JP6264429B2 - Batteries, battery packs, electronic devices, electric vehicles, power storage devices, and power systems - Google Patents

Description

  The present technology relates to a battery, a battery pack, an electronic device, an electric vehicle, a power storage device, and a power system.

  In secondary batteries such as lithium ion secondary batteries, there is an increasing demand for higher performance, and it is required to improve battery characteristics such as high capacity and high output. For example, the following Patent Documents 1 and 2 disclose a technique related to a separator of a secondary battery, and Patent Documents 3 to 4 disclose a technique related to high output of the secondary battery.

JP 2001-68088 A JP 2008-152985 A JP 2009-146612 A JP 2011-175933 A

  Batteries are required to be compatible with both high capacity and high output.

  Accordingly, an object of the present technology is to provide a battery capable of achieving both high capacity and high output, a battery pack, an electronic device, an electric vehicle, a power storage device, and a power system using the battery.

In order to solve the above-described problem, a first technique includes a positive electrode having a positive electrode active material layer provided on both surfaces of a positive electrode current collector, a negative electrode, and a separator including at least a porous film, The material includes at least one kind of lithium nickel composite oxide represented by Chemical Formula 1, the area density S (mg / cm ² ) of the positive electrode active material layer is 34 mg / cm ² or more, and the porous film is empty. The porosity ε (%) and the air permeability t (sec / 100 cc) satisfy the following (formula).
Li _x Ni _y Co _z M1 _(1-yz) O _b
(In the formula, M1 represents boron (B), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), chromium (Cr), iron (Fe ), Copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), barium (Ba), tungsten (W ), Indium (In), tin (Sn), lead (Pb) and antimony (Sb), where x, y, z and b are each 0.8 <x ≦ 1.2. , 0.5 ≦ y ≦ 1.0, 0 ≦ z ≦ 0.5, y + z ≦ 1, 1.8 ≦ b ≦ 2.2 The composition of lithium is the state of charge and discharge. The value of x represents a value in a fully discharged state.
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm The second technique includes a positive electrode having a positive electrode active material layer provided on both surfaces of a positive electrode current collector, a negative electrode, and a separator including at least a porous film. The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more, and the porosity ε (% ) And air permeability t (sec / 100 cc) are batteries satisfying the following (formula).
(Chemical Formula 3) Li _v Mn _(2-w) M3 _w O _s
(Wherein M3 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), at least one selected from the group consisting of v, w and s are values within the range of 0.9 ≦ v ≦ 1.1, 0 ≦ w ≦ 0.6, 3.7 ≦ s ≦ 4.1, where the composition of lithium is the state of charge and discharge. And the value of v represents a value in a fully discharged state.)
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm The third technique includes a positive electrode having a positive electrode active material layer provided on both surfaces of a positive electrode current collector, a negative electrode, and a separator including at least a porous film. And the area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more, and the porosity ε (% ) And air permeability t (sec / 100 cc) are batteries satisfying the following (formula).
(Of _{4) Li u Fe r M4 (} 1- r) PO 4
(Wherein, M4 is cobalt (Co), manganese (Mn), 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), at least one selected from the group consisting of r. , 0 <r ≦ 1, and u is a value within the range of 0.9 ≦ u ≦ 1.1 Note that the composition of lithium varies depending on the state of charge and discharge, and the value of u Represents the value in the fully discharged state.)
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: Natural logarithm The fourth technique includes a positive electrode having a positive electrode active material layer provided on both surfaces of a positive electrode current collector, a negative electrode, and a separator including at least a porous film. The positive electrode active material is lithium nickel Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ (x is a value in the range of 0.8 <x ≦ 1.2. The composition of lithium varies depending on the state of charge and discharge, The value represents a value in a complete discharge state.), The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more, and the porosity ε (% ) And air permeability t (sec / 100 cc) are batteries satisfying the following (formula).
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm The fifth technique includes a positive electrode having a positive electrode active material layer provided on both surfaces of a positive electrode current collector, a negative electrode, and a separator including at least a porous film. The positive electrode active material has a layered structure. Lithium-nickel-cobalt-manganese composite oxide having a low nickel content and containing at least lithium, nickel, cobalt and manganese, and a lithium having a spinel structure and containing at least lithium and manganese A mixture of manganese composite oxides, wherein the mass ratio of the mixture (mass of lithium nickel cobalt manganese composite oxide: mass of lithium manganese composite oxide) is in the range of 5: 5 to 9: 1; area of the layer density S (mg / cm ²⁾ is at 30 mg / cm ² or more, a porosity epsilon (%) of porous film and air permeability t sec / 100 cc) is a battery satisfying the following (expression).
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm

  The battery pack, the electronic device, the electric vehicle, the power storage device, and the power system of the present technology include the above-described battery.

  According to the present technology, both high capacity and high output of the battery can be achieved.

FIG. 1 is a cross-sectional view showing an example of a battery according to the first embodiment of the present technology. FIG. 2 is an enlarged cross-sectional view showing a part of the spirally wound electrode body 20 shown in FIG. FIG. 3A is a schematic cross-sectional view illustrating a configuration example of a first separator of the present technology. FIG. 3B is a schematic cross-sectional view illustrating a configuration example of a second separator of the present technology. FIG. 4 is a block diagram illustrating a configuration example of the battery pack according to the second embodiment of the present technology. FIG. 5 is a schematic diagram illustrating an example applied to a residential power storage system using a battery of the present technology. FIG. 6 is a schematic diagram schematically illustrating an example of a configuration of a hybrid vehicle that employs a series hybrid system to which the present technology is applied. FIG. 7 is a graph showing a region satisfying (Expression) in the three-axis coordinate space of t-ε-S of air permeability (t), porosity (ε), and area density (S). FIG. 8A is a graph in which measured values of the separators of Example 1 and Comparative Examples 1 and 2 are plotted on the ε-t coordinate plane of area density (S) = 31 mg / cm ² . FIG. 8B is a graph in which measured values of the separators of Example 2 and Comparative Example 3 are plotted on the ε-t coordinate plane of area density (S) = 32 mg / cm ² . FIG. 9A is a graph in which measured values of the separators of Example 3 and Comparative Example 4 are plotted on the ε-t coordinate plane of area density (S) = 33 mg / cm ² . FIG. 9B is a graph in which the measured values of the separators of Example 4 and Comparative Example 5 are plotted on the ε-t coordinate plane of area density (S) = 34 mg / cm ² . FIG. 10A is a graph in which measured values of the separators of Example 5 and Comparative Example 6 are plotted on the ε-t coordinate plane of area density (S) = 35 mg / cm ² . FIG. 10B is a graph in which measured values of the separators of Example 6, Comparative Example 7, Comparative Example 8, and Comparative Example 9 are plotted on the ε-t coordinate plane of area density (S) = 37 mg / cm ² . FIG. 11A is a graph in which measured values of the separators of Example 7 and Comparative Example 10 are plotted on the ε-t coordinate plane of area density (S) = 40 mg / cm ² . FIG. 11B is a graph in which the measured values of the separator of Example 8 are plotted on the ε-t coordinate plane of area density (S) = 42 mg / cm ² . FIG. 12A is a graph in which measured values of the separators of Example 9 and Comparative Examples 11 to 13 are plotted on the ε-t coordinate plane of area density (S) = 43 mg / cm ² . FIG. 12B is a graph in which measured values of the separator of Example 10 are plotted on the ε-t coordinate plane of area density (S) = 45 mg / cm ² . FIG. 13 is a graph in which measured values of Example 11 and Comparative Example 14 separators are plotted on an ε-t coordinate plane of area density (S) = 49 mg / cm ² .

Hereinafter, embodiments of the present technology will be described with reference to the drawings. The description will be given in the following order.
1. First embodiment (example of battery)
2. Second embodiment (example of battery pack)
3. Third embodiment (an example of a power storage system)
4). Other embodiment (modification)
The embodiments described below are suitable specific examples of the present technology, and the contents of the present technology are not limited to these embodiments. Moreover, the effect described in this specification is an illustration to the last, is not limited, and does not deny that the effect different from the illustrated effect exists.

1. First embodiment (technical background)
First, in order to facilitate understanding of the present technology, the technical background of the present technology will be described. For example, in a battery such as a lithium ion secondary battery, when increasing the capacity and output with a rated size such as 18650 (diameter 18 mm and length 65 mm), the current density increases, The total amount of lithium ions that move in the pores per unit time (that is, the amount of electricity) increases.

  Lithium ion movement in a system with increased current density is preferentially performed at the place where the movement resistance is the lowest, so in a separator with non-uniform conductivity, an overvoltage is generated due to local current density bias. As a result, the internal resistance is increased by the formation of a film by the decomposition of the electrolytic solution.

  For example, the separators described in Patent Document 1 (Japanese Patent Laid-Open No. 2001-68088) and Patent Document 2 (Japanese Patent Laid-Open No. 2008-152985) described above are sulfonated with a microporous film such as a polyethylene film, fluorine Is subjected to chemical treatment, corona treatment, and the like. In such a separator, the uniformity of processing becomes important, and when the processing is non-uniform, the separator becomes non-uniform in conductivity and increases internal resistance, so that high output cannot be achieved.

  To increase the capacity within the rated size, the thickness of the electrode must be increased. In this case, the amount of lithium ions that give rise to the reaction tends to increase in the unit area of the electrode. Therefore, unless an optimum separator is selected, diffusion of lithium ions released from the positive electrode on the negative electrode surface is deteriorated, resulting in overvoltage. When an overvoltage is generated, the film formation reaction due to the decomposition of the electrolyte proceeds and the internal resistance is increased, so that it is impossible to achieve both high capacity and high output.

Therefore, the inventors of the present application have made extensive studies, and when the area density of the positive electrode active material layer is set to 30 mg / cm ² or more to increase the battery capacity, a separator satisfying a predetermined structure is used. The inventors have found that an increase in internal resistance can be suppressed and that both high capacity and high output can be achieved.

  Hereinafter, the battery according to the first embodiment of the present technology capable of achieving both high capacity and high output will be described in detail.

(Battery configuration)
The structure of the battery according to the first embodiment of the present technology will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an example of a battery according to the first embodiment of the present technology. The battery according to the first embodiment of the present technology is, for example, a nonaqueous electrolyte battery, a nonaqueous electrolyte secondary battery that can be charged and discharged, and a lithium ion secondary battery, for example. . This battery is a so-called cylindrical type, and a strip-shaped positive electrode 21 and a negative electrode 22 together with a non-aqueous electrolyte, which is a liquid electrolyte (not shown), form a separator 23 in a substantially hollow cylindrical battery can 11. The wound electrode body 20 is wound around.

  The battery can 11 is made of, for example, iron plated with nickel, and has one end closed and the other end open. Inside the battery can 11, a pair of insulating plates 12 a and 12 b are respectively arranged perpendicular to the winding peripheral surface so as to sandwich the winding electrode body 20.

  Examples of the material of the battery can 11 include iron (Fe), nickel (Ni), stainless steel (SUS), aluminum (Al), titanium (Ti), and the like. The battery can 11 may be plated with nickel or the like, for example, in order to prevent corrosion due to the electrochemical non-aqueous electrolyte accompanying charging / discharging of the battery. At the open end of the battery can 11, a battery lid 13 that is a positive electrode lead plate, and a safety valve mechanism and a thermal resistance element (PTC element: Positive Temperature Coefficient) 17 provided inside the battery lid 13 are insulated and sealed. It is attached by caulking through a gasket 18 for

  The battery lid 13 is made of, for example, the same material as that of the battery can 11 and has an opening for discharging gas generated inside the battery. In the safety valve mechanism, a safety valve 14, a disk holder 15, and a shut-off disk 16 are sequentially stacked. The protrusion 14 a of the safety valve 14 is connected to a positive electrode lead 25 led out from the wound electrode body 20 through a sub disk 19 disposed so as to cover a hole 16 a provided in the center of the shutoff disk 16. . By connecting the safety valve 14 and the positive electrode lead 25 via the sub disk 19, the positive electrode lead 25 is prevented from being drawn from the hole 16a when the safety valve 14 is reversed. Further, the safety valve mechanism is electrically connected to the battery lid 13 via the heat sensitive resistance element 17.

