JP5633747B2 - Lithium ion secondary battery - Google Patents

Description

  The present invention relates to a lithium ion secondary battery. Specifically, the present invention relates to a lithium ion secondary battery provided with a lithium composite oxide containing nickel as a positive electrode active material.

A lithium ion secondary battery includes a positive electrode and a negative electrode, and an electrolyte solution (nonaqueous electrolyte solution) interposed between the two electrodes, and the lithium ion contains a positive electrode through an electrolyte solution containing an electrolyte such as a lithium salt. Charge and discharge by moving back and forth between the battery and the negative electrode. A typical negative electrode of this type of lithium ion secondary battery is a particulate carbon containing a graphite structure (layered structure) at least partially as a material (negative electrode active material) capable of reversibly occluding and releasing lithium ions. Material (for example, graphite material) is provided.
In general, at the time of charging / discharging of a lithium ion secondary battery, since insertion and extraction of lithium ions are performed with respect to the carbon material, the carbon material expands (that is, during charging) and contracts (that is, during discharging). By repeatedly charging and discharging, the negative electrode is deformed little by little and the distance between the positive and negative electrodes is varied, which may deteriorate the battery capacity. In particular, capacity deterioration tends to appear at high temperatures (for example, approximately 60 ° C.). In order to cope with such a problem, Patent Document 1 is cited as a prior art. Patent Document 1 describes a technique for preventing capacity deterioration by defining the packing density of a negative electrode including a graphite material (carbon material) as 1.0 to 1.2 g / cm ³ .

JP 2010-238469 A

However, although the technology described in Patent Document 1 can prevent deterioration of capacity at high temperatures, the output of the battery is low in a state where the SOC (State of charge) is low (for example, SOC 10% to 40%). There is a risk that it will be greatly reduced and it will be difficult to supply a stable output. In particular, when a lithium ion secondary battery is used as a power source for driving a vehicle, use under relatively severe environmental conditions is assumed, and a stable output is required in a wide SOC range.
Accordingly, the present invention has been created to solve the above-described conventional problems, and its purpose is to prevent lithium ions that can prevent deterioration of capacity at high temperatures and lower output in a low SOC region. It is to provide a secondary battery.

In order to achieve the above object, the present invention provides a lithium ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte. That is, in the lithium ion secondary battery disclosed herein, the positive electrode has a positive electrode mixture layer containing at least a positive electrode active material on the positive electrode current collector, and the negative electrode has at least a negative electrode active material on the negative electrode current collector. It has a negative electrode mixture layer containing a substance. The negative active material is a graphite material, the packing density of the negative-electrode mixture layer containing a graphite material is ^{1.0g / cm 3 ~1.2g / cm 3} . The positive electrode active material is a nickel-containing lithium composite oxide having a layered structure, and the oxide has a composition containing zirconium (Zr) and tungsten (W), and zirconium in the oxide The molar ratio (Zr / W) of tungsten to tungsten is 0.1 to 0.86.
Here, “packing density” refers to the abundance (content) per unit volume of solids constituting the negative electrode mixture layer on the negative electrode current collector. Therefore, typically, the packing density (abundance) is determined by applying a predetermined weight per unit area (in terms of solid content) of the negative electrode mixture layer forming composition (typically a paste-like composition) on the negative electrode current collector. It is possible to adjust by adding with a suitable pressing means after adding in (preferably).

In the lithium ion secondary battery provided by the present invention, the packing density of the negative electrode mixture layer is 1.0 g / cm ^{3 to} 1.2 g / cm ³ , and the positive electrode mixture layer has a molar ratio of zirconium and tungsten. Since the nickel containing lithium complex oxide whose is 0.1-0.86 is contained, the characteristic of a lithium ion secondary battery can be improved. That is, it is possible to prevent the capacity from being deteriorated at a high temperature and to prevent the output from being lowered in the low SOC region (that is, to realize the improvement in the output in the low SOC region).

  In a preferred embodiment of the lithium ion secondary battery disclosed herein, the zirconium content when the total amount of other constituent elements excluding lithium and oxygen in the nickel-containing lithium composite oxide is 100 mol% is 0. 0.05 mol% to 0.6 mol%. According to such a configuration, a good output can be obtained even in a low SOC region.

  In a preferred aspect of the lithium ion secondary battery disclosed herein, the nickel-containing lithium composite oxide is an oxide containing cobalt (Co) and manganese (Mn) as constituent elements. According to such a configuration, a battery with higher output can be realized in the low SOC region.

  As described above, any of the lithium ion secondary batteries disclosed herein can be a secondary battery that prevents deterioration in capacity at high temperatures and prevents reduction in output in a low SOC region. Typically, it can be used as a drive power source for automobiles, particularly automobiles equipped with electric motors such as hybrid cars, electric cars, and fuel cell cars. As another aspect of the present invention, any of the lithium ion secondary batteries disclosed herein (which may be in the form of an assembled battery in which a plurality of batteries are typically connected in series) is used as a driving power source. Provided as a vehicle.

It is a perspective view which shows typically the external shape of the lithium ion secondary battery which concerns on one Embodiment. It is sectional drawing which follows the II-II line | wire in FIG. It is a perspective view which shows typically the external shape of the assembled battery which concerns on one Embodiment. It is a graph which shows the relationship between the packing density of a negative electrode compound-material layer and a capacity | capacitance maintenance factor in one experimental example. It is a graph which shows the relationship between the packing density of the negative electrode compound-material layer in another one experimental example, and an output. It is a graph which shows the relationship between the molar ratio of Zr and W in another test example, and an output. It is a side view which shows typically the vehicle (automobile) provided with the lithium ion secondary battery which concerns on this invention.

  Hereinafter, preferred embodiments of the present invention will be described. It should be noted that matters other than matters specifically mentioned in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

  The lithium ion secondary battery provided by the present invention includes a negative electrode mixture layer having a predetermined packing density as described above, and a positive electrode mixture layer having a positive electrode active material containing zirconium and tungsten in a predetermined molar ratio. It is characterized by having. Hereinafter, the lithium ion secondary battery disclosed herein will be described in detail.

