JP6775974B2 - Electrode active material for non-aqueous electrolyte batteries, electrodes for non-aqueous electrolyte batteries, non-aqueous electrolyte batteries and battery packs - Google Patents

Description

Embodiments of the present invention relate to electrode active materials for non-aqueous electrolyte batteries, electrodes for non-aqueous electrolyte batteries, non-aqueous electrolyte batteries, and battery packs.

In recent years, with the rapid spread of small mobile terminals such as smartphones and tablets, there is an increasing demand for small batteries with high energy density to drive them. On the other hand, battery-equipped vehicles such as EVs and PHEVs are becoming widespread, and improvement of energy density is also required for large batteries. The application of lithium-ion batteries is being considered for both batteries mounted on small mobile terminals and batteries mounted on vehicles such as automobiles. Generally, a graphite-based material is used for the negative electrode of a lithium ion battery. The theoretical capacity of the graphite-based material is 372 mAh / g (LiC6), which is almost the limit at present. In order to further improve the energy density, it is necessary to develop a new electrode material. In particular, as a negative electrode material, a material system that has a low potential next to carbon and lithium and has a small electrochemical equivalent and alloys with lithium such as silicon and tin is attracting attention.
Among them, silicon can occlude lithium atoms up to a ratio of 4.4 to 1 silicon atom, and theoretically can have a capacity about 10 times that of a graphite-based carbon material. However, since the volume of silicon particles expands about 3 to 4 times when lithium is occluded, the particles themselves crack and become finer due to repeated charging and discharging, and affect other members that make up the electrode. I have a problem. Therefore, it has been proposed to try to suppress the volume expansion of silicon particles by covering the periphery of silicon with a conductive carbonaceous material, or to use silicon as a silicon compound instead of alone.

For example, silicon oxide, which is a compound of silicon and oxygen, can precipitate nano-sized silicon particles in and on the surface of silicon oxide by disproportionation treatment by heating or chemical / electrochemical reduction reaction. .. As a result, the silicon particles are immobilized on the silicon oxide, and grain growth and shedding of the silicon particles can be prevented. Further, by coating the silicon oxide with a carbonaceous material, it is possible to impart electron conductivity to the silicon oxide and suppress the silicon particles from falling off from the silicon oxide. However, the silicon oxide is originally chemically stable, and it is difficult to obtain a sufficient capacity and cycle life when silicon particles are precipitated from the silicon oxide.

International Publication No. 2014/11928

An object to be solved by the present invention is to provide an electrode active material for a non-aqueous electrolyte battery, an electrode for a non-aqueous electrolyte battery, a non-aqueous electrolyte battery, and a battery pack having excellent discharge capacity and cycle characteristics.

The electrode active material for a non-aqueous electrolyte battery of the embodiment has silicon oxide particles represented by SiOx (1.8 ≦ x ≦ 2.2) and a carbon material. The silicon oxide particles are dispersed in the carbon material. The silicon oxide particles are the first peak having a maximum value in the range of 800 to 820 cm ^-1 in the infrared absorption spectrum (IR spectrum) measured by the total reflection measurement method (Attenuated Total Reflection: ATR), 1030 to 50 cm. ^It has a second peak with a maximum value in the range of ^-1 , a third peak with a maximum value in the range of 1085-1115 cm ^-1 , and a fourth peak with a maximum value in the range of 1160-1210 cm ^-1. .. The area of the second peak is in the range of 10% or more and 75% or less with respect to the total area of the first to fourth peaks. The silicon oxide particles have a particle size distribution having peaks in each of a first region having a particle size in the range of 20 nm or more and less than 100 nm and a second region having a particle size in the range of 100 nm or more and 600 nm or less.

The conceptual diagram of the electrode which concerns on 2nd Embodiment. The cross-sectional view which shows an example of the non-aqueous electrolyte battery which concerns on 3rd Embodiment. An enlarged cross-sectional view of part A shown in FIG. A partially cutaway perspective view showing another example of the non-aqueous electrolyte battery according to the third embodiment. The enlarged sectional view of the part B shown in FIG. The conceptual diagram of the battery pack which concerns on 4th Embodiment. The block diagram which shows the electric circuit of the battery pack which concerns on 4th Embodiment. The figure which shows the IR spectrum measured by the ATR method.

Hereinafter, the electrode active material for a non-aqueous electrolyte battery, the electrode for a non-aqueous electrolyte battery, the non-aqueous electrolyte battery, and the battery pack of the embodiment will be described with reference to the drawings.

(First Embodiment)
In the first embodiment, an electrode active material for a non-aqueous electrolyte battery is provided. Hereinafter, the electrode active material for a non-aqueous electrolyte battery of the present embodiment will be described as an active material used for the active material mixture layer of the negative electrode of the non-aqueous electrolyte battery, but the active material of the present embodiment is the active material mixture of the positive electrode. It can also be used as an active material used for layers. Further, although the electrode using the active material will be described as being used for the non-aqueous electrolyte secondary battery, the electrode using the active material of the embodiment can be used for various batteries.

The electrode active material for a non-aqueous electrolyte battery of the first embodiment is a composite particle containing silicon oxide particles represented by SiOx (1.8 ≦ x ≦ 2.2) and a carbon material.
It is known that the Si—O bond in the silicon oxide forms a chain / cyclic structure and exhibits a characteristic absorption in the transmitted IR spectrum. In examining various silicon oxides, the inventor has found that silicon oxide particles having the following characteristics are preferable as a material for an electrode active material for a non-aqueous electrolyte battery.
That is, the silicon oxide particles used in the present embodiment have a first peak having a maximum value in the range of 800 to 820 cm ^-1 in the IR spectrum measured by the ATR method, and a maximum value in the range of 1030 to 1050 cm ^-1. The second peak has a second peak with a maximum value in the range of 1085 to 1115 cm ^-1 , a third peak having a maximum value in the range of 1160 to 1210 cm ^-1 , and a fourth peak having a maximum value in the range of 1160 to 1210 cm ^-1. The area of is in the range of 10% or more and 75% or less with respect to the total area of the first to fourth peaks. The ratio of the area of the second peak to the total area of the first to fourth peaks is preferably in the range of 20% or more and 65% or less, and more preferably in the range of 30% or more and 55% or less. ..

An example of the IR spectrum of the silicon oxide particles measured by the ATR method will be described with reference to FIG. In the IR spectrum after measurement, the four peaks 1 to 4 overlap, and from this IR spectrum, a chart of the vertical axis absorbance and the horizontal axis wave number (linear) is drawn, and the spectrum in the region of 600 to 1500 cm ^-1 is drawn. extracting, obtaining the I spectrum underlying corrects the absorbance of 900 cm ^-1 and 1300 cm ^-1 as a baseline (indicating referred to as "IR spectrum" in FIG. 8). Then, by peaks separating the IR spectrum with a Gaussian ^{function, 800~820cm -1, 1030~1050cm -1,} with a maximum value in each of the wavelength range of 1085～1115Cm ^-1, and 1160～1210Cm ^-1 It can be separated into four peaks (referred to as "first peak", "second peak", "third peak", and "fourth peak" in FIG. 8 respectively). The second peak area is converted into a ratio to the total value of the four peak areas from the first peak to the fourth peak.

The IR spectrum of the silicon oxide particles is 900 cm when the spectrum in the region of 600 to 1500 cm ^-1 is extracted and the vertical axis absorbance and horizontal axis wavenumber (linear) charts are drawn and the maximum peak absorbance is 1. The absorbance at ^-1 and 1300 cm ^-1 is preferably 0.1 or less. If the absorbance at 900 cm ^-1 and 1300 cm ^-1 in the case where the absorbance of the maximum peak was 1 exceeds 0.1, represents that overlap different peaks from the first to fourth peak, sufficient There is a risk that the characteristics cannot be obtained. Further preferred values for the absorbance at 900 cm ^-1 and 1300 cm ^-1 in the case where the absorbance of the maximum peak was 1 is 0.05 or less.

