JP5468723B2 - Anode for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using the same - Google Patents

Description

  The present invention relates to a negative electrode for a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte secondary battery using the same, and more particularly to a negative electrode for a non-aqueous electrolyte secondary battery with improved charge / discharge cycle life and a non-aqueous electrolyte secondary using the same. Next battery.

  With the widespread use of mobile devices such as mobile phones and laptop computers, the role of secondary batteries as power sources is gaining importance. Since these secondary batteries are small, light and have a high capacity and are required to have a performance that does not easily deteriorate even after repeated charge and discharge, lithium ion secondary batteries are most frequently used.

  Carbon such as graphite and hard carbon is mainly used for the negative electrode of the lithium ion secondary battery. Although carbon can repeat charge / discharge cycles satisfactorily, it has not been expected to have a significant capacity in the future because it has improved capacity to near the theoretical capacity. On the other hand, since there is a strong demand for improving the capacity of lithium ion secondary batteries, negative electrode materials having a higher capacity, that is, a higher energy density than carbon, have been studied.

  In the negative electrode of lithium ion secondary batteries, metal lithium has been studied from the viewpoint of high energy density and light weight, but as the charge / discharge cycle progresses, dendrites (dendrites) are formed on the surface of the metal lithium during charging. There is a problem that the crystals are deposited and the crystal penetrates the separator, causing an internal short circuit and a short life.

As a material for increasing the energy density, it has been studied to use, as a negative electrode active material, a Li storage material that forms an alloy with lithium represented by the composition formula Li _X A (A is an element such as aluminum). This negative electrode has a large amount of occlusion and release of lithium ions per unit volume, and has a high capacity. Recently, the use of silicon as a negative electrode active material is described in Non-Patent Document 1. It is said that a high capacity negative electrode can be obtained by using such a negative electrode material.

  Although this type of silicon-based negative electrode has a large amount of lithium ion storage and release per unit volume and high capacity, the electrode active material itself expands and contracts when lithium ion is stored and released. Progressed, the irreversible capacity in the first charge / discharge was large, and the charge / discharge cycle life was short.

  Patent Document 1 proposes a method of using silicon oxide as an active material as a measure for reducing irreversible capacity using silicon and improving charge / discharge cycle life. In Patent Document 1, since the volume expansion / shrinkage per unit weight of the active material can be reduced by using silicon oxide as the active material, improvement in cycle characteristics has been confirmed. On the other hand, since the conductivity of the oxide is low, there is a problem that the current collecting property is lowered and the irreversible capacity is large. In addition, Patent Document 2 proposes that iron or titanium is added to silicon oxide in order to improve current collecting performance when silicon oxide is used as an active material. However, since these metals have weak corrosion resistance and oxidation resistance with respect to the electrolyte, there is a problem that the conductivity decreases when the cycle is repeated only by adding the metal. Furthermore, as a countermeasure for improving capacity and charge / discharge cycle life, Patent Document 3 proposes a method using particles obtained by combining a carbon material with silicon and silicon oxide as an active material. Although this improved the cycle characteristics, it was still insufficient.

  On the other hand, it has been conventionally reported that a resin material having thermosetting properties is used as a binder (binder) for the purpose of improving cycle characteristics. Specifically, a method of mixing and sintering tin oxide, silicon oxide, and carbon with a polyimide binder is proposed in Patent Document 4, and a mixture of active material particles containing silicon and / or silicon alloy and conductive metal powder is prepared. Patent Document 5 proposes a method of sintering a mixture with a polyimide binder on the surface of the current collector in a non-oxidizing atmosphere. However, these have not led to the realization of cycle characteristics comparable to those of a carbon negative electrode, which is a judgment in actual use.

Japanese Patent No. 2999741 Japanese Patent No. 3010226 JP 2004-139886 A JP 2002-117835 A Japanese Patent Laid-Open No. 2002-260637 Li and four others, “A High Capacity Nano-Si Composite Anode Material for Lithium Rechargeable Batteries”, Electrochemical and Solid State Letters Solid-State Letters), Vol. 2, No. 11, p547-549 (1999)

  An object of the present invention is to improve the current collecting performance, to have high charge / discharge efficiency in the first charge / discharge, and to have a good cycle characteristic with high energy density and a non-aqueous electrolyte secondary battery negative electrode using the same The object is to provide a water electrolyte secondary battery.

