JP2001076719A - Negative electrode material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery - Google Patents

Abstract

[PROBLEMS] To provide a highly reliable non-aqueous electrolyte secondary battery having a high capacity and a high energy density without a short circuit due to a dendrite having an extremely excellent cycle life. SOLUTION: Formula (1): represented by M ¹ _a M ² , where 0 ≦ a ≦
The whole or a part of the surface of the particles having the phase A having the composition satisfying Formula 5 is represented by Formula (2): M ¹ ′ _b M ² ′ _c , where c = 1 or c = 0 and c = 1 Is a material coated with a B phase having a composition satisfying a <b, and M ¹ and M ¹ ′
Are Na, K, Rb, Cs, Ce, Ti, Zr, Hf,
V, Nb, Ta, Ca, Sr, Ba, Y, La, Cr,
Mo, W, Mn, Tc, Ru, Os, Co, Rh, I
an element selected from the group (m ¹ ) consisting of r, Ni, Pd, Cu, Ag, and Fe; M ² and M ² ′
Represents Al, Ga, In, Si, Ge, Sn, Pb, Sb
And a negative electrode material for a non-aqueous electrolyte secondary battery, which is an element selected from the group (m ² ) consisting of Bi.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a negative electrode material for a non-aqueous electrolyte secondary battery, a method for producing the same, and a non-aqueous electrolyte secondary battery having both high electric capacity and long life.

[0002]

2. Description of the Related Art A non-aqueous electrolyte secondary battery using lithium or a lithium compound as a negative electrode can be expected to have a high voltage and a high energy density, and much research has been conducted. The positive electrode active material of the nonaqueous electrolyte secondary battery includes a transition metal oxide and a chalcogen compound, for example, LiMn ₂ O ₄ , LiCoO ₂ , L
iNiO ₂ , V ₂ O ₅ , Cr ₂ O ₅ , MnO ₂ , TiS ₂ , M
oS _{2 and the} like are known. These have a layered structure or a tunnel structure, and have a crystal structure through which lithium ions can enter and exit.

On the other hand, as a negative electrode active material, metallic lithium has been widely studied. However, when metal lithium is used, there is a problem that dendritic lithium, ie, dendrite, precipitates on the surface of lithium during charging, which lowers the charging / discharging efficiency or causes an internal short circuit due to contact with the positive electrode. Therefore, studies have been made to use a lithium-based alloy capable of absorbing and releasing lithium, such as a lithium-aluminum alloy, as a negative electrode active material, while suppressing dendritic growth of lithium. However, when deep charge / discharge is repeated, the electrode material becomes finer, which causes a problem in cycle characteristics.

At present, a lithium ion battery using a graphite-based carbon material for a negative electrode, which has a smaller capacity than metallic lithium and a lithium-based alloy, can reversibly insert and extract lithium, and has excellent cycle characteristics and safety. Has been put to practical use. However, when a graphite-based carbon material is used for the negative electrode, its practical capacity is the theoretical capacity (372 mAh / g).
350 mAh / g. The theoretical density is 2.
The density is as low as 2 g / cc, and if a sheet-shaped negative electrode is actually used, the density is further reduced. Therefore, in order to further increase the capacity of the battery, it is necessary to use a metal-based inorganic material having a high capacity per unit volume as the negative electrode active material.

[0005] When a metal-based inorganic material is used as a negative electrode active material, there are problems such as pulverization of the active material caused by repetition of expansion and contraction accompanying occlusion and release of lithium, and a reaction between the electrolyte and the active material. There are two problems of the deposition of the organic film. Both have the effect of reducing the reactivity of the active material and shorten the charge / discharge cycle life.

In order to solve the problem of pulverization, for example, a technique of coexisting a phase occluding lithium and a phase not occluding lithium in one particle to relieve stress in a charged state (occluding state) by a phase not occluding lithium. (Japanese Patent Application Laid-Open No. H11-86853), a technique in which two or more phases that occlude lithium in one particle coexist to alleviate the stress due to the structural change of each phase during occlusion of lithium (Japanese Patent Application Laid-Open No. H11-86853). Is disclosed. However, even a negative electrode material incorporating these techniques has not yet sufficiently solved the problem of pulverization.