Si-O bond of a general silicon oxide is in the IR ^{spectrum, 1010~1020cm -1, 1080~1090cm -1, 1050~1080cm} -1, 4 one having the maximum value in the region of 1020～1090Cm ^-1 It is known to have a peak, and is attributed to three-membered annular Si-O expansion and contraction vibration, four-membered annular Si-O expansion and contraction vibration, large annular Si-O expansion and contraction vibration, and chain Si-O expansion and contraction vibration, respectively. The silicon oxide particles used in this embodiment have peaks at positions different from those of general silicon oxide, and the origin of each peak is not clear, but cyclic Si-O expansion and contraction vibration and chain Si- It is also considered to be derived from O expansion / contraction vibration.

The silicon oxide particles may be a mixture of two or more types of silicon oxide particles having different peak shapes 1 to 4.

Further, lithium silicate such as Li ₄ SiO ₄ may be dispersed on the surface or inside of the silicon oxide.

A lithium compound may be added together with the silicon oxide and the carbon material. By adding these substances to the carbon material, the bond between the silicon oxide and the carbon material is strengthened, and Li ₄ SiO ₄ having excellent lithium ion conductivity is formed in the silicon oxide phase. Examples of the lithium compound include lithium carbonate, lithium oxide, lithium hydroxide, lithium oxalate, lithium chloride and the like.

The silicon oxide particles may contain trace elements such as phosphorus and boron.
The silicon oxide particles are preferably those in which silicon nanoparticles are precipitated in the range in which the composition is represented by SiOx (1.8 ≦ x ≦ 2.2). Silicon nanoparticles undergo a volume change each time they repeatedly occlude and release lithium. This volume change can cause the active material to collapse. Therefore, it is preferable to make the size as fine as possible. The particle size of the silicon nanoparticles is preferably 2 nm or more and 150 nm or less. This is because those having a size smaller than 2 nm are practically difficult to produce, and those having a size larger than 150 nm may be finely divided by repeated charging and discharging. These silicon nanoparticles have a structure in which the periphery is coated with a silicon oxide.

The silicon oxide constituting the silicon oxide particles has the ability to alleviate the volume expansion due to the insertion of lithium during charging, and can prevent the growth and dropout of the silicon nanoparticles in the charge / discharge cycle. It is preferably crystalline.
The silicon oxide particles may contain a crystalline silicon oxide phase.

Silicon oxide particles have a large expansion and contraction when lithium is occluded and released, and it is preferable that the silicon oxide particles are as finely divided and dispersed as possible in order to relieve this stress. As a specific example, it is preferable that the particles are dispersed in a particle size having an average particle size of 5 nm or more and 600 nm or less. The silicon oxide particles also have a particle size distribution having peaks in each of a first region having a particle size in the range of 20 nm or more and less than 100 nm and a second region having a particle size in the range of 100 nm or more and 600 nm or less. Is preferable.
This is because, when the cycle characteristics are taken into consideration, if the average particle size is set in this range, there is no significant deterioration and stable charge / discharge characteristics can be obtained. The average particle size referred to here means that the cross section of the electrode is ion-milled, or the powder of silicon oxide particles is subjected to a scanning electron microscope (SEM) or a transmission electron microscope (TEM). When observed at a magnification of 20000 times or more, 20 or more particles existing on the diagonal line of the visual field can be selected and obtained as the average diameter thereof. The particle size is the average value of the major axis and the minor axis of one particle in a two-dimensional image. The method for measuring the average diameter (particle size) of the silicon nanoparticles is the same as the method for measuring the average primary particle size of the silicon oxide particles.

The electrode active material for a non-aqueous electrolyte battery of the present embodiment preferably contains silicon oxide particles in a range of 40% by mass or more and 80% by mass or less. If the amount of silicon oxide particles in the active material for a non-aqueous electrolyte battery is less than 40% by mass, the effect of increasing the capacity may not be sufficient. When the silicon oxide particles in the active material for a non-aqueous electrolyte battery exceed 80% by mass, the carbon that imparts conductivity may be insufficient, and the silicon oxide may not function sufficiently.

As the carbon material used in the present embodiment, it is preferable to use any one or more of carbonaceous materials such as graphite, hard carbon, soft carbon, amorphous carbon and acetylene black. Graphite is preferable in that it increases the conductivity of the active material and increases the capacity. The carbon material preferably has a crystal plane spacing d002 measured by powder X-ray diffraction in the range of 0.337 nm or more and 0.430 nm or less. In the carbon material, when the crystal plane spacing d002 measured by the powder X-ray diffraction method is less than 0.337 nm, the crystallinity becomes high, and the layer structure of graphite is cleaved by the volume change of the silicon oxide due to charging and discharging. , The active material for non-aqueous electrolyte batteries may be plastically deformed. If the crystal plane spacing d002 exceeds 0.430, sufficient conductivity may not be obtained and the capacitance may decrease. More preferably, it is amorphous carbon. Amorphous carbon does not have a well-developed planar structure of graphite, and its layer structure is less likely to cleavage than graphite. Further, since the volume change during charging / discharging is smaller than that of graphite, the volume change of the active material for a non-aqueous electrolyte battery can be suppressed.

The electrode active material for a non-aqueous electrolyte battery of the present embodiment may contain silicon particles having a composition represented by SiOy (y ≦ 0.2). When the average particle size of the silicon oxide particles is D1 and the average particle size of the silicon particles is D2, D2 / D1, which is the ratio of D2 to D1, is preferably in the range of 0.5 or more and 0.8 or less. .. Silicon particles having a composition represented by SiOy (y ≦ 0.2) are preferable because they have a small lossy capacity at the time of initial charge / discharge. The content of the silicon particles is preferably in the range of 0.1% by mass or more and 10% by mass or less. If it is less than 0.1% by mass, the effect of increasing the capacity may not be sufficient. If it exceeds 10% by mass, the active material for a non-aqueous electrolyte battery may be plastically deformed due to a volume change during charging and discharging.

The electrode active material for a non-aqueous electrolyte battery of the present embodiment may also contain silicon carbide. Silicon carbide is preferable because it has conductivity and does not cleave. The content of silicon carbide is preferably in the range of 1% by mass or more and 5% by mass or less. If it is less than 1% by mass, the effect of improving conductivity may not be sufficient. If it exceeds 5% by mass, the content of the carbon material is relatively reduced, and the conductivity may be lowered.

The electrode active material for a non-aqueous electrolyte battery of the present embodiment may further contain a fibrous carbonaceous material different from the carbon material and fine voids. Examples of the fibrous carbonaceous material different from the carbon material include carbonaceous materials such as carbon nanofibers and carbon nanotubes. The diameter of the fibrous carbonaceous material preferably has an average diameter of 10 nm or more and 1000 nm or less. The content of the fibrous carbonaceous material is preferably in the range of 0.1% by mass or more and 8% by mass or less. If it exceeds 8% by mass, since the specific surface area is large, a larger amount of carbon material phase is required to enclose it, and as a result, the silicon oxide content may decrease. More preferably, it is 0.5% by mass or more and 5% by mass or less. The fine voids preferably have a diameter of 10 nm or more and 10 μm or less.

Next, a method for producing an electrode active material for a non-aqueous electrolyte battery according to the first embodiment will be described. First, a method for producing silicon oxide particles will be described. Silicon oxide particles can be obtained by various methods. Among them, silicon oxide precursor particles are formed by a wet method such as a precipitation method, a gel method, a sol-gel method, and a spray dry method, and heated at 600 ° C. or higher and 1100 ° C. or lower in an IR spectrum of 800 to 820 cm ^-1 . Silicon oxide particles having four peaks in the regions 1030-1050 cm ^-1 , 1085-1115 cm ^-1 , and 1160-1210 cm ^-1 can be obtained.