  In the safety valve mechanism, when the internal pressure of the battery becomes a certain level or more due to internal short circuit or heating from the outside of the battery, the safety valve 14 is reversed, and the electrical connection between the protruding portion 14a, the battery lid 13 and the wound electrode body 20 is achieved. Disconnects the connection. That is, when the safety valve 14 is reversed, the positive electrode lead 25 is pressed by the shut-off disk 16 and the connection between the safety valve 14 and the positive electrode lead 25 is released. The disc holder 15 is made of an insulating material, and when the safety valve 14 is reversed, the safety valve 14 and the shut-off disc 16 are insulated.

  Further, when further gas is generated inside the battery and the internal pressure of the battery further increases, a part of the safety valve 14 is broken and the gas can be discharged to the battery lid 13 side.

  In addition, for example, a plurality of vent holes (not shown) are provided around the hole 16a of the shut-off disk 16, and when gas is generated from the wound electrode body 20, the gas is effectively removed from the battery lid. It is set as the structure which can discharge | emit to 13 side.

  The resistance element 17 increases in resistance when the temperature rises, cuts off the current by disconnecting the electrical connection between the battery lid 13 and the wound electrode body 20, and generates abnormal heat due to an excessive current. To prevent. The gasket 18 is made of, for example, an insulating material, and the surface is coated with asphalt.

  The wound electrode body 20 accommodated in the battery is wound around the center pin 24. The wound electrode body 20 is formed by sequentially laminating a positive electrode 21 and a negative electrode 22 with a separator 23 interposed therebetween, and is wound in the longitudinal direction.

  A positive electrode lead 25 is connected to the positive electrode 21, and a negative electrode lead 26 is connected to the negative electrode 22. As described above, the positive electrode lead 25 is welded to the safety valve 14 and is electrically connected to the battery lid 13, and the negative electrode lead 26 is welded to and electrically connected to the battery can 11.

FIG. 2 is an enlarged cross-sectional view showing a part of the spirally wound electrode body 20 shown in FIG. In the battery according to the first embodiment of the present technology, the area density S (mg / cm ² ) of the positive electrode active material layer 21B is set to 30 mg / cm ² or more, and the separator 23 has a predetermined value. It has a structure.

  Hereinafter, the positive electrode 21, the negative electrode 22, and the separator 23 will be described in detail.

(Positive electrode)
The positive electrode 21 has, for example, a double-sided formation part in which a positive electrode active material layer 21B is provided on both surfaces of a positive electrode current collector 21A having one main surface and another main surface. Although not shown, the single-sided formation portion in which the positive electrode active material layer 21B is provided only on one side of the positive electrode current collector 21A may be provided. The positive electrode current collector 21A is made of, for example, a metal foil such as an aluminum foil.

  The positive electrode active material layer 21B contains one or more positive electrode materials capable of inserting and extracting lithium as a positive electrode active material. The positive electrode active material layer 21B may include other materials such as a binder and a conductive agent as necessary.

As the positive electrode material, a positive electrode active material suitable for high output use is used. Examples of such positive electrode active materials include layered nickel-based lithium nickel composite oxides, layered lithium nickel cobalt manganese composite oxides, spinel lithium manganese composite oxides, and olivine lithium iron phosphate compounds. At least one selected from the group can be used. Note that a composite oxide containing a layered cobalt that does not contain nickel, such as lithium cobalt oxide (LiCoO ₂ ), has a large calorific value in high-load discharge, and thus is not suitable for high-power applications.

  The nickel-based lithium nickel composite oxide having a layered structure is a lithium nickel composite oxide having a layered structure, a high nickel content, and containing at least lithium and nickel. Note that the high nickel content means that, for example, the nickel component of the elements constituting the lithium nickel composite oxide (the constituent elements excluding lithium and oxygen, and the constituent elements excluding the halogen element if a halogen element is included) It means containing 50% or more by fraction.

  The lithium nickel cobalt manganese composite oxide having a layered structure is a lithium nickel cobalt manganese composite oxide having a layered structure, a low nickel content, and containing at least lithium, nickel, cobalt, and manganese. The low nickel content means, for example, the nickel component of the elements constituting the lithium nickel cobalt manganese composite oxide (constituent elements excluding lithium and oxygen, and constituent elements excluding halogen elements when halogen elements are included) Is included in a molar fraction of 50% or less.

  The spinel structure lithium manganese composite oxide is a lithium manganese composite oxide having a spinel structure and containing at least lithium and manganese.

  The lithium iron phosphate compound having an olivine structure is a lithium iron phosphate compound having an olivine structure and containing at least lithium, iron, and phosphorus.

Examples of the nickel-based lithium nickel composite oxide having a layered structure include a composite oxide represented by Chemical Formula 1 and the like.
(Chemical formula 1)
Li _x Ni _y Co _z M1 _(1-yz) O _b
(In the formula, M1 represents boron (B), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), chromium (Cr), manganese (Mn ), Iron (Fe), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), barium (Ba) ), Tungsten (W), indium (In), tin (Sn), lead (Pb) and antimony (Sb), where x, y, z and b are each 0.8 < x ≦ 1.2, 0.5 ≦ y ≦ 1.0, 0 ≦ z ≦ 0.5, y + z ≦ 1, 1.8 ≦ b ≦ 2.2 The composition of lithium Depends on the state of charge and discharge, and the value of x is in the fully discharged state. It represents the value.)

Specific examples of the composite oxide represented by Chemical Formula 1 include Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ (x is as defined above), Li _x Ni _0.5 Co _0.2 Mn _0.3 O ₂ ( x is as defined above), Li _x Ni _0.7 Co _0.1 Mn _0.2 O ₂ (x is as defined above), and the like.

  Examples of the lithium nickel cobalt manganese composite oxide include a composite oxide represented by Chemical Formula 2 and the like.

(Chemical formula 2)
Li _f Ni _g Co _i Mn _(1-gih) M2 _h O _(2-j)
(Wherein M2 is 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), f, g, h, j , I and k are 0.8 ≦ f ≦ 1.2, 0 <g ≦ 0.5, 0 ≦ h ≦ 0.5, g + h + i <1, −0.1 ≦ j ≦ 0.2, 0 <i (It is a value within the range of ≦ 0.5. Note that the composition of lithium varies depending on the state of charge and discharge, and the value of f represents a value in the complete discharge state.)

Specific examples of the composite oxide represented by Chemical Formula 2 include Li _f Ni _1/3 Co _1/3 Mn _1/3 O ₂ (f is as defined above).

Examples of the spinel structure lithium manganese composite oxide include a composite oxide represented by Chemical Formula 3 and the like.
(Chemical formula 3)
Li _v Mn _(2-w) M3 _w O _s
(Wherein M3 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), at least one selected from the group consisting of v, w and s are values within the range of 0.9 ≦ v ≦ 1.1, 0 ≦ w ≦ 0.6, 3.7 ≦ s ≦ 4.1, where the composition of lithium is the state of charge and discharge. And the value of v represents a value in a fully discharged state.)

Specific examples of the complex oxide represented by Chemical Formula 3 include Li _v Mn ₂ O ₄ (v is as defined above).

Examples of the olivine-structured lithium iron phosphate compound include a phosphate compound represented by Chemical formula 4 below.
(Chemical formula 4)
_{Li u Fe r M4 (1-} r) PO 4
(Wherein, M4 is cobalt (Co), manganese (Mn), 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), at least one selected from the group consisting of r. , 0 <r ≦ 1, and u is a value within the range of 0.9 ≦ u ≦ 1.1 Note that the composition of lithium varies depending on the state of charge and discharge, and the value of u Represents the value in the fully discharged state.)

Examples of the phosphoric acid compound represented by Chemical Formula ₄ include Li _u FePO ₄ (u is as defined above).

(Composition of positive electrode material)
The positive electrode material preferably contains Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ (x is as defined above) as a nickel-based lithium nickel composite oxide having a layered structure. In this case, the content of Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ (x is as defined above) is preferably 80% by mass or more and 98% by mass or less with respect to the total mass of the positive electrode material. When the content of Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ is within the above range, a battery with a higher capacity can be realized and a sufficiently high output can be obtained.

  The positive electrode material is preferably a mixture of a lithium nickel cobalt manganese composite oxide having a layered structure and a lithium manganese composite oxide having a spinel structure, for example. The mass ratio (mass of layered lithium nickel cobalt manganese composite oxide: mass of spinel lithium manganese composite oxide) is preferably in the range of 5: 5 to 9: 1. When the mass ratio of the mixture is within the above range, a battery having a higher capacity can be realized, and an increase in battery internal resistance when the charge / discharge cycle is repeated can be suppressed.

  The positive electrode material is, for example, a positive electrode active material composed of a nickel-based lithium nickel composite oxide having a layered structure or a mixture of a nickel-based lithium nickel composite oxide having a layered structure and a lithium manganese composite oxide having a spinel structure (one positive electrode (Referred to as an active material). The mass ratio of this one positive electrode active material (mass of layered nickel-based lithium nickel composite oxide: mass of spinel lithium manganese composite oxide) is preferably 5: 5 to 10: 0. By adding the lithium manganese composite oxide, it is possible to suppress an increase in battery internal resistance when the charge / discharge cycle is repeated, and when the mass ratio is within the above range, a battery having a higher capacity can be realized.

(Conductive agent)
As the conductive agent, for example, a carbon material such as carbon black or graphite is used.

(Binder)
Examples of the binder include resin materials such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), styrene butadiene rubber (SBR), and carboxymethyl cellulose (CMC), and these resin materials. At least one selected from a copolymer or the like mainly composed of is used.

(Area density of positive electrode active material layer)
The area density S (mg / cm ² ) of the positive electrode active material layer 21B is set to, for example, 30 mg / cm ² or more from the viewpoint of increasing the capacity. In addition, when the area density S (mg / cm ² ) of the positive electrode active material layer 21B is increased in this way, the amount of lithium ions that give a reaction per unit area of the electrode tends to increase. If a separator is not used, the internal resistance is increased, and it is impossible to achieve both high capacity and high output.

In addition, the area density S (mg / cm ² ) of the positive electrode active material layer 21B is an area (a double-sided forming portion) of the positive electrode 21 where the positive electrode active material layer 21B is provided on both surfaces of the positive electrode current collector 21A ( 1 cm ² ) is the total mass of the positive electrode active material layer 21B on one side and the positive electrode active material layer 21B on the other side. The area density S (mg / cm ² ) of the positive electrode active material layer 21B can be measured, for example, as follows.

(Measurement method of area density S (mg / cm ² ) of positive electrode active material layer)
After the battery is completely discharged, it is disassembled and the positive electrode plate (positive electrode 21) is taken out, washed with a solvent (for example, DMC (dimethyl carbonate), etc.), and then sufficiently dried. A portion where the positive electrode active material layer 21B is formed on both surfaces of the positive electrode current collector 21A (both surface forming portions) is punched out with a predetermined area (cm ² ) (referred to as a punched area), and mass (mg) (referred to as mass A). ), And a portion where the mixture layer is not applied on both sides is punched out in the same manner, and mass (mg) (referred to as mass B) is measured. And it calculates with the following formula.
Calculation formula: area density S (mg / cm ² ) = (mass A−mass B) ÷ punched area

(Negative electrode)
The negative electrode 22 has, for example, a structure having a double-sided formation part in which a negative electrode active material layer 22B is provided on both sides of a negative electrode current collector 22A having one main surface and another main surface. In addition, although not shown in figure, you may have the single-sided formation part by which the negative electrode active material layer 22B was provided only in the single side | surface of 22 A of negative electrode collectors. The anode current collector 22A is made of, for example, a metal foil such as a copper foil.

  The negative electrode active material layer 22B includes one or more negative electrode materials capable of inserting and extracting lithium as the negative electrode active material, and the positive electrode active material layer 21B as necessary. Other materials such as a conductive agent and a binder similar to those described above may be included.