The positive electrode provided in the lithium ion secondary battery disclosed herein can have the same configuration as the conventional one except that the positive electrode active material characterizing the present invention is provided. Such a positive electrode includes a positive electrode current collector and a positive electrode mixture layer formed on the positive electrode current collector.
As the positive electrode current collector, a conductive member made of a metal having good conductivity is preferably used, like the current collector used in the positive electrode of a conventional lithium ion secondary battery. For example, aluminum or an alloy containing aluminum as a main component can be used. The shape of the positive electrode current collector may vary depending on the shape of the lithium ion secondary battery, and is not particularly limited, and may be various forms such as a rod shape, a plate shape, a sheet shape, a foil shape, and a mesh shape.

  The positive electrode active material used in the positive electrode of the lithium ion secondary battery disclosed herein is a nickel-containing lithium composite oxide having a layered structure, and at least zirconium (Zr) and tungsten (W) as trace essential metal elements And lithium composite oxides containing The lithium composite oxide can contain one or more elements (typically metal elements) in addition to Li, Ni, W, and Zr as long as the effects of the present invention are not significantly impaired. . Examples of such elements include Co, Mn, Al, Cr, Fe, V, Mg, Ti, Mo, Cu, Zn, Ga, In, Sn, La, Ce, Ca, Na, F, and B. Can do. In particular, a lithium composite oxide having a layered structure containing Co and / or Mn together with Ni is preferable.

The molar ratio (Zr / W) of Zr [mol%] and W [mol%] in the nickel-containing lithium composite oxide is 0.1 to 0.86 (for example, 0.1 to 0.8, preferably 0.1-0.75, more preferably 0.2-0.4). When the molar ratio (Zr / W) is too smaller than 0.1 and when the molar ratio is too larger than 0.86, the low temperature range (for example, a low temperature range lower than 0 ° C., such as −40 ° C. to − The output in the low SOC region (for example, when the SOC is 10% to 40%) at 10 ° C. may be greatly reduced.
Further, the Zr content when the total amount (total amount) of other constituent elements excluding lithium and oxygen in the nickel-containing lithium composite oxide (positive electrode active material) is 100 mol% is about 0.01 mol% to 3 mol%. (Preferably 0.05 mol% to 0.6 mol%). When the content of Zr is within the above range, a higher output can be obtained in a low SOC region (for example, SOC is approximately 10% to 40%).
Further, the W content may be appropriately selected within the range where the molar ratio (Zr / W) satisfies the above conditions. The W content can be, for example, about 0.012 mol% to 3.5 mol% (preferably about 0.5 mol% to 1 mol%). If the content of W is too small, the battery performance improvement effect (for example, improvement in output) to the nickel-containing lithium composite oxide (positive electrode active material) having a composition not containing W may not be sufficiently exhibited. When the content of W is too large, the specific capacity of the nickel-containing lithium composite oxide decreases, which is not preferable.

The nickel-containing lithium composite oxide typically has a general formula:
_{Li 1 + α Ni x M 1} -x-y-z Zr y W z O 2 (I);
Can be expressed as Here, in the above formula (I), α is 0 ≦ α ≦ 0.2 (for example, 0.05 ≦ α ≦ 0.2). X is x> 0, y is 0.0001 ≦ y ≦ 0.03 (preferably 0.0005 ≦ y ≦ 0.006), z is z> 0, and 0 <x + y + z ≦ 1. And 0.1 ≦ (y / z) ≦ 0.86. Examples of M in the above formula (I) include Co, Mn, Al, Cr, Fe, V, Mg, Ti, Mo, Cu, Zn, Ga, In, Sn, La, Ce, Ca, Na, and F. , B and the like.

The positive electrode active material disclosed here, that is, the nickel-containing lithium composite oxide is preferably an oxide containing Co and Mn as constituent elements in addition to Li, Ni, W and Zr. Such nickel-containing lithium composite oxide has a general formula:
_{Li 1 + α Ni x Co p} Mn q M 1-x-y-z-p-q Zr y W z O 2 (II);
Can be expressed as Here, in the above formula (II), α is 0 ≦ α ≦ 0.2 (for example, 0.05 ≦ α ≦ 0.2). X is 0 <x ≦ 0.6 (typically 0.1 <x ≦ 0.6), and y is 0.0001 ≦ y ≦ 0.03 (preferably 0.0005 ≦ y ≦ 0). .006), z is z> 0, p is 0 <p ≦ 0.5, q is 0 <q ≦ 0.5, satisfies 0 <x + y + z + p + q ≦ 1, and 0.1 ≦ (y / z) ≦ 0.86 is satisfied.

As a method for producing such a nickel-containing lithium composite oxide (positive electrode active material), a method capable of preparing the oxide as a final product may be appropriately employed. For example, the case where a nickel-containing lithium composite oxide (that is, a composite oxide containing all of Ni, Co, and Mn as constituent metal elements) when x + y + z + p + q = 1 in the above formula (II) will be described as an example. However, it is not intended to limit the application object of the technology disclosed herein to an oxide having such a composition. Such nickel-containing lithium composite oxide has a general formula:
_{Li 1 + α Ni x Co p} Mn q Zr y W z O 2 (III);
Can be expressed as In the above formula (III), the meanings of α, x, y, z, p and q are the same as in the above formula (II).

As a method for producing the nickel-containing lithium composite oxide (III):
(I) a salt containing a metal element in which x, p and q in formula (III) are greater than 0 (a nickel-containing lithium composite oxide containing two or more metal elements including Ni among Ni, Co and Mn) In the case of production, a salt containing each metal element alone may be used, or a salt containing two or more metal elements may be used) and an aqueous solution containing a zirconium salt (hereinafter referred to as transition metal-Zr). Salt aqueous solution) and an aqueous solution containing a tungsten-containing salt, these aqueous solutions are mixed under basic conditions of pH 11 to 14, and a general formula:
_{Ni x Co p Mn q Zr y} W z (OH) 2 + m (IV);
(Ii) a step of calcining a mixture of the precursor and a lithium salt to prepare a nickel-containing lithium composite oxide of the general formula (III);
The method including can be preferably employed. Here, in the above formula (IV), x is 0 <x ≦ 0.6 (typically 0.1 <x ≦ 0.6), and y is 0.0001 ≦ y ≦ 0.03 (preferably Is 0.0005 ≦ y ≦ 0.006), z is z> 0, p is 0 <p ≦ 0.5, q is 0 <q ≦ 0.5, and m is 0 ≦ 0. m ≦ 0.5, and 0.1 ≦ (y / z) ≦ 0.86 is satisfied. According to this method, the nickel-containing lithium composite oxide (positive electrode active material) can be preferably produced. In the step (i), the transition metal-Zr salt aqueous solution and the aqueous solution containing a tungsten-containing salt may be mixed with a basic aqueous solution having an initial pH of 11 to 14 while the initial pH is generally maintained. .