Further, the silicon oxide particles that are amorphous and have the above four peaks are sol-gel method such as hydrolysis of alkoxysilane, acid neutralization precipitation / gel method from alkaline silicic acid aqueous solution, or heat-melted silicon. It can be obtained by quenching the oxide. As the alkoxysilane, tetraethoxysilane, tetraisopropoxysilane, or the like can be obtained by putting it in acidic to neutral water and heating the obtained precipitate to 800 to 1100 ° C. The alkaline silicic acid can be obtained by dissolving sodium silicate in water, adding hydrochloric acid or nitric acid, and heating the obtained precipitate to 800 to 1100 ° C.

Next, a method of compositing the silicon oxide particles and the carbon material (composite treatment) will be described.
In the compounding treatment, the silicon oxide particles are mixed with a carbon material such as graphite and an organic material composed of a carbon material precursor to form a composite. Mixing can be performed using a continuous ball mill, a planetary ball mill, or the like. As the organic material, at least one of carbon materials such as graphite, coke, low-temperature calcined charcoal, and pitch, and carbon material precursors can be used. In particular, those that are melted by heating, such as pitch, are melted during the mechanical milling process and the compounding does not proceed well. Therefore, it is preferable to mix and use coke, graphite, and other non-melting materials.

The method of compounding by mixing and stirring in the liquid phase will be described below. The mixing and stirring process can be performed by, for example, various stirring devices, ball mills, bead mill devices, and combinations thereof. For the composite of the silicon oxide particles with the carbon material precursor and the carbon material, it is preferable to perform liquid phase mixing in a liquid using a dispersion medium. This is to disperse more evenly. As the dispersion medium, an organic solvent, water or the like can be used, but it is preferable to use a liquid having good affinity with both the silicon oxide particles and the carbon material precursor and the carbon material. Specific examples include ethanol, acetone, isopropyl alcohol, methyl ethyl ketone, ethyl acetate, N-methylpyrrolidone and the like.

The carbon material precursor is preferably soluble in a liquid or dispersion medium at the mixing stage in order to be uniformly mixed with the silicon oxide, and particularly preferably a liquid and easily polymerizable monomer or oligomer. For example, organic materials such as furan resin, xylene resin, ketone resin, amino resin, melamine resin, urea resin, aniline resin, urethane resin, polyimide resin, polyester resin, phenol resin, resol resin, and sculose can be mentioned. The material mixed in the liquid phase undergoes a solidification or drying step to form a carbon-coated silicon oxide particle-organic material composite.

When a carbon material precursor is used as the organic material, carbonization firing is required to carbonize the carbon material precursor. Carbonization firing is performed in an inert atmosphere such as Ar. In carbonization firing, carbon material precursors such as polymers or pitches in silicon oxide particle-organic material composites are carbonized. The temperature of this carbonization firing varies depending on the thermal decomposition temperature of the organic material compound used, but it is preferably 700 ° C. or higher and 1300 ° C. or lower as an appropriate range. Although it depends on the particle size of the silicon oxide particles, a temperature higher than 1300 ° C. is not preferable because the formation of silicon carbide may proceed excessively and the capacity may decrease. The firing time is preferably in the range of 10 minutes to 12 hours, although it depends on the firing temperature.

The electrode active material for a non-aqueous electrolyte battery according to the present embodiment can be obtained by the above synthesis method. The product after carbonization and firing may have a particle size, a specific surface area, and the like adjusted by using various mills, crushers, grinders, and the like.
The silicon oxide particles may be partially crystalline. The crystalline silicon oxide may be a composite of a carbon material and a carbon material precursor together with the amorphous silicon oxide in the compounding treatment, or silicon in the production of the amorphous silicon oxide. It may be added to the amorphous silicon oxide production process together with the oxide precursor.

The electrode active material (composite particles) for a non-aqueous electrolyte battery of the present embodiment obtained as described above has an average particle size (average primary particle size) of the primary particles in the range of 0.1 μm or more and 50 μm or less. Is preferable. If the average particle size is smaller than 0.1 μm, the specific surface area becomes large, and a large amount of binder is required for electrodeification. On the other hand, if the average particle size is larger than 50 μm, an unintended space is likely to be formed when the electrode is formed, resulting in a decrease in volume per volume. Also, coarse particles are an obstacle in the coating process. More preferably, it is in the range of 0.2 μm or more and 20 μm or less. Composite particles of this size can be obtained, for example, by crushing and classifying particles once composited. The method is not limited to this, and may be produced with the aim of producing small particles from the beginning, such as a spray-drying method. The method for measuring the average particle size of the composite particles is the same as the method for measuring the average particle size of the silicon oxide particles.

The specific surface area of the electrode active material for a non-aqueous electrolyte battery of the present embodiment is preferably in the range of 0.5 m ² / g or more and 100 m ² / g or less. The particle size and specific surface area affect the speed of the lithium insertion / removal reaction and are considered to have a large effect on the negative electrode characteristics, but if the values are in this range, the characteristics can be stably exhibited. The specific surface area is determined by the BET method (Brunauer, Emmett, Teller) by adsorbing nitrogen gas.
The ratio of the silicon oxide phase to the carbon material phase in the active material for the water electrolyte battery of the present embodiment is in the range of 0.2 ≤ silicon oxide / carbon material ≤ 2 in terms of the mass ratio of the silicon oxide to the carbon material. Is preferable. This is because, within this range, a large capacity and good cycle characteristics can be obtained as an active material.

According to the present embodiment described above, it is possible to provide an electrode active material for a non-aqueous electrolyte battery.
The electrode active material for a non-aqueous electrolyte battery according to the present embodiment is a composite particle containing silicon oxide particles represented by SiOx (1.8 ≦ x ≦ 2.2) and a carbon material. Silicon oxide particles in the IR spectrum measured by ATR method, a first peak having a maximum value in the range of 800～820Cm ^-1, a second peak having a maximum value in the range of 1030~1050cm ^-1, 1085 third peak having the maximum value in the range of ～1115Cm ^-1, and a fourth peak having the maximum value in the range of 1160～1210Cm ^-1, the area of the second peak, the first to fourth It is in the range of 10% or more and 75% or less with respect to the total area of the peaks of. It is presumed that the electrode active material for a non-aqueous electrolyte battery according to the present embodiment exhibits excellent discharge capacity and cycle characteristics because the silicon oxide particles have a characteristic surface structure showing the above IR spectrum.

(Second Embodiment)
In the second embodiment, electrodes for non-aqueous electrolyte batteries are provided.
As the electrode for the non-aqueous electrolyte battery according to the second embodiment, the electrode active material for the non-aqueous electrolyte battery of the first embodiment is used. Specifically, the electrode for a non-aqueous electrolyte battery according to the present embodiment has a current collector and an electrode mixture layer formed on one side or both sides of the current collector. The electrode mixture layer contains the electrode active material for a non-aqueous electrolyte battery of the first embodiment, a conductive agent, and a binder.
Hereinafter, the electrode for a non-aqueous electrolyte battery of this embodiment will be described as a negative electrode, but the non-aqueous electrode of this embodiment may be used as a positive electrode. Further, in the following description, the electrode according to the present embodiment will be described as being used for a non-aqueous electrolyte secondary battery, but the electrode according to the present embodiment can be used for various batteries.

The negative electrode according to the second embodiment will be specifically described with reference to FIG. FIG. 1 is a conceptual diagram of a negative electrode (electrode for a non-aqueous electrolyte battery) according to the second embodiment.
As shown in the conceptual diagram of FIG. 1, the negative electrode 100 of the second embodiment includes a negative electrode current collector 101 and a negative electrode mixture layer 102. The negative electrode mixture layer 102 is a layer of a mixture containing an active material arranged and formed on the surface of the negative electrode current collector 101. The negative electrode mixture layer 102 contains a negative electrode active material, a conductive material, and a binder. The binder joins the negative electrode mixture layer 102 and the current collector.

