JP6634318B2 - Active material for non-aqueous electrolyte battery, electrode for non-aqueous electrolyte battery, non-aqueous electrolyte battery and battery pack - Google Patents

Description

  Embodiments of the present invention relate to an 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.

2. Description of the Related Art In recent years, various portable electronic devices have been spreading due to rapid development of technology for miniaturizing electronic devices. In addition, there is a demand for miniaturization of a battery as a power source of these portable electronic devices, and a non-aqueous electrolyte secondary battery having a high energy density has attracted attention.
In particular, attempts have been made to use a substance having a large lithium storage capacity and a high density, such as an element which alloys with lithium such as silicon and tin, and an amorphous chalcogen compound. Above all, silicon can occlude lithium up to a ratio of 4.4 lithium atoms to 1 silicon atom. For this reason, when used as a negative electrode material of a non-aqueous electrolyte secondary battery, the negative electrode capacity per mass is about ten times as large as when conventionally used graphitic carbon is used as a negative electrode material. However, silicon has a large change in volume due to insertion and desorption of lithium in a charge and discharge cycle, and has a problem in cycle characteristics such as pulverization of active material particles.

In order to solve the above-mentioned problems, studies have been made to achieve an increase in capacity and an improvement in cycle characteristics by using an active material in which silicon oxide particles and a carbonaceous material are combined.
However, even with such an active material, compatibility between high capacity and cycle characteristics is insufficient, and further improvement in capacity and compatibility with cycle characteristics are required.

JP 2004-119176 A JP 2014-2890 A JP 2012-14939 A JP 2013-73920 A JP 2013-219059 A

  An object of the present invention is to provide an 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 which are excellent in high capacity and cycle characteristics.

The active material for a nonaqueous electrolyte battery according to the embodiment has silicon oxide particles and a carbonaceous material. The silicon oxide particles are composed of silicon and silicon oxide, or silicon oxide, and have a composition formula represented by SiOx (0.1 ≦ x ≦ 2). The average primary particle size of the silicon oxide particles is 3 nm or more and 50 nm or less. In the active material for a nonaqueous electrolyte battery of the embodiment, in the type II desorption isotherm in the pore distribution measurement by the N ₂ adsorption method, the first measurement point where P / P ₀ is larger than 0.5 and P / P ₀ are The slope a of the straight line connecting the first measurement points smaller than 0.7 is negative.

2 is an image taken by a transmission electron microscope of a cross section of the active material for a nonaqueous electrolyte battery according to the first embodiment. 3 is an adsorption / desorption isotherm in pore distribution measurement of the active material for a non-aqueous electrolyte battery according to the first embodiment by the N ₂ adsorption method. The conceptual diagram of the electrode which concerns on 2nd Embodiment. FIG. 9 is a sectional view showing an example of a nonaqueous electrolyte battery according to a third embodiment. FIG. 5 is an enlarged sectional view of a portion A shown in FIG. 4. FIG. 13 is a partially cutaway perspective view showing another example of the nonaqueous electrolyte battery according to the third embodiment. FIG. 7 is an enlarged sectional view of a part B shown in FIG. 6. FIG. 9 is a conceptual diagram of a battery pack according to a fourth embodiment. FIG. 10 is a block diagram showing an electric circuit of a battery pack according to a fourth embodiment. 9 is an adsorption / desorption isotherm in the pore distribution measurement of the negative electrode active material obtained in Example 5 by an N ₂ adsorption method. 9 is an adsorption / desorption isotherm in the pore distribution measurement of the negative electrode active material obtained in Comparative Example 4 by the N ₂ adsorption method.

  Hereinafter, an 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 of the embodiment will be described with reference to the drawings.

(First embodiment)
In the first embodiment, an active material for a non-aqueous electrolyte battery is provided.
The active material for a non-aqueous electrolyte battery of the first embodiment (hereinafter also referred to as “active material”) includes silicon oxide particles and a carbonaceous material. The silicon oxide particles are composed of silicon and silicon oxide, or silicon oxide, and have a composition formula represented by SiOx (0.1 ≦ x ≦ 2).

The present inventors have come to the idea that the pore morphology of the conventionally studied active material containing silicon oxide particles and carbonaceous material greatly affects the life characteristics. Then, as a result of examining the relationship, it has been found that an active material having a pore morphology exhibiting a specific characteristic in the N ₂ adsorption method can obtain high life characteristics.
The active material for a non-aqueous electrolyte battery of the present embodiment has the first measurement point where P / P ₀ is larger than 0.5 and P / P ₀ is 0. ₀ in the desorption isotherm in the pore distribution measurement by the N ₂ adsorption method. The slope a of the straight line connecting the first measurement points smaller than 7 becomes negative.

  Hereinafter, the active material for a non-aqueous electrolyte battery of the present embodiment will be described as an active material used for an active material mixture layer of a negative electrode of a non-aqueous electrolyte battery. It can be used also as an active material used for. Further, an electrode using an active material will be described as being used for a non-aqueous electrolyte secondary battery, but the electrode using an active material of the embodiment can be used for various batteries.

  The carbonaceous material used in the present embodiment contains at least amorphous carbon. The silicon oxide particles described below are dispersed in the carbonaceous material. Preferably, a carbonaceous material is present around the silicon oxide particles.

FIG. 1 shows the active material of this embodiment. FIG. 1 is a TEM (Transmission Electron Microscope) image of a cross section of the active material. In FIG. 1, silicon oxide particles 1 are shown in a dark color, and carbonaceous material 2 is shown in a light color. FIG. 1 shows a part of the cross section of the active material, and a portion 3 without silicon oxide particles on the lower side of FIG. 1 is outside the active material.
An image as shown in FIG. 1 is obtained by preparing a negative electrode including the active material of the present embodiment, and performing TEM observation after pretreatment by an ion milling method so that a cut surface of the prepared active material mixture layer of the negative electrode becomes smooth. It can be obtained by doing. The reason for preparing the negative electrode for observing the active material is that the active material is preferably fixed in order to apply the ion milling method for smoothing the cross section of the active material, and the form of the negative electrode is suitable. It is. However, a form other than the negative electrode may be used as long as the ion milling method can be applied, and another method may be used as long as a smooth cross section of the active material capable of TEM observation can be formed. The fact that the carbonaceous material 2 around the obtained silicon oxide particles 1 is amorphous carbon can be measured by using a TEM-EDX method after pretreating the electrode by the same method as described above. Specifically, silicon oxide particles and portions other than the silicon oxide particles are grasped by observing the inside of the active material with a TEM, and elemental analysis by spot analysis is performed on the portions other than the silicon oxide particles by EDX. TEM-EDX measurement conditions are an acceleration voltage of 200 kV and a beam diameter of about 1 nm. Whether the carbonaceous material 2 is amorphous carbon can be determined by the absence of a crystal lattice in the TEM image. As a result of the measurement, if there is a portion other than the silicon oxide particles 1 that is amorphous and contains 90 atomic% or more of carbon, the portion is determined to be amorphous carbon. Note that the carbon content is not always 100 atomic% because, in the analysis by the TEM-EDX method, minute impurities mixed during the production of the active material are detected, or the amount of amorphous carbon with respect to the silicon oxide particles is small. In some cases, substances around the amorphous carbon are detected at the same time.

  The carbonaceous material 2 may include a conductive carbonaceous material other than amorphous carbon. As such a carbonaceous material, one or more selected from the group consisting of graphite, hard carbon, soft carbon, carbon nanofiber, carbon nanotube and carbon black can be used. These are preferable in that they increase the conductivity of the active material or make it easier to suppress deformation of the active material particles during charge and discharge as an internal skeleton of the active material. The conductive carbonaceous material is used to impart conductivity to the negative electrode material. As these conductive carbonaceous substances, these substances may be used alone, or a plurality of substances may be used in combination. The conductive carbonaceous material is not particularly limited, but fibrous carbon having an aspect ratio of 10 or more is particularly preferable. As the fibrous carbon, a fibrous carbon nanotube (CNT) -based carbon material or the like is used. The average diameter of the fibrous carbon is preferably 5 nm or more and 1000 nm or less, more preferably 7 nm or more and 100 nm or less. If the content of the fibrous carbon is too large, the battery capacity is reduced. Therefore, the content of the fibrous carbon is preferably 5% by mass or less in the negative electrode active material.