Hereinafter, the method for producing the nickel-containing lithium composite oxide (III) will be described in more detail.
In a preferred embodiment of such a production method, a precursor represented by the above formula (IV) prepared by the step (i) (which can also be grasped as a liquid phase reaction step or a liquid-liquid mixing step) is appropriately used. The desired nickel-containing lithium composite oxide is formed by mixing with a suitable lithium salt and firing at a predetermined temperature. Here, in the step (i), an aqueous solution containing a nickel salt, a cobalt salt, a manganese salt and a zirconium salt (hereinafter referred to as an NiCoMnZr aqueous solution) while maintaining the initial pH in a basic aqueous solution having an initial pH of 11 to 14 And an aqueous solution containing a tungsten-containing salt (hereinafter sometimes referred to as an aqueous W solution) may be added, mixed, and stirred at a desired rate. At this time, the temperature of the reaction solution is preferably in the range of 20 to 60 ° C.

  By using the precursor (IV) obtained by the step (i), the composite oxide represented by the formula (III) can be suitably formed. The composite oxide (III) produced by such a method may be one in which Zr and W are sufficiently compounded. In addition, a lithium ion secondary battery using such a composite oxide as a positive electrode active material can be excellent in both output characteristics at low SOC and high temperature durability. When mixing the precursor (IV) and the lithium salt, either wet mixing or dry mixing without using a solvent may be employed. From the viewpoint of simplicity and cost, dry mixing is preferable.

  The basic aqueous solution includes a strong base (such as an alkali metal hydroxide) and a weak base (such as ammonia). When a predetermined amount of NiCoMnZr aqueous solution and aqueous W solution are added, the pH at a liquid temperature of 25 ° C. Those which are maintained at about 11 to 14 and do not inhibit the production of the precursor (IV) can be preferably used. Typically, a mixed solution of an aqueous sodium hydroxide solution and aqueous ammonia is used. The mixed solution is preferably prepared so that the pH is in the range of 11 to 14 (for example, about pH 12) and the ammonia concentration is 3 g / L to 25 g / L. While the basic aqueous solution, the NiCoMnZr aqueous solution and the W aqueous solution are mixed to form a reaction solution and the formation reaction of the precursor (IV) proceeds, the ammonia concentration of the reaction solution is 3 g / L to 25 g / L. It is preferable that the degree is maintained.

  The NiCoMnZr aqueous solution can be prepared by, for example, dissolving predetermined amounts of desired nickel salt, cobalt salt, manganese salt, and zirconium salt in an aqueous solvent. The order in which these salts are added to the aqueous solvent is not particularly limited. Moreover, you may prepare by mixing the aqueous solution of each salt. Or you may mix the aqueous solution of a zirconium salt with the aqueous solution containing nickel salt, cobalt salt, and manganese salt. The anions of these metal salts (the above nickel salt, cobalt salt, manganese salt, zirconium salt) may be selected so that the salt has a desired water solubility. For example, it may be sulfate ion, nitrate ion, chloride ion, carbonate ion and the like. That is, the metal salt may be nickel, cobalt, manganese, zirconium sulfate, nitrate, hydrochloride, carbonate, etc., respectively. All or part of these metal salt anions may be the same or different from each other. For example, nickel, cobalt, and manganese sulfates and zirconium carbonate can be used in combination. These salts may be solvates such as hydrates. The order of addition of these metal salts is not particularly limited. The concentration of the NiCoMnZr aqueous solution is preferably such that the total of all the constituent elements (typically transition metal elements) (Ni, Co, Mn, Zr) is about 1 mol / L to 2.2 mol / L.

  Similarly, the aqueous W solution can be prepared by dissolving a predetermined amount of a W-containing salt in an aqueous solvent. As the W-containing salt, a salt of tungstic acid (an oxo acid having W as a central element) is typically used. The cation contained in the W-containing salt may be selected so that the salt is water-soluble. For example, it can be ammonium ion, sodium ion, potassium ion and the like. As the W-containing salt, for example, ammonium paratungstate can be preferably used. The W-containing salt may be a solvate such as a hydrate. The concentration of the aqueous W solution is preferably about 0.01 mol / L to 1 mol / L based on the W element.

  The aqueous solvent used in preparing the NiCoMnZr aqueous solution and the W aqueous solution is typically water, and water containing a reagent (acid, base, etc.) that improves solubility depending on the solubility of each salt used. May be used.

  The Ni salt, Co salt, Mn salt, Zr salt, and W-containing salt are used so that x, y, z, p, and q in the formula (III) have a desired ratio within the predetermined range. , Co, Mn, Zr, and W may be selected and appropriately determined based on the molar ratio.

  The precursor (IV) deposited from the liquid phase in the step (i) may be prepared in the form of particles having a desired particle size by washing with water, filtering and drying after the completion of crystallization. The precursor (IV) is preferably subjected to the next step after being heated in an air atmosphere at a temperature of 100 ° C. to 300 ° C. (eg, 150 ° C.) for 5 hours to 24 hours (eg, 12 hours).

  The nickel-containing lithium composite oxide (III) can be formed by firing a mixture of the precursor (IV) and an appropriate lithium salt, typically in air. As said lithium salt, the general lithium salt used for formation of lithium complex oxide can be especially used without a restriction | limiting. Specific examples include lithium carbonate and lithium hydroxide. These lithium salts can be used alone or in combination of two or more. The mixing ratio of the precursor (IV) to the lithium salt is such that (x + y + z + p + q) :( 1 + α) in the formula (III) is a desired ratio so that all transition metals contained in the precursor (III) The number of moles of lithium in the lithium salt relative to the total number of moles may be selected and appropriately determined based on that.

  The firing temperature is preferably in the range of about 700 to 1000 ° C. Firing may be performed at the same temperature at a time, or may be performed stepwise at different temperatures. The firing time can be appropriately selected. For example, it may be baked at about 800 to 1000 ° C. for about 2 to 24 hours, or after baking at about 700 to 800 ° C. for about 1 to 12 hours and then at about 800 to 1000 ° C. for about 2 to 24 hours. Also good.