The thickness of the negative electrode mixture layer 102 is preferably in the range of 1.0 μm or more and 150 μm or less. Therefore, when the negative electrode current collector 101 is supported on both surfaces, the total thickness of the negative electrode mixture layer 102 is in the range of 2.0 μm or more and 300 μm or less. A more preferable range of the thickness of one side is 30 μm or more and 100 μm or less. Within this range, the large current discharge characteristics and cycle life are greatly improved.

The conductive material constituting the negative electrode mixture layer 102 has an effect of increasing the conductivity of the negative electrode, and is preferably dispersed in the negative electrode mixture layer 102. Examples of the conductive material include acetylene black, carbon black, and graphite. Various shapes such as scaly, crushed, and fibrous are used, and they may be used alone or in combination.

The binder constituting the negative electrode mixture layer 102 is a material having excellent binding properties between the negative electrode active materials and excellent bonding properties between the negative electrode mixture layer 102 and the negative electrode current collector 101. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), polyvinyl alcohol, polyvinyl acetate, polyacrylic acid, polyacrylic acid metal salt, polysaccharides such as alginic acid and cellulose, and derivatives thereof. , Ethylene-propylene-diene copolymer (EPDM), styrene-butadiene rubber (SBR), polyimide, polyaramid and the like can be used. Further, two or more kinds of binders may be used in combination as the binder, and the binder having excellent binding between active materials and the binding agent having excellent binding between the active material and the current collector. A negative electrode having excellent life characteristics can be produced by using a combination of the above and a combination of a high hardness one and an excellent flexibility one.
In the binder of the embodiment, the negative electrode mixture layer 102 and the negative electrode current collector 101 are bonded, but the negative electrode mixture layer 102 and the negative electrode current collector 101 are bonded by an azole compound or the like having an amino group as a substituent. It may be in the form of

When the composite particles containing the silicon oxide particles as the negative electrode active material and the carbon material are integrated with the current collector together with the binder, the negative electrode mixture layer 102 is peeled off from the negative electrode current collector 101, and further. By heating at 500 to 1100 ° C. in an oxygen-containing atmosphere, the binder and the carbon material can be decomposed, and an IR spectrum can be obtained for the remaining silicon oxide particles.
Further, when an electrode having composite particles containing silicon oxide particles and a carbon material is housed in a battery and has a charging history, the electrode is subjected to a constant current under the condition of an upper limit of 3.0 to 4.5 V in comparison with lithium potential. -Discharge at a constant voltage, peel the negative electrode mixture layer 102 from the negative electrode current collector 101, and further heat at 500 to 1100 ° C. in an oxygen-containing atmosphere to decompose the binder and carbonaceous material, and the remaining silicon oxidation. The IR spectrum can be obtained for the object particles. When the negative electrode current collector 101 is a copper foil, copper may elute when discharged at a voltage of 3.0 V or higher. Therefore, the negative electrode mixture layer 102 is peeled off from the negative electrode current collector 101 (copper foil) to be brought into close contact with an aluminum or titanium foil to prepare an electrode, and the obtained electrode is subjected to an upper limit of 3.0 to 4 in a lithium potential comparison. Decomposes the binder and carbonaceous material by discharging at a constant current and voltage under the condition of .5 V, peeling the negative electrode mixture layer 102 from the aluminum or titanium foil, and further heating at 500 to 1100 ° C. in an oxygen-containing atmosphere. Then, an IR spectrum can be obtained for the remaining silicon oxide particles.

The blending ratio of the negative electrode active material, the conductive agent and the binder in the negative electrode mixture layer 102 is 57% by mass or more and 95% by mass or less for the negative electrode active material, 3% by mass or more and 20% by mass or less for the conductive agent, and the binder. It is preferable to set it in the range of 2% by mass or more and 40% by mass or less in order to obtain good large current discharge characteristics and cycle life.

The negative electrode current collector 101 of the embodiment is a conductive member that binds to the negative electrode mixture layer 102. As the negative electrode current collector 101, a conductive substrate having a porous structure or a non-porous conductive substrate can be used. These conductive substrates can be formed from, for example, copper, stainless steel or nickel. The thickness of the current collector is preferably 5 μm or more and 20 μm or less. This is because the electrode strength and the weight reduction can be balanced within this range.

Next, a method of manufacturing the negative electrode 100 of the embodiment will be described.
First, the negative electrode active material, the conductive agent and the binder are suspended in a general-purpose solvent to prepare a slurry. The negative electrode 100 is produced by applying the slurry to the negative electrode current collector 101, drying the slurry, and then pressing the slurry. The embedding of the negative electrode active material in the negative electrode current collector 101 can be adjusted by the pressure of the press. Pressing at a pressure lower than 0.2 kN is not preferable because embedding may be difficult to occur. Further, pressing at a pressure higher than 10 kN is not preferable because the negative electrode active material and the negative electrode current collector 101 may be damaged such as cracking. Therefore, the press pressure of the layer in which the slurry is dried is preferably 0.5 kN or more and 5 kN or less.

According to the present embodiment described above, it is possible to provide an electrode for a non-aqueous electrolyte battery.
The electrode for a non-aqueous electrolyte battery according to the present embodiment has a current collector and an electrode mixture layer. The electrode mixture layer contains the electrode active material for a non-aqueous electrolyte battery, the conductive agent, and the binder according to the first embodiment described above. Therefore, the non-aqueous electrolyte battery to which the electrode for the non-aqueous electrolyte battery according to the present embodiment is applied exhibits high capacity and excellent cycle characteristics.

(Third Embodiment)
In the third embodiment, a non-aqueous electrolyte battery is provided.
As the non-aqueous electrolyte battery according to the third embodiment, the electrode for the non-aqueous electrolyte battery of the second embodiment is used. Specifically, the non-aqueous electrolyte battery according to the present embodiment is spatially separated from the exterior material, the positive electrode housed in the exterior material, and the positive electrode in the exterior material, and is stored, for example, with a separator interposed therebetween. The negative electrode is provided with a non-aqueous electrolyte filled in the exterior material. The electrode for a non-aqueous electrolyte battery of the second embodiment is used as a negative electrode.

It will be described in more detail with reference to the conceptual diagram of FIG. 2 showing an example of the non-aqueous electrolyte battery 200 according to the present embodiment. FIG. 2 is a conceptual cross-sectional view of a flat non-aqueous electrolyte battery 200 in which the bag-shaped exterior material 202 is made of a laminated film.
The flat wound electrode group 201 is housed in a bag-shaped exterior material 202 made of a laminated film in which an aluminum foil is interposed between two resin layers. The flat wound electrode group 201 is laminated in the order of the negative electrode 203, the separator 204, the positive electrode 205, and the separator 204, as shown in FIG. 3, which is an excerpted conceptual diagram. Then, it is formed by winding the laminate in a spiral shape and press-molding it. The electrode closest to the bag-shaped exterior material 202 is a negative electrode, and in this negative electrode, a negative electrode mixture is not formed on the negative electrode current collector on the bag-shaped exterior material 202 side, and the battery inner surface side of the negative electrode current collector It has a structure in which a negative electrode mixture is formed on only one side of the above. The other negative electrode 203 is configured by forming a negative electrode mixture on both sides of the negative electrode current collector. The positive electrode 205 is configured by forming a positive electrode mixture on both sides of the positive electrode current collector.