  The silicon oxide particles 1 used in the present embodiment are composed of silicon and silicon oxide, or silicon oxide, and are represented by a composition formula SiOx (0.1 ≦ x ≦ 2). Particles of SiOx in which the value of x is less than 0.1 are substantially composed of only silicon, and it is very difficult to exist even in the vicinity of the particle surface without being oxidized in air. Further, silicon dioxide is well known as a stable silicon oxide, and an oxide of SiOx in which the value of x exceeds 2 is unstable. It is desirable that the value of x of SiOx is 2, that is, SiOx is silicon dioxide. This is because silicon dioxide has the most stable composition among silicon oxides, the particle diameter and structure of the raw material are easily controlled, and it is hard to change in the production process of the active material.

  The fact that the particles are silicon oxide particles 1 is determined by detecting elements of silicon and oxygen as a result of the measurement by the TEM-EDX method described above, and the value of x of SiOx can be obtained by the same measurement. When the silicon oxide particles are composed of silicon and silicon oxide, a plurality of points in the silicon oxide particles, desirably 10 points, are arbitrarily selected and measured. Make sure it is included and take its average. In addition, when the active material contains only a small amount of about 1% by weight or less other than the silicon oxide particles and the carbonaceous material, the value of x of SiOx can be obtained more accurately by elemental composition analysis. . Specifically, the content ratio of silicon atoms in the active material is determined by acid decomposition-ICP emission spectroscopy, and the content ratio of oxygen atoms is determined by inert gas fusion-infrared absorption method, and the atomic molar ratio of Si and O is determined. calculate. Although the upper limit of x of SiOx in the present embodiment is 2, the value of x may exceed 2 due to a measurement error in the measurement of silicon dioxide. Therefore, a difference of about 10% is allowed, and the case where x of SiOx is 2.2 as a result of the measurement is also included in the present embodiment.

  The average primary particle size of the silicon oxide particles 1 is desirably 3 nm or more and 50 nm or less. If the average primary particle size is too small, the dispersion in the carbonaceous material 2 becomes uneven, and the active material is cracked due to local generation of internal stress during charge / discharge when used as the active material of the nonaqueous electrolyte secondary battery. It will be easier. On the other hand, if the average primary particle size is too large, the diffusion of lithium into the inside of the silicon oxide particles will be slow, making it difficult for charging and discharging to proceed. A more desirable average particle size is 5 nm or more and 30 nm or less, and more preferably 5 nm or more and 15 nm or less. The average primary particle diameter of such silicon oxide particles is determined by observing the active material by the above-described TEM and randomly selecting each of the silicon oxide particles on the 10 randomly selected in the obtained image. The average value of the sizes in the ten directions is calculated. Here, it is assumed that it is confirmed after selecting at random that ten directions mentioned here do not overlap in the same direction. However, it is permissible to include silicon oxide particles out of this particle size range to the extent that battery performance is not affected.

Further, lithium silicate such as Li ₄ SiO ₄ may be dispersed on the surface of silicon constituting silicon oxide particles 1 or on the surface or inside of silicon oxide. The silicon oxide particles containing the lithium silicate are, for example, heat-treated silicon or a mixture containing the silicon oxide and the lithium salt constituting the silicon oxide particles 1 to react the silicon or the silicon oxide with the lithium salt. To form a lithium silicate. As the lithium salt, lithium hydroxide, lithium acetate, lithium oxide, lithium carbonate and the like can be used. Further, the surface of the silicon oxide particles may contain an additive other than lithium silicate.

The active material of the present embodiment is a particle that inserts and desorbs Li, and has an average primary particle size of 0.5 μm to 100 μm and a specific surface area of 0.5 m ² / g to 100 m ² / g. . The particle size and specific surface area of the active material affect the rate of lithium insertion / desorption reaction, and greatly affect the characteristics of the negative electrode. When the average primary particle size and the specific surface area are within the above ranges, the active material can exhibit stable characteristics. In particular, the average primary particle size is preferably 1 μm or more and 80 μm or less, and more preferably 3 μm or more and 30 μm or less. The particle size of the active material affects the speed of the lithium insertion / desorption reaction, and has a large effect on the negative electrode characteristics. However, if the value is within this range, the characteristics can be exhibited stably. At the same time, when performing coating on the current collector, problems such as aggregation and current collector deformation hardly occur. The average primary particle size of the active material was determined by observing the active material with a scanning electron microscope (SEM), and determining the average primary particle size for each of 50 or more active materials randomly selected from the obtained images. The average value of the sizes in the ten directions selected by the user is calculated. Here, it is assumed that it is confirmed after selecting at random that ten directions mentioned here do not overlap in the same direction.
Further, in order to maintain the structure of the active material particles and prevent aggregation of the silicon oxide particles, the active material preferably contains zirconia or stabilized zirconia. There is an advantage that the cycle characteristics are improved by preventing the aggregation of the silicon oxide particles.

In the active material according to the present embodiment, in the desorption isotherm in the pore distribution measurement by the N ₂ adsorption method, the first measurement point where P / P ₀ is larger than 0.5 and the first measurement point where P / P ₀ is smaller than 0.7 A negative electrode active material for a non-aqueous electrolyte battery, characterized in that the slope a of a straight line connecting measurement points is negative. Further, in the above desorption isotherms, P / P ₀ is located the measuring point and the P / P ₀ of the beginning is greater than 0.3 is the slope of the straight line a 'connecting the measurement points smaller than 0.5 initially plus And the absolute value of the gradient a ′ is larger than the absolute value of the gradient a.

FIG. 2 shows an example of the adsorption / desorption isotherm in the pore distribution measurement of the active material of the present embodiment by the N ₂ adsorption method. There are two lines connecting the measurement points, upper and lower, the upper line is the desorption isotherm, and the lower line is the adsorption isotherm. Regarding P / P ₀ on the horizontal axis, P ₀ indicates a saturated vapor pressure, and P / P ₀ indicates a relative pressure (dimensionless number) by making the unit of pressure P at the measurement point the same as P ₀ . On the other hand, the adsorption amount on the vertical axis is expressed in units of [cm ³ / g STP], and represents the adsorption amount [cm ³ ] of N ₂ adsorbed per 1 g of sample in terms of standard state. The standard state is 0 ° C. 101.13 kPa. Therefore, the units of the slopes a and a ′ are [cm ³ / g STP], but the description of the units is omitted in this specification. In addition, the standard state represented by STP (Standard Temperature and Pressure) is 0 ° C. and 101.13 kPa.

In the embodiment shown in FIG. 2, the first measurement point where P / P ₀ is larger than 0.5 is P / P ₀ = 0.506, and the adsorption amount at that time is 20.21 cm ³ / g STP. The first measurement point where P / P ₀ is smaller than 0.7 is P / P ₀ = 0.681, and the adsorption amount at that time is 19.92 cm ³ / g STP. The slope a of the straight line connecting these two points is -1.7 [= (20.21-19.92) / (0.506-0.681)], which is negative. In the evaluation of the gradient a, the first measurement point where P / P ₀ is larger than 0.5 is smaller than P / P ₀ = 0.55, and the first measurement point where P / P ₀ is smaller than 0.7 is P / P _0. It is desirable that P ₀ is larger than 0.65. When the adsorption amount obtained at these measurement points is significantly different from the average value of the adsorption amounts obtained at the preceding and following measurement points, for example, ± 1% of the average value of the adsorption amount is used. If the value exceeds the value, the point is regarded as a singular point or a point having a problem in measurement, and is excluded, and the next point is adopted.