  In this battery, for example, the electrochemical equivalent of the negative electrode material capable of inserting and extracting lithium is larger than the electrochemical equivalent of the positive electrode 21, and theoretically, the negative electrode 22 is charged with lithium during the charging. The metal is not deposited.

  Examples of the negative electrode material capable of inserting and extracting lithium include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, glassy carbons, and fired organic polymer compounds And carbon materials such as carbon fiber and activated carbon. Of these, examples of coke include pitch coke, needle coke, and petroleum coke. An organic polymer compound fired body is a carbonized material obtained by firing a polymer material such as a phenol resin or a furan resin at an appropriate temperature, and part of it is non-graphitizable carbon or graphitizable carbon. Some are classified as: These carbon materials are preferable because the change in crystal structure that occurs during charge and discharge is very small, a high charge and discharge capacity can be obtained, and good cycle characteristics can be obtained. In particular, graphite is preferable because it has a high electrochemical equivalent and can provide a high energy density. Further, non-graphitizable carbon is preferable because excellent cycle characteristics can be obtained. Furthermore, those having a low charge / discharge potential, specifically, those having a charge / discharge potential close to that of lithium metal are preferable because a high energy density of the battery can be easily realized.

  Examples of the negative electrode material capable of inserting and extracting lithium include materials capable of inserting and extracting lithium and containing at least one of a metal element and a metalloid element as a constituent element. This is because a high energy density can be obtained by using such a material. In particular, the use with a carbon material is more preferable because a high energy density can be obtained and excellent cycle characteristics can be obtained. The negative electrode material may be a single element, alloy or compound of a metal element or metalloid element, or may have at least a part of one or more of these phases. In the present technology, the alloy includes an alloy including one or more metal elements and one or more metalloid elements in addition to an alloy composed of two or more metal elements. Moreover, the nonmetallic element may be included. Some of the structures include a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or two or more of them.

  Examples of the metal element or metalloid element constituting the negative electrode material include a metal element or metalloid element capable of forming an alloy with lithium. Such a negative electrode material containing an element capable of forming an alloy with lithium is referred to as an alloy-based negative electrode material. Specific examples of metal elements or metalloid elements capable of forming an alloy with lithium include magnesium (Mg), boron (B), aluminum (Al), titanium (Ti), gallium (Ga), and 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), or platinum (Pt). These may be crystalline or amorphous.

  The negative electrode material preferably includes a 4B group metal element or metalloid element in the short periodic table as a constituent element, and more preferably includes at least one of silicon (Si) and tin (Sn) as a constituent element. And particularly preferably those containing at least silicon. This is because silicon (Si) and tin (Sn) have a large ability to occlude and release lithium, and a high energy density can be obtained. Examples of the negative electrode material having at least one of silicon and tin include at least a part of a simple substance, an alloy or a compound of silicon, a simple substance, an alloy or a compound of tin, or one or more phases thereof. The materials possessed by

  As an alloy of silicon, for example, as a second constituent element other than silicon, tin (Sn), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc ( One containing at least one of the group consisting of Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb) and chromium (Cr) Can be mentioned. Examples of tin alloys include silicon (Si), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), and manganese (Mn) as second constituent elements other than tin (Sn). , Zinc (Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb) and chromium (Cr). Including.

  Examples of the tin (Sn) compound or silicon (Si) compound include those containing oxygen (O) or carbon (C). In addition to tin (Sn) or silicon (Si), the above-described compounds are used. Two constituent elements may be included.

  Among these, as the negative electrode material, cobalt (Co), tin (Sn), and carbon (C) are included as constituent elements, and the carbon content is 9.9 mass% or more and 29.7 mass% or less. And the SnCoC containing material whose ratio of cobalt (Co) with respect to the sum total of tin (Sn) and cobalt (Co) is 30 mass% or more and 70 mass% or less is preferable. This is because a high energy density can be obtained in such a composition range, and excellent cycle characteristics can be obtained.

  This SnCoC-containing material may further contain other constituent elements as necessary. Examples of other constituent elements include silicon (Si), iron (Fe), nickel (Ni), chromium (Cr), indium (In), niobium (Nb), germanium (Ge), titanium (Ti), and molybdenum. (Mo), aluminum (Al), phosphorus (P), gallium (Ga) or bismuth (Bi) are preferable and may contain two or more. This is because the capacity or cycle characteristics can be further improved.

  This SnCoC-containing material has a phase containing tin (Sn), cobalt (Co), and carbon (C), and this phase has a low crystallinity or an amorphous structure. It is preferable. In this SnCoC-containing material, it is preferable that at least a part of carbon (C) as a constituent element is bonded to a metal element or a metalloid element as another constituent element. The decrease in cycle characteristics is considered to be due to aggregation or crystallization of tin (Sn) or the like. However, the combination of carbon (C) with other elements suppresses such aggregation or crystallization. Because it can.

  As a measuring method for examining the bonding state of elements, for example, X-ray photoelectron spectroscopy (XPS) can be cited. In XPS, the peak of the carbon 1s orbital (C1s) appears at 284.5 eV in an energy calibrated apparatus so that the peak of the gold atom 4f orbital (Au4f) is obtained at 84.0 eV if it is graphite. . Moreover, if it is surface contamination carbon, it will appear at 284.8 eV. On the other hand, when the charge density of the carbon element increases, for example, when carbon is bonded to a metal element or a metalloid element, the C1s peak appears in a region lower than 284.5 eV. That is, when the peak of the synthetic wave of C1s obtained for the SnCoC-containing material appears in a region lower than 284.5 eV, at least a part of the carbon contained in the SnCoC-containing material is a metal element or a half of other constituent elements. Combined with metal elements.

  In XPS measurement, for example, the C1s peak is used to correct the energy axis of the spectrum. Usually, since surface-contaminated carbon exists on the surface, the C1s peak of the surface-contaminated carbon is set to 284.8 eV, which is used as an energy standard. In the XPS measurement, the waveform of the C1s peak is obtained as a shape including the surface contamination carbon peak and the carbon peak in the SnCoC-containing material. Therefore, by analyzing using, for example, commercially available software, the surface contamination The carbon peak and the carbon peak in the SnCoC-containing material are separated. In the waveform analysis, the position of the main peak existing on the lowest bound energy side is used as the energy reference (284.8 eV).

Examples of the negative electrode material capable of inserting and extracting lithium include metal oxides or polymer compounds capable of inserting and extracting lithium. Examples of the metal oxide include lithium titanate (Li ₄ Ti ₅ O ₁₂ ), iron oxide, ruthenium oxide, and molybdenum oxide. Examples of the polymer compound include polyacetylene, polyaniline, and polypyrrole.

  The negative electrode material capable of inserting and extracting lithium may be other than the above. Moreover, 2 or more types of said negative electrode materials may be mixed by arbitrary combinations.

  The negative electrode active material layer 22B may be formed by any of, for example, a gas phase method, a liquid phase method, a thermal spray method, a baking method, or a coating method, or a combination of two or more thereof. When the negative electrode active material layer 22B is formed using a vapor phase method, a liquid phase method, a thermal spraying method or a firing method, or two or more of these methods, the negative electrode active material layer 22B and the negative electrode current collector 22A include It is preferable to alloy at least a part of the interface. Specifically, the constituent elements of the negative electrode current collector 22A diffuse into the negative electrode active material layer 22B at the interface, the constituent elements of the negative electrode active material layer 22B diffuse into the negative electrode current collector 22A, or the constituent elements thereof It is preferable that they diffuse to each other. This is because breakage due to expansion and contraction of the negative electrode active material layer 22B due to charging / discharging can be suppressed, and electronic conductivity between the negative electrode active material layer 22B and the negative electrode current collector 22A can be improved. .

  As the vapor phase method, for example, physical deposition method or chemical deposition method, specifically, vacuum evaporation method, sputtering method, ion plating method, laser ablation method, thermal chemical vapor deposition (CVD) Or plasma chemical vapor deposition. As the liquid phase method, a known method such as electroplating or electroless plating can be used. The firing method is, for example, a method in which a particulate negative electrode active material is mixed with a binder or the like and dispersed in a solvent, followed by heat treatment at a temperature higher than the melting point of the binder or the like. A known method can also be used for the firing method, for example, an atmospheric firing method, a reactive firing method, or a hot press firing method.

(Separator)
The separator 23 includes at least a porous film 23a. The thickness of the separator 23 can be arbitrarily set as long as it is equal to or greater than a thickness that can maintain a required strength. The thickness of the separator 23 provides insulation between the positive electrode 21 and the negative electrode 22 to prevent a short circuit and the like, and has ion permeability for suitably performing a battery reaction via the separator 23, and the battery in the battery. It is preferable to set the thickness so that the volume efficiency of the active material layer contributing to the reaction can be as high as possible. Specifically, the thickness of the separator 23 is preferably 3 μm or more and 18 μm or less, for example.

  Examples of such a separator 23 include a first separator and a second separator. FIG. 3A shows a configuration example of the first separator. FIG. 3B shows a configuration example of the second separator.

(First separator)
As shown in FIG. 3A, the first separator is composed only of the porous film 23a.

(Porous film)
The porous film 23a has a structure satisfying the following (formula).
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm

As described above, the area density S (mg / cm ² ) of the positive electrode active material layer 21B is 30 mg / cm ² or more. In consideration of the range in which the above (formula) is established, the area density S (mg / cm ² ) of the positive electrode active material layer 21B is preferably 50 mg / cm ² or less.

  As the resin material constituting the porous film 23a, for example, a polyolefin resin such as polypropylene or polyethylene, an acrylic resin, a styrene resin, a polyester resin, or a nylon resin can be used. Among these, it is preferable to use a polyolefin resin (polyolefin film) that can easily form a structure satisfying the above (formula), has an excellent short-circuit preventing effect, and can improve battery safety by a shutdown effect. The porous film 23a may have a structure in which two or more resin layers made of a resin material are stacked. The porous film 23a may be a resin film formed by melting and kneading two or more kinds of resin materials. The porous film 23a may contain additives such as an antioxidant.

(Method for producing porous film)
The porous film 23a can be produced as follows, for example. For example, a uniform solution prepared by mixing a polymer such as polyolefin resin and a solvent (plasticizer) at a high temperature is formed into a film by T-die method, inflation method, etc., and then stretched, and then the solvent is replaced with another volatile solvent. By extracting and removing, the porous film 23a is formed. As the solvent, a non-volatile organic solvent that dissolves the polymer at high temperature is used alone or in combination. The form of phase separation differs depending on the combination of the polymer and the solvent, and the porous structure also changes. As the stretching method, sequential biaxial stretching by roll stretching and tenter stretching, simultaneous biaxial stretching by simultaneous biaxial tenter, and the like are applicable. In the production process, the porous film 23a having a desired porosity and desired air permeability can be obtained by adjusting at least one of the amount of the plasticizer, the draw ratio, and the draw temperature. In addition, the manufacturing method of the porous film 23a is not limited to the said example.

(Porosity)
The porosity ε (%) of the porous film 23a is preferably 20% or more, for example, from the viewpoint of securing good ionic conductivity, and from the viewpoint of maintaining physical strength and suppressing the occurrence of short circuits. It is preferable that it is 57% or less.

(Measurement method of porosity)
The porosity ε (%) of the porous film 23a can be measured using a gravimetric method. In this method, 10 portions of the porous film 23a are punched into a circle having a diameter of 2 cm in the thickness direction of the porous film 23a, and the thickness h of the center portion of the punched circular film and the mass w of the film are determined. Measure each. Furthermore, using the thickness h and the mass w, the volume V of 10 films and the mass W of 10 films can be obtained, and the porosity ε (%) can be calculated from the following equation. it can.
Porosity ε [%] = {(ρV−W) / (ρV)} × 100
Here, ρ is the density of the material of the porous film 23a.