In the vicinity of the outer peripheral end of the wound electrode group 201, the negative electrode terminal is electrically connected to the negative electrode current collector of the outermost negative electrode 203, and the positive electrode terminal is electrically connected to the positive electrode current collector of the inner positive electrode 205. ing. These negative electrode terminals 206 and positive electrode terminals 207 extend outward from the opening of the bag-shaped exterior material 202. For example, the liquid non-aqueous electrolyte is injected through the opening of the bag-shaped exterior material 202. The wound electrode group 201 and the liquid non-aqueous electrolyte are completely sealed by heat-sealing the opening of the bag-shaped exterior material 202 with the negative electrode terminal 206 and the positive electrode terminal 207 sandwiched between them.

Examples of the negative electrode terminal 206 include aluminum or an aluminum alloy containing elements such as Mg, Ti, Zn, Mn, Fe, Cu, and Si. The negative electrode terminal 206 is preferably made of the same material as the negative electrode current collector in order to reduce the contact resistance with the negative electrode current collector.

For the positive electrode terminal 207, a material having electrical stability and conductivity in a potential range of 3 to 4.25 V with respect to the lithium ion metal can be used. Specific examples thereof include aluminum or an aluminum alloy containing elements such as Mg, Ti, Zn, Mn, Fe, Cu and Si. The positive electrode terminal 207 is preferably made of the same material as the positive electrode current collector in order to reduce the contact resistance with the positive electrode current collector.

Hereinafter, the bag-shaped exterior material 202, the positive electrode 205, the electrolyte, and the separator 204, which are constituent members of the non-aqueous electrolyte battery 200, will be described in detail.

1) Bag-shaped exterior material 202
The bag-shaped exterior material 202 is formed of a laminated film having a thickness of 0.5 mm or less. Alternatively, a metal container having a thickness of 1.0 mm or less is used as the exterior material. The metal container is more preferably 0.5 mm or less in thickness.

The shape of the bag-shaped exterior material 202 can be selected from a flat type (thin type), a square type, a cylindrical type, a coin type, and a button type. Examples of the exterior material include, for example, an exterior material for a small battery loaded on a portable electronic device or the like, an exterior material for a large battery loaded on a two-wheeled or four-wheeled automobile or the like, depending on the battery size.

As the laminated film, a multilayer film having a metal layer interposed between resin layers is used. The metal layer is preferably an aluminum foil or an aluminum alloy foil for weight reduction. As the resin layer, for example, a polymer material such as polypropylene (PP), polyethylene (PE), nylon, or polyethylene terephthalate (PET) can be used. The laminated film can be sealed into the shape of an exterior material by heat fusion.

The metal container is made of aluminum, an aluminum alloy, or the like. The aluminum alloy is preferably an alloy containing elements such as magnesium, zinc and silicon. When the alloy contains transition metals such as iron, copper, nickel and chromium, the amount thereof is preferably 100 mass ppm or less.

2) Positive electrode 205
The positive electrode 205 has a structure in which a positive electrode mixture containing an active material is supported on one side or both sides of a positive electrode current collector.
The thickness of one side of the positive electrode mixture is preferably in the range of 1.0 μm to 150 μm from the viewpoint of maintaining the large current discharge characteristics of the battery and the cycle life. Therefore, when it is supported on both sides of the positive electrode current collector, the total thickness of the positive electrode mixture is preferably in the range of 20 μm to 300 μm. A more preferred range for one side is 30 μm to 120 μm. Within this range, the large current discharge characteristics and cycle life are improved.

The positive electrode mixture may contain a conductive agent in addition to the binder that binds the positive electrode active material and the positive electrode active material to each other.
Examples of the positive electrode active material include various oxides such as manganese dioxide, lithium manganese composite oxide, lithium-containing nickel cobalt oxide (for example, LiCOO ₂ ), and lithium-containing nickel cobalt oxide (for example, LiNi _0.8 CO _0.2 O). ₂ ), Lithium-manganese composite oxide (for example, LiMn ₂ O ₄ , LiMn O ₂ ) is preferable because a high voltage can be obtained.

Examples of the conductive agent include acetylene black, carbon black, and graphite.
As specific examples of the binder, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), ethylene-propylene-diene copolymer (EPDM), styrene-butadiene rubber (SBR) and the like can be used. ..

The blending ratio of the positive electrode active material, the conductive agent and the binder is 80% by mass or more and 95% by mass or less of the positive electrode active material, 3% by mass or more and 20% by mass or less of the conductive agent, and 2% by mass or more and 7% by mass or less of the binder. The range is preferable because good high current discharge characteristics and cycle life can be obtained.

As the current collector, a conductive substrate having a porous structure or a non-porous conductive substrate can be used. The thickness of the current collector is preferably 5 μm or more and 20 μm or less. This is because the electrode strength and the weight reduction can be balanced within this range.
The positive electrode 205 is produced by, for example, suspending an active material, a conductive agent, and a binder in a general-purpose solvent to prepare a slurry, applying the slurry to a current collector, drying the slurry, and then pressing the slurry. Will be done. The positive electrode 205 may also be produced by forming an active material, a conductive agent, and a binder in the form of pellets to form a positive electrode layer, which is formed on a current collector.

3) Negative electrode 203
As the negative electrode 203, the negative electrode 100 described in the second embodiment is used.

4) Electrolyte As the electrolyte, a non-aqueous electrolyte solution, an electrolyte-impregnated polymer electrolyte, a polymer electrolyte, or an inorganic solid electrolyte can be used.
The non-aqueous electrolyte solution is a liquid electrolyte solution prepared by dissolving an electrolyte in a non-aqueous solvent, and is held in a void in the electrode group.
As the non-aqueous solvent, a non-aqueous solvent mainly composed of a mixed solvent of propylene carbonate (PC) or ethylene carbonate (EC) and a non-aqueous solvent having a viscosity lower than that of PC or EC (hereinafter referred to as a second solvent) is used. Is preferable.

As the second solvent, for example, chain carbon is preferable, and among them, dimethyl carbonate (DMC), methyl ethyl carbonate (MEC), diethyl carbonate (DEC), ethyl propionate, methyl propionate, γ-butyrolactone (BL), acetonitrile ( AN), ethyl acetate (EA), toluene, xylene, methyl acetate (MA) and the like. These second solvents can be used alone or in the form of a mixture of two or more. In particular, the number of donors of the second solvent is more preferably 16.5 or less.

The viscosity of the second solvent is preferably 2.8 cmp or less at 25 ° C. The blending amount of ethylene carbonate or propylene carbonate in the mixed solvent is preferably 1.0% to 80% by volume. A more preferable blending amount of ethylene carbonate or propylene carbonate is 20% to 75% by volume.

Examples of the electrolyte contained in the non-aqueous electrolyte solution include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiBF ₄ ), and lithium hexafluorophosphate (LiAsF ₆ ). , Lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), bistrifluoromethylsulfonylimide lithium [LiN (CF ₃ SO ₂ ) ₂ ] and other lithium salts (electrolytes). Of these, LiPF ₆ and LiBF ₄ are preferably used.
The amount of the electrolyte dissolved in the non-aqueous solvent is preferably 0.5 mol / L or more and 2.0 mol / L or less.

5) Separator 204
The separator 204 can be used when a non-aqueous electrolyte solution is used and when an electrolyte-impregnated polymer electrolyte is used. A porous separator is used as the separator 204. As the material of the separator 204, for example, polyethylene, polypropylene, a porous film containing polyvinylidene fluoride (PVdF), a non-woven fabric made of synthetic resin, or the like can be used. Of these, a porous film made of polyethylene, polypropylene, or both is preferable because it can improve the safety of the secondary battery.

The thickness of the separator 204 is preferably 30 μm or less. If the thickness exceeds 30 μm, the distance between the positive and negative electrodes may increase and the internal resistance may increase. The lower limit of the thickness is preferably 5 μm. If the thickness is less than 5 μm, the strength of the separator 204 may be significantly reduced and an internal short circuit may easily occur. The upper limit of the thickness is more preferably 25 μm, and the lower limit is more preferably 1.0 μm.