Furthermore, in FIG. 2, the first measurement point where P / P ₀ is larger than 0.3 is P / P ₀ = 0.301, and the adsorption amount at that time is 19.23 cm ³ / g STP. P / _{P 0} is the measuring point _P / _P 0 = 0.481 for less than 0.5 initially adsorbed amount at that time is 20.23cm ³ / g STP. The slope a 'of the straight line connecting these two points is 5.6 [= (19.23-20.23) / (0.301-0.481)], which is positive. In the evaluation of the slope a ′, the first measurement point where P / P ₀ is larger than 0.3 is smaller than P / P ₀ = 0.35, and the first measurement point where P / P ₀ is smaller than 0.5 is P / P _0. Desirably, P ₀ is greater than 0.45.

The adsorption isotherm is a line showing a change in the amount of N ₂ adsorbed when P / P ₀ is increased while keeping the temperature of the active material constant, and the desorption isotherm is when P / P ₀ is decreased. is a line indicating variation of N ₂ adsorption. Desorption isotherms as shown in FIG. 2, N ₂ adsorption amount with respect to the from the vicinity of P / P 0 = ₁ to around 0.7 decrease in P / P ₀ is decreased, the slope is positive. From around P / P ₀ = 0.7, the amount of adsorbed N ₂ increases as P / P ₀ decreases, and the slope changes from plus to minus. Then, from around P / P ₀ = 0.5, the N ₂ adsorption amount decreases with decreasing P / P ₀ , and the slope changes from minus to plus.
The feature of the active material of the present embodiment is that the slope of the desorption isotherm changes from plus to minus near P / P ₀ = 0.7. The fact that the slope of the desorption isotherm becomes negative in the region between P / P ₀ = around 0.7 and around 0.5 means that the N ₂ adsorption amount was increased by reducing the pressure P. and which shows that the composition or structure specific phenomenon occurs in N ₂ gas adsorption carbonaceous material has. On the other hand, the reason why the slope of the desorption isotherm becomes positive in a region lower than P / P ₀ = 0.5 is because the pores in a small range (about 2 to 10 nm) of pores generally called mesopores This is probably due to the relatively large number of desorptions.

  The active material of the present embodiment is characterized in that the slope a is negative, and the magnitude of the slope a is desirably −1.0 or less, and more desirably −1.3 or less. This is because the cycle characteristics tend to increase as the absolute value of the slope a increases. On the other hand, the slope a is preferably −3.0 or more, and more preferably −2.0 or more. It is very difficult to manufacture an active material having the slope a lower than −3.0, and even if the active material can be manufactured, the active material tends to have low charge / discharge capacity or charge / discharge rate characteristics.

  The active material of the present embodiment is characterized in that the absolute value of the gradient a ′ is larger than the absolute value of the gradient a, and more desirably, the absolute value of the gradient a ′ is twice or more the absolute value of the gradient a. , And more than three times. If the absolute value of the gradient a 'is equal to or less than the absolute value of the gradient a, the cycle characteristics tend to be low. On the other hand, the absolute value of the gradient a 'is desirably 10 times or less, and more desirably 5 times or less, of the absolute value of the gradient a. If the absolute value of the gradient a 'is greater than 10 times the absolute value of the gradient a, there is a possibility that a problem may occur in the safety during use when the battery is manufactured.

  Further, the absolute value of the gradient a 'is preferably 1.0 or more and 15 or less, more preferably 2.0 or more and 10 or less, and further more preferably 4.5 or more and 7.5 or less. It is considered that the active material having an absolute value of the gradient a ′ of less than 1.0 has few pores in a small range (about 2 to 10 nm) among pores called mesopores. It is difficult to absorb the volume change accompanying the inside of the active material, and the cycle characteristics tend to be low. On the other hand, an active material having an absolute value of the gradient a ′ of more than 15 has many pores called mesopores in a small range (about 2 to 10 nm) and a very large specific surface area. When manufactured, safety issues during use are likely to occur.

In this embodiment, the pore distribution measurement by the N ₂ adsorption method described above is performed by collecting 0.2-0.5 g of a sample in a １ ／ inch cell, and first, as a pretreatment, vacuprep manufactured by Shimadzu-Micromeritics. After performing a degassing treatment by drying under reduced pressure at a temperature of about 200 ° C. for about 15 hours, the measurement was performed using a Tristar II3020 manufactured by Shimadzu Corporation-Micromeritics. First, a 1/2 inch cell was cooled by placing it in liquid nitrogen, N ₂ was introduced into the cell, the pressure P of N ₂ was gradually increased, and the amount of N ₂ adsorbed at each equilibrium pressure was measured. Then, the adsorption amount of N ₂ is plotted as a measurement point to obtain an adsorption isotherm. Next, the pressure P of N ₂ is gradually decreased, the amount of N ₂ adsorbed at each equilibrium pressure is measured, and the amount of N ₂ adsorbed is plotted as a measurement point to obtain a desorption isotherm. N number of points of adsorption amount of _2, between the measurement point of the first P / _{P 0} is the measuring point and the P / _{P 0} of the beginning is greater than 0.5 is smaller than 0.7, and P / _{P 0} 0 It is preferable that the number of points between the first measurement point larger than 0.3 and the first measurement point with P / P ₀ smaller than 0.5 be 6 points or more including the measurement points at both ends. If the number of measurement points is small, the accuracy of the slope a and the slope a ′ may be reduced. The measurement is performed in such a manner that the range of the relative pressure (P / P ₀ ) is the same as in FIG.

(Production method)
Next, a method for producing an active material for a non-aqueous electrolyte battery will be described.
The active material is obtained by mixing silicon and silicon oxide, or silicon oxide particles made of silicon oxide, and at least a carbonaceous carbon precursor using a dispersion medium to obtain a mixture, and then drying and mixing the obtained mixture. It is produced by firing after solidification and, if necessary, crushing and sieving.

  Particles composed of silicon and silicon oxide or silicon oxide are silicon oxide particles represented by a composition formula SiOx (0.005 ≦ x ≦ 2). Examples of such particles include particles in which the surfaces of fine particles of crystalline silicon are covered with an oxide film, particles in which silicon monoxide is heated to about 1100 ° C. in an inert gas to precipitate crystalline silicon inside, or gas phase synthesis. And the like. Particles in which the value of x in SiOx is less than 0.005 are substantially composed of only silicon, and it is extremely difficult for the surface layer of the particles to exist in air without being oxidized even to this extent. Further, oxides of SiOx in which the value of x exceeds 2 are unstable. X of SiOx can be obtained by the elemental composition analysis. Specifically, for example, the content ratio of silicon atoms in silicon oxide particles is determined by alkali fusion-ICP emission spectroscopy, and the content ratio of oxygen atoms is determined by inert gas fusion-infrared absorption method. The ratio can be calculated. Although the upper limit of x of SiOx in the present embodiment is 2, the value of x may exceed 2 due to a measurement error in the measurement of silicon dioxide. Therefore, a difference of about 10% is allowed, and the case where x of SiOx is 0.0045 or 2.2 as a result of the measurement is also included in the present embodiment. Particles composed of silicon and silicon oxide or silicon oxide may be composed of one kind of silicon oxide particles or plural kinds of silicon oxide particles. The type of the silicon oxide particles referred to here means that the silicon oxide particles have the same value of x or the same primary particle size in the composition formula SiOx. That is, when composed of a plurality of types of silicon oxide particles, silicon oxide particles having different values of x or primary particle diameters in the composition formula SiOx are included. The determination as to whether or not the silicon oxide particles used in the manufacturing method are within the desirable range for the present embodiment is based on the value of x or the primary particle size of the composition formula SiOx, and the average of the entire silicon oxide particles used in the manufacturing method is This is performed by obtaining a value considered to be close to the value. Therefore, silicon oxide particles outside the range of the present embodiment may be contained as long as the average value does not have an effect outside the range desired in the present embodiment.