(Air permeability)
The air permeability t (sec / 100 cc) of the porous film 23 a is preferably 100 sec / 100 cc or more from the viewpoint of maintaining physical strength and suppressing the occurrence of short-circuits, and from the viewpoint of ensuring good ionic conductivity. Therefore, it is preferably 1000 sec / 100 cc or less.

(Measurement method of air permeability)
The air permeability t (sec / 100 cc) is the Gurley air permeability. The Gurley air permeability can be measured according to JIS P8117. The Gurley air permeability indicates the number of seconds that 100 cc of air passes through the membrane at a pressure of 1.22 kPa.

(Second separator)
As shown in FIG. 3B, the second separator is composed of a porous film 23a and a surface layer 23b provided on at least one surface of the porous film 23a. 3B is an example in which the surface layer 23b is provided on one surface of the porous film 23a. Although illustration is omitted, the surface layer 23b may be provided on both surfaces of the porous film 23a.

(Porous film 23a)
The porous film 23a has the same configuration as described above.

(Surface layer)
The surface layer 23b includes a resin material and particles such as inorganic particles and organic particles.

(Resin material)
The resin material is contained in the surface layer 23b in order to bind the particles to the surface of the porous film 23a or to bind the particles. This resin material may have, for example, a three-dimensional network structure in which the fibers are fibrillated and the fibrils are continuously connected to each other. The particles can be maintained in a dispersed state without being connected to each other by being supported on the resin material having the three-dimensional network structure. In addition, the resin material may be bound to the surface of the porous film 23a or particles without being fibrillated. In this case, higher binding properties can be obtained.

  Examples of the resin material contained in the surface layer 23b include fluorine-containing resins such as polyvinylidene fluoride and polytetrafluoroethylene, fluorine-containing rubbers such as vinylidene fluoride-tetrafluoroethylene copolymer and ethylene-tetrafluoroethylene copolymer, Styrene-butadiene copolymer and its hydride, acrylonitrile-butadiene copolymer and its hydride, acrylonitrile-butadiene-styrene copolymer and its hydride, methacrylic acid ester-acrylic acid ester copolymer, styrene-acrylic acid Ester copolymer, acrylonitrile-acrylic acid ester copolymer, ethylene propylene rubber, polyvinyl acetate, etc., cellulose such as ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose Melting point and glass transition temperature of conductor, polyphenylene ether, polysulfone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide (especially aramid), polyamideimide, polyacrylonitrile, polyvinyl alcohol, polyether, acrylic resin or polyester Examples thereof include resins having at least one of 180 ° C. or higher, thermosetting resins such as phenol resins and epoxy resins.

(Inorganic particles)
Examples of the inorganic particles constituting the surface layer 23b include metal oxides, metal oxide hydrates, metal hydroxides, metal nitrides, metal carbides and metal sulfides which are electrically insulating inorganic particles. it can. Examples of the metal oxide or metal oxide hydrate include aluminum oxide (alumina, Al ₂ O ₃ ), boehmite (Al ₂ O ₃ H ₂ O or AlOOH), magnesium oxide (magnesia, MgO), titanium oxide (titania, TiO ₂ ), zirconium oxide (zirconia, ZrO ₂ ), silicon oxide (silica, SiO ₂ ), yttrium oxide (yttria, Y ₂ O ₃ ), zinc oxide (ZnO), or the like can be suitably used. As the metal nitride, silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), boron nitride (BN), titanium nitride (TiN), or the like can be preferably used. As the metal carbide, silicon carbide (SiC) or boron carbide (B ₄ C) can be suitably used. As the metal sulfide, barium sulfate (BaSO ₄ ) or the like can be suitably used. As the metal hydroxide, aluminum hydroxide (Al (OH) ₃ ) or the like can be used. Further, zeolite _{(M 2 / n O · Al} 2 O 3 · xSiO 2 · yH 2 O, M represents a metal element, x ≧ 2, y ≧ 0 ) porous aluminosilicates such as, talc (Mg ₃ Si ₄ O Layered silicates such as ₁₀ (OH) ₂ ), minerals such as barium titanate (BaTiO ₃ ) or strontium titanate (SrTiO ₃ ) may be used. It may also be used _{Li 2 O 4, Li 3 PO} 4, lithium compound such as LiF. Carbon materials such as graphite, carbon nanotubes, and diamond may be used. Among these, alumina, boehmite, talc, titania (particularly those having a rutile structure), silica or magnesia are preferably used, and alumina or boehmite is more preferably used.

  These inorganic particles may be used alone or in combination of two or more. The shape of the inorganic particles is not particularly limited, and any of a spherical shape, a fiber shape, a needle shape, a scale shape, a plate shape, a random shape, and the like can be used.

(Organic particles)
Examples of the material constituting the organic particles include fluorine-containing resins such as polyvinylidene fluoride and polytetrafluoroethylene, fluorine-containing rubbers such as vinylidene fluoride-tetrafluoroethylene copolymer and ethylene-tetrafluoroethylene copolymer, styrene- Butadiene copolymer or its hydride, acrylonitrile-butadiene copolymer or its hydride, acrylonitrile-butadiene-styrene copolymer or its hydride, methacrylic acid ester-acrylic acid ester copolymer, styrene-acrylic acid ester copolymer Polymers, acrylonitrile-acrylic acid ester copolymers, ethylene propylene rubber, polyvinyl acetate, etc., cellulose derivatives such as ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, Melting points of polyamides such as rephenylene ether, polysulfone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, wholly aromatic polyamide (aramid), polyamideimide, polyacrylonitrile, polyvinyl alcohol, polyether, acrylic resin or polyester In addition, a resin having high heat resistance in which at least one of the glass transition temperatures is 180 ° C. or higher, a thermosetting resin such as a phenol resin, an epoxy resin, and the like. These materials may be used alone or in combination of two or more. The shape of the organic particles is not particularly limited, and any of a spherical shape, a fiber shape, a needle shape, a scale shape, a plate shape, a random shape, and the like can be used.

  For example, the surface layer 23b is obtained by mixing a resin material and particles, adding the mixture to a dispersion solvent such as N-methyl-2-pyrrolidone, and dissolving the resin material to obtain a resin solution. It can be obtained by applying on at least one surface of the film 23a and drying.

(Nonaqueous electrolyte)
The nonaqueous electrolytic solution includes an electrolyte salt and a nonaqueous solvent that dissolves the electrolyte salt.

The electrolyte salt contains, for example, one or more light metal compounds such as lithium salts. Examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), lithium tetraphenylborate _{(LiB (C 6 H 5)} 4), methanesulfonic acid lithium (LiCH ₃ SO _3), lithium trifluoromethanesulfonate (LiCF ₃ SO _3), tetrachloroaluminate lithium (LiAlCl _4), six Examples thereof include dilithium fluorosilicate (Li ₂ SiF ₆ ), lithium chloride (LiCl), and lithium bromide (LiBr). Among these, at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, and lithium hexafluoroarsenate is preferable, and lithium hexafluorophosphate is more preferable.

  Examples of the non-aqueous solvent include lactone solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, and ε-caprolactone, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate, ethyl methyl carbonate, Carbonate esters such as diethyl carbonate, ether solvents such as 1,2-dimethoxyethane, 1-ethoxy-2-methoxyethane, 1,2-diethoxyethane, tetrahydrofuran or 2-methyltetrahydrofuran, and nitriles such as acetonitrile Nonaqueous solvents such as solvents, sulfolane-based solvents, phosphoric acids, phosphate ester solvents, and pyrrolidones are exemplified. Any one of the non-aqueous solvents may be used alone, or two or more thereof may be mixed and used.

  In addition, it is preferable to use a mixture of a cyclic carbonate and a chain carbonate as the non-aqueous solvent, and it may contain a compound in which a part or all of the hydrogen of the cyclic carbonate or the chain carbonate includes a fluorination. preferable. Examples of the fluorinated compound include fluoroethylene carbonate (4-fluoro-1,3-dioxolan-2-one: FEC) or difluoroethylene carbonate (4,5-difluoro-1,3-dioxolan-2-one: DFEC) is preferably used. This is because even when the negative electrode 22 containing a compound such as silicon (Si), tin (Sn), or germanium (Ge) is used as the negative electrode active material, charge / discharge cycle characteristics can be improved. Of these, difluoroethylene carbonate is preferably used as the non-aqueous solvent. This is because the cycle characteristic improvement effect is excellent.

(Battery manufacturing method)
(Production method of positive electrode)
A positive electrode material, a conductive agent, and a binder are mixed to prepare a positive electrode mixture, and the positive electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone to obtain a paste-like positive electrode mixture slurry. Make it. Next, the positive electrode mixture slurry is applied to the positive electrode current collector 21A, the solvent is dried, and the positive electrode active material layer 21B is formed by compression molding with a roll press machine or the like, and the positive electrode 21 is manufactured.

(Method for producing negative electrode)
A negative electrode material and a binder are mixed to prepare a negative electrode mixture, and the negative electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone to prepare a paste-like negative electrode mixture slurry. Next, the negative electrode mixture slurry is applied to the negative electrode current collector 22A, the solvent is dried, and the negative electrode active material layer 22B is formed by compression molding with a roll press or the like, thereby producing the negative electrode 22.

(Preparation of non-aqueous electrolyte)
The nonaqueous electrolytic solution is prepared by dissolving an electrolyte salt in a nonaqueous solvent.

(Battery assembly)
The positive electrode lead 25 is attached to the positive electrode current collector 21A by welding or the like, and the negative electrode lead 26 is attached to the negative electrode current collector 22A by welding or the like. Then, the positive electrode 21 and the negative electrode 22 are wound through the separator 23 of the present technology to form a wound electrode body 20.

  Subsequently, the tip of the positive electrode lead 25 is welded to the safety valve mechanism, and the tip of the negative electrode lead 26 is welded to the battery can 11. Thereafter, the wound surface of the wound electrode body 20 is sandwiched between the pair of insulating plates 12 a and 12 b and housed in the battery can 11. After the wound electrode body 20 is accommodated in the battery can 11, a non-aqueous electrolyte is injected into the battery can 11 and impregnated in the separator 23. After that, the safety valve mechanism including the battery lid 13 and the safety valve 14 and the heat sensitive resistance element 17 are fixed to the opening end of the battery can 11 by caulking through the gasket 18. Thereby, the battery of the present technology shown in FIG. 1 is formed.

  In this battery, when charged, for example, lithium ions are released from the positive electrode active material layer 21 </ b> B and inserted in the negative electrode active material layer 22 </ b> B through the nonaqueous electrolyte impregnated in the separator 23. In addition, when discharging is performed, for example, lithium ions are released from the negative electrode active material layer 22B and inserted into the positive electrode active material layer 21B through the nonaqueous electrolytic solution impregnated in the separator 23.

2. Second embodiment (example of battery pack)
FIG. 4 is a block diagram illustrating a circuit configuration example when the battery according to the first embodiment of the present technology (hereinafter appropriately referred to as a secondary battery) is applied to a battery pack. The battery pack includes a switch unit 304 including an assembled battery 301, an exterior, a charge control switch 302a, and a discharge control switch 303a, a current detection resistor 307, a temperature detection element 308, and a control unit 310.

  In addition, the battery pack includes a positive electrode terminal 321 and a negative electrode terminal 322. During charging, the positive electrode terminal 321 and the negative electrode terminal 322 are connected to the positive electrode terminal and the negative electrode terminal of the charger, respectively, and charging is performed. Further, when the electronic device is used, the positive electrode terminal 321 and the negative electrode terminal 322 are connected to the positive electrode terminal and the negative electrode terminal of the electronic device, respectively, and discharge is performed.

  The assembled battery 301 is formed by connecting a plurality of secondary batteries 301a in series and / or in parallel. The secondary battery 301a is a secondary battery of the present technology. In FIG. 4, the case where six secondary batteries 301a are connected in two parallel three series (2P3S) is shown as an example, but in addition, n parallel m series (n and m are integers) Any connection method may be used.