In order to solve the above problems, a negative electrode for a non-aqueous electrolyte secondary battery according to the present invention comprises active material particles in which a mixture of simple silicon and silicon oxide is coated with carbon composed of a mixed composition of amorphous carbon and graphite, and by heating. It includes a mixture of thermosetting resins that cause a dehydration condensation reaction, and is characterized in that the active material particles are bound to each other and the active material particles and the current collector by the thermosetting resin. Further, the carbon contained in the active material particles is preferably 5% to 50% by weight, and the electrode density is preferably 0.5 g / cm ^{3 to} 1.5 g / cm ^3. The particle diameter D ₉₅ of the mixture of simple substance silicon and silicon oxide in the material particles is preferably 5 μm or more and 30 μm or less, and the particle diameter D ₉₅ of the active material particles is preferably 10 μm or more and 50 μm or less.

  The nonaqueous electrolyte secondary battery according to the present invention is characterized in that the negative electrode for a nonaqueous electrolyte secondary battery is used and a discharge end voltage value is 1.5 V or more and 2.7 V or less.

  According to the present invention, the expansion and contraction of the electrode active material itself is mitigated by mixing silicon oxide with simple silicon that exhibits high capacity and large volume expansion by charging, and further coating the periphery with amorphous carbon. Therefore, it leads to the improvement of the charge / discharge cycle life of the nonaqueous electrolyte secondary battery. On the other hand, by coating graphite on a mixture of simple silicon and silicon oxide, not only improves current collection and improves the initial charge / discharge capacity, but also provides corrosion resistance and oxidation resistance to the active silicon electrolyte. I can keep it. In addition, since the thermosetting resin that functions as a binder causes a dehydration condensation reaction by heating, it exhibits an action of firmly binding between the active material particles and between the active material particles and the current collector. The initial charge / discharge capacity of the nonaqueous electrolyte secondary battery can be improved by improving the current collecting property.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic cross-sectional view of active material particles of a negative electrode for a non-aqueous electrolyte secondary battery of the present invention.

As shown in FIG. 1, the active material particles 5 of the negative electrode preferably have a particle size in which simple silicon 1 and silicon oxide 2 are used as the core, and the mixture is coated with carbon which is a mixture of amorphous carbon 3 and graphite 4 around the mixture. D ₉₅ is a particle having a size of 10 μm or more and 50 μm or less, more preferably 10 μm or more and 20 μm or less. D ₉₅ indicates the particle size when the sum of the volume ratios below a certain particle size is 95%. Here the core particles in the active material, although the particle size of the mixture of elemental silicon and silicon oxide is desirably D ₉₅ is 5μm or more 30μm or less, it had a 5μm or more in handling in the manufacturing process In consideration of this, the reason why the thickness is 30 μm or less is to prevent deterioration of the discharge capacity due to repeated charge and discharge. Further, D ₉₅ of the negative electrode active material particles is set to 10 μm or more and 50 μm or less for the same reason as that for defining the particle size of the mixture of simple silicon and silicon oxide. That is, the thickness is set to 10 μm or more in consideration of handling in the manufacturing process, and the thickness is set to 50 μm or less in order to prevent the discharge capacity from being deteriorated due to repeated charge and discharge.

  The simple silicon 1 occludes or releases Li during charge / discharge. The silicon oxide 2 has a role of relaxing expansion and contraction of the active material itself. The carbon coating layer on the outside is a mixture of amorphous carbon 3 and graphite 4. The carbon coated in the negative electrode active material is preferably 5% or more and less than 50% by weight. The reason for this is that when the carbon weight ratio is less than 5%, there is a problem that the deterioration of the discharge capacity due to repeated charge and discharge is large, and when it is 50% or more, the absolute value of the discharge capacity is small, which is an advantage over conventional carbon materials. This is because cannot be obtained.

  As a method for producing the negative electrode active material particles, first, silicon and silicon oxide as nuclei are mixed and sintered under high temperature and reduced pressure. Next, a mixed sintered product of silicon and silicon oxide is introduced into a gaseous atmosphere of an organic compound in a high temperature non-oxygen atmosphere, or a mixed sintered product of silicon and silicon oxide and a precursor of carbon in a high temperature non-oxygen atmosphere. By mixing the body resin, a carbon coating layer is formed around the core of silicon and silicon oxide. Here, the proportion of graphite in the carbon coating layer increases as the temperature during the coating layer formation increases.