On the other hand, an attempt has been made to improve the charge / discharge efficiency of a battery by covering the surface of an active material with a film of a fluorine compound or a carbonate compound (JP-A-11-135153). However, these coatings have low mechanical strength and are insufficient for suppressing pulverization. The components of these films are compounds that are formed as organic films when a general lithium-ion battery electrolyte is used, and have the potential to promote the deposition of the films.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a non-volatile semiconductor device having a high capacity and excellent charge-discharge cycle characteristics which prevents both the problem of pulverization due to the expansion and contraction and the problem of an organic film deposited on the surface of an active material. An object of the present invention is to provide a negative electrode material for a water electrolyte secondary battery.

[0009]

According to the present invention, there is provided an image processing device comprising the following formula (1): M
All or part of the surface of the particles having the phase A represented by ¹ _a M ² and having a composition satisfying 0 ≦ a ≦ 5 is represented by the formula (2): M ¹ ′
_b M ² ' _c , where c = 1 or c = 0 and c = 1
Is a material coated with a B phase having a composition satisfying a <b, and M ¹ in the formula (1) and M ¹ ′ in the formula (2)
Are Na, K, Rb, Cs, Ce, Ti, Zr, Hf,
V, Nb, Ta, Ca, Sr, Ba, Y, La, Cr,
Mo, W, Mn, Tc, Ru, Os, Co, Rh, I
At least one element selected from the group (m ¹ ) consisting of r, Ni, Pd, Cu, Ag and Fe, wherein M ² in the formula (1) and M ² ′ in the formula (2) are A
The present invention relates to a negative electrode material for a non-aqueous electrolyte secondary battery, which is at least one element selected from the group (m ² ) consisting of 1, Ga, In, Si, Ge, Sn, Pb, Sb, and Bi.

In the negative electrode material for a non-aqueous electrolyte secondary battery, it is preferable that 50% or more of the surface of the particles having the A phase is coated with the B phase. Further, it is preferable that the concentration of at least one element selected from the group (m ¹ ) gradually decreases from the surface to the inside of the negative electrode material particles.

The present invention also relates to a material in which the negative electrode material for a non-aqueous electrolyte secondary battery has absorbed lithium. In particular, the composition of the phase in which phase A has absorbed lithium is represented by the formula (1 ′): Li _x M ¹ _a
It indicated M ^2, the composition of the phase B phase has occluded a lithium, Formula (2 '): When shown by ^{_{Li y M 1' b M 2}} 'c, 0 ≦ (y /
x) Materials satisfying ≦ 0.5 are preferred.

The negative electrode material for a non-aqueous electrolyte secondary battery of the present invention is preferably particles having an average particle diameter of 45 μm or less.

[0013] The present invention also provides a method of (i) plating at least one element selected from the group (m ¹ ) on the surface layer of the particles having A phase, and (ii) a mechanical alloying method. , A step of compounding at least one element selected from the group (m ¹ ), and (iii) a step of compounding at least one element selected from the group (m ¹ ) by a mechanochemical method. And a method for producing the negative electrode material for a non-aqueous electrolyte secondary battery. The particles obtained by this method are preferably further subjected to a heat treatment in a reducing atmosphere or an inert gas atmosphere.

Further, the present invention provides a non-aqueous electrolyte in which particles having phase A and an organic compound containing at least one element selected from the group (m ¹ ) are mixed and heat-treated in a reducing atmosphere. A method for producing a negative electrode material for a secondary battery and at least one selected from the group (m ¹ ) selected from the group (m ¹ ) by a plasma method or an ion implantation method for a surface layer of particles having an A phase.
The present invention relates to a method for producing a negative electrode material for a non-aqueous electrolyte secondary battery having a step of introducing (compositing) various kinds of elements.