  It is particularly desirable that the value of x in the composition formula SiOx of the silicon oxide used as the raw material is 2, that is, the SiOx is silicon dioxide. This is because silicon dioxide has the most stable composition among silicon oxides, the particle diameter and structure of the raw material are easily controlled, and it is hard to change in the production process of the active material. As x of SiOx increases, the charge / discharge capacity tends to decrease, while the cycle characteristics tend to improve. Therefore, when the charge / discharge capacity obtained by using silicon dioxide particles for all of the silicon oxide particles used in the above-mentioned manufacturing method is less than the required capacity, silicon oxide particles in which x of SiOx is smaller than 2 are partially mixed. I do. The silicon oxide particles partially mixed are desirably represented by a composition formula SiOx (0.005 ≦ x ≦ 0.1), and more desirably SiOx (0.01 ≦ x ≦ 0.1). . The mixing ratio is preferably from 1% by weight to 15% by weight, more preferably from 3% by weight to 12% by weight, based on the silicon dioxide particles. When the mixing ratio is lower than 1% by weight, the effect of increasing the charge / discharge capacity is small, and when the mixing ratio is higher than 15% by weight, the effect of lowering the cycle characteristics becomes remarkable.

It is desirable that the silicon oxide particles have an average primary particle size of 3 nm or more and 50 nm or less. A more desirable average primary particle size is 5 nm or more and 25 nm or less, and more preferably 5 nm or more and 15 nm or less. The silicon oxide particles preferably have a BET specific surface area of 100 m ² / g or more and 450 m ² / g or less. A more desirable BET specific surface area is from 150 m ² / g to 400 m ² / g, and more preferably from 250 m ² / g to 350 m ² / g. The silicon oxide particles satisfying the average primary particle size and the BET specific surface area at the same time have a very fine space between the particles, and it is difficult to completely fill the space with a carbonaceous material. active material particles dispersed in the carbonaceous material, said of N ₂ desorption isotherm by pore distribution measurement by adsorption method is becoming a unique microstructure showing the specific features.

  As the carbon precursor, a substance that forms amorphous carbon by thermal decomposition by heating is used, and saccharides and sugar acids are particularly suitable, and among them, sucrose, lactose, maltose, trehalose, cellobiose, glucose, fructose, Galactose, ascorbic acid and glucuronic acid are preferred, and sucrose and ascorbic acid are more preferred. These substances all have a molecular weight of 150 or more and less than 400, and are characterized in that the peak of thermal decomposition is at a relatively low temperature. The peak of the thermal decomposition is preferably 400 ° C. or lower, more preferably 320 ° C. or lower. The peak temperature of pyrolysis can be measured by, for example, pyrolysis mass spectrometry. Specifically, the temperature of the sample is increased by a pyrolyzer, the amount of gas generated at each temperature is measured by a mass spectrometer, and the temperature at which the total amount of generated gas is the highest is defined as the peak temperature of thermal decomposition. In the measurement by the pyrolysis mass spectrometry, it is desirable to dry the sample for measurement in advance in order to reduce the peak due to evaporation of the moisture previously adsorbed on the sample. Using a 2120 iD manufactured by Frontier Lab as a pyrolyzer, using helium as a carrier gas, holding the sample at 40 ° C. for 8 minutes, then increasing the temperature to 800 ° C. at 5 ° C./min, and a gas chromatograph mass spectrometer as a mass spectrometer. As a result of performing mass spectrometry using 6890/5973 manufactured by Agilent Technology as a column and UA-DTM manufactured by Frontier Lab, the peak of the thermal decomposition of sucrose was 300 ° C and that of ascorbic acid was 205 ° C.

In the firing step in the production of the active material, after pyrolysis at relatively low temperatures as described above is caused by the firing is accounted baked performed at higher temperatures, the pores by the the N ₂ adsorption method Unique microstructures with specific characteristics of the desorption isotherm are obtained in distribution measurements. It is desirable that these carbon precursors are pulverized so that the average particle size becomes 10 μm or less before the mixing process.
Further examples of the carbon precursor include liquid and easily polymerizable resins or monomers thereof. Resins are, for example, furan resin, xylene resin, ketone resin, amino resin, melamine resin, urea resin, aniline resin, urethane resin, polyimide resin, polyester resin, phenol resin, and as the monomer, furfuryl alcohol, furfural, Furan compounds such as furfural derivatives are exemplified. The polymerization is performed in the drying / solidification step of the production of the active material, and the method of polymerization varies depending on the carbon precursor, but may be, for example, adding hydrochloric acid or an acid anhydride, or heating. The molecular weight of the polymer is higher than that of the above sugars and saccharides, and therefore, the peak of thermal decomposition is often at a relatively high temperature of 400 ° C. or higher. When using these carbon precursors, in the drying / solidification step, it is particularly important that the entire mixture including the silicon oxide particles is dried / solidified in a homogeneous state, and the solidification obtained in this manner is obtained. When the substance is thermally decomposed at a relatively high temperature, it becomes easy to obtain a unique microstructure in which the desorption isotherm shows specific characteristics in the pore distribution measurement by the N2 adsorption method.

  Examples of the dispersion medium include water, ketones such as ethanol, isopropyl alcohol and acetone, fatty acids such as N-methylpyrrolidone, oleic acid and linoleic acid, and glycols such as ethylene glycol and propylene glycol. Alternatively, a liquid in which a binder agent or a surfactant is mixed therewith may be used. As a mixing method using a dispersion medium, a kneading method in which the amount of the liquid phase with respect to the solid phase is small, or a mixing and stirring method in which the amount of the liquid phase with respect to the solid phase is large may be used. In the mixing by the stiffening method, the mixture to be mixed has a lower fluidity than that of the mixing and stirring method, but uniform mixing is possible by applying a shearing force. As a specific method, kneading may be performed by mixing with a pestle and a mortar while applying a manual shearing force, or mixing may be performed while applying a shearing force using a machine such as a planetary mixer or an extrusion granulator. It may be kneaded by doing. The mixing and stirring method can be performed by, for example, various stirring devices, a ball mill, a bead mill device, and a combination thereof. The mixing may be performed while heating in a part of the mixing process. Which mixing method is best depends on the types of the silicon oxide particles, the carbon precursor, and the dispersion medium, or the compounding ratio thereof, and desorbs the produced active material by pore distribution measurement using the N2 adsorption method. The combinations are selected so that the isotherm becomes the active material of the above embodiment. Note that the characteristics of the active material are affected not only by the types and amounts of the raw materials and the combination of the mixing methods described above, but also by the active material production conditions described below. Therefore, it is necessary that the active material finally obtained through all these combinations falls within the scope of the present embodiment.

  The mixture obtained by mixing is dried and solidified to obtain a solidified product. Drying can be performed, for example, by standing in the atmosphere or by heating. Drying may be performed under reduced pressure or may be performed in a state where a gas such as air is circulated. The purpose of drying is to vaporize the dispersion medium and reduce it from within the mixture, and an appropriate method is selected according to the boiling point and vapor pressure of the dispersion medium. When the obtained mixture is in a solid state or in a state of extremely low fluidity, drying and solidification can be performed by heating and holding at a temperature of, for example, 150 ° C. On the other hand, when the obtained mixture is in a liquid or fluid state, depending on the method of drying and solidification, for example, a phenomenon such as sedimentation of silicon oxide particles occurs, and a large unevenness occurs in the solidified material. become. On the other hand, in order to dry and solidify the entire mixture including the silicon oxide particles in a homogeneous state as described above, the mixture is spread thinly or fluidized using a machine such as an evaporator. It is desirable to carry out the drying / solidification step in the state where it is kept.