As another method for producing the nickel-containing lithium composite oxide (III), for example, a hydroxide (typically Ni _x Co _p Mn _q (OH) from an NiCoMn aqueous solution containing a predetermined amount of nickel, cobalt, and manganese, respectively. ₂ : a precursor) is prepared, and a mixture of the hydroxide, a zirconium compound, a tungsten compound, and a lithium compound is fired. As the above compound, an oxide containing Zr, W, Li (for example, zirconia (ZrO ₂ ), tungsten oxide (WO ₃ ), etc.) may be used, and a compound that becomes an oxide by heating (for example, lithium carbonate, Lithium hydroxide, sodium tungstate, ammonium tungstate, zirconium hydroxide, zirconium sulfate, etc.) may also be used. As another manufacturing method, an oxide (typically Ni _x Co _p Mn _q O ₂ containing a predetermined amount of nickel, cobalt, and manganese is prepared, and the oxide, the zirconium compound, and the tungsten compound are prepared. And a method of firing a mixture of the above lithium compounds.

As said positive electrode active material, what has the form of the secondary particle which the primary particle aggregated is preferable. For example, a nickel-containing lithium composite oxide powder substantially composed of secondary particles having an average particle size in the range of about 2 μm to 15 μm (typically 3 μm to 8 μm) is disclosed in the lithium ion secondary disclosed herein. It can preferably be employed as a positive electrode active material used for a positive electrode of a battery. In addition, the average particle diameter here means a median diameter (D50), and can be easily measured by a particle size distribution measuring apparatus based on various commercially available laser diffraction / scattering methods. The specific surface area based on BET method of the positive electrode active material ^is preferably in the range of 0.5m ² /g~1.9m 2 / g. As the specific surface area based on the BET method, a value measured according to JIS K1477 (JIS Z 8830) is adopted.

The positive electrode mixture layer may contain an optional component such as a conductive material and a binder (binder) in addition to the positive electrode active material.
The conductive material is not limited to a specific conductive material as long as it is conventionally used in this type of lithium ion secondary battery. For example, carbon materials such as carbon powder and carbon fiber can be used. As the carbon powder, various carbon blacks (for example, acetylene black, furnace black, ketjen black, etc.), carbon powders such as graphite powder can be used. Among these, you may use together 1 type, or 2 or more types.

  As said binder (binder), the thing similar to the binder used for the positive electrode of a common lithium ion secondary battery can be employ | adopted suitably. For example, when using a water-based paste-like composition (a paste-like composition includes a slurry-like composition and an ink-like composition) as the composition for forming the positive electrode mixture layer, Polymer materials that dissolve or disperse can be preferably employed. For example, polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC) and the like can be mentioned. Alternatively, when a solvent-based paste is used, a polymer material that dissolves in an organic solvent (non-aqueous solvent) such as polyvinylidene fluoride (PVDF) or polyvinylidene chloride (PVDC) can be used. In addition, the polymer material illustrated above may be used as a thickener and other additives in the above composition in addition to being used as a binder.

  Here, the “aqueous paste-like composition” is a concept indicating a composition using water or a mixed solvent mainly composed of water as a dispersion medium of the positive electrode active material. As a solvent other than water constituting such a mixed solvent, one or more organic solvents (lower alcohol, lower ketone, etc.) that can be uniformly mixed with water can be appropriately selected and used. The “solvent-based paste composition” is a concept that refers to a composition in which the dispersion medium of the positive electrode active material is mainly an organic solvent. As the organic solvent, for example, N-methylpyrrolidone (NMP) can be used.

The positive electrode mixture layer is prepared, for example, by preparing a paste-like composition for forming a positive electrode mixture layer in which the positive electrode active material and other optional components (conductive material, binder, etc.) are dispersed in an appropriate solvent ( The positive electrode mixture layer is formed by applying (applying) the composition to the surface of the positive electrode current collector and drying the composition. Compressing the positive electrode mixture layer and (pressed), it is preferable to adjust the filling density of the positive-electrode mixture layer so as to ^{2.0g / cm 3 ~2.6g / cm 3} .
As a method of applying the composition to the positive electrode current collector, a technique similar to a conventionally known method can be appropriately employed. For example, the paste can be suitably applied to the positive electrode current collector by using an appropriate application device such as a slit coater, a die coater, or a gravure coater. Moreover, as a compression (pressing) method, conventionally known compression methods such as a roll press method and a flat plate press method can be employed.

Next, the negative electrode provided in the lithium ion secondary battery disclosed here will be described. The negative electrode includes a negative electrode current collector and a negative electrode mixture layer formed on the negative electrode current collector.
Examples of the negative electrode active material used in the negative electrode of the lithium ion secondary battery disclosed herein include graphite materials (for example, natural graphite, artificial graphite, etc.) capable of reversibly occluding and releasing lithium ions. Preferably, it is a coated graphite material in which the surface of the graphite material is coated with an amorphous carbon film. Amorphous carbon Motomaku covering the surface of the graphite material is a low crystallinity carbon, very small crystallites, sp ² hybrid orbital composed of carbon atoms laminated irregular, sp ² hybrid orbital of the carbon surface Carbon having a bond formation other than the above, etc. The ratio of the amorphous carbon film is preferably about 1 to 10 parts by mass (for example, 2 to 6 parts by mass) with respect to 100 parts by mass of the graphite material as the negative electrode active material.

The method for coating the surface of the graphite material with an amorphous carbon film is not particularly limited as long as the amorphous carbon film can be formed on the surface of the graphite material. For example, various pitches (for example, petroleum pitch, coal tar pitch, naphtha pitch, etc.) or an organic polymer compound (for example, phenol resin, cellulose resin, polyamide resin) whose surface of the graphite material is an amorphous carbon precursor. Etc.), and then heat treatment (for example, firing) at a temperature at which the precursor is not graphitized (for example, approximately 1000 ° C. to 1300 ° C.).
The median diameter (D50) of the graphite material (including the coated graphite material coated on the amorphous carbon film) is preferably about 5 μm to 15 μm (for example, about 8 μm to 11 μm). When the median diameter is too larger than 15 μm, the effective capacity of the negative electrode may be reduced due to the time required for the diffusion of lithium ions into the center of the graphite material. If the median diameter is too smaller than 5 μm, the side reaction rate on the surface of the graphite material increases, and the irreversible capacity of the lithium ion secondary battery may increase. The specific surface area based on BET method of the graphite material (including coated graphite material) is preferably in the range of approximately 3.5m ² /g~5.5m ² / g.