The present invention also relates to a non-aqueous electrolyte secondary battery including a chargeable / dischargeable positive electrode, a non-aqueous electrolyte, and a negative electrode made of the negative electrode material.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The negative electrode material for a non-aqueous electrolyte secondary battery of the present invention is represented by the following formula (1): M ¹ _a M ² , where 0 ≦ a ≦
5, preferably all or part of the surface of the particles having the A phase having a composition satisfying 0.5 ≦ a ≦ 3 is represented by the formula (2): M ¹ ′ _b
M ² ′ _c , where c = 1 or c = 0 and c = 1
In the case of, it is covered with the B phase having a composition satisfying a <b.
In the formula (1), if a exceeds 5, the elemental composition ratio of M ^{1 having} low reactivity with lithium increases, resulting in low capacity. When a is less than 0.5, the expansion of the A phase
The difference in shrinkage is large, and there is a tendency that the powder is easily pulverized. On the other hand, in Expression (2), when c = 1, 1 ≦ b <
20, more preferably 2 ≦ b ≦ 10. The phase A is expressed as (m ² ) when a = 0 in the equation (1).
It becomes a simple substance or an alloy composed of only at least one element selected from the group, and the B phase is c = 0 in the formula (2).
In the case of ( ¹ ), it is a simple substance or an alloy composed of only at least one element selected from the group (m ¹ ). A phase and B phase
Only one kind of each may be present, but two or more kinds of each may be present. In this case, c = 1 and a
There may be two or more combinations of the A phase and the B phase that satisfy the relationship <b, but it is sufficient that at least one combination that satisfies the relationship exists.

The B phase generally has a lower reactivity to lithium than the A phase. Therefore, when the particles having the A phase are coated with the B phase, the activity on the surface of the negative electrode material particles is reduced and the reaction between the A phase and the electrolytic solution is suppressed,
The deposition of the organic film is suppressed. Further, the mechanical strength of the negative electrode material particles also increases, so that pulverization of the material is suppressed. As a result, a long-life negative electrode material can be obtained.
From this viewpoint, it is preferable that 50% or more, more preferably 55 to 85%, of the surface of the particles having the A phase is coated with the B phase. When the coated surface is less than 50%,
The effect of suppressing the formation of the organic film and the pulverization of the material is reduced.

M ¹ in the formula (1) and M ¹ ′ in the formula (2)
Are Na, K, Rb, Cs, Ce, Ti, Zr, Hf,
V, Nb, Ta, Ca, Sr, Ba, Y, La, Cr,
Mo, W, Mn, Tc, Ru, Os, Co, Rh, I
At least one element selected from the group (m ¹ ) consisting of r, Ni, Pd, Cu, Ag and Fe. When one phase contains only one element selected from the (m ¹ ) group, the element includes Ti, Zr, V, N
b, La, Sr, Ba, Cr, Mn, Co, Ni, Cu
Or, it is preferably Fe, and Ti, V, Nb, M
Particularly preferred is n, Co, Ni, Cu or Fe.

On the other hand, M ² in the formula (1) and M ² ′ in the formula (2) represent Al, Ga, In, Si, Ge, Sn, P
At least one element selected from the group (m ² ) consisting of b, Sb and Bi. Only one type (m
² ) When an element selected from the group is included, the element is preferably Al, In, Si, Ge, Sn or Pb, and preferably Al, Si or Sn.
Particularly preferred.

It is preferable that the concentration of at least one element selected from the group (m ¹ ) decreases gradually from the surface of the negative electrode material particles toward the inside. When the negative electrode material has such a gradient phase that continuously changes from a phase having low reactivity to lithium to an active phase, the effect of suppressing the pulverization of the material is further improved.