  The switch unit 304 includes a charge control switch 302a and a diode 302b, and a discharge control switch 303a and a diode 303b, and is controlled by the control unit 310. The diode 302b has a reverse polarity with respect to the charging current flowing from the positive terminal 321 in the direction of the assembled battery 301 and the forward polarity with respect to the discharging current flowing from the negative terminal 322 in the direction of the assembled battery 301. The diode 303b has a forward polarity with respect to the charging current and a reverse polarity with respect to the discharging current. In the example, the switch unit 304 is provided on the + side, but may be provided on the-side.

  The charge control switch 302 a is turned off when the battery voltage becomes the overcharge detection voltage, and is controlled by the charge / discharge control unit so that the charge current does not flow in the current path of the assembled battery 301. After the charging control switch 302a is turned off, only discharging is possible via the diode 302b. Further, it is turned off when a large current flows during charging, and is controlled by the control unit 310 so that the charging current flowing in the current path of the assembled battery 301 is cut off.

  The discharge control switch 303a is turned off when the battery voltage becomes the overdischarge detection voltage, and is controlled by the control unit 310 so that the discharge current does not flow through the current path of the assembled battery 301. After the discharge control switch 303a is turned off, only charging is possible via the diode 303b. Further, it is turned off when a large current flows during discharging, and is controlled by the control unit 310 so as to cut off the discharging current flowing in the current path of the assembled battery 301.

  The temperature detection element 308 is, for example, a thermistor, is provided in the vicinity of the assembled battery 301, measures the temperature of the assembled battery 301, and supplies the measured temperature to the control unit 310. The voltage detection unit 311 measures the voltage of the assembled battery 301 and each secondary battery 301a constituting the assembled battery 301, performs A / D conversion on the measured voltage, and supplies the voltage to the control unit 310. The current measurement unit 313 measures the current using the current detection resistor 307 and supplies this measurement current to the control unit 310.

  The switch control unit 314 controls the charge control switch 302a and the discharge control switch 303a of the switch unit 304 based on the voltage and current input from the voltage detection unit 311 and the current measurement unit 313. The switch control unit 314 sends a control signal to the switch unit 304 when any voltage of the secondary battery 301a falls below the overcharge detection voltage or overdischarge detection voltage, or when a large current flows suddenly. By sending, overcharge, overdischarge, and overcurrent charge / discharge are prevented.

  Here, for example, when the secondary battery is a lithium ion secondary battery, the overcharge detection voltage is determined to be 4.20 V ± 0.05 V, for example, and the overdischarge detection voltage is determined to be 2.4 V ± 0.1 V, for example. .

  As the charge / discharge switch, for example, a semiconductor switch such as a MOSFET can be used. In this case, the parasitic diode of the MOSFET functions as the diodes 302b and 303b. When a P-channel FET is used as the charge / discharge switch, the switch control unit 314 supplies control signals DO and CO to the gates of the charge control switch 302a and the discharge control switch 303a, respectively. When the charge control switch 302a and the discharge control switch 303a are P-channel type, they are turned on by a gate potential that is lower than the source potential by a predetermined value or more. That is, in normal charging and discharging operations, the control signals CO and DO are set to the low level, and the charging control switch 302a and the discharging control switch 303a are turned on.

  For example, during overcharge or overdischarge, the control signals CO and DO are set to a high level, and the charge control switch 302a and the discharge control switch 303a are turned off.

  The memory 317 includes a RAM and a ROM, and includes, for example, an EPROM (Erasable Programmable Read Only Memory) that is a nonvolatile memory. In the memory 317, the numerical value calculated by the control unit 310, the internal resistance value of the battery in the initial state of each secondary battery 301a measured in the manufacturing process, and the like are stored in advance, and can be appropriately rewritten. . (Also, by storing the full charge capacity of the secondary battery 301a, for example, the remaining capacity can be calculated together with the control unit 310.

  The temperature detection unit 318 measures the temperature using the temperature detection element 308, performs charge / discharge control during abnormal heat generation, and performs correction in the calculation of the remaining capacity.

3. Third Embodiment The battery according to the first embodiment of the present technology described above and the battery pack according to the second embodiment using the same are mounted on devices such as an electronic device, an electric vehicle, and a power storage device, for example. Can be used to supply power.

  Examples of electronic devices include notebook computers, PDAs (personal digital assistants), mobile phones, cordless phones, video movies, digital still cameras, electronic books, electronic dictionaries, music players, radios, headphones, game consoles, navigation systems, Memory card, pacemaker, hearing aid, electric tool, electric shaver, refrigerator, air conditioner, TV, stereo, water heater, microwave oven, dishwasher, washing machine, dryer, lighting equipment, toy, medical equipment, robot, road conditioner, traffic light Etc.

  Further, examples of the electric vehicle include a railway vehicle, a golf cart, an electric cart, an electric vehicle (including a hybrid vehicle), and the like, and these are used as a driving power source or an auxiliary power source.

  Examples of the power storage device include a power storage power source for buildings such as houses or power generation facilities.

  Below, the specific example of the electrical storage system using the electrical storage apparatus to which the battery of this technique mentioned above is applied among the application examples mentioned above is demonstrated.

  This power storage system has the following configuration, for example. The first power storage system is a power storage system in which a power storage device is charged by a power generation device that generates power from renewable energy. The second power storage system is a power storage system that includes a power storage device and supplies power to an electronic device connected to the power storage device. The third power storage system is an electronic device that receives power supply from the power storage device. These power storage systems are implemented as a system for efficiently supplying power in cooperation with an external power supply network.

  Furthermore, the fourth power storage system includes an electric vehicle having a conversion device that receives power supplied from the power storage device and converts the power into a driving force of the vehicle, and a control device that performs information processing related to vehicle control based on information related to the power storage device. It is. The fifth power storage system is a power system that includes a power information transmission / reception unit that transmits / receives signals to / from other devices via a network, and performs charge / discharge control of the power storage device described above based on information received by the transmission / reception unit. . The sixth power storage system is a power system that receives power from the power storage device described above or supplies power from the power generation device or the power network to the power storage device. Hereinafter, the power storage system will be described.

(3-1) Power Storage System in a House as an Application Example An example in which a power storage device using a battery of the present technology is applied to a power storage system for a house will be described with reference to FIG. For example, in a power storage system 400 for a house 401, power is stored from a centralized power system 402 such as a thermal power generation 402a, a nuclear power generation 402b, and a hydroelectric power generation 402c through a power network 409, an information network 412, a smart meter 407, a power hub 408, and the like. Supplied to the device 403. At the same time, power is supplied to the power storage device 403 from an independent power source such as the power generation device 404 in the home. The electric power supplied to the power storage device 403 is stored. Electric power used in the house 401 is supplied using the power storage device 403. The same power storage system can be used not only for the house 401 but also for buildings.

  The house 401 is provided with a power generation device 404, a power consumption device 405, a power storage device 403, a control device 410 that controls each device, a smart meter 407, and a sensor 411 that acquires various types of information. Each device is connected by a power network 409 and an information network 412. A solar cell, a fuel cell, or the like is used as the power generation device 404, and the generated power is supplied to the power consumption device 405 and / or the power storage device 403. The power consuming device 405 is a refrigerator 405a, an air conditioner 405b, a television receiver 405c, a bath 405d, and the like. Furthermore, the electric power consumption device 405 includes an electric vehicle 406. The electric vehicle 406 is an electric vehicle 406a, a hybrid car 406b, and an electric motorcycle 406c.

  The battery of the present technology is applied to the power storage device 403. The battery of the present technology may be configured by, for example, the above-described lithium ion secondary battery. The smart meter 407 has a function of measuring the usage amount of commercial power and transmitting the measured usage amount to an electric power company. The power network 409 may be any one or a combination of DC power supply, AC power supply, and non-contact power supply.

  The various sensors 411 are, for example, human sensors, illuminance sensors, object detection sensors, power consumption sensors, vibration sensors, contact sensors, temperature sensors, infrared sensors, and the like. Information acquired by various sensors 411 is transmitted to the control device 410. Based on the information from the sensor 411, the weather condition, the condition of the person, and the like can be grasped, and the power consumption device 405 can be automatically controlled to minimize the energy consumption. Furthermore, the control apparatus 410 can transmit the information regarding the house 401 to an external electric power company etc. via the internet.

  The power hub 408 performs processing such as branching of the power line and DC / AC conversion. Communication methods of the information network 412 connected to the control device 410 include a method using a communication interface such as UART (Universal Asynchronous Receiver-Transceiver), wireless communication such as Bluetooth, ZigBee, and Wi-Fi. There is a method of using a sensor network according to the standard. The Bluetooth method is applied to multimedia communication and can perform one-to-many connection communication. ZigBee uses the physical layer of IEEE (Institute of Electrical and Electronics Engineers) 802.15.4. IEEE 802.15.4 is the name of a short-range wireless network standard called PAN (Personal Area Network) or W (Wireless) PAN.

  The control device 410 is connected to an external server 413. The server 413 may be managed by any one of the house 401, the power company, and the service provider. The information transmitted and received by the server 413 is, for example, information related to power consumption information, life pattern information, power charges, weather information, natural disaster information, and power transactions. These pieces of information may be transmitted / received from a power consuming device (for example, a television receiver) in the home, or may be transmitted / received from a device outside the home (for example, a mobile phone). Such information may be displayed on a device having a display function, such as a television receiver, a mobile phone, or a PDA (Personal Digital Assistants).

  A control device 410 that controls each unit includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and is stored in the power storage device 403 in this example. The control device 410 is connected to the power storage device 403, the domestic power generation device 404, the power consumption device 405, various sensors 411, the server 413 and the information network 412, and adjusts, for example, the amount of commercial power used and the amount of power generation It has a function to do. In addition, you may provide the function etc. which carry out an electric power transaction in an electric power market.

  As described above, not only the centralized power system 402 such as the thermal power generation 402a, the nuclear power generation 402b, and the hydroelectric power generation 402c but also the power generation device 404 (solar power generation, wind power generation) in the home is used as the electric power. Can be stored. Therefore, even if the generated power of the power generation device 404 in the home fluctuates, it is possible to perform control such that the amount of power transmitted to the outside is constant or discharge is performed as necessary. For example, the power obtained by solar power generation is stored in the power storage device 403, and the nighttime power at a low charge is stored in the power storage device 403 at night, and the power stored by the power storage device 403 is discharged during a high daytime charge. You can also use it.

  In this example, the example in which the control device 410 is stored in the power storage device 403 has been described. However, the control device 410 may be stored in the smart meter 407 or may be configured independently. Furthermore, the power storage system 400 may be used for a plurality of homes in an apartment house, or may be used for a plurality of detached houses.

(3-2) Power Storage System in Vehicle as Application Example An example in which the present technology is applied to a power storage system for a vehicle will be described with reference to FIG. FIG. 6 schematically shows an example of the configuration of a hybrid vehicle that employs a series hybrid system to which the present technology is applied. A series hybrid system is a car that runs on an electric power driving force conversion device using electric power generated by a generator driven by an engine or electric power once stored in a battery.

  The hybrid vehicle 500 includes an engine 501, a generator 502, a power driving force conversion device 503, driving wheels 504 a, driving wheels 504 b, wheels 505 a, wheels 505 b, a battery 508, a vehicle control device 509, various sensors 510, and a charging port 511. Is installed. The battery of the present technology described above is applied to the battery 508.

  The hybrid vehicle 500 travels using the power driving force conversion device 503 as a power source. An example of the power / driving force conversion device 503 is a motor. The electric power / driving force converter 503 is operated by the electric power of the battery 508, and the rotational force of the electric power / driving force converter 503 is transmitted to the driving wheels 504a and 504b. In addition, by using DC-AC (DC-AC) or reverse conversion (AC-DC conversion) at a required place, the power driving force conversion device 503 can be applied to either an AC motor or a DC motor. The various sensors 510 control the engine speed through the vehicle control device 509 and control the opening (throttle opening) of a throttle valve (not shown). Various sensors 510 include a speed sensor, an acceleration sensor, an engine speed sensor, and the like.