The separator 204 preferably has a heat shrinkage rate of 20% or less when left at 120 ° C. for 1 hour. If the heat shrinkage rate exceeds 20%, the possibility of a short circuit due to heating increases. The heat shrinkage rate is more preferably 15% or less.
The separator 204 preferably has a porosity in the range of 30 to 70%. This is due to the following reasons. If the porosity is less than 30%, it may be difficult to obtain high electrolyte retention in the separator 204. On the other hand, if the porosity exceeds 60%, sufficient separator 204 strength may not be obtained. A more preferred range of porosity is 35-70%.

The separator 204 preferably has an air transmittance of 500 seconds / 1.00 cm ³ or less. If the air transmittance exceeds 500 seconds / 1.00 cm ³ , it may be difficult to obtain high lithium ion mobility in the separator 204. The lower limit of the air transmittance is 30 seconds / 1.00 cm ³ . When the air permeability less than 30 seconds /1.00cm ^3, because there may not be obtained a sufficient separator strength.
The upper limit of the air transmittance is more preferably 300 seconds / 1.00 cm ³ , and the lower limit is more preferably 50 seconds / 1.00 cm ³ .

The non-aqueous electrolyte battery according to the third embodiment is not limited to the battery having the configuration shown in FIGS. 2 and 3 described above, and may be, for example, a battery having the configuration shown in FIGS. 4 and 5. FIG. 4 is a partially cutaway perspective view schematically showing another flat non-aqueous electrolyte battery according to the third embodiment, and FIG. 5 is an enlarged cross-sectional view of a portion B shown in FIG.

The non-aqueous electrolyte battery 300 shown in FIGS. 4 and 5 is configured such that the laminated electrode group 301 is housed in the exterior material 302. As shown in FIG. 5, the laminated electrode group 301 has a structure in which a positive electrode 303 and a negative electrode 304 are alternately laminated with a separator 305 interposed therebetween.

There are a plurality of positive electrode 303s, each of which includes a positive electrode current collector 303a and a positive electrode mixture layer 303b supported on both sides of the positive electrode current collector 303a. The positive electrode mixture layer 303b contains a positive electrode active material.

There are a plurality of negative electrode 304s, each of which includes a negative electrode current collector 304a and a negative electrode mixture layer 304b supported on both sides of the negative electrode current collector 304a. The negative electrode mixture layer 304b contains a negative electrode active material. One side of the negative electrode current collector 304a of each negative electrode 304 protrudes from the negative electrode 304. The protruding negative electrode current collector 304a is electrically connected to the strip-shaped negative electrode terminal 306. The tip of the strip-shaped negative electrode terminal 306 is pulled out from the exterior material 302. Further, although not shown, in the positive electrode current collector 303a of the positive electrode 303, a side located on the opposite side to the protruding side of the negative electrode current collector 304a protrudes from the positive electrode 303. The positive electrode current collector 303a protruding from the positive electrode 303 is electrically connected to the band-shaped positive electrode terminal 307. The tip of the strip-shaped positive electrode terminal 307 is located on the side opposite to the negative electrode terminal 306, and is drawn out from the side of the exterior material 302.

The materials, compounding ratios, dimensions, etc. of the members constituting the non-aqueous electrolyte battery 300 shown in FIGS. 4 and 5 are the same as those of the components of the non-aqueous electrolyte battery 200 described in FIGS. 2 and 3. ..

According to the present embodiment described above, a non-aqueous electrolyte battery can be provided.
The non-aqueous electrolyte battery according to the present embodiment includes a negative electrode, a positive electrode, a non-aqueous electrolyte, a separator, and an exterior material. The negative electrode is formed by using the electrode active material for a non-aqueous electrolyte battery according to the second embodiment described above. Therefore, the non-aqueous electrolyte battery according to the present embodiment exhibits high capacity and excellent cycle characteristics.

(Fourth Embodiment)
Next, the battery pack according to the fourth embodiment will be described.
The battery pack according to the fourth embodiment has one or more non-aqueous electrolyte batteries (that is, single batteries) according to the third embodiment. When the battery pack contains a plurality of cells, each cell is electrically connected in series, in parallel, or connected in parallel with the series.

The battery pack according to the fourth embodiment may further include a protection circuit. The protection circuit controls the charging / discharging of the non-aqueous electrolyte battery. Alternatively, a circuit included in a device that uses the battery pack as a power source (for example, an electronic device, an automobile, etc.) can be used as a protection circuit of the battery pack.
Further, the battery pack according to the fourth embodiment may further include an external terminal for energization. The external terminal for energization is for outputting the current from the non-aqueous electrolyte battery to the outside and for inputting the current to the non-aqueous electrolyte battery. In other words, when the battery pack is used as a power source, current is supplied to the outside through an external terminal for energization. Further, when charging the battery pack, the charging current (including the regenerative energy of the power of the automobile) is supplied to the battery pack through the external terminal for energization.

The battery pack according to the fourth embodiment will be specifically described with reference to FIGS. 6 and 7. FIG. 6 is a conceptual diagram of the battery pack according to the fourth embodiment, and FIG. 7 is a block diagram showing an electric circuit of the battery pack according to the fourth embodiment. In the battery pack 400 shown in FIG. 6, the flat non-aqueous electrolyte battery 200 shown in FIG. 2 is used as the cell 401.

The plurality of cell cells 401 are laminated so that the negative electrode terminals 206 and the positive electrode terminals 207 extending to the outside are aligned in the same direction, and are fastened with adhesive tape 402 to form the assembled battery 403. These cell units 401 are electrically connected in series with each other as shown in FIGS. 6 and 7.

The printed wiring board 404 is arranged so as to face the side surface of the cell 401 in which the negative electrode terminal 206 and the positive electrode terminal 207 extend. As shown in FIG. 7, the printed wiring board 404 is equipped with a thermistor 405, a protection circuit 406, and a terminal 407 for energizing an external device. An insulating plate (not shown) is attached to the surface of the printed wiring board 404 facing the assembled battery 403 in order to avoid unnecessary connection with the wiring of the assembled battery 403.

The positive electrode side lead 408 is connected to the positive electrode terminal 207 located at the bottom layer of the assembled battery 403, and the tip thereof is inserted into the positive electrode side connector 409 of the printed wiring board 404 and electrically connected. The negative electrode side lead 410 is connected to the negative electrode terminal 206 located on the uppermost layer of the assembled battery 403, and the tip thereof is inserted into the negative electrode side connector 411 of the printed wiring board 404 and electrically connected. The positive electrode side connector 409 and the negative electrode side connector 411 are connected to the protection circuit 406 through the wirings 412 and 413 formed on the printed wiring board 404.

The thermistor 405 is used to detect the temperature of the cell 401, and although not shown in FIG. 6, it is provided in the vicinity of the cell 401 and its detection signal is transmitted to the protection circuit 406. .. The protection circuit 406 controls the charging / discharging of the cell 401 in order to protect the battery pack. The positive side wiring 414a and the negative side wiring 414b between the protection circuit 406 and the energizing terminal 407 to the external device can be cut off under predetermined conditions. The predetermined condition is, for example, when the detection temperature of the thermistor 405 becomes equal to or higher than the predetermined temperature. Further, the predetermined condition is when overcharge, overdischarge, overcurrent, etc. of the cell 401 are detected. The detection of overcharging or the like is performed for each individual cell 401 or the entire cell 401. When detecting the individual cell 401, the battery voltage may be detected, or the positive electrode potential or the negative electrode potential may be detected. In the latter case, a lithium electrode used as a reference electrode is inserted into each cell 401. In the case of FIGS. 8 and 9, a wiring 415 for voltage detection is connected to each of the cell units 401, and a detection signal is transmitted to the protection circuit 406 through these wirings 415.