The negative electrode mixture layer may contain an optional component such as a binder (binder) and a thickener as necessary in addition to the negative electrode active material (graphite material).
As said binder (binder), the thing similar to the binder used for the negative electrode of a general lithium ion secondary battery can be employ | adopted suitably. For example, when an aqueous paste composition is used to form the negative electrode mixture layer, a polymer material that is dissolved or dispersed in water can be preferably used. Polymer materials that disperse in water (water dispersible) include rubbers such as styrene butadiene rubber (SBR) and fluorine rubber; fluorine resins such as polyethylene oxide (PEO) and polytetrafluoroethylene (PTFE); vinyl acetate Examples thereof include copolymers.

  Moreover, as the thickener, a polymer material that is dissolved or dispersed in water or a solvent (organic solvent) can be employed. Examples of water-soluble (water-soluble) polymer materials include cellulose polymers such as carboxymethyl cellulose (CMC), methyl cellulose (MC), cellulose acetate phthalate (CAP), and hydroxypropylmethyl cellulose (HPMC); polyvinyl alcohol ( PVA); and the like.

For the negative electrode composite layer, for example, a paste-like composition for forming a negative electrode composite layer in which the negative electrode active material and other optional components (binder, thickener, etc.) are dispersed in an appropriate solvent is prepared. (Preparation, purchase, etc.) After applying (applying) the composition to the surface of the negative electrode current collector and drying the composition, the negative electrode mixture layer is formed by pressing (compressing) as necessary. It is formed. Packing density of the negative-electrode mixture layer disclosed herein is ^{1.0g / cm 3 ~1.2g / cm 3} . With such a packing density, it is possible to better prevent a decrease in capacity retention rate (particularly, capacity retention rate at a high temperature (for example, 60 ° C.)). The filling density of the negative electrode mixture layer can be adjusted by the degree of pressing.

Hereinafter, although one form of the lithium ion secondary battery constructed | assembled using the said positive electrode and the said negative electrode is demonstrated referring drawings, it is not intending limiting this invention to this embodiment. That is, as long as the positive electrode and the negative electrode are employed, the shape (outer shape and size) of the lithium ion secondary battery to be constructed is not particularly limited. In the following embodiment, a lithium ion secondary battery having a configuration in which a wound electrode body and an electrolytic solution are housed in a rectangular battery case will be described as an example.
In addition, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show | plays the same effect | action, and the overlapping description may be abbreviate | omitted. Moreover, the dimensional relationship (length, width, thickness, etc.) in each drawing does not necessarily reflect the actual dimensional relationship.

FIG. 1 is a perspective view schematically showing a lithium ion secondary battery 10 according to the present embodiment. FIG. 2 is a longitudinal sectional view taken along line II-II in FIG.
As shown in FIG. 1, the lithium ion secondary battery 10 according to this embodiment includes a battery case 15 made of metal (a resin or a laminate film is also suitable). The case (outer container) 15 includes a flat cuboid case main body 30 having an open upper end, and a lid body 25 that closes the opening 20. The lid body 25 seals the opening 20 of the case main body 30 by welding or the like. On the upper surface of the case 15 (that is, the lid body 25), a positive electrode terminal 60 electrically connected to the positive electrode sheet (positive electrode) 64 of the wound electrode body 50 and a negative electrode terminal electrically connected to the negative electrode sheet 84 of the electrode body. 80 is provided. In addition, the lid 25 is provided with a safety valve 40 for discharging the gas generated inside the case 15 to the outside of the case 15 when the battery is abnormal, as in the case of the conventional lithium ion secondary battery. . In the case 15, the positive electrode sheet 64 and the negative electrode sheet 84 are laminated together with a total of two separator sheets 95 and wound, and then the obtained wound body is crushed from the side direction and ablated. A flat wound electrode body 50 and a non-aqueous electrolyte are accommodated.

  At the time of the above lamination, as shown in FIG. 2, the positive electrode mixture layer non-formed portion of the positive electrode sheet 64 (that is, the portion where the positive electrode current collector 62 is exposed without forming the positive electrode mixture layer 66) and the negative electrode sheet The negative electrode composite material layer non-formed portion 84 (that is, the portion where the negative electrode current collector 82 is exposed without forming the negative electrode composite material layer 90) protrudes from both sides in the width direction of the separator sheet 95. And the negative electrode sheet 84 are overlapped with a slight shift in the width direction. As a result, in the lateral direction with respect to the winding direction of the wound electrode body 50, the electrode composite material layer non-forming portions of the positive electrode sheet 64 and the negative electrode sheet 84 are respectively wound core portions (that is, the positive electrode composite material layer forming portion of the positive electrode sheet 64). And a portion where the negative electrode mixture layer forming portion of the negative electrode sheet 84 and the two separator sheets 95 are wound tightly) protrude outward. The positive electrode terminal 60 is joined to the protruding portion on the positive electrode side, and the positive electrode sheet 64 and the positive electrode terminal 60 of the wound electrode body 50 formed in the flat shape are electrically connected. Similarly, the negative electrode terminal 80 is joined to the negative electrode side protruding portion, and the negative electrode sheet 84 and the negative electrode terminal 80 are electrically connected. The positive and negative electrode terminals 60 and 80 and the positive and negative electrode current collectors 62 and 82 can be joined by, for example, ultrasonic welding, resistance welding, or the like.

As said non-aqueous electrolyte, the thing similar to the non-aqueous electrolyte conventionally used for the lithium ion secondary battery can be used without limitation. Such a nonaqueous electrolytic solution typically has a composition in which a supporting salt is contained in a suitable nonaqueous solvent. As said non-aqueous solvent, 1 type, or 2 or more types selected from EC, PC, DMC, DEC, EMC etc. can be used, for example. Further, as the supporting salt (supporting electrolyte), for _example, it can be used lithium salts such as LiPF 6, LiBF _4. Further, difluorophosphate (LiPO ₂ F ₂ ) or lithium bisoxalate borate (LiBOB) may be dissolved in the non-aqueous electrolyte.
Moreover, as said separator sheet, a conventionally well-known thing can be especially used without a restriction | limiting. For example, a porous sheet made of resin (a microporous resin sheet) can be preferably used. Porous polyolefin resin sheets such as polyethylene (PE), polypropylene (PP), and polystyrene (PS) are preferred.