  FIG. 2 shows a cross-sectional view of the nonaqueous electrolyte secondary battery of the present invention. As shown in FIG. 2, the non-aqueous electrolyte secondary battery of the present invention is formed on a negative electrode 8 comprising an active material layer 6 formed on a negative electrode current collector 7 such as a copper foil and a positive electrode current collector 10 such as an aluminum foil. The positive electrode 11 made of the active material layer 9 is arranged so as to face each other with the separator 12 interposed therebetween. As the separator 12, a polyolefin film such as polypropylene or polyethylene, or a porous film such as a fluororesin can be used. From the negative electrode 8 and the positive electrode 11, a negative electrode lead tab 14 and a positive electrode lead tab 15 for taking out electrode terminals are drawn out, respectively, and are packaged using an exterior film 13 such as a laminate film except for the respective ends.

The negative electrode active material layer 6 is composed of negative electrode active material particles produced by the above-described method and a thermosetting bond represented by polyimide, polyamide, polyamideimide, polyacrylic acid resin, and polymethacrylic acid resin as a binder. The adhesive is formed by dispersing and kneading in a solvent such as N-methyl-2-pyrrolidone (NMP), applying the mixture onto the negative electrode current collector 7, and drying in a high temperature atmosphere. In the active material layer 6 of the negative electrode, carbon black, acetylene black, or the like may be mixed in order to impart conductivity as necessary. The electrode density of the produced negative electrode active material layer 6 is preferably 0.5 g / cm ³ or more and 1.5 g / cm ³ or less. When the electrode density is low, the absolute value of the discharge capacity is small, and a merit over the conventional carbon material cannot be obtained. On the other hand, when it is high, it is difficult to impregnate the electrode with an electrolyte, and the discharge capacity is also lowered. The thickness of the negative electrode current collector 7 is preferably 4 to 100 μm because it is preferable to maintain the strength, and more preferably 5 to 30 μm in order to increase the energy density.

  The active material layer 9 of the positive electrode includes, as an active material, lithium manganate, lithium cobaltate, lithium nickelate, and a mixture thereof, and manganese, cobalt, nickel portions substituted with aluminum, magnesium, titanium, zinc, etc. May be lithium iron phosphate.

Moreover, as electrolyte used for a battery, cyclic carbonates, such as propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), and vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), Chain carbonates such as ethyl methyl carbonate (EMC) and dipropyl carbonate (DPC), aliphatic carboxylic acid esters such as methyl formate, methyl acetate and ethyl propionate, γ-lactones such as γ-butyrolactone, Chain ethers such as 2-ethoxyethane (DEE) and ethoxymethoxyethane (EME), cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, acetamide Dimethylformamide, dioxolane, acetonitrile, propylnitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2 -Using an aprotic organic solvent such as oxazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, ethyl ether, 1,3-propane sultone, anisole, N-methylpyrrolidone, or a mixture of two or more of these, A lithium salt that dissolves in an organic solvent is dissolved. Examples of the lithium salt include LiPF ₆ , LiAsF ₆ , LiAlCl ₄ , LiClO ₄ , LiBF ₄ , LiSbF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , Li (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ). ₂ , LiB ₁₀ Cl ₁₀ , lower aliphatic lithium carboxylate, lithium chloroborane, lithium tetraphenylborate, LiBr, LiI, LiSCN, LiCl, imides and the like. Further, a polymer electrolyte may be used instead of the electrolyte.

  The non-aqueous electrolyte secondary battery produced as described above preferably has a discharge end voltage value of 1.5 V or more and 2.7 V or less. There is a problem that the deterioration of the discharge capacity due to repeated charge / discharge increases as the discharge end voltage value decreases. Setting the voltage to 1.5 V or less has a high degree of difficulty in circuit design. Further, when the voltage is 2.7 V or more, the absolute value of the discharge capacity is small and no merit over the conventional carbon material can be obtained.

  Examples of the present invention will be described below.