  The solid obtained by drying and solidifying is fired. In the firing, heating is performed in an inert atmosphere such as argon (Ar) to change a carbon precursor into amorphous carbon, and at the same time, disproportionate SiOx to obtain silicon particles, thereby obtaining a carbonaceous material and a carbonaceous material. A composite comprising at least two types of silicon-containing particles dispersed in a substance is obtained. The preferable temperature of the calcination is in the range of 600 ° C to 1500 ° C, preferably 800 ° C to 1300 ° C, more preferably 800 ° C to 1100 ° C. As the temperature decreases, the crystallinity of the amorphous carbon decreases, and as the temperature increases, the crystallinity of the amorphous carbon tends to increase. The firing time is from 1 hour to 12 hours, preferably from 2 hours to 8 hours, and more preferably from 2 hours to 5 hours.

According to the embodiment described above, an active material for a non-aqueous electrolyte battery can be provided.
The active material for a non-aqueous electrolyte battery according to the present embodiment has an initial measurement point where P / P ₀ is larger than 0.5 and P / P ₀ is 0 in the desorption isotherm in the pore distribution measurement by the N ₂ adsorption method. Since the characteristic is that the slope a of the straight line connecting the first measurement points smaller than 0.7 is negative, it exhibits high capacity and excellent cycle characteristics.

(Second embodiment)
In the second embodiment, an electrode for a non-aqueous electrolyte battery is provided.
The nonaqueous electrolyte battery electrode according to the present embodiment uses the nonaqueous electrolyte battery active material of the first embodiment. 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 or both surfaces of the current collector. The electrode mixture layer contains the 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 the present embodiment will be described as a negative electrode, but the non-aqueous electrode of the present embodiment may be used as a positive electrode. Further, in the following description, the electrode according to the present embodiment is described as being used for a nonaqueous 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. 3 is a conceptual diagram of a negative electrode (electrode for a non-aqueous electrolyte battery) according to the second embodiment. The negative electrode 100 of the second embodiment includes a negative electrode mixture layer 102 and a negative electrode current collector 101. The negative electrode mixture layer 102 is a layer of a mixture containing an active material disposed on the negative electrode current collector 101. The negative electrode mixture layer 102 includes a negative electrode active material, a conductive material, and a binder. The binder joins the negative electrode mixture layer and the negative electrode current collector 101.

  The thickness of the negative electrode mixture layer 102 is preferably in the range of 1 μm to 150 μm. Therefore, when it is carried on both surfaces of the negative electrode current collector 101, the total thickness of the negative electrode mixture layer 102 is in the range of 2 μm or more and 300 μm or less. A more preferable range of the thickness on one side is 10 μm or more and 100 μm or less, and further preferably 30 μm or more and 100 μm or less. Within this range, large current discharge characteristics and cycle characteristics of the nonaqueous electrolyte battery including the negative electrode 100 are significantly improved.

  The mixing ratio of the negative electrode active material, the conductive agent, and the binder in the negative electrode mixture layer 102 is such that the negative electrode active material is 57% by mass to 95% by mass, the conductive agent is 3% by mass to 20% by mass, and the binder is The content is preferably in the range of 2% by mass to 40% by mass. By setting the mixing ratio of the negative electrode active material, the conductive agent, and the binder within this range, good large-current discharge characteristics and cycle characteristics of the nonaqueous electrolyte battery including the negative electrode 100 can be obtained.

  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 is used. These conductive substrates can be formed from, for example, copper, stainless steel, or nickel. The thickness of the negative electrode current collector 101 is preferably 5 μm or more and 20 μm or less. This is because if the thickness of the negative electrode current collector 101 is within this range, the balance between electrode strength and weight reduction can be achieved.

  The conductive agent has an effect of increasing the conductivity of the negative electrode 100 and is preferably present in the negative electrode mixture layer 102 in a dispersed state. Examples of the conductive agent include conductive carbonaceous materials such as acetylene black, carbon black, and graphite. As the conductive agent, one having a shape such as a flake shape, a crushed shape, or a fibrous shape is used. These conductive agents may be used alone or in combination of two or more. In many cases, the conductive agent can also insert and desorb Li, but its charge / discharge capacity is smaller than that of the active material of the present embodiment. In the present embodiment, as a negative electrode active material mainly responsible for the insertion and desorption of Li, a composite composed of at least two kinds of carbonaceous materials and silicon oxide particles dispersed in the carbonaceous materials (for the nonaqueous electrolyte battery of the first embodiment) The conductive carbonaceous material is mainly used as a conductive agent.

  The binder fills the gap between the dispersed negative electrode active materials to bind the negative electrode active material and the conductive agent, and also binds the negative electrode active material and the negative electrode current collector 101. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), polyacrylic acid, polysaccharides such as alginic acid and cellulose and derivatives thereof, ethylene-propylene-diene copolymer (EPDM), Styrene-butadiene rubber (SBR), polyimide, polyamide, polyamide imide, and the like. Among these, a polymer such as polyimide having an imide skeleton is more preferable because it has a high binding force with the negative electrode current collector 101 and can enhance the binding force between the negative electrode active materials. The binder may be used alone or in combination of two or more. When two or more kinds are used in combination, a combination of a binder excellent in binding between the negative electrode active materials and a binder excellent in binding between the negative electrode active material and the negative electrode current collector 101, and a hardness of By employing a combination of a high binder and a binder having excellent flexibility, the cycle characteristics of the negative electrode 100 can be improved.

Next, a method for manufacturing the negative electrode will be described.
First, a slurry is prepared by suspending a negative electrode active material, a conductive agent and a binder in a commonly used solvent.
Next, the slurry is applied to the negative electrode current collector 101, dried to form the negative electrode mixture layer 102, and then pressed to manufacture the negative electrode 100. Note that the degree of embedding of the negative electrode active material in the negative electrode current collector 101 can be adjusted by the pressure of the press. If the pressing pressure is lower than 0.2 kN / cm, the negative electrode active material is hardly embedded in the negative electrode current collector 101, which is not preferable. On the other hand, if the pressing pressure is higher than 10 kN / cm, the negative electrode active material and the negative electrode current collector 101 may be broken, which is not preferable. Therefore, the pressing pressure of the negative electrode mixture layer 102 obtained by drying the slurry is preferably 0.5 kN / cm or more and 5 kN / cm or less.
Here, the pressing pressure is a numerical value when a roller press is used, and is a value obtained by dividing the pressure [kN] measured at the time of pressing by the width [cm] of the negative electrode mixture layer. The width of the negative electrode mixture layer is the length in the direction parallel to the roll axis of the roller press, for example, when the negative electrode mixture layer having a rectangular shape as viewed from above is obliquely passed through the roller press. , A representative length shall be adopted.

According to the embodiment described above, an electrode for a nonaqueous electrolyte battery can be provided.
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 active material for a non-aqueous electrolyte battery of the first embodiment, a conductive agent, and a binder. For this reason, the nonaqueous electrolyte battery to which the electrode for a nonaqueous electrolyte battery according to the present embodiment is applied exhibits high capacity and excellent cycle characteristics.

(Third embodiment)
In a third embodiment, a non-aqueous electrolyte battery is provided.
The nonaqueous electrolyte battery according to the third embodiment uses the electrode for a nonaqueous electrolyte battery of the second embodiment. Specifically, the nonaqueous electrolyte battery according to the present embodiment includes an exterior material, a positive electrode housed in the exterior material, and a space separated from the positive electrode in the exterior material by, for example, a separator. And a non-aqueous electrolyte filled in an exterior material. The electrode for a non-aqueous electrolyte battery of the second embodiment is used as a negative electrode.

  Hereinafter, the negative electrode, the positive electrode, the nonaqueous electrolyte, the separator, and the packaging material, which are constituent members of the nonaqueous electrolyte battery according to the present embodiment, will be described in detail.

