in the X direction is a first side surface portion, and a side surface portion of the exterior member facing the second portion in the X direction is a second side surface portion,
When the linear expansion amount in the X direction of the first portion during charging is ΔX ₁ , and the linear expansion amount in the X direction of the second portion during charging is ΔX ₂ ,
ΔX ₁ >ΔX ₂
And, at the time of charging, at least a part of the first portion is in contact with the first side surface portion of the exterior member, and the second portion is not in contact with the second side surface portion of the exterior member ,
The boundary between the first portion and the second portion passes through the winding center of the wound structure and is in the middle of the thickness direction in the XZ plane, or the boundary between the first portion and the second portion is the thickness of the laminated structure. Ri XZ plane der in the thickness direction of the intermediate passing through the center of the direction, and
A lithium ion battery in which the Young's modulus of the exterior member is higher than the Young's modulus of the first portion and the Young's modulus of the second portion .

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