Example 1
Single silicon and silicon oxide were mixed at a molar ratio of 1: 1, and melted and rapidly cooled at 1400 ° C. and 13.3 Pa to form a silicon-silicon oxide mixed powder. The particle size D _{95 of the} mixture was 20 μm or less. It grind | pulverized to the maximum particle size of 50 micrometers or less with the ball mill in the ethanol solution. Mixing the powder and the phenol resin, under a nitrogen atmosphere, after calcination at 900 ° C., it was subjected to grinding processing so that the D ₉₅ is 30μm or less. This produced active material particles in which the carbon ratio in the active material was 20% by weight. Using the active material particles thus generated, an active material layer was prepared as follows.

The active material layer of the negative electrode was prepared by applying an electrode material mixed with the above active material particles, polyimide, and NMP onto a negative electrode current collector made of 10 μm copper foil, drying at 125 ° C. for 5 minutes, and then using a roll press. It compression-molded and produced again by drying at 300 degreeC for 10 minutes in a drying furnace. The active material layer formed on the negative electrode current collector made of copper foil was punched out to 30 × 28 mm to form a negative electrode, and a negative electrode lead tab made of nickel for taking out charges was fused by ultrasonic waves. For the active material layer of the positive electrode, an active material particle made of lithium cobaltate, an electrode material mixed with polyvinylidene fluoride as a binder, and NMP as a solvent were applied on a positive electrode current collector made of 20 μm aluminum foil, and 125 ° C. It was prepared by drying for 5 minutes. The active material layer formed on the positive electrode current collector made of aluminum foil was punched out to 30 × 28 mm to form a positive electrode, and a positive electrode lead tab made of aluminum for charge extraction was fused by ultrasonic waves. After laminating the negative electrode, the separator, and the positive electrode in this order so that the active material layer faces the separator, the laminate film was sandwiched, the electrolyte was injected, and the laminate type battery was sealed under vacuum. The electrolyte used was a solution of 1 mol / l LiPF ₆ in a 3: 5: 2 mixed solvent of EC, DEC, and EMC.

(Example 2)
Active material particles were produced in the same manner as in Example 1 except that the carbon ratio in the active material particles was 3% by weight, and a battery was produced.

(Example 3)
Active material particles were produced in the same manner as in Example 1 except that the carbon ratio in the active material particles was 5% by weight, and a battery was produced.

Example 4
Active material particles were produced in the same manner as in Example 1 except that the carbon ratio in the active material particles was 10% by weight, and a battery was produced.

(Example 5)
Active material particles were produced in the same manner as in Example 1 except that the carbon ratio in the active material particles was 50% by weight, and a battery was produced.

(Example 6)
Active material particles were produced in the same manner as in Example 1 except that the carbon ratio in the active material particles was 70% by weight, and a battery was produced.

(Example 7)
A mixture of simple silicon and silicon oxide as a core having a particle size D ₉₅ of 20 μm or less and a negative electrode active material D ₉₅ of 50 μm or less was prepared. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Example 8)
A mixture of single silicon and silicon oxide serving as a nucleus having a particle size D ₉₅ of 30 μm and a negative electrode active material D ₉₅ of 50 μm was prepared. Otherwise, a battery was fabricated in the same manner as in Example 1.

Example 9
A mixture of single silicon and silicon oxide serving as a core having a particle size D ₉₅ of 40 μm and a negative electrode active material D ₉₅ of 50 μm was prepared. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Example 10)
A particle having a particle size D ₉₅ of 20 μm and a negative electrode active material D ₉₅ of 70 μm was prepared. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Example 11)
Instead of polyimide, a polyacrylic acid-based resin was used as a binder when producing the active material layer of the negative electrode. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Comparative Example 1)
Polyvinylidene fluoride resin was used as a binder when producing the active material layer of the negative electrode. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Comparative Example 2)
Single silicon and silicon oxide were mixed at a molar ratio of 1: 1, and melted and rapidly cooled at 1400 ° C. and 13.3 Pa to form a silicon-silicon oxide mixed powder. The particle size D _{95 of the} mixture was 20 μm. It grind | pulverized so that it might become a maximum particle size of 50 micrometers with the ball mill in an ethanol solution. The powder and the phenol resin were mixed and fired at 500 ° C. in a nitrogen atmosphere, and then pulverized so that the particle size D ₉₅ was 30 μm. Thus, composite particles having a carbon ratio in the active material of 20% were produced. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Comparative Example 3)
Single silicon and silicon oxide were mixed at a molar ratio of 1: 1, and melted and rapidly cooled at 1400 ° C. and 13.3 Pa to form a silicon-silicon oxide mixed powder. The particle size D _{95 of the} mixture was 20 μm. _{D 95} in ethanol in a ball mill was pulverized so that 50 [mu] m. The above powder, graphite powder, and polyvinylidene fluoride were mixed, fired at 900 ° C. in a nitrogen atmosphere, and then pulverized to a D ₉₅ of 30 μm. Thus, composite particles having a carbon ratio in the active material of 20% were produced. Otherwise, a battery was fabricated in the same manner as in Example 1.