(1) Negative electrode As the negative electrode, the negative electrode according to the above-described second embodiment is used.

(2) Positive Electrode The positive electrode includes a positive electrode current collector and a positive electrode mixture layer formed on one or both surfaces of the positive electrode current collector and containing a positive electrode active material, a conductive agent, and a binder. The conductive agent and the binder are optional components.

The thickness of one surface of the positive electrode mixture layer is preferably in the range of 1 μm or more and 150 μm or less, and more preferably 30 μm or more and 120 μm or less. Therefore, when the positive electrode mixture layers are provided on both surfaces of the positive electrode current collector, the total thickness of the positive electrode mixture layers is in the range of 2 μm or more and 300 μm or less.
When the thickness of the positive electrode mixture layer is within the above range, large current discharge characteristics and cycle characteristics of the nonaqueous electrolyte battery provided with the positive electrode are significantly improved.

As the positive electrode active material, various oxides, for example, manganese dioxide, lithium manganese composite oxide, lithium-containing nickel cobalt oxide (for example, LiCoO ₂ ), lithium-containing nickel cobalt oxide (for example, LiNi _0.8 Co _{0) .2} O ₂ ) and lithium manganese composite oxide (eg, LiMn ₂ O ₄ , LiMnO ₂ ). By using these positive electrode active materials, a nonaqueous electrolyte secondary battery is preferable because a high voltage can be obtained.

  The average primary particle size of the positive electrode active material is preferably from 100 nm to 1 μm. A positive electrode active material having an average primary particle size of 100 nm or more is easy to handle in industrial production. In addition, a positive electrode active material having an average particle size of 1 μm or less can smoothly diffuse lithium ions in a solid.

The conductive agent enhances the current collecting performance of the positive electrode active material and suppresses the contact resistance between the positive electrode active material and the positive electrode current collector. Examples of the conductive agent include those containing acetylene black, carbon black, artificial graphite, natural graphite, carbon fiber, a conductive polymer, and the like.
The kind of the conductive agent can be one kind or two or more kinds.

The binder fills the gap between the dispersed positive electrode active materials, binds the positive electrode active material and the conductive agent, and binds the positive electrode active material and the positive electrode current collector.
Examples of the binder include organic substances including polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluororubber, and polyacrylic acid.
The kind of the binder can be one kind or two or more kinds.
Further, as the organic solvent for dispersing the binder, for example, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF) and the like are used.

  The mixing ratio of the positive electrode active material, the conductive agent and the binder in the positive electrode mixture layer is such that the positive electrode active material is 80% by mass or more and 95% by mass or less, the conductive agent is 3% by mass or more and 20% by mass or less, and the binder is The content is preferably in the range of 2% by mass to 7% by mass. A nonaqueous electrolyte battery provided with a positive electrode in which the mixing ratio of the positive electrode mixture layer is in this range can obtain good high-current discharge characteristics and cycle characteristics.

The positive electrode current collector is a conductive member that binds to the positive electrode mixture layer. As the positive electrode current collector, a conductive substrate having a porous structure or a non-porous conductive substrate is used.
The thickness of the positive electrode current collector is preferably 8 μm or more and 15 μm or less. The reason why the thickness of the positive electrode current collector is preferably within this range is because the balance between electrode strength and weight reduction can be achieved.

Next, a method for manufacturing the positive electrode will be described.
First, a slurry is prepared by suspending a positive electrode active material, a conductive agent and a binder in a commonly used solvent.
Next, the slurry is applied on a positive electrode current collector, dried to form a positive electrode mixture layer, and then pressed to obtain a positive electrode.
The positive electrode is produced by forming a positive electrode active material, a binder, and a conductive agent to be blended as necessary into a pellet to form a positive electrode mixture layer, and arranging this on a positive electrode current collector. Is also good.

(3) Non-aqueous electrolyte As the non-aqueous electrolyte, a non-aqueous electrolyte, an electrolyte-impregnated polymer electrolyte, a polymer electrolyte or an inorganic solid electrolyte is used.
The non-aqueous electrolyte is a liquid electrolyte prepared by dissolving an electrolyte in a non-aqueous solvent (organic solvent), and is held in a gap in the electrode group.

  Examples of the non-aqueous solvent include cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC), and vinylene carbonate (hereinafter, referred to as “first solvent”), and non-aqueous solvents having a lower viscosity than the cyclic carbonate (hereinafter, referred to as “first solvent”). It is preferable to use a non-aqueous solvent mainly composed of a mixed solvent with “a second solvent”.

Examples of the second solvent include chain carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (MEC), ethyl propionate, methyl propionate, γ-butyrolactone (GBL), and 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, if the number of donors in the second solvent is too large, bonding with Li ions becomes too strong, and the Li ion conductivity is lowered. Therefore, the number of donors is more preferably 16.5 or less.
The viscosity of the second solvent at 25 ° C. is preferably 2.8 cPs or less.

  The blending amount of ethylene carbonate or propylene carbonate in the mixed solvent of the first solvent and the second solvent is preferably from 1.0% to 80% by volume, more preferably from 20% to 75%. preferable. If the volume ratio of the second solvent is too small, the viscosity of the non-aqueous electrolyte increases, and the Li ion conductivity decreases. On the other hand, if the volume ratio of the second solvent is too large, the action of PC and EC is hindered and Li The above range is preferable because the ionic conductivity is reduced.

Examples of the electrolyte contained in the non-aqueous electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), and lithium arsenic hexafluoride (LiAsF). ₆ ), lithium trifluorometasulfonate (LiCF ₃ SO ₃ ), and lithium salts such as lithium bistrifluoromethylsulfonylimide [LiN (CF ₃ SO ₂ ) ₂ ]. Among these, it is preferable to use lithium hexafluorophosphate or lithium tetrafluoroborate. The amount of the electrolyte dissolved in the nonaqueous solvent contained in the nonaqueous electrolyte is preferably 0.5 mol / L or more and 2.0 mol / L or less. If the dissolved amount of the electrolyte is too small, the migration of ions becomes difficult to occur, so that the Li ion conductivity decreases. On the other hand, if the dissolved amount of the electrolyte exceeds 2.0 mol / L, the viscosity of the non-aqueous electrolyte increases, so that the Li ion This is because the conductivity decreases.

(4) Separator The separator is disposed between the positive electrode and the negative electrode.
The separator is formed of, for example, a porous film containing polyethylene (PE), polypropylene (PP), cellulose, or polyvinylidene fluoride (PVdF), or a synthetic resin nonwoven fabric. Among these, a porous film formed of polyethylene or polypropylene is preferable because it can be melted at a certain temperature and cut off the current, thereby improving safety.

  The thickness of the separator is preferably 5 μm or more and 30 μm or less, more preferably 10 μm or more and 25 μm or less. When the thickness of the separator is less than 5 μm, the strength of the separator is significantly reduced, and an internal short circuit may easily occur. On the other hand, if the thickness of the separator exceeds 30 μm, the distance between the positive electrode and the negative electrode increases, and the internal resistance may increase.

The heat shrinkage of the separator when left at 120 ° C. for 1 hour is preferably 20% or less, more preferably 15% or less. When the heat shrinkage of the separator exceeds 20%, the possibility of short circuit between the positive electrode and the negative electrode due to heating increases.
The porosity of the separator is preferably 30% or more and 70% or less, and more preferably 35% or more and 70% or less.

  The reason why the porosity of the separator is preferably within the above range is as follows. If the porosity is less than 30%, it may be difficult to obtain high electrolyte retention in the separator. On the other hand, if the porosity exceeds 70%, sufficient strength may not be obtained for the separator.