As shown in FIG. 6, protective sheets 416 made of rubber or resin are arranged on the three side surfaces of the assembled battery 403 except for the side surfaces on which the positive electrode terminal 207 and the negative electrode terminal 206 project.

The assembled battery 403 is housed in the storage container 417 together with each protective sheet 416 and the printed wiring board 404. That is, the protective sheet 416 is arranged on both inner side surfaces in the long side direction and the inner side surface in the short side direction of the storage container 417, and the printed wiring board 404 is placed on the inner side surface opposite to the protective sheet 416 in the short side direction. Be placed. The assembled battery 403 is located in the space surrounded by the protective sheet 416 and the printed wiring board 404. The lid 418 is attached to the upper surface of the storage container 417.

A heat-shrinkable tape may be used instead of the adhesive tape 402 to fix the assembled battery 403. In this case, protective sheets are arranged on both side surfaces of the assembled battery, the heat-shrinkable tape is circulated, and then the heat-shrinkable tape is heat-shrinked to bind the assembled battery.

6 and 7 show the form in which the cell units 401 are connected in series, but in order to increase the battery capacity, the cell cells 401 may be connected in parallel or a combination of series connection and parallel connection may be used. Good. The assembled battery packs can also be connected in series or in parallel.

The mode of the battery pack is appropriately changed depending on the application. The battery pack is preferably used to exhibit excellent cycle characteristics when a large current is taken out. Specific examples thereof include a power source for a digital camera and an in-vehicle use for a vehicle such as a two-wheel to four-wheel hybrid electric vehicle, a two-wheel to four-wheel electric vehicle, and an assisted bicycle. In particular, a battery pack using a non-aqueous electrolyte secondary battery having excellent high temperature characteristics is suitably used for in-vehicle use. In a vehicle equipped with a battery pack, the battery pack recovers, for example, the regenerative energy of the power of the automobile.

According to the present embodiment described above, a battery pack can be provided.
The battery pack according to the present embodiment includes at least one non-aqueous electrolyte battery according to the third embodiment. Therefore, the battery pack according to the present embodiment exhibits high capacity and excellent cycle characteristics.

According to at least one embodiment described above, the electrode active material for a non-aqueous electrolyte battery is a composite containing silicon oxide particles represented by SiOx (1.8 ≦ x ≦ 2.2) and a carbon material. It is a particle. Silicon oxide particles in the IR spectrum measured by ATR method, a first peak having a maximum value in the range of 800～820Cm ^-1, a second peak having a maximum value in the range of 1030~1050cm ^-1, 1085 third peak having the maximum value in the range of ～1115Cm ^-1, and a fourth peak having the maximum value in the range of 1160～1210Cm ^-1, the area of the second peak, the first to fourth It is in the range of 10% or more and 75% or less with respect to the total area of the peaks of. In the present embodiment, the silicon oxide particles have a characteristic surface structure showing the above IR spectrum, so that the electrode active material for a non-aqueous electrolyte battery and the non-aqueous electrolyte battery are excellent in discharge capacity and cycle characteristics. Electrodes, non-aqueous electrolyte batteries and battery packs can be realized.

Specific examples will be given below, and the effects will be described. However, the present invention is not limited to these examples.

(Example 1)
Tetraethoxysilane was mixed with water, the resulting white precipitate was filtered, dried and then calcined at 1000 ° C. to give a silicon oxide powder. The obtained silicon oxide powder was a silicon oxide powder having a composition of SiO ₂ . Further, according to SEM observation, the average particle size of the obtained silicon oxide powder by the particle size distribution meter was 120 nm. Example 1 is a reference example of the present invention.

The obtained silicon oxide powder (1.2 g), graphite powder (0.3 g), furfuryl alcohol (2.4 g), and ethanol (20 g) were kneaded to form a slurry, and 0.5 g of dilute hydrochloric acid was further added and left at room temperature. The obtained mass was dried by heating, fired at 1100 ° C. in an Ar atmosphere for 1 hour, cooled, and then pulverized, and classified into a diameter of 10 μm or less to obtain an electrode active material.

The obtained electrode active material was heated in air at 600 ° C. for 5 hours to obtain a white silicon oxide powder. The IR spectrum of the obtained white silicon oxide powder was measured by the ATR method. By the IR spectrum obtained by the ATR method was treated with Origin (TM) as abscissa linear wavenumber corrects the absorbance of 900 cm ^-1 and 1300 cm ^-1 as a baseline, to peaks separated by a Gaussian function, 809cm ^-1 It was separated into four peaks with maximum values at (first peak), 1048 cm ^-1 (second peak), 1101 cm ^-1 (third peak), and 1166 cm ^-1 (fourth peak). When the second peak area was converted into the ratio of the four peak areas to the total value, it was 55%. Absorbance at 900 cm ^-1 and 1300 cm ^-1 in the case of the maximum peak absorbance in the region of the base line before correction 600～1500Cm ^-1 and 1 was 0.02.
The average particle size of the white silicon oxide powder measured by the particle size distribution meter was 120 nm.

0.6 g of the obtained electrode active material is mixed with 0.1 g of graphite having an average particle size of 3 μm, and the polyimide is mixed with a solution dissolved in an N-methylpyrrolidone dispersion medium so as to have 16% by mass, and a rotation / revolution mixer is used. Used and mixed. The obtained paste-like slurry was applied onto a copper foil having a thickness of 12 μm, rolled, and then heat-treated at 400 ° C. for 2 hours in Ar gas to obtain an electrode.

The electrode was cut into a size of 20 mm × 20 mm and then vacuum dried at 100 ° C. for 12 hours to prepare a test electrode. A battery in which the counter electrode and the reference electrode are metallic Li and the electrolytic solution is an EC / DEC (volume ratio EC: DEC = 1: 2) solution of LiN (CF ₃ SO ₂ ) ₂ (1M) is prepared in an argon atmosphere and charged / discharged. The test was conducted.
The conditions of the charge / discharge test were to charge with a constant current of 1 mA up to a potential difference of 0.01 V between the reference electrode and the test electrode, and then charge with a constant voltage (CC / CV charging). Discharge was performed up to 1.5 V with a constant current of 1 mA (CC discharge). After that, the cycle of charging with a constant current of 6 mA to a potential difference of 0.01 V between the reference electrode and the test electrode, then charging with a constant voltage, and discharging to 1.5 V with a constant current of 6 mA was repeated 100 times, and at this 6 mA. The ratio of the 100th discharge capacity to the 1st discharge capacity of the charge / discharge of the above was taken as the discharge capacity retention rate. The discharge capacity retention rate of the obtained battery was 94%. The discharge capacity retention rate was calculated from the following formula.
Discharge capacity retention rate (%) = (100th discharge capacity) / (1st discharge capacity) x 100

Only the parts different from those of Example 1 will be described with respect to the following Examples and Comparative Examples, and the other synthesis and evaluation procedures have been carried out in the same manner as in Example 1, and thus the description thereof will be omitted.

(Example 2)
Sodium silicate was dissolved in water, hydrochloric acid was added, and the white precipitate formed was filtered, dried, and calcined at 1000 ° C. to obtain a silicon oxide powder. The obtained silicon oxide powder was a silicon oxide powder having a composition of SiO ₂ . Further, according to SEM observation, the particle size of the obtained silicon oxide powder was 30 nm.
From the obtained silicon oxide powder, an electrode active material / battery was prepared by the same method as in Example 1. The discharge capacity retention rate of the obtained battery was 96%. Example 2 is a reference example of the present invention.

Further, the obtained electrode active material was oxidized by the same method as in Example 1 to obtain a silicon oxide powder, and the second peak area calculated from the IR spectrum was applied to the total value of the four peak areas. When converted to a ratio, it was 11%. Absorbance at 900 cm ^-1 and 1300 cm ^-1 in the case of the maximum peak absorbance in the region of the base line before correction 600～1500Cm ^-1 and 1 was 0.07. The average particle size measured by the particle size distribution meter was 30 nm.