(Comparative Example 4)
Graphite powder was used for the negative electrode active material particles. Otherwise, a battery was fabricated in the same manner as in Example 1.

  For each battery produced by the above method, the electrode density of the negative electrode was first measured. Next, the discharge capacity characteristic in the range of voltage 4.2V to 3.0, 2.7, 2.5, and 2.2V was measured by setting the produced battery to a charge / discharge current of 20 mA. In addition, a charge / discharge cycle test was performed in a voltage range of 4.2 V to 2.5 V.

Table 1 shows the particle diameter D ₉₅ (μm) of the silicon-silicon oxide mixtures of Examples 1 to 11 and Comparative Examples 1 to 4, the particle diameter D ₉₅ (μm) of the active material particles, the electrode density, Initial charge / discharge efficiency, relative initial electrode discharge capacity when the initial electrode discharge capacity (per unit volume of the active material layer) of Comparative Example 4 is 1, and capacity retention rate after 100 cycles ((in the 100th cycle) Discharge capacity) / (discharge capacity in the first cycle)).

  Furthermore, with respect to Comparative Example 4 when the discharge end voltage value in Examples 1 to 11 and Comparative Examples 1 to 4 was changed to 3.0, 2.7, 2.5, and 2.2 V Table 2 shows the relative electrode discharge capacity (per unit volume of the active material layer).

  In Examples 1 to 6, the carbon ratio in the active material is changed. As a result, the electrode discharge capacity was larger than that of Comparative Example 4 except for Example 6. Moreover, the electrode discharge capacity of Example 6 was almost the same as that of the comparative example. The capacity maintenance rate after the cycle was inferior only when the carbon ratio of Example 2 was 3%, but it was good at other levels. From this, it can be seen that if the carbon ratio of the active material in the composite particles is 5% or more, the electrode discharge capacity, the initial charge / discharge efficiency, and the improvement of the capacity retention rate after 100 cycles are all effective.

In Example 7 to Example 9, the particle size D ₉₅ of the mixture of silicon and silicon oxide as active material particles is changed. In any level, the electrode discharge capacity is larger than that of Comparative Example 4, but the capacity retention rate after the cycle and the initial charge / discharge efficiency decrease as the particle size of the mixture increases. In Example 9, the characteristics decrease. From this, it can be seen that the effect is large when the particle size D ₉₅ of the mixture of silicon and silicon oxide of the active material particles is at least 30 μm or less.

In Examples 1, 7, and 10, the particle diameter D ₉₅ of the negative electrode active material particles is changed. In all the levels, the electrode discharge capacity was larger than that of Comparative Example 4, but the capacity retention rate after the cycle and the initial charge / discharge efficiency were decreased as the particle size of the negative electrode active material particles was larger. In addition to the decrease in the initial capacity, the initial capacity is also decreased. From this, it can be seen that the effect is large when the particle diameter D ₉₅ of the negative electrode active material particles is at least 50 μm or less.

  In Examples 1 and 11 and Comparative Example 1, the type of binder used for the negative electrode active material is changed. There is no difference in the electrode discharge capacity at any level. In Examples 1 and 11, a thermosetting binder is used and the capacity retention rate after cycling is good, but in Comparative Example 1, a heat-swellable binder is used and the capacity maintenance rate after cycling tends to decrease. . Furthermore, the polyimide binder of Example 1 has a higher thermosetting property than the polyacrylic acid resin of Example 11, and this appears as a difference in cycle characteristics between Examples 1 and 11. From this, it is necessary to use a thermosetting binder for the negative electrode active material, and it can be seen that the greater the thermosetting property, the better the cycle characteristics.