  The rotational force of the engine 501 is transmitted to the generator 502, and the electric power generated by the generator 502 by the rotational force can be stored in the battery 508.

  When the hybrid vehicle 500 decelerates by a braking mechanism (not shown), the resistance force at the time of deceleration is applied as a rotational force to the electric power driving force conversion device 503, and the regenerative electric power generated by the electric power driving force conversion device 503 by this rotational force becomes the battery 508. Accumulated in.

  The battery 508 is connected to an external power source of the hybrid vehicle 500, so that the battery 508 can receive power from the external power source using the charging port 511 as an input port and store the received power.

  Although not shown, an information processing apparatus that performs information processing related to vehicle control based on information related to the secondary battery may be provided. As such an information processing apparatus, for example, there is an information processing apparatus that displays a battery remaining amount based on information on the remaining amount of the battery.

  In addition, the above demonstrated as an example the series hybrid vehicle which drive | works with a motor using the electric power generated with the generator driven by an engine, or the electric power once stored in the battery. However, the present technology is also effective for a parallel hybrid vehicle in which the engine and motor outputs are both driving sources, and the system is switched between the three modes of driving with only the engine, driving with the motor, and engine and motor. Applicable. Furthermore, the present technology can be effectively applied to a so-called electric vehicle that travels only by a drive motor without using an engine.

  Hereinafter, the present technology will be described in detail by way of examples. In addition, the structure of this technique is not limited to the following Example.

<Example 1>
(Preparation of positive electrode)
5 g of polyvinylidene fluoride as a binder (binding agent), 10 g of carbon black as a conductive agent, and 85 g of LiNi _0.80 Co _0.15 Al _0.05 O ₂ as a positive electrode active material were mixed, and this was mixed with N-methyl-2-pyrrolidone (hereinafter referred to as NMP). To prepare a paste-like positive electrode mixture slurry. Note that the amount of NMP was appropriately adjusted so that the paste could be applied onto an aluminum foil as a current collector.

The positive electrode mixture slurry is applied to an aluminum foil (both sides) having a thickness of 30 μm as a positive electrode current collector, NMP is dried and removed by heating with hot air, pressing is performed, the density is adjusted with the thickness, and the positive electrode current collector is adjusted. A positive electrode having a positive electrode active material layer formed on both sides was obtained. In this pressing step, the area density can be adjusted by compression molding using a roll press or the like while adjusting the thickness and density while heating as necessary. In this case, compression molding may be repeated a plurality of times. In Example 1, the area density of the positive electrode active material layer was adjusted to 31 mg / cm ² .

(Preparation of negative electrode)
3 g of polyvinylidene fluoride as a binder (binder) and 95 g of natural graphite as a negative electrode active material are mixed, and N-methyl-2-pyrrolidone (hereinafter referred to as NMP) is added thereto to prepare a paste-like negative electrode mixture slurry. did. Note that the amount of NMP was appropriately adjusted so that the paste could be applied on the copper foil as the negative electrode current collector.

  The negative electrode mixture slurry was applied onto a 20 μm thick copper foil (both sides) as a negative electrode current collector, NMP was dried and removed by heating with hot air, pressing was performed, the density was adjusted with the thickness, and a negative electrode was obtained.

(Preparation of separator)
The following polyethylene films were produced as separators. A raw material resin obtained by mixing 2 parts by mass of ultrahigh molecular weight polyethylene having a weight average molecular weight (Mw) of 2.5 × 10 ⁶ and 13 parts by mass of polyethylene having a weight average molecular weight (Mw) of 2.4 × 10 ⁵ , and desired The liquid paraffin was mixed in an amount corresponding to the porosity and air permeability (in Example 1, porosity 35%, air permeability 394 sec / 100 cc) to prepare a polyethylene composition solution.

  Next, 100 parts by mass of this polyethylene composition solution was added 0.125 parts by mass of 2,5-di-t-butyl-p-cresol and tetrakis [(methylene) -3- (3,5-di-t. -Butyl-4-hydroxylphenyl) -propionate)] 0.25 part by weight of methane was added as an antioxidant. This mixed solution was filled in an autoclave equipped with a stirrer and stirred at 200 ° C. for 90 minutes to obtain a uniform solution.

  This solution was extruded from a T die by an extruder having a diameter of 45 mm, and a gel-like sheet was formed while being taken up by a cooling roll.

  The obtained sheet was set in a biaxial stretching machine, and according to the desired film thickness, porosity and air permeability (in Example 1, film thickness 12 μm, porosity 35%, air permeability 394 sec / 100 cc) Simultaneous biaxial stretching was performed at the same stretching temperature and stretch ratio.

  The obtained stretched membrane was washed with methylene chloride to remove the remaining liquid paraffin, and then dried to obtain a polyethylene film having a thickness of 12 μm, a porosity of 35%, and an air permeability of 394 sec / 100 cc.

(Preparation of electrolyte)
The electrolyte used was a mixture of ethylene carbonate (EC): dimethyl carbonate (DMC) = 25: 75 (mass ratio), and 1.1 mol of lithium hexafluorophosphate (LiPF ₆ ) as a supporting salt. What was melt | dissolved so that it might become / l was used.

(Assembling the cell)
The positive electrode and the negative electrode were cut into a predetermined size, and current collector tabs were ultrasonically welded to unformed portions where the positive electrode active material layer was not formed. As the current collecting tab, an aluminum lead piece was used for the positive electrode and a nickel lead piece was used for the negative electrode. Thereafter, a separator made of a porous polyethylene film was wound while being sandwiched between the positive electrode and the negative electrode. The wound body was inserted into the battery can, the negative electrode tab was connected to the bottom of the battery can by resistance welding, and the positive electrode lid was connected to the positive electrode tab by ultrasonic welding. Next, an electrolytic solution was poured, and then the positive electrode lid was caulked and sealed to obtain a target lithium ion secondary battery.

<Example 2>
The area density of the positive electrode active material layer was adjusted to 32 mg / cm ² . As a separator, a polyethylene film having a film thickness of 12 μm, a porosity of 42%, and an air permeability of 152 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 3>
The area density of the positive electrode active material layer was adjusted to 33 mg / cm ² . As a separator, a polyethylene film having a film thickness of 12 μm, a porosity of 42%, and an air permeability of 113 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 4>
The area density of the positive electrode active material layer was adjusted to 34 mg / cm ² . As a separator, a polyethylene film having a film thickness of 9 μm, a porosity of 35%, and an air permeability of 197 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 5>
The area density of the positive electrode active material layer was adjusted to 35 mg / cm ² . As a separator, a polyethylene film having a film thickness of 7 μm, a porosity of 32%, and an air permeability of 206 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 6>
The area density of the positive electrode active material layer was adjusted to 37 mg / cm ² . As a separator, a polyethylene film having a film thickness of 16 μm, a porosity of 45%, and an air permeability of 166 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 7>
The area density of the positive electrode active material layer was adjusted to 40 mg / cm ² . As a separator, a polyethylene film having a film thickness of 16 μm, a porosity of 49%, and an air permeability of 120 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 8>
The area density of the positive electrode active material layer was adjusted to 42 mg / cm ² . As a separator, a polyethylene film having a film thickness of 7 μm, a porosity of 44%, and an air permeability of 110 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 9>
The area density of the positive electrode active material layer was adjusted to 43 mg / cm ² . As a separator, a polyethylene film having a film thickness of 5 μm, a porosity of 35%, and an air permeability of 119 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 10>
The area density of the positive electrode active material layer was adjusted to 45 mg / cm ² . As a separator, a polyethylene film having a film thickness of 7 μm, a porosity of 40%, and an air permeability of 121 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Example 11>
The area density of the positive electrode active material layer was adjusted to 49 mg / cm ² . As a separator, a polyethylene film having a film thickness of 16 μm, a porosity of 46%, and an air permeability of 113 sec / 100 cc was produced. A lithium ion secondary battery was produced in the same manner as Example 1 except for the above.

<Comparative Example 1>
A lithium ion secondary battery was produced in the same manner as in Example 1 except that a polyethylene film having a film thickness of 16 μm, a porosity of 36%, and an air permeability of 451 sec / 100 cc was produced as a separator.

<Comparative example 2>
A lithium ion secondary battery was produced in the same manner as in Example 1 except that a polyethylene film having a film thickness of 16 μm, a porosity of 38%, and an air permeability of 505 sec / 100 cc was produced as a separator.

<Comparative Example 3>
A lithium ion secondary battery was produced in the same manner as in Example 2 except that a polyethylene film having a film thickness of 16 μm, a porosity of 35%, and an air permeability of 445 sec / 100 cc was produced as a separator.

<Comparative Example 4>
A lithium ion secondary battery was produced in the same manner as in Example 3 except that a polyethylene film having a film thickness of 12 μm, a porosity of 35%, and an air permeability of 389 sec / 100 cc was produced as a separator.

<Comparative Example 5>
A lithium ion secondary battery was produced in the same manner as in Example 4 except that a polyethylene film having a film thickness of 9 μm, a porosity of 29%, and an air permeability of 423 sec / 100 cc was produced as a separator.

<Comparative Example 6>
A lithium ion secondary battery was produced in the same manner as in Example 5 except that a polyethylene film having a film thickness of 12 μm, a porosity of 34%, and an air permeability of 405 sec / 100 cc was produced as a separator.

<Comparative Example 7>
A lithium ion secondary battery was produced in the same manner as in Example 6 except that a polyethylene film having a thickness of 9 μm, a porosity of 33%, and an air permeability of 276 sec / 100 cc was produced as a separator.

<Comparative Example 8>
A lithium ion secondary battery was produced in the same manner as in Example 6 except that a polyethylene film having a film thickness of 12 μm, a porosity of 39%, and an air permeability of 249 sec / 100 cc was produced as a separator.

<Comparative Example 9>
A lithium ion secondary battery was produced in the same manner as in Example 6 except that a polyethylene film having a film thickness of 16 μm, a porosity of 42%, and an air permeability of 235 sec / 100 cc was produced as a separator.

<Comparative Example 10>
A lithium ion secondary battery was produced in the same manner as in Example 7 except that a polyethylene film having a film thickness of 16 μm, a porosity of 42%, and an air permeability of 163 sec / 100 cc was produced as a separator.

<Comparative Example 11>
A lithium ion secondary battery was produced in the same manner as in Example 9 except that a separator having a film thickness of 12 μm, a porosity of 42%, and an air permeability of 152 sec / 100 cc was produced.

<Comparative Example 12>
A lithium ion secondary battery was produced in the same manner as in Example 9, except that a separator was produced with a film thickness of 9 μm, a porosity of 35%, and an air permeability of 197 sec / 100 cc.

<Comparative Example 13>
A lithium ion secondary battery was produced in the same manner as in Example 9 except that a polyethylene film having a film thickness of 7 μm, a porosity of 32%, and an air permeability of 206 sec / 100 cc was produced as a separator.

<Comparative example 14>
A lithium ion secondary battery was produced in the same manner as in Example 11 except that a polyethylene film having a film thickness of 12 μm, a porosity of 38%, and an air permeability of 157 sec / 100 cc was produced as a separator.

In Examples 1 to 11 and Comparative Examples 1 to 14, the porosity ε (%), the air permeability t (sec / 100 cc), and the area density S (mg / cm ² ) of the positive electrode active material layer are Measured as follows.

(Measurement method of porosity)
The porosity of the separator was measured using a gravimetric method. In this method, 10 portions of the separator were punched into a circle having a diameter of 2 cm in the thickness direction of the separator, and the thickness h and the mass w of the film were measured respectively. Furthermore, using the thickness h and the mass w, the volume V of the film for 10 sheets of separator and the mass W of the film for 10 sheets were determined, and the porosity was determined from the following equation.
Porosity [%] = {(ρV−W) / (ρV)} × 100
ρ: Density of separator material In addition, an electronic balance (manufactured by Sartorius Co., Ltd., MC210P) was used as the mass measuring instrument.