The composition of the phase in which the phase A has absorbed lithium is 0%.
Formula (1 ′) satisfying ≦ a ≦ 5 and 0 <x: Li _x M ¹ _a M ²
And the composition of the phase in which the phase B has absorbed lithium is c = 1.
Or, when c = 0 and c = 1, formula (2 ′) that satisfies a <b: 0 ≦ (y / x) where Li _y M ¹ ′ _b M ² ′ _c
≦ 0.5, and more preferably 0.05 ≦ (y / x) ≦ 0.25. When y / x exceeds 0.5, the effect of suppressing the formation of the organic film and the pulverization of the material is reduced.

The average particle size of the negative electrode material of the present invention is preferably 45 μm or less, more preferably 1 to 30 μm, since the negative electrode of a non-aqueous electrolyte secondary battery is generally in the form of a sheet of about 80 μm. When the average particle size exceeds 45 μm, the surface of the sheet-shaped negative electrode has many irregularities, and battery characteristics tend to be reduced.

It is desirable that the phase A be composed of crystal grains as fine as possible in order to obtain good battery characteristics. Specifically, the average grain size of the crystal grains is 10 μm or less, and more preferably 0.1 μm.
It is preferably from 01 to 2.5 μm, particularly preferably from 0.01 to 1 μm. By making the average grain size of the crystal grains fine,
The grain boundary region between the crystals increases, and lithium ions are easily diffused. As a result, the reaction starts to occur uniformly,
Stable battery characteristics can be obtained without applying a large load to a part of the material. It is desirable that the B phase also be composed of crystal grains as fine as possible in order to obtain good battery characteristics. Specifically, the average grain size of the crystal grains is preferably 10 μm or less, more preferably 0.01 to 2.5 μm, and particularly preferably 0.01 to 1 μm. As described above, lithium ions are easily diffused due to the fine average grain size of the crystal grains,
Lithium ions diffuse throughout the phase A, and the reaction easily proceeds uniformly.

As a method for obtaining the negative electrode material of the present invention, A
A step of plating at least one element selected from the group (m ¹ ) on the surface layer of the particles having a phase, for example, applying the phase A to an electroless plating solution of the element selected from the group (m ¹ ). 5-60 while keeping the temperature at an appropriate temperature.
A method including a step of stirring for minutes. Further, as another method, a step of compounding at least one element selected from the group (m ¹ ) with the surface layer of the particles having the A phase by a mechanical alloy method, for example, (m ¹ )
A simple substance or an alloy of 5 to 20 parts by weight of an element selected from the group is mechanically stirred and mixed together with 80 to 95 parts by weight of particles having an A phase (100 parts by weight in total) to cause a solid-phase reaction between the two. And a method including a step. Further, as still another method, a method including a step of compounding at least one element selected from the group (m ¹ ) by a mechanochemical method on the surface layer of the particles having the A phase can be mentioned.

The particles obtained by the above method are preferably further subjected to a heat treatment in a reducing atmosphere or an atmosphere of an inert gas such as argon or nitrogen. The heat treatment cannot be said unconditionally because it varies depending on the type of particles, but for example, a treatment in which the temperature is raised to 100 to 1500 ° C. over 1 to 10 hours and then heating is performed for 1 to 72 hours is preferable.

Further, the particles having the A phase and an organic compound containing at least one element selected from the group (m ¹ ), for example, an alkoxide compound such as triethoxyiron and pentaethoxymolybdenum are mixed under a reducing atmosphere. Mixing and heat-treating the surface layer of the particles having the A phase by a plasma method or an ion implantation method to obtain (m ¹ )
The negative electrode material of the present invention can also be obtained by a method including a step of introducing at least one element selected from the group.

[0027]

Next, the present invention will be described more specifically based on examples. << Examples 1 to 24 >> Material compositions shown in Tables 1 and 2 and Table 1
Particles having the type A phase shown in Nos. 1 to 2 were prepared by the following procedure. Fe (lump), Cu (granular), Co (granular), M
Table 1 from among n (lump), Ni (granular), Ti (lump), Sn (granular), Si (granular) and Al (powder)
The necessary raw materials according to the material composition of No. 2 were selected, mixed at a predetermined molar ratio, and cast in an arc melting furnace. The obtained casting was converted into spherical particles by using a gas atomizing method. This compound was passed through a 45-micron mesh sieve to obtain particles having an average particle size of 28 μm. When X-ray diffraction analysis was performed on the obtained particles, the presence of the predetermined A phase shown in Tables 1 and 2 was confirmed in each particle. When an EPMA analysis was performed on each particle, the average particle size of the crystal grains constituting the A phase was 0.3 to 2.5 μm in any of the particles.
And the maximum was 5 μm.