Next, an example of an assembled battery in which the lithium ion secondary battery 10 having such a configuration is a single battery and includes a plurality of the single batteries will be described.
As shown in FIG. 3, the assembled battery 200 includes a plurality of (typically 10 or more, preferably about 10 to 30, for example, 20) lithium ion secondary batteries (unit cells) 10 respectively. The wide surfaces of the battery case 15 are arranged in the facing direction (stacking direction) while being inverted one by one so that the positive electrode terminals 60 and the negative electrode terminals 80 are alternately arranged. A cooling plate 110 having a predetermined shape is sandwiched between the arranged cells 10. The cooling plate 110 functions as a heat dissipating member for efficiently dissipating the heat generated in each unit cell 10 during use, and preferably a cooling fluid (typically air) between the unit cells 10. ) (For example, a shape in which a plurality of parallel grooves extending vertically from one side of the rectangular cooling plate to the opposite side are provided on the surface). A cooling plate made of metal having good thermal conductivity or lightweight and hard polypropylene or other synthetic resin is suitable.

A pair of end plates (restraint plates) 120 and 120 are disposed at both ends of the unit cell 10 and the cooling plate 110 arranged as described above. One or a plurality of sheet-like spacer members 150 as length adjusting means may be sandwiched between the cooling plate 110 and the end plate 120. The cell 10, the cooling plate 110 and the spacer member 150 arranged in the above manner are applied with a predetermined restraining pressure in the stacking direction by a fastening restraint band 130 attached so as to bridge between both end plates. It is restrained. More specifically, by tightening and fixing the end portion of the restraining band 130 to the end plate 120 with screws 155, the unit cells and the like are restrained so that a predetermined restraining pressure is applied in the arrangement direction. Thereby, restraint pressure is also applied to the wound electrode body 50 housed in the battery case 15 of each unit cell 10.
In addition, between the adjacent unit cells 10, one positive electrode terminal 60 and the other negative electrode terminal 70 are electrically connected by a connection member (bus bar) 140. Thus, the assembled battery 200 of the desired voltage is constructed | assembled by connecting each cell 10 in series.

  EXAMPLES Examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in the examples.

<Experimental example 1>
[Construction of lithium ion secondary battery]
<Example 1>
A reaction vessel equipped with a stirrer and a nitrogen introduction tube was charged with about half of its capacity, and heated to 40 ° C. with stirring. After the reaction vessel was purged with nitrogen, an appropriate amount of 25% aqueous sodium hydroxide and 25% aqueous ammonia was added while maintaining the inside of the reaction vessel in a non-oxidizing atmosphere with an oxygen concentration of about 2.0% under a nitrogen stream. A basic aqueous solution was obtained by adjusting the pH at a liquid temperature of 25 ° C. to 12.0 and the ammonia concentration in the liquid phase to 20 g / L. The oxygen concentration in the reaction vessel was about 2.0%.
Nickel sulfate, cobalt sulfate, manganese sulfate and zirconium sulfate are dissolved in water so that the molar ratio of metal elements Ni: Co: Mn: Zr is 0.33: 0.33: 0.33: 0.005. A mixed aqueous solution A having a total concentration of these metals of 1.8 mol / L was prepared. Moreover, ammonium paratungstate was dissolved in water to prepare a mixed aqueous solution B having a tungsten (W) concentration of 0.05 mol / L.
In the basic aqueous solution in the reaction vessel, the mixed aqueous solution A and the mixed aqueous solution B obtained above, a 25% aqueous sodium hydroxide solution, and 25% aqueous ammonia are maintained at a pH of 12.0. Added and mixed. The pH was adjusted by adjusting the supply rate of each solution to the reaction vessel.

The precipitated product was separated, washed and dried, and the element molar ratio Ni: Co: Mn: Zr: W was 0.33: 0.33: 0.33: 0.005: 0.005 (that is, Ni, Hydroxides (Ni _0.33 Co _0.33 Mn _0.33 ) containing mol% of Co, Mn, W and Zr are 33%, 33%, 33%, 0.5% and 0.5%, respectively. Zr _0.005 W _0.005 (OH) _{2 + m} (0 ≦ m ≦ 0.5); precursor) was obtained. This precursor (hydroxide particles) was subjected to heat treatment at 150 ° C. for 12 hours in an air atmosphere.
The total number of moles of all transition metals in the precursor (ie, Ni + Co + Mn + Zr + W) is defined as Me, and lithium carbonate is weighed so that the molar ratio of lithium to Me (Li / Me) is 1.15. Mixed with precursor. The obtained mixture was fired at 950 ° C. for 10 hours in air containing 21% by volume of oxygen, and nickel-containing lithium composite oxide (Li _1.15 Ni _0.33 Co _0.33 Mn _0.33 W _{0. A} positive electrode active material according to Example 1 represented by ( ₀₀₅ Zr _0.005 O ₂ ) was obtained. At this time, the molar ratio of Me: Zr: W was 1: 0.005: 0.005, and the molar ratio of tungsten and zirconium (Zr / W) was 1.

The positive electrode active material according to Example 1, acetylene black (AB) as a conductive material, and PVDF as a binder are weighed so as to have a mass ratio of 90: 8: 2, and these materials are dispersed in NMP. A paste-like composition for forming a positive electrode mixture layer according to Example 1 was prepared. The paste was applied to both sides of an aluminum foil having a thickness of 15 μm and coated at a basis weight (solid content basis) of 11.8 mg / cm ² and dried to form a positive electrode mixture layer. Subsequently, it pressed so that the packing density of the positive electrode compound material layer might be 2.3 g / cm < ³ > with a rolling press, and the sheet-like positive electrode which concerns on Example 1 was produced.