The air permeability of the separator is preferably 30 seconds / 100 cm ³ or more and 500 seconds / 100 cm ³ or less, and more preferably 50 seconds / 100 cm ³ or more and 300 seconds / 100 cm ³ or less.
If the air permeability is less than 30 seconds / 100 cm ³ , sufficient strength may not be obtained for the separator. On the other hand, if the air permeability exceeds 500 seconds / 100 cm ³ , high lithium ion mobility may not be obtained in the separator.

(5) Outer material As the outer material in which the positive electrode, the negative electrode, and the nonaqueous electrolyte are accommodated, a metal container or a laminated film outer container is used.
As the metal container, a metal can made of aluminum, an aluminum alloy, iron, stainless steel or the like and having a square or cylindrical shape is used. Further, the thickness of the metal container is preferably 1 mm or less, more preferably 0.5 mm or less, and still more preferably 0.2 mm or less.

  As the aluminum alloy, an alloy containing elements such as magnesium, zinc, and silicon is preferable. When a transition metal such as iron, copper, nickel, and chromium is contained in the aluminum alloy, the content is preferably 100 ppm or less. Since the strength of the metal container made of an aluminum alloy is dramatically increased as compared with the metal container made of aluminum, the thickness of the metal container can be reduced. As a result, it is possible to realize a nonaqueous electrolyte battery that is thin, lightweight, has high output, and is excellent in heat dissipation.

  Examples of the laminated film include a multilayer film in which an aluminum foil is covered with a resin film. As a resin constituting the resin film, a polymer compound such as polypropylene (PP), polyethylene (PE), nylon, and polyethylene terephthalate (PET) is used. The thickness of the laminate film is preferably 0.5 mm or less, more preferably 0.2 mm or less. The purity of the aluminum foil is preferably 99.5% or more.

The nonaqueous electrolyte battery according to the present embodiment can be applied to various types of nonaqueous electrolyte batteries such as a flat type (thin type), a square type, a cylindrical type, a coin type, and a button type.
In addition, the nonaqueous electrolyte battery according to the present embodiment can further include a lead electrically connected to the electrode group including the positive electrode and the negative electrode. The non-aqueous electrolyte battery according to the embodiment may include, for example, two leads. In that case, one lead is electrically connected to the positive electrode current collection tab, and the other lead is electrically connected to the negative electrode current collection tab.
Although the material of the lead is not particularly limited, for example, the same material as the positive electrode current collector and the negative electrode current collector is used.

The nonaqueous electrolyte battery according to the present embodiment may further include a terminal electrically connected to the lead and extending from the exterior material. The non-aqueous electrolyte battery according to the embodiment may include, for example, two terminals. In that case, one terminal is connected to a lead electrically connected to the positive electrode current collecting tab, and the other terminal is connected to a lead electrically connected to the negative electrode current collecting tab.
Although the material of the terminal is not particularly limited, for example, the same material as the positive electrode current collector and the negative electrode current collector is used.

(6) Nonaqueous Electrolyte Battery Next, as an example of the nonaqueous electrolyte battery according to the present embodiment, a flat nonaqueous electrolyte secondary battery (nonaqueous electrolyte battery) 200 shown in FIGS. 4 and 5 will be described. FIG. 4 is a conceptual cross-sectional view of a flat nonaqueous electrolyte secondary battery (nonaqueous electrolyte battery) according to the third embodiment, and FIG. 5 is an enlarged schematic conceptual view of a portion A shown in FIG.

  The flat type non-aqueous electrolyte secondary battery 200 shown in FIG. 4 includes a flat wound electrode group 201 housed in an exterior material 202. The exterior material 202 may be a laminate film formed in a bag shape or a metal container. In addition, the flat wound electrode group 201 is formed by spirally winding a laminate in which the negative electrode 203, the separator 204, the positive electrode 205, and the separator 204 are sequentially stacked from the outside, that is, from the exterior material 202 side, and press-molded. It is formed by this. The electrode located in the outermost layer is the negative electrode 203, and the negative electrode 203 has a configuration in which the negative electrode mixture layer 203b is formed only on one surface of the negative electrode current collector 203a on the inner side of the battery. The negative electrode 203 other than the outermost layer has a configuration in which a negative electrode mixture layer 203b is formed on both surfaces of a negative electrode current collector 203a. The positive electrode 205 has a configuration in which a positive electrode mixture layer 205b is formed on both surfaces of a positive electrode current collector 205a. Note that, instead of the separator 204, a gel non-aqueous electrolyte such as the above-described electrolyte-impregnated polymer electrolyte and polymer electrolyte may be used.

  In the wound electrode group 201 shown in FIG. 4, the negative electrode terminal 206 is electrically connected to the negative electrode current collector 203a of the outermost negative electrode 203 near the outer peripheral end. The positive electrode terminal 207 is electrically connected to the positive electrode current collector 205a of the inner positive electrode 205. The negative electrode terminal 206 and the positive electrode terminal 207 extend to the outside of the exterior material 202 or are connected to an extraction electrode provided on the exterior material 202.

When manufacturing the flat type nonaqueous electrolyte secondary battery 200 provided with the exterior material made of a laminated film, the wound electrode group 201 to which the negative electrode terminal 206 and the positive electrode terminal 207 are connected is formed by a bag-shaped exterior having an opening. The wound electrode group is charged by charging the liquid non-aqueous electrolyte through the opening of the package 202 and heat-sealing the opening of the package 202 with the negative electrode terminal 206 and the positive electrode terminal 207 sandwiched therebetween. 201 and the liquid non-aqueous electrolyte are completely sealed.
Further, when manufacturing the flat type nonaqueous electrolyte secondary battery 200 provided with the exterior material formed of a metal container, the wound electrode group 201 to which the negative electrode terminal 206 and the positive electrode terminal 207 are connected is formed by using a metal container having an opening. , And the liquid non-aqueous electrolyte is injected from the opening of the exterior material 202, and a lid is attached to the metal container to close the opening.

  As the negative electrode terminal 206, for example, a material having electrical stability and conductivity can be used when the potential with respect to lithium is in the range of 1 V to 3 V. Specifically, aluminum or an aluminum alloy containing elements such as Mg, Ti, Zn, Mn, Fe, Cu, and Si can be used. The negative electrode terminal 206 is preferably made of the same material as the negative electrode current collector 203a in order to reduce the contact resistance with the negative electrode current collector 203a.

  As the positive electrode terminal 207, a material having electrical stability and conductivity can be used when the potential with respect to lithium is in the range of 3 V to 4.25 V. Specifically, aluminum or an aluminum alloy containing elements such as Mg, Ti, Zn, Mn, Fe, Cu, and Si can be used. 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 exterior material 202, the negative electrode 203, the positive electrode 205, the separator 204, and the nonaqueous electrolyte, which are components of the flat nonaqueous electrolyte secondary battery 200, will be described in detail.
(1) Exterior material As the exterior material 202, the above-mentioned exterior material is used.
(2) Negative electrode As the negative electrode 203, the above-described negative electrode is used.
(3) Positive electrode As the positive electrode 205, the above-described positive electrode is used.
(4) Separator As the separator 204, the above-described separator is used.
(5) Non-aqueous electrolyte As the non-aqueous electrolyte, the above-mentioned non-aqueous electrolyte is used.

  The nonaqueous electrolyte battery according to the third embodiment is not limited to the configuration shown in FIGS. 4 and 5 described above, and may be, for example, a battery having the configuration shown in FIGS. 6 and 7. FIG. 6 is a partially cutaway perspective view schematically showing another flat type nonaqueous electrolyte secondary battery according to the third embodiment, and FIG. 7 is an enlarged sectional view of a portion B shown in FIG. .

  The non-aqueous electrolyte secondary battery 300 shown in FIGS. 6 and 7 has a configuration in which a stacked electrode group 301 is housed in an exterior material 302. As shown in FIG. 7, the stacked electrode group 301 has a structure in which a positive electrode 303 and a negative electrode 304 are alternately stacked with a separator 305 interposed therebetween.