Next, the surface layer of the particles having the phase A was subjected to the surface treatments shown in Tables 1 and 2, and the heat treatment was performed at the temperatures shown in Tables 1 and 2 to form the phase B. Table 1
2 to 2, the elements in the column of the surface treatment indicate elements selected from the group (m ¹ ) used for the surface treatment, and the indication “powder” in parentheses indicates a predetermined number using the powder of the element. That the particles were treated by the mechanical alloy method, and the indication "plating" indicates that predetermined particles were plated. Further, "-" in the column of the surface treatment and the column of the heat treatment temperature (° C.) indicate that the surface treatment and the heat treatment were not performed, respectively.

In the mechanical alloy method, Cu powder, Fe powder and Ti powder having an average particle size of 0.05 μm, Ni powder having an average particle size of 0.03 μm, and an average particle size of 0.1
μm Mn powder was used. Predetermined particles and predetermined powder,
After mixing at a ratio of 10: 1 (weight ratio), the mixture was rotated and stirred by a planetary ball mill for 10 minutes.

In the plating treatment, a commercially available Ni electroless plating solution, Co electroless plating solution, and Cu electroless plating solution were used. The particles are placed in a predetermined electroless plating bath, and the temperature is 50 ° C. for the Ni electroless plating solution, 70 ° C. for the Co electroless plating solution, and 2 ° C. for the Cu electroless plating solution.
The mixture was left for 30 minutes with stirring at 0 ° C.

Next, the particles subjected to the surface treatment were subjected to an optional heat treatment. Specifically, the particles were heated to a predetermined heat treatment temperature shown in Tables 1 and 2 over 3 hours in an argon atmosphere, and then kept at that temperature for 12 hours. Cooling was performed by natural cooling. This step is a step for realizing a structure in which the concentration of an element selected from the (m ¹ ) group decreases gradually from the surface toward the inside.

As a result of the above steps, the surface layer of each particle has:
The types B phases shown in Tables 1 and 2 were formed, respectively. When the cross section of each particle was observed by SEM, it was confirmed that 50% or more of the surface of all the particles was covered with the B phase.

Next, a test cell shown in FIG. 1 was prepared by using the obtained particles as a negative electrode active material. To 7.5 g of the negative electrode active material, 2 g of graphite powder as a conductive agent and 0.5 g of polyethylene powder as a binder were mixed to form a mixture. 0.1 g of this mixture was press-molded to a diameter of 17.5 mm to form an electrode 1
And placed in Case 3. A microporous polypropylene separator 7 was placed on the electrode. A 1: 1 by volume mixed solution of ethylene carbonate and dimethoxyethane in which lithium perchlorate (LiClO ₄ ) was dissolved at a concentration of 1 mol / liter was injected as a non-aqueous electrolyte onto the separator. On this, metal lithium 4 having a diameter of 17.5 mm was adhered on the inside, and a sealing plate 6 with a polypropylene gasket 8 attached on the outer periphery was placed and sealed to form a test cell. In FIG. 1, reference numeral 2 denotes a current collector of the electrode 1, and reference numeral 5 denotes a current collector of the metallic lithium 4.