Also, weigh the natural graphite powder as the negative electrode active material and the petroleum pitch so that the mass ratio is 96: 4, mix these materials, and fire at 1000 ° C. to 1300 ° C. for 10 hours in an inert atmosphere. Thus, natural graphite whose surface was coated with an amorphous carbon film (coated natural graphite) was produced. The average particle diameter (D50) of the coated natural graphite was 10 μm, and the specific surface area was 4 m ² / g.
The above-produced coated natural graphite, SBR as a binder, and CMC as a thickener are weighed so that the mass ratio is 98.6: 0.7: 0.7, and these materials are ion-exchanged. A paste-like composition for forming a negative electrode mixture layer according to Example 1 was prepared by dispersing in water. The composition was applied to both sides of a copper foil having a thickness of 10 μm and coated at a basis weight (solid content basis) of 7.5 mg / cm ² and dried to form a negative electrode mixture layer. Subsequently, it pressed so that the packing density of a negative electrode compound-material layer might be set to 1.0 g / cm < ³ > with a rolling press, and the sheet-like negative electrode concerning Example 1 was produced.

Then, the prepared positive electrode according to Example 1 and the negative electrode according to Example 1 were wound through a separator sheet (polypropylene / polyethylene composite porous film) to prepare a wound electrode body. A lithium ion secondary battery (hereinafter simply referred to as “secondary battery”) according to Example 1 was constructed by housing the electrode body together with a non-aqueous electrolyte in a rectangular case. As an electrolytic solution, a solution obtained by dissolving 1.1 mol / L LiPF ₆ in a mixed solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio of 3: 3: 4. used.

<Example 2>
A lithium ion secondary battery according to Example 2 was produced in the same manner as in Example 1 except that the negative electrode composite material layer was pressed so that the packing density was 1.1 g / cm ³ .
<Example 3>
A lithium ion secondary battery according to Example 3 was produced in the same manner as in Example 1, except that the negative electrode composite material layer was pressed so that the packing density was 1.2 g / cm ³ .
<Example 4>
A lithium ion secondary battery according to Example 4 was produced in the same manner as in Example 1, except that the negative electrode mixture layer was pressed so that the packing density of the negative electrode mixture layer was 1.3 g / cm ³ .
<Example 5>
A lithium ion secondary battery according to Example 5 was produced in the same manner as in Example 1 except that the negative electrode composite material layer was pressed so that the packing density was 1.4 g / cm ³ .

<Conditioning process>
Appropriate conditioning treatment was performed on the lithium ion secondary batteries of Examples 1 to 5. That is, after charging to 4.1 V with a constant current of 1 C, it was paused for 5 minutes. Next, the battery was charged at a constant voltage for 1.5 hours and rested for 5 minutes.

<Capacity retention measurement>
About each secondary battery after the said conditioning process, the capacity | capacitance maintenance factor [%] after preserve | saving for 30 days on 60 degreeC temperature conditions was measured. That is, after each secondary battery was discharged to 3 V at a constant current of 1 C under a temperature condition of 25 ° C., it was discharged at a constant voltage for 2 hours and rested for 10 minutes. Next, the battery was charged to 4.1 V with a constant current of 1 C, then charged with a constant voltage for 2.5 hours and rested for 10 minutes. Next, after discharging to 3 V at a constant current of 0.5 C, the battery was discharged at a constant voltage for 2 hours and rested for 10 minutes. The capacity obtained at this time was defined as the initial battery capacity (rated capacity). For each secondary battery whose initial battery capacity was measured, after charging at a constant current of 3 V to 1 C under a temperature condition of 25 ° C. and adjusting to a charged state (SOC 80%) of 80% of the initial battery capacity, The battery was charged at a constant voltage for 2.5 hours. Each secondary battery with the adjusted SOC is stored in a constant temperature bath at 60 ° C. for 30 days, and each secondary battery after storage is stored in the same manner as the initial battery capacity after storage (after storage) Battery capacity) was measured. (Battery capacity after storage) / (initial battery capacity) × 100 was defined as a capacity retention rate [%] after 30 days storage. The above results are shown in Table 1 and FIG.

As shown in Table 1 and FIG. 4, it was confirmed that the capacity retention rate of the lithium ion secondary battery was reduced as the packing density of the negative electrode mixture layer was increased. In particular, it was confirmed that when the filling density of the negative electrode mixture layer was higher than 1.2 g / cm ³ , the rate of decrease in the capacity retention rate was increased. From this result, the filling density of the negative electrode material layer was confirmed to be valid in the range of ^{1.0g / cm 3 ~1.2g / cm 3} .

<Experimental example 2>
[Construction of lithium ion secondary battery]
<Example 6>
A lithium ion secondary battery according to Example 6 was produced in the same manner as in Example 1 except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.002: 0.005 was used. At this time, the molar ratio (Zr / W) of tungsten and zirconium was 0.4.
<Example 7>
A lithium ion secondary battery according to Example 7 was produced in the same manner as in Example 6 except that the negative electrode composite material layer was pressed so that the filling density was 1.1 g / cm ³ .
<Example 8>
A lithium ion secondary battery according to Example 8 was produced in the same manner as in Example 6 except that the negative electrode composite material layer was pressed so that the filling density was 1.2 g / cm ³ .
<Example 9>
A lithium ion secondary battery according to Example 9 was produced in the same manner as in Example 6 except that the negative electrode composite material layer was pressed so that the packing density was 1.3 g / cm ³ .
<Example 10>
A lithium ion secondary battery according to Example 10 was produced in the same manner as in Example 6 except that the negative electrode composite material layer was pressed so that the packing density was 1.4 g / cm ³ .

<Low SOC output measurement>
For the lithium ion secondary batteries of Examples 1 to 10, the output at low SOC was measured. That is, under the temperature condition of 25 ° C., each of the secondary batteries was charged with a constant current of 1 C and adjusted to SOC 27%, and then charged with a constant voltage at the SOC 27% for 1 hour. After each secondary battery with adjusted SOC is left in a -30 ° C constant temperature bath for 6 hours, the temperature is -30 ° C and the SOC is 27% to 2 V (cut voltage) at a constant output [W]. The time required for discharging was measured. Discharging at predetermined outputs determined within the range of 80W to 200W, taking the time measured when discharging at each output on the horizontal axis, and taking the output [W] at the time of measurement on the vertical axis, The output [W] at 2 seconds was calculated from the approximate curve. The above results are shown in Tables 1 and 2 and FIG.