(Measurement method of air permeability)
The air permeability is the Gurley air permeability. The Gurley air permeability was measured according to JIS P8117. In addition, the air permeability resistance measuring device (Corporation | KK Toyo Seiki Seisakusho make, G-B2C) was used for the measuring machine.

(Measurement method of area density of positive electrode active material layer)
After the battery was completely discharged, it was disassembled, the positive electrode plate was taken out, washed with a solvent (DMC: dimethyl carbonate), and then sufficiently dried. A portion where the positive electrode active material layer is formed on both sides of the positive electrode current collector (both sides forming portion) is punched out with a predetermined area (punched area), and the mass (mg) (referred to as mass A) is measured. The portion where the agent layer was not applied was punched in the same manner, and the mass (mg) (referred to as mass B) was measured. And it computed with the following formula.
Calculation formula: area density (mg / cm ² ) = (mass A−mass B) ÷ punched area

(Evaluation)
In order to evaluate the high output characteristics of the produced battery, the following high load charge / discharge test was performed.

(High load charge / discharge test)
The manufactured battery was charged at 23 ° C. with a constant current of 0.1 C until it reached 4.2 V, and then charged with a constant voltage at 4.2 V for 2.5 hours. After a 30-minute pause, constant current discharge was performed up to 2.5 V with a constant current of 0.1 C. This operation was performed twice, and the second discharge capacity was defined as the low load discharge capacity of the battery. Next, the same battery was charged under the above conditions, and then discharged at a constant current of 12 C to obtain a high load discharge capacity.

  Then, {(high load discharge capacity) ÷ (low load discharge capacity)} × 100 (%) was determined as a capacity maintenance rate (%) in high load discharge.

  Note that 1 C is a current value at which the theoretical capacity can be discharged (or charged) in one hour. 0.1 C is a current value at which the theoretical capacity can be discharged (or charged) in 10 hours, and 12 C is a current value at which the theoretical capacity can be discharged (or charged) in 5 minutes. 12C represents a current value 120 times that of 0.1C.

  Table 1 shows the measurement results and evaluation results of Examples 1 to 11 and Comparative Examples 1 to 14.

Moreover, the graph for making it easy to understand whether an Example and a comparative example satisfy | fill the following (Formula) is shown in FIGS. FIG. 7 shows a three-axis coordinate space of t-ε-S of air permeability (t), porosity (ε), and area density (S), and FIGS. 8 to 13 show the area density (S). Is a predetermined value (31 mg / cm ² , 32 mg / cm ² , 33 mg / cm ² , 34 mg / cm ² , 35 mg / cm ² , 37 mg / cm ² , 40 mg / cm ² , 42 mg / cm ² , 43 mg / cm ² , 45 mg / Cm ² or 49 mg / cm ² ).

(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm

  In FIG. 7, ranges of air permeability (t) and porosity (ε) satisfying (Expression) at S = the predetermined value are indicated by regions S1 to S11. And the measured value of each Example and each comparative example was plotted on the epsilon coordinate plane of FIGS. When the plotted points are within the range of the region S1 to the region S11, the separator (polyethylene film) satisfies the relationship of (formula), and when the plotted point is outside the range of the region S1 to the region S11, the separator (polyethylene film) is ( Indicates that the relationship of (formula) is not satisfied.

The ε-t coordinate plane (ε-t plane) in FIGS. 8 to 13 represents the ε-t coordinate plane when the area density (S) is as follows.
8A: ε-t coordinate plane of S = 31 (mg / cm ² ), FIG. 8B: ε-t coordinate plane of S = 32 (mg / cm ² ) FIG. 9A: S = 33 (mg / cm ² ) ε-t coordinate plane, FIG. 9B: ε-t coordinate plane of S = 34 (mg / cm ² ) FIG. 10A: ε-t coordinate plane of S = 35 (mg / cm ² ), FIG. 10B: S = 37 ( mg / cm ² ) ε-t coordinate plane FIG. 11A: ε-t coordinate plane of S = 40 (mg / cm ² ), FIG. 11B: ε-t coordinate plane of S = 42 (mg / cm ² ) : Ε-t coordinate plane of S = 43 (mg / cm ² ), FIG. 12B: ε-t coordinate plane of S = 45 (mg / cm ² ) FIG. 13: ε− of S = 49 (mg / cm ² ) t coordinate plane

  Further, the regions S1 to S11, tmin, and tmax shown in FIGS. 8 to 13 are derived according to the above (formula). The relational expressions of the areas S1 to S11, tmin, tmax are described below. A separator having a porous film having an air permeability t (sec / 100 cc) smaller than tmin cannot secure a good shutdown function and tends to lower the safety of the battery.

(Region S1)
Region S1: S = 31 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 31 ^−4.96 )

(Region S2)
Region S2: S = 32 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 32 ^−4.96 )

(Region S3)
Region S3: S = 33 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 33 ^−4.96 )

(Region S4)
Region S4: S = 34 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 34 ^−4.96 )

(Region S5)
Region S5: S = 35 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 35 ^−4.96 )

(Region S6)
Region S6: S = 37 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 37 ^−4.96 )

(Region S7)
Region S7: S = 40 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 40 ^−4.96 )

(Region S8)
Region S8: S = 42 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 42 ^−4.96 )

(Region S9)
Region S9: S = 43 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 43 ^−4.96 )

(Region S10)
Region S10: S = 45 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 45 ^−4.96 )

(Region S11)
Region S11: S = 49 (mg / cm ² ), tmin ≦ t ≦ tmax
tmin: a × Ln (ε) −4.02a + 100 (a = −40)
tmax: a × Ln (ε) −4.02a + 100 (a = −1.87 × 10 ¹⁰ × 49 ^−4.96 )

  As shown in Table 1 and FIGS. 7 to 13, high load discharge was excellent in Examples 1 to 11 satisfying the relationship of the above (formula). On the other hand, in Comparative Examples 1 to 14 that do not satisfy the relationship of the above (formula), high-load discharge was not excellent. In addition, since the capacity maintenance rate in a high load discharge test required for general users is about 60%, in this characteristic evaluation, this value (60%) is used as a reference value, and high load discharge is superior to a reference value or more. It was determined that

4). Other Embodiments The present technology is not limited to the above-described embodiments of the present technology, and various modifications and applications can be made without departing from the gist of the present technology.

  For example, the numerical values, structures, shapes, materials, raw materials, manufacturing processes and the like given in the above-described embodiments and examples are merely examples, and different numerical values, structures, shapes, materials, raw materials, and the like as necessary. A manufacturing process or the like may be used.

  The configurations, methods, processes, shapes, materials, numerical values, and the like of the above-described embodiments and examples can be combined with each other without departing from the gist of the present technology.

  The battery according to the above-described embodiment is not limited to a secondary battery, and may be a primary battery.

  In the above-described embodiments and examples, a battery having a cylindrical battery structure and a battery having a winding structure in which an electrode is wound have been described, but the present invention is not limited thereto. For example, the same applies to batteries having other battery structures such as a laminate film type battery using a laminate film for the exterior, a stack type having a structure in which electrodes are stacked, a square type, a coin type, a flat type or a button type battery. In addition, the present technology can be applied. In the stack type, for example, a battery structure in which a positive electrode and a negative electrode are stacked via a sheet separator, a battery structure in which a positive electrode and a negative electrode are stacked through a single strip-shaped separator folded, and a negative electrode are sandwiched Examples thereof include a battery structure in which a positive electrode and a negative electrode are stacked through a pair of separators folded by spelling in a state.

  Further, as the electrolyte, a gel electrolyte in which a nonaqueous electrolytic solution is held by a polymer compound may be used. The polymer compound that holds the non-aqueous electrolyte is not particularly limited as long as it absorbs the non-aqueous solvent and gels. For example, polyvinylidene fluoride (PVdF) or vinylidene fluoride (VdF) and hexafluoropropylene (HFP). And a fluorine-based polymer compound such as a copolymer containing a repeating unit, an ether-based polymer compound such as polyethylene oxide (PEO) or a crosslinked product containing polyethylene oxide (PEO), polyacrylonitrile (PAN), polypropylene oxide (PPO) ) Or polymethyl methacrylate (PMMA) as a repeating unit. Any one of these polymer compounds may be used alone, or two or more thereof may be mixed and used.

  In particular, from the viewpoint of redox stability, a fluorine-based polymer compound is desirable, and among them, a copolymer containing vinylidene fluoride and hexafluoropropylene as components is preferable. Further, this copolymer is composed of unsaturated dibasic acid monoester such as maleic acid monomethyl ester (MMM), halogenated ethylene such as ethylene trifluorochloride (PCTFE), and unsaturated compound such as vinylene carbonate (VC). The cyclic carbonate ester or epoxy group-containing acrylic vinyl monomer may be included as a component. This is because higher characteristics can be obtained.

  Further, a solid electrolyte or the like may be used as the electrolyte. The electrolyte may contain an ionic liquid (room temperature molten salt).

  According to the above-described embodiment of the present technology, it is possible to provide a high-capacity and high-output battery by preventing a decrease in capacity when discharged at a high output. In addition, by suppressing the increase in internal resistance, it is possible to suppress the generation of Joule heat associated with discharge and suppress heat generation during high load discharge, so the separator contracts due to heat generation during high load discharge, and the positive electrode and negative electrode Can reduce the risk of short circuit.

  The present technology can also take the following configurations.