The test cell was cathode-polarized at a constant current of 0.5 mA until the electrode 1 became 0 V with respect to the lithium counter electrode 4 (corresponding to charging when the electrode 1 was viewed as a negative electrode). Then, the electrode was anodically polarized until the voltage of the electrode reached 1.5 V (this corresponds to discharge when the electrode 1 is viewed as a negative electrode). Thereafter, cathodic polarization and anodic polarization were repeated. Table 1 shows the initial discharge capacity per gram of active material.
It is shown in FIG. Thereafter, the test cell was disassembled, and the electrode 1 after cathode polarization and after repeating cathode polarization and anodic polarization for 10 cycles was taken out and observed. As a result, no deposition (dendrite) of metallic lithium on the electrode surface was observed. When the electrode after the cathode polarization was subjected to IPC analysis, the amount of lithium occluded in the A phase and the B phase in the negative electrode material was 0.05 ≦ (y / x) ≦
0.25 was satisfied.

[0035]

[Table 1]

[0036]

[Table 2]

Next, in order to evaluate the cycle characteristics of the battery using the negative electrode active material, a cylindrical battery shown in FIG. 2 was manufactured in the following procedure. LiMn _1.8 Co as the positive electrode active material
_0.2 O ₄ was synthesized by mixing Li ₂ CO ₃ , Mn ₃ O _4, and CoCO ₃ at a predetermined molar ratio and heating at 900 ° C. Furthermore, what classified this into 100 mesh or less was used as the positive electrode active material. To 100 g of the positive electrode active material, 10 g of carbon powder as a conductive agent, 8 g of an aqueous dispersion of polytetrafluoroethylene as a binder, and 8 g of pure water as a resin component are added to form a paste, which is applied to a titanium core material. Then, drying and rolling were performed to obtain a positive electrode plate 11. Also, a predetermined negative electrode active material, graphite powder as a conductive agent, and Teflon (registered trademark) binder as a binder are used in a ratio of 70: 20: 1.
The mixture was mixed at a ratio of 0 (weight ratio), made into a paste using a petroleum solvent, applied to a copper core material, and dried at 100 ° C. to obtain a negative electrode plate 12. As the separator 13, a porous polypropylene was used.

Between the positive electrode plate 11 having the positive electrode lead 14 of the same material as the core material attached by spot welding and the negative electrode plate 12 having the negative electrode lead 15 of the same material as the core material attached by spot welding, Wide band-shaped separator 1
3 and the whole was spirally wound. An upper insulating plate 16 made of polypropylene is provided on each of the upper and lower sides of the obtained electrode body.
And the lower insulating plate 17 were arranged and inserted into the battery case 18. After forming a step on the upper part of the battery case 18, a non-aqueous electrolyte is injected with an equispecific volume mixed solution of ethylene carbonate and dimethoxyethane in which lithium perchlorate is dissolved at a concentration of 1 mol / liter. The battery was sealed with a sealing plate 19 and provided with a positive electrode terminal 20.

The obtained battery was tested at a test temperature of 30 ° C.
, Charge / discharge current 1 mA / cm ² , charge / discharge voltage range 4.3
A charge / discharge cycle test was performed at -2.6 V, and the capacity retention ratio at the 200th cycle relative to the first cycle was determined. The results are shown in Tables 1 and 2.

Comparative Examples 1 to 7 As comparative examples, Tables 1 and 2
The initial discharge capacity of the test cell and the first cycle of the cylindrical battery when the particles having the material composition shown in Table 1 and the particles having the type A shown in Tables 1 and 2 were used as the negative electrode active material without providing the phase B were used. The capacity retention ratio at the 200th cycle was determined in the same manner as in the example. The results are shown in Tables 1 and 2. Tables 1 and 2 show that the battery using the negative electrode material of the present invention has significantly improved cycle characteristics as compared with the comparative example.

Although the cylindrical battery has been described in the examples, the same tendency was observed in coin-type, square-type and flat-type secondary batteries. In the embodiment,
It has been described LiMn _1.8 Co _0.2 O ₄ as the positive electrode active _{material, LiMn 2 O 4, LiCoO 2} , LiNiO goes without saying that the same effect can be obtained when using ₂ or the like.

[0042]

According to the present invention, a high-density non-aqueous electrolyte secondary battery having a high capacity and an extremely excellent cycle life without a short circuit due to dendrite can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a test cell used in an example for evaluating characteristics of a negative electrode material of the present invention.