As shown in Tables 1 and 2 and FIG. 5, when the packing density of the negative electrode mixture layer is 1.4 g / cm ³ , there is almost no influence due to the molar ratio of Zr and W (Zr / W), and the output is comparable. It was confirmed that it was obtained. However, as the packing density of the negative electrode mixture layer decreases, the influence of Zr / W increases, and the range of the packing density of the negative electrode mixture layer in which a high capacity retention rate was obtained from the results of Experimental Example 1 (that is, 1 g / cm ^{3 to} 1.2 g / cm ³ ), the influence of Zr / W was particularly strong, and it was confirmed that there was a significant difference in output.

<Experimental example 3>
[Construction of lithium ion secondary battery]
<Example 11>
A lithium ion secondary battery according to Example 11 was produced in the same manner as in Example 2 except that a positive electrode active material having a (Ni + Co + Mn + W): W molar ratio of 1: 0.005 was used. Since the positive electrode active material did not contain Zr, the molar ratio (Zr / W) was 0.
<Example 12>
A lithium ion secondary battery according to Example 12 was produced in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.0005: 0.005 was used. The molar ratio (Zr / W) at this time was 0.1.
<Example 13>
A lithium ion secondary battery according to Example 13 was fabricated in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.001: 0.007 was used. The molar ratio (Zr / W) at this time was 0.14.
<Example 14>
A lithium ion secondary battery according to Example 14 was fabricated in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.002: 0.01 was used. The molar ratio (Zr / W) at this time was 0.2.
<Example 15>
A lithium ion secondary battery according to Example 15 was fabricated in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.003: 0.009 was used. The molar ratio (Zr / W) at this time was 0.33.
<Example 16>
A lithium ion secondary battery according to Example 16 was produced in the same manner as the lithium ion secondary battery according to Example 7. The molar ratio (Zr / W) at this time was 0.4.

<Example 17>
A lithium ion secondary battery according to Example 17 was fabricated in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.003: 0.005 was used. The molar ratio (Zr / W) at this time was 0.6.
<Example 18>
A lithium ion secondary battery according to Example 18 was produced in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.006: 0.008 was used. The molar ratio (Zr / W) at this time was 0.75.
<Example 19>
A lithium ion secondary battery according to Example 19 was fabricated in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.004: 0.005 was used. The molar ratio (Zr / W) at this time was 0.8.
<Example 20>
A lithium ion secondary battery according to Example 20 was produced in the same manner as in Example 2, except that a positive electrode active material having a Me: Zr: W molar ratio of 1: 0.006: 0.007 was used. The molar ratio (Zr / W) at this time was 0.86.
<Example 21>
A lithium ion secondary battery according to Example 21 was produced in the same manner as the lithium ion secondary battery according to Example 2. The molar ratio (Zr / W) at this time was 1.0.

<Low SOC output measurement>
About each lithium ion secondary battery which concerns on the said Example 11- Example 21, output [W] is measured on the same conditions as the measurement of the output in the low SOC performed with respect to each secondary battery of the said Example 1- Example 10. did. The measurement results are shown in Table 3 and FIG.

  As shown in Table 3 and FIG. 6, it was confirmed that when the molar ratio (Zr / W) is in the range of 0.1 to 0.86, high output can be obtained in the low SOC region. In particular, it was confirmed that a high output was obtained when the molar ratio was in the range of 0.1 to 0.8 (preferably 0.1 to 0.75, more preferably 0.2 to 0.4). On the other hand, when the molar ratio (Zr / W) was too smaller than 0.1 or too larger than 0.86, it was confirmed that the output decreased greatly in the low SOC region, and sufficient output could not be obtained.

  As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The lithium ion secondary battery according to the present invention is used as a lithium ion secondary battery for various applications because it prevents deterioration of capacity at high temperatures and suppresses a decrease in output in a low SOC region and has excellent battery performance. Is possible. For example, as shown in FIG. 7, it can be suitably used as a power source (drive power source) for a vehicle drive motor mounted on a vehicle 100 such as an automobile. The lithium ion secondary battery 10 used for the vehicle 100 may be used alone, or may be used in the form of an assembled battery 200 that is connected in series and / or in parallel.

DESCRIPTION OF SYMBOLS 10 Lithium ion secondary battery 15 Battery case 20 Opening part 25 Cover body 30 Case main body 40 Safety valve 50 Winding electrode body 60 Positive electrode terminal 62 Positive electrode current collector 64 Positive electrode sheet (positive electrode)
66 Positive electrode mixture layer 80 Negative electrode terminal 82 Negative electrode current collector 84 Negative electrode sheet (negative electrode)
90 Negative electrode composite material layer 95 Separator sheet 100 Vehicle (automobile)
110 Cooling plate 120 End plate 130 Restraint band 140 Connection member 150 Spacer member 155 Screw 200 Battery assembly

Claims (4)

A lithium ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte,
The positive electrode has a positive electrode mixture layer containing at least a positive electrode active material on a positive electrode current collector, and the negative electrode has a negative electrode mixture layer containing at least a negative electrode active material on the negative electrode current collector,
The negative active material is a graphite material, the packing density of the negative-electrode mixture layer containing a graphite material is ^{1.0g / cm 3 ~1.2g / cm 3} ,
The positive electrode active material has the following general formula (I):
_{Li 1 + α Ni x M 1} -x-y-z Zr y W z O 2 (I)
(In the formula (I), α is 0 ≦ α ≦ 0.2, x is x> 0, y is 0.0001 ≦ y ≦ 0.03, z is z> 0, 0 <X + y + z ≦ 1 is satisfied, 0.1 ≦ (y / z) ≦ 0.86 is satisfied, and M is Co, Mn, Al, Cr, Fe, V, Mg, Ti, Mo, Cu, Zn, Ga, In , Sn, La, Ce, Ca, Na, F and B, which is one or more selected from the group consisting of: lithium ion that is a nickel-containing lithium composite oxide having a layered structure Secondary battery.   The zirconium content is from 0.05 mol% to 0.6 mol% when the total amount of other constituent elements excluding lithium and oxygen in the nickel-containing lithium composite oxide is 100 mol%, Item 2. A lithium ion secondary battery according to Item 1. 3. The general formula (I), wherein the element M includes at least cobalt and manganese, and y / z satisfies 0.2 ≦ (y / z) ≦ 0.4. 4. Lithium ion secondary battery.   The lithium ion secondary battery according to claim 1, wherein the lithium ion secondary battery is used as a driving power source for a vehicle.

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