  In Example 1 and Comparative Examples 2 and 3, the kind of carbon coated around the mixture of silicon and silicon oxide is different. When X-ray diffraction measurement was performed on the negative electrode before battery assembly, it was confirmed that Example 1 had a mixed composition of amorphous and graphite, Comparative Example 2 was amorphous carbon, and Comparative Example 3 was graphite. In Comparative Example 2, the capacity retention rate after cycling is as good as in Example 1, but the initial charge / discharge efficiency is greatly reduced. In Comparative Example 3, on the contrary, the capacity retention rate after the cycle is lowered. From these results, it is understood that both amorphous and graphite are required as the types of carbon to be coated.

Table 1 shows that the electrode density is 1.5 g / cm ³ or less, and good characteristics can be obtained by designing it at a lower density than the graphite negative electrode of Comparative Example 3. Furthermore, from Table 2, except for Comparative Example 4 in which graphite powder is used for the negative electrode active material particles, the capacity is reduced when the final discharge voltage value is 3.0 V compared to 2.7 V. If the discharge end voltage value is at least 2.7 V or less, the capacity of the negative electrode active material can be extracted.

  As described above, it was confirmed that by optimizing the structure, composition, and battery design of the negative electrode active material particles, a battery having high initial charge / discharge efficiency, high electrode energy density, and good cycle characteristics can be provided.

The schematic cross section of the active material particle of the negative electrode for nonaqueous electrolyte secondary batteries of this invention. Sectional drawing of the nonaqueous electrolyte secondary battery of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elementary silicon 2 Silicon oxide 3 Amorphous carbon 4 Graphite 5 (Negative electrode) Active material particle 6 (Negative electrode) Active material layer 7 Negative electrode collector 8 Negative electrode 9 (Positive electrode) Active material layer 10 Positive electrode collector 11 Positive electrode 12 Separator 13 Exterior film 14 Negative electrode lead tab 15 Positive electrode lead tab

Claims (7)

A negative electrode used in a non-aqueous electrolyte secondary battery having a negative electrode, a positive electrode, and a lithium ion conductive non-aqueous electrolyte,
Active material particles having a mixed sinter of simple silicon and silicon oxide as a core, and a coating layer of carbon composed of a mixed composition of amorphous carbon and graphite,
Including a mixture of thermosetting resins that undergo a dehydration condensation reaction upon heating;
A negative electrode for a non-aqueous electrolyte secondary battery, wherein the active material particles are bound between the active material particles and the active material particles and a current collector by the thermosetting resin.
A negative electrode used in a non-aqueous electrolyte secondary battery having a negative electrode, a positive electrode, and a lithium ion conductive non-aqueous electrolyte is formed by mixing a mixed sintered product and a phenol resin around a mixed sintered product of simple silicon and silicon oxide. A mixture of active material particles coated with carbon having a mixed composition of amorphous carbon and graphite, obtained by mixing and firing at 900 ° C. in a nitrogen atmosphere, and a thermosetting resin that causes a dehydration condensation reaction upon heating. A negative electrode for a non-aqueous electrolyte secondary battery, wherein the active material particles are bound between the active material particles and the active material particles and a current collector. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1 or 2 , wherein the carbon contained in the active material particles is 5% or more and 50% or less by weight. The electrode density of the negative electrode 0.5 g / cm ³ or more 1.5 g / cm ³ negative electrode for a non-aqueous electrolyte secondary battery according to any one of claims 1-3, characterized in that less. The non-aqueous solution according to any one of claims 1 to 4 , wherein a particle size D ₉₅ of a mixed sintered product of simple silicon and silicon oxide in the active material particles is 5 µm or more and 30 µm or less. Negative electrode for electrolyte secondary battery. The active material particle size negative electrode for a non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, characterized in that D ₉₅ is 10μm or more 50μm or less of the particles. It is a nonaqueous electrolyte secondary battery using the negative electrode for nonaqueous electrolyte secondary batteries of any one of Claims 1-6 , Comprising: Discharge final voltage value is 1.5V or more and 2.7V or less A non-aqueous electrolyte secondary battery.

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