[1]
A positive electrode including a positive electrode current collector and a positive electrode active material, and having a positive electrode active material layer provided on both surfaces of the positive electrode current collector;
A negative electrode,
A separator including at least a porous film;
With electrolyte,
The positive electrode active material has a layered structure, a high nickel content, a nickel-based lithium nickel composite oxide containing at least lithium and nickel, a layered structure, and a nickel content. Low, lithium nickel cobalt manganese composite oxide containing at least lithium, nickel, cobalt and manganese, a spinel structure, and a lithium manganese composite oxide containing at least lithium and manganese, and an olivine structure And having at least one selected from the group consisting of lithium iron phosphate compounds containing at least lithium, iron and phosphorus,
The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more,
A battery satisfying the following (formula) in terms of porosity ε (%) and air permeability t (sec / 100 cc) of the porous film.
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm [2]
The battery according to [1], wherein the area density of the positive electrode active material layer is 50 mg / cm ² or less.
[3]
The battery according to any one of [1] to [2], wherein the nickel-based lithium nickel composite oxide is at least one of the composite oxides represented by Chemical Formula 1.
(Chemical formula 1)
Li _x Ni _y Co _z M1 _(1-yz) O _b
(In the formula, M1 represents boron (B), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), chromium (Cr), manganese (Mn ), Iron (Fe), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), barium (Ba) ), Tungsten (W), indium (In), tin (Sn), lead (Pb) and antimony (Sb), where x, y, z and b are each 0.8 < x ≦ 1.2, 0.5 ≦ y ≦ 1.0, 0 ≦ z ≦ 0.5, y + z ≦ 1, 1.8 ≦ b ≦ 2.2 The composition of lithium Depends on the state of charge and discharge, and the value of x is in the fully discharged state. It represents the value.)
[4]
The lithium nickel cobalt manganese composite oxide is a battery according to any one of [1] to [3], which is at least one of composite oxides represented by Chemical Formula 2.
(Chemical formula 2)
Li _f Ni _g Co _i Mn _(1-gih) M2 _h O _(2-j)
(Wherein M2 is 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), f, g, h, j , I and k are 0.8 ≦ f ≦ 1.2, 0 <g ≦ 0.5, 0 ≦ h ≦ 0.5, g + h + i <1, −0.1 ≦ j ≦ 0.2, 0 <i (It is a value within the range of ≦ 0.5. Note that the composition of lithium varies depending on the state of charge and discharge, and the value of f represents a value in the complete discharge state.)
[5]
The battery according to any one of [1] to [4], wherein the lithium manganese composite oxide is at least one of composite oxides represented by Chemical formula 3.
(Chemical formula 3)
Li _v Mn _(2-w) M3 _w O _s
(Wherein M3 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), at least one selected from the group consisting of v, w and s are values within the range of 0.9 ≦ v ≦ 1.1, 0 ≦ w ≦ 0.6, 3.7 ≦ s ≦ 4.1, where the composition of lithium is the state of charge and discharge. And the value of v represents a value in a fully discharged state.)
[6]
The battery according to any one of [1] to [5], wherein the lithium iron phosphate compound is at least one of phosphoric acid compounds represented by Chemical formula 4.
(Chemical formula 4)
_{Li u Fe r M4 (1-} r) PO 4
(Wherein, M4 is cobalt (Co), manganese (Mn), 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), at least one selected from the group consisting of r. , 0 <r ≦ 1, and u is a value within the range of 0.9 ≦ u ≦ 1.1 Note that the composition of lithium varies depending on the state of charge and discharge, and the value of u Represents the value in the fully discharged state.)
[7]
The positive electrode active material includes Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ (x is as defined above) as the nickel-based lithium nickel composite oxide,
The content of the _{Li x Ni 0.80 Co 0.15 Al 0.05} O 2 is the based on the total weight of the positive electrode active material is not more than 80 wt% or more 98 wt% [1] to according to any one of [6] battery.
[8]
The positive electrode active material is a mixture of the lithium nickel cobalt manganese composite oxide and the lithium manganese composite oxide,
The mass ratio of the lithium nickel cobalt manganese composite oxide and the mixture of the lithium manganese composite oxide (the mass of the lithium nickel cobalt manganese composite oxide: the mass of the lithium manganese composite oxide) is in the range of 5: 5 to 9: 1. The battery according to any one of [1], [2], [4] and [5].
[9]
The positive electrode active material is one positive electrode active material composed of the nickel-based lithium nickel composite oxide or a mixture of the nickel-based lithium nickel composite oxide and the lithium manganese composite oxide,
The mass ratio of the one positive electrode active material (the mass of the nickel-based lithium nickel composite oxide: the mass of the lithium manganese composite oxide) is in the range of 5: 5 to 10: 0 [1], [2] The battery according to any one of [3] and [5].
[10]
The battery according to any one of [1] to [9], wherein the separator further includes a surface layer including particles and a resin provided on at least one main surface of the porous film.
[11]
The battery according to any one of [1] to [10], wherein the porous film is a polyolefin resin film.
[12]
The battery according to any one of [1] to [11], wherein the separator has a thickness of 3 μm to 18 μm.
[13]
The battery according to any one of [1] to [12];
A control unit for controlling the battery;
A battery pack having an exterior housing the battery.
[14]
[1] An electronic apparatus comprising the battery according to any one of [12] and receiving power supply from the battery.
[15]
The battery according to any one of [1] to [12];
A conversion device that receives supply of electric power from the battery and converts it into driving force of the vehicle;
An electric vehicle having a control device that performs information processing related to vehicle control based on the information related to the battery.
[16]
A power storage device that includes the battery according to any one of [1] to [12] and supplies electric power to an electronic device connected to the battery.
[17]
A power information control device that transmits and receives signals to and from other devices via a network,
The power storage device according to [16], wherein charge / discharge control of the battery is performed based on information received by the power information control device.
[18]
[1] A power system that receives supply of power from the battery according to any one of [12], or that supplies power to the battery from a power generation device or a power network.

  DESCRIPTION OF SYMBOLS 11 ... Battery can, 12a, 12b ... Insulating plate, 13 ... Battery cover, 14 ... Safety valve, 14a ... Projection part, 15 ... Disc holder, 16 ... Shut-off disc, 16a ... Hole, 17 ... Heat sensitive resistor, 18 ... Gasket, 19 ... Subdisk, 20 ... Winding electrode body, 21 ... Positive electrode, 21A ... Positive electrode collection Electrode, 21B ... positive electrode active material layer, 22 ... negative electrode, 22A ... negative electrode current collector, 22B ... negative electrode active material layer, 23 ... separator, 23a ... porous film, 23b ... surface layer, 24 ... center pin, 25 ... positive electrode lead, 26 ... negative electrode lead, 301 ... assembled battery, 301a ... secondary battery, 302a ... charge control switch , 302b ... diode, 303a ... discharge control switch, 03b ... Diode, 304 ... Switch part, 307 ... Current detection resistor, 308 ... Temperature detection element, 310 ... Control part, 311 ... Voltage detection part, 313 ... Current measurement 314 ... Switch control unit 317 ... Memory 318 ... Temperature detection unit 321 ... Positive terminal 322 ... Negative terminal 400 ... Power storage system 401 ... House 402 ... Centralized power system, 402a ... Thermal power generation, 402b ... Nuclear power generation, 402c ... Hydroelectric power generation, 403 ... Power storage device, 404 ... Power generation device, 405 ... Electric power Consuming device, 405a ... refrigerator, 405b ... air conditioner, 405c ... television receiver, 405d ... bath, 406 ... electric vehicle, 406a ... electric vehicle, 406b ... c Bridcar, 406c ... Electric bike, 407 ... Smart meter, 408 ... Power hub, 409 ... Power network, 410 ... Control device, 411 ... Sensor, 412 ... Information network, 413 ... Server, 500 ... Hybrid vehicle, 501 ... Engine, 502 ... Generator, 503 ... Power driving force converter, 504a ... Driving wheel, 504b ... Driving wheel, 505a ... Wheel, 505b ... Wheel, 508 ... Battery, 509 ... Vehicle control device, 510 ... Sensor, 511 ... Charging port

Claims (22)

A positive electrode having a positive electrode active material layer provided on both sides of the positive electrode current collector;
A negative electrode,
A separator including at least a porous film,
The positive electrode active material includes at least one lithium nickel composite oxide represented by Chemical Formula 1,
The area density S (mg / cm ² ) of the positive electrode active material layer is 34 mg / cm ² or more,
A battery satisfying the following (formula) in terms of porosity ε (%) and air permeability t (sec / 100 cc) of the porous film.
Li _x Ni _y Co _z M1 _(1-yz) O _b
(In the formula, M1 represents boron (B), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), chromium (Cr), iron (Fe ), Copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), barium (Ba), tungsten (W ), Indium (In), tin (Sn), lead (Pb) and antimony (Sb), where x, y, z and b are each 0.8 <x ≦ 1.2. , 0.5 ≦ y ≦ 1.0, 0 ≦ z ≦ 0.5, y + z ≦ 1, 1.8 ≦ b ≦ 2.2 The composition of lithium is the state of charge and discharge. The value of x represents a value in a fully discharged state.
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm A positive electrode having a positive electrode active material layer provided on both sides of the positive electrode current collector;
A negative electrode,
A separator including at least a porous film,
The positive electrode active material includes at least one lithium manganese composite oxide represented by Chemical Formula 3,
The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more,
A battery satisfying the following (formula) in terms of porosity ε (%) and air permeability t (sec / 100 cc) of the porous film.
(Chemical Formula 3) Li _v Mn _(2-w) M3 _w O _s
(Wherein M3 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), at least one selected from the group consisting of v, w and s are values within the range of 0.9 ≦ v ≦ 1.1, 0 ≦ w ≦ 0.6, 3.7 ≦ s ≦ 4.1, where the composition of lithium is the state of charge and discharge. And the value of v represents a value in a fully discharged state.)
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm A positive electrode having a positive electrode active material layer provided on both sides of the positive electrode current collector;
A negative electrode,
A separator including at least a porous film,
The positive electrode active material contains at least one lithium iron phosphate compound represented by Chemical Formula 4,
The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more,
A battery satisfying the following (formula) in terms of porosity ε (%) and air permeability t (sec / 100 cc) of the porous film.
(Of _{4) Li u Fe r M4 (} 1- r) PO 4
(Wherein, M4 is cobalt (Co), manganese (Mn), 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), at least one selected from the group consisting of r. , 0 <r ≦ 1, and u is a value within the range of 0.9 ≦ u ≦ 1.1 Note that the composition of lithium varies depending on the state of charge and discharge, and the value of u Represents the value in the fully discharged state.)
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm A positive electrode having a positive electrode active material layer provided on both sides of the positive electrode current collector;
A negative electrode,
A separator including at least a porous film,
The positive electrode active material is Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ (x is a value in the range of 0.8 <x ≦ 1.2. The composition of lithium is Depending on the state of discharge, the value of x represents the value in a fully discharged state)
The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more,
A battery satisfying the following (formula) in terms of porosity ε (%) and air permeability t (sec / 100 cc) of the porous film.
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm A positive electrode having a positive electrode active material layer provided on both sides of the positive electrode current collector;
A negative electrode,
A separator including at least a porous film,
The positive electrode active material has a layered structure, a low nickel content, a lithium nickel cobalt manganese composite oxide containing at least lithium, nickel, cobalt, and manganese, and a spinel structure, and Including a mixture of lithium manganese composite oxide containing at least lithium and manganese,
The mass ratio of the above mixture (mass of lithium nickel cobalt manganese composite oxide: mass of lithium manganese composite oxide) is in the range of 5: 5 to 9: 1,
The area density S (mg / cm ² ) of the positive electrode active material layer is 30 mg / cm ² or more,
A battery satisfying the following (formula) in terms of porosity ε (%) and air permeability t (sec / 100 cc) of the porous film.
(formula)
t = a × Ln (ε) −4.02a + 100, and
−1.87 × 10 ¹⁰ × S ^−4.96 ≦ a ≦ −40
ε: Porosity (%)
t: Air permeability (sec / 100cc)
S: Area density of positive electrode active material layer (mg / cm ² )
Ln: natural logarithm The battery according to claim 1, wherein the positive electrode active material layer has an area density of 50 mg / cm ² or less. _5. The battery according to claim 4, wherein a content of the Li _x Ni _0.80 Co _0.15 Al _0.05 O ₂ is 80% by mass or more and 98% by mass or less with respect to a total mass of the positive electrode active material.   The battery according to any one of claims 1 to 7, wherein the separator further includes a surface layer including particles and a resin provided on at least one main surface of the porous film.   The battery according to any one of claims 1 to 8, wherein the porous film is a polyolefin resin film.   The battery according to claim 1, wherein the separator has a thickness of 3 μm or more and 18 μm or less.   The negative electrode includes carbon (C), magnesium (Mg), boron (B), aluminum (Al), titanium (Ti), 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) or platinum The battery according to any one of claims 1 to 10, comprising (Pt). The negative electrode includes an alloy containing silicon and a second constituent element other than silicon,
As the second constituent element, tin (Sn), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In), silver ( The composition according to any one of claims 1 to 11, comprising at least one member selected from the group consisting of Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), and chromium (Cr). battery. The negative electrode includes an alloy containing tin and a second constituent element other than tin,
As the second constituent element, silicon (Si), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In), silver ( The composition according to any one of claims 1 to 11, comprising at least one member selected from the group consisting of Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), and chromium (Cr). battery. The negative electrode includes a compound of tin (Sn) or a compound of silicon (Si),
The battery according to claim 1, wherein each of the compounds contains oxygen (O) or carbon (C).   The battery according to claim 14, wherein the compound further contains one of the second constituent elements listed in claim 12 or 13.   The battery according to claim 1, wherein the negative electrode contains lithium titanate, iron oxide, ruthenium oxide, or molybdenum oxide. A battery according to any one of claims 1 to 16,
A control unit for controlling the battery;
A battery pack having an exterior housing the battery.   An electronic device comprising the battery according to claim 1 and receiving supply of electric power from the battery. A battery according to any one of claims 1 to 16,
A conversion device that receives supply of electric power from the battery and converts it into driving force of the vehicle;
An electric vehicle having a control device that performs information processing related to vehicle control based on the information related to the battery.   A power storage device comprising the battery according to claim 1 and supplying power to an electronic device connected to the battery. A power information control device that transmits and receives signals to and from other devices via a network,
The power storage device according to claim 20, wherein charge / discharge control of the battery is performed based on information received by the power information control device.   An electric power system that receives supply of electric power from the battery according to claim 1 or supplies electric power to the battery from a power generation device or an electric power network.

Images