FIG. 2 is a schematic cross-sectional view of a cylindrical battery used in an example to evaluate characteristics of a negative electrode material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode 2 Current collector of electrode 1 3 Case 4 Metallic lithium 5 Metallic lithium current collector 6 Sealing plate 7 Separator 8 Gasket 11 Positive electrode plate 12 Negative electrode plate 13 Separator 14 Positive electrode lead 15 Negative electrode lead 16 Upper insulating plate 17 Lower insulating plate 18 Battery case 19 Sealing plate 20 Positive electrode terminal

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideharu Takezawa 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (Reference) 5H003 AA02 AA04 BA00 BA01 BA03 BA07 BA09 BB02 BC01 BC05 BD02 BD03 5H029 AJ03 AJ05 AK03 AL07 AL11 AM03 AM04 AM05 AM07 CJ01 CJ02 CJ08 CJ11 CJ14 CJ24 CJ28 DJ16 HJ01 HJ02 HJ05 H07

Claims (10)

[Claims] 1. Formula (1): represented by M ¹ _a M ² and 0 ≦ a ≦
The whole or a part of the surface of the particles having the phase A having the composition satisfying Formula 5 is represented by Formula (2): M ¹ ′ _b M ² ′ _c , where c = 1 or c = 0 and c = 1 Is a material coated with a B phase having a composition satisfying a <b, and M ¹ in the formula (1)
And M ¹ ′ in the formula (2) is Na, K, Rb, Cs, C
e, Ti, Zr, Hf, V, Nb, Ta, Ca, Sr,
Ba, Y, La, Cr, Mo, W, Mn, Tc, Ru,
At least one selected from the group (m ¹ ) consisting of Os, Co, Rh, Ir, Ni, Pd, Cu, Ag and Fe
M ² in the formula (1) and M ² ′ in the formula (2) are Al, Ga, In, Si, Ge, Sn, Pb,
A negative electrode material for a non-aqueous electrolyte secondary battery, which is at least one element selected from the group (m ² ) consisting of Sb and Bi. 2. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1, wherein 50% or more of the surface of the particles having the A phase is coated with the B phase. 3. At least one member selected from the group (m ¹ )
The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the concentration of the species element decreases in a gradient from the surface toward the inside. The composition of claim 4] phase A phase was absorb lithium, the formula (1 '): shown in Li _x M ¹ _a M ^2, the composition of the phase B phase has occluded a lithium, Formula (2') : when shown by _{^{Li y M 1 'b M 2}} ' c, 0 ≦ (y /
2. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1, wherein x) ≦ 0.5. 5. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1, which has an average particle size of 45 μm or less. 6. The surface layer of the particles having the phase A,
(I) a step of plating at least one element selected from the group (m ¹ ), (ii) a mechanical alloy method,
( ^I ) combining at least one element selected from the (m ¹ ) group and (iii) combining at least one element selected from the (m ¹ ) group by a mechanochemical method. The method for producing a negative electrode material for a non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein 7. The method for producing a negative electrode material for a non-aqueous electrolyte secondary battery according to claim 6, wherein after the step, the particles are further heat-treated in a reducing atmosphere or an inert gas atmosphere. 8. The method according to claim 1, wherein the particles having phase A and an organic compound containing at least one element selected from the group (m ¹ ) are mixed and heat-treated in a reducing atmosphere. A method for producing a negative electrode material for a non-aqueous electrolyte secondary battery according to any of the above items. 9. The method according to claim 1, further comprising the step of introducing at least one element selected from the group (m ¹ ) into the surface layer of the particles having the phase A by a plasma method or an ion implantation method. The method for producing a negative electrode material for a nonaqueous electrolyte secondary battery according to any one of the above. 10. A chargeable / dischargeable positive electrode, a non-aqueous electrolyte,
A non-aqueous electrolyte secondary battery comprising a negative electrode made of the negative electrode material according to claim 1.