(Example 3)
Sodium silicate was dissolved in water, hydrochloric acid was added, and the white precipitate formed was filtered, dried, and calcined at 1000 ° C. to obtain a first silicon oxide powder. The first silicon oxide powder obtained was a silicon oxide powder having a composition of SiO _2.1 . Further, according to SEM observation, the particle size of the obtained first silicon oxide was 30 nm.
Tetraethoxysilane was mixed with water, and the resulting white precipitate was filtered, dried, and calcined at 1000 ° C. to obtain a second silicon oxide powder. The second silicon oxide powder obtained was a silicon oxide powder having a composition of SiO ₂ . Further, according to SEM observation, the particle size of the obtained second silicon oxide was 120 nm.
The first silicon oxide and the second silicon oxide were mixed in the same weight to prepare an electrode active material / battery by the same method as in Example 1. The discharge capacity retention rate of the obtained battery was 95%.

The obtained electrode active material was oxidized by the same method as in Example 1 to obtain a silicon oxide powder, and the second peak area calculated from the IR spectrum was set as a ratio to the total value of the four peak areas. When converted, it was 26%. Absorbance at 900 cm ^-1 and 1300 cm ^-1 in the case of the maximum peak absorbance in the region of the base line before correction 600～1500Cm ^-1 and 1 was 0.04. Moreover, according to the particle size distribution meter, it had two peaks at a particle size of 30 nm and 120 nm.

(Example 4)
Silicon chloride was injected into a hydrogen flame to obtain a silicon oxide powder. The obtained silicon oxide powder was a silicon oxide powder having a composition of SiO ₂ . Further, according to SEM observation, the particle size of the obtained silicon oxide powder was 20 nm.
From the obtained silicon oxide powder, an electrode active material / battery was prepared by the same method as in Example 1. The discharge capacity retention rate of the obtained battery was 90%. Example 4 is a reference example of the present invention.

The obtained electrode active material was oxidized by the same method as in Example 1 to obtain a silicon oxide powder, and the second peak area calculated from the IR spectrum was set as a ratio to the total value of the four peak areas. When converted, it was 11%. Absorbance at 900 cm ^-1 and 1300 cm ^-1 in the case of the maximum peak absorbance in the region of the base line before correction 600～1500Cm ^-1 and 1 was 0.07. The average particle size measured by the particle size distribution meter was 20 nm.

(Comparative Example 1)
Sodium silicate was dissolved in water, hydrochloric acid was added, and the white precipitate formed was filtered, dried, calcined at 1400 ° C., and then pulverized to obtain a silicon oxide powder. The obtained silicon oxide powder was a silicon oxide powder having a composition of SiO ₂ . Further, according to SEM observation, the particle size of the silicon oxide was 200 nm.
From the obtained silicon oxide, an electrode active material / battery was prepared by the same method as in Example 1. The discharge capacity retention rate of the obtained battery was 81%.
The obtained electrode active material was oxidized in the same manner as in Example 1 to obtain a silicon oxide powder. And IR spectrum, Origin (TM) treated to correct the absorbance at 900 cm ^-1 and 1300 cm ^-1 as the baseline, were peaks separated by a Gaussian function, a peak in the range of 800~820cm ^-1 (first Peak) did not exist. Absorbance of 900 cm ^-1 in the case where the absorbance of the maximum peak was 1 in the region of the base line before correction 600～1500Cm ^-1 is the absorbance is 0.05 at 0.3,1300cm ^-1, 800~820cm ^-1 The absorbance of was negative from the baseline.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

100 ... Negative electrode, 101 ... Negative electrode current collector, 102 ... Negative electrode mixture layer, 200 ... Non-aqueous electrolyte battery, 201 ... Winding electrode group, 202 ... Bag-shaped exterior material, 203 ... Negative electrode, 203a ... Negative electrode current collector, 203b ... Negative electrode mixture layer, 204 ... Separator, 205 ... Positive electrode, 205a ... Positive electrode current collector, 205b ... Positive electrode mixture layer, 206 ... Negative electrode terminal, 207 ... Positive electrode terminal, 300 ... Non-aqueous electrolyte battery, 301 ... Laminated type Electrode group, 302 ... Exterior material, 303 ... Positive electrode, 303a ... Positive electrode current collector, 303b ... Positive electrode mixture layer, 304 ... Negative electrode, 304a ... Negative electrode current collector, 304b ... Negative electrode mixture layer, 305 ... Separator, 306 ... Negative electrode terminal, 307 ... Positive electrode terminal, 400 ... Battery pack, 401 ... Single cell, 402 ... Adhesive tape, 403 ... Assembly battery, 404 ... Printed wiring board, 405 ... Thermista, 406 ... Protection circuit, 407 ... Energizing terminal, 408 ... Positive electrode side lead, 409 ... Positive electrode side connector, 410 ... Negative electrode side lead, 411 ... Negative electrode side connector, 412 ... Wiring, 413 ... Wiring, 414a ... Positive side wiring, 414b ... Minus side wiring, 415 ... Wiring, 416 ... Protection Sheet, 417 ... Storage container, 418 ... Lid

Claims (10)

It contains silicon oxide particles represented by SiOx (1.8 ≦ x ≦ 2.2) and a carbon material.
The silicon oxide particles are dispersed in the carbon material, and the silicon oxide particles are dispersed in the carbon material.
In the infrared absorption spectrum measured by the total reflection measurement method, the silicon oxide particles have a first peak having a maximum value in the range of 800 to 820 cm ^-1 , and a first peak having a maximum value in the range of 1030 to 1050 cm ^-1 . second peak, a fourth peak having the maximum value in the range of the third peak, and 1160～1210Cm ^-1 having a maximum value in the range of 1085～1115Cm ^-1,
The area of the second peak, Ri said first to fourth total of 75% or less near 10% or more with respect to the area of the peak,
The silicon oxide particles are
The first region, and a particle size that have a particle size distribution having a peak in each of the second regions in the range of 100nm or more 600nm or less non-aqueous electrolyte battery electrode having a particle size in the range of less than 100nm or 20nm Active material. The carbon material is
The electrode active material for a non-aqueous electrolyte battery according to claim 1, wherein the crystal plane spacing d002 measured by the powder X-ray diffraction method is in the range of 0.337 nm or more and 0.430 nm or less. Further, it contains silicon particles represented by SiOy (y ≦ 0.2), and contains silicon particles.
When the average particle size of the silicon oxide particles is D1 and the average particle size of the silicon particles is D2, D2 / D1, which is the ratio of D2 to D1, is in the range of 0.5 or more and 0.8 or less. Item 2. The electrode active material for a non-aqueous electrolyte battery according to Item 1 or 2 . The electrode active material for a non-aqueous electrolyte battery according to any one of claims 1 to 3 , which contains the silicon oxide particles in a range of 40% by mass or more and 80% by mass or less. The electrode active material for a non-aqueous electrolyte battery according to any one of claims 1 to 4 , further comprising silicon carbide. A current collector and an electrode mixture layer formed on one side or both sides of the current collector are provided.
An electrode for a non-aqueous electrolyte battery, wherein the electrode mixture layer contains the electrode active material for a non-aqueous electrolyte battery, a conductive agent, and a binder according to any one of claims 1 to 5 . The exterior material, the positive electrode housed in the exterior material, the negative electrode stored in the exterior material with a separator spatially separated from the positive electrode, and the non-filled in the exterior material. Equipped with water electrolyte,
The negative electrode is a non-aqueous electrolyte battery comprising the electrode for the non-aqueous electrolyte battery according to claim 6 . A battery pack comprising the non-aqueous electrolyte battery according to claim 7 . The battery pack according to claim 8 , further comprising an external terminal for energization and a protection circuit. A vehicle comprising the battery pack according to claim 8 or 9 .

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