  There are a plurality of positive electrodes 303, each of which includes a positive electrode current collector 303a and a positive electrode mixture layer 303b carried on both surfaces 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 electrodes 304, each of which includes a negative electrode current collector 304a and a negative electrode mixture layer 304b supported on both surfaces 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 304 a of each negative electrode 304 protrudes from the negative electrode 304. The protruding negative electrode current collector 304 a is electrically connected to a strip-shaped negative electrode terminal 306. The tip of the strip-shaped negative electrode terminal 306 is drawn out from the exterior material 302. Although not shown, the positive electrode current collector 303a of the positive electrode 303 has a side located on the side opposite to the side of the negative electrode current collector 304a protruding from the positive electrode 303. The positive electrode current collector 303 a protruding from the positive electrode 303 is electrically connected to a belt-shaped positive electrode terminal 307. The tip of the band-shaped positive electrode terminal 307 is located on the opposite side of the negative electrode terminal 306, and is drawn out from the side of the exterior material 302.

  The materials, blending ratios, dimensions, and the like of the members constituting the nonaqueous electrolyte secondary battery 300 shown in FIGS. 6 and 7 are the same as those of the nonaqueous electrolyte secondary battery 200 described in FIGS. 4 and 5. It is a structure of.

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

(Fourth embodiment)
Next, a battery pack according to a fourth embodiment will be described.
The battery pack according to the fourth embodiment has one or more nonaqueous electrolyte batteries (that is, unit cells) according to the third embodiment. When a plurality of cells are included in the battery pack, the cells are electrically connected in series, in parallel, or connected in series and in parallel.

  The battery pack according to the fourth embodiment will be specifically described with reference to FIGS. FIG. 8 is a conceptual diagram of the battery pack according to the fourth embodiment, and FIG. 9 is a block diagram illustrating an electric circuit of the battery pack according to the fourth embodiment. In the battery pack 400 shown in FIG. 8, the flat nonaqueous electrolyte secondary battery 200 shown in FIG.

  The plurality of cells 401 are stacked so that the negative electrode terminal 206 and the positive electrode terminal 207 extending to the outside are aligned in the same direction, and the assembled battery 403 is configured by fastening with an adhesive tape 402. These cells 401 are electrically connected to each other in series as shown in FIGS.

  The printed wiring board 404 is disposed to face the side surface of the unit cell 401 from which the negative electrode terminal 206 and the positive electrode terminal 207 extend. As shown in FIG. 7, a thermistor 405, a protection circuit 406, and a terminal 407 for supplying power to an external device are mounted on the printed wiring board 404. An insulating plate (not shown) is attached to the surface of the printed wiring board 404 facing the battery pack 403 to avoid unnecessary connection with the wiring of the battery pack 403.

  The positive electrode lead 408 is connected to the positive electrode terminal 207 located at the lowermost layer of the battery pack 403, and the tip is inserted into the positive electrode connector 409 of the printed wiring board 404 and is electrically connected. The negative electrode lead 410 is connected to the negative electrode terminal 206 located at the uppermost layer of the battery pack 403, and the tip is inserted into the negative electrode connector 411 of the printed wiring board 404 and is electrically connected. The positive connector 409 and the negative connector 411 are connected to the protection circuit 406 through 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 is not shown in FIG. 8, but is provided in the vicinity of the cell 401 and a detection signal is transmitted to the protection circuit 406. . The protection circuit 406 controls charging and discharging of the cell 401. Under a predetermined condition, the positive wiring 414a and the negative wiring 414b between the protection circuit 406 and the terminal 407 for supplying power to the external device can be cut off. The predetermined condition is, for example, when the temperature detected by the thermistor 405 becomes equal to or higher than the predetermined temperature. The predetermined condition is when overcharge, overdischarge, overcurrent, and the like of the cell 401 are detected. The detection of the overcharge or the like is performed for each of the single cells 401 or the entire single cell 401. When detecting the individual cells 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 unit cell 401. In the case of FIGS. 8 and 9, a wiring 415 for voltage detection is connected to each of the unit cells 401, and a detection signal is transmitted to the protection circuit 406 through these wirings 415.

  As shown in FIG. 8, protective sheets 416 made of rubber or resin are arranged on three sides of the battery pack 403 except for the side faces from which the positive electrode terminal 207 and the negative electrode terminal 206 protrude.

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

  Note that a heat-shrinkable tape may be used for fixing the battery pack 403 instead of the adhesive tape 402. In this case, the protective sheets are arranged on both side surfaces of the battery pack, and after the heat shrink tape is circulated, the heat shrink tape is heat shrunk to bind the battery pack.

  8 and 9 show the configuration in which the cells 401 are connected in series. However, in order to increase the battery capacity, the 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 be further connected in series and in parallel.

  The mode of the battery pack is appropriately changed depending on the use. As a use of the battery pack, a battery pack exhibiting excellent cycle characteristics when a large current is taken out is preferable. Specific examples include a power source for a digital camera, and a vehicle for a vehicle such as a two-wheel or four-wheel hybrid electric vehicle, a two-wheel or four-wheel electric vehicle, or an assist bicycle. In particular, a battery pack using a nonaqueous electrolyte secondary battery having excellent high-temperature characteristics is suitably used for vehicles.

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

According to at least one embodiment described above, in the desorption isotherm in the pore distribution measurement of the active material for a nonaqueous electrolyte battery by the N ₂ adsorption method, the first measurement point where P / P ₀ is larger than 0.5 An electrode for a non-aqueous electrolyte battery, a non-aqueous electrolyte battery, and a battery exhibiting a high capacity and excellent cycle characteristics because the slope a of a straight line connecting the first measurement points where P / P ₀ is smaller than 0.7 is negative. Pack can be realized.

  The effects will be described below with reference to specific examples.

(Example 1)
The negative electrode active material of Example 1 was obtained under the following conditions. 1.5 g of hydrophilic silicon dioxide powder (commercially available, average primary particle size: 12 nm, BET specific surface area: 302 m ² / g, x = 2.0 of SiOx) and silicon powder (commercially available, average primary particle size: 40 nm, BET) Specific surface area of 60 m ² / g, SiOx (x = 0.024) and 0.075 g were mixed to obtain a silicon oxide powder. 4.0 g of ascorbic acid powder was added to the obtained silicon oxide powder, and dry-mixed in an agate mortar for 5 minutes. Next, while adding pure water to the obtained mixed powder using a dropper, the mixture was kneaded for 30 minutes to obtain a water-containing mixture. This water-containing mixture was formed into a dumpling (ball shape) to obtain a dumped water-containing mixture. The hydrated mixture in a dumpling state was placed in an alumina mortar, allowed to stand on a hot plate at 150 ° C. for 1 hour, dried and solidified. The obtained dumpling-like solid was held at 1000 ° C. for 3 hours in an Ar atmosphere and fired. The obtained dumpling-like fired product was pulverized in an agate mortar, and the pulverized product obtained through the pulverization was sieved through a 20 μm sieve to remove coarse particles to obtain a negative electrode active material.

(Charge and discharge test)
A slurry was prepared by suspending 77% by mass of the obtained negative electrode active material, 15% by mass of graphite having an average particle diameter of 3 μm, and 8% by mass of polyimide in N-methylpyrrolidone. This slurry was applied on a copper foil having a thickness of 12 μm and rolled, and then heat-treated at 250 ° C. for 2 hours in Ar gas to dry the slurry and form a negative electrode mixture layer on the copper foil. . Next, the copper foil with the negative electrode mixture layer was cut into a predetermined size, and then dried in vacuum at 100 ° C. for 12 hours to obtain a test electrode.

A battery was manufactured in an argon atmosphere using the test electrode, the metal lithium foil as a counter electrode and a reference electrode, and an electrolytic solution, and a charge / discharge test was performed on the battery. As the electrolytic solution, a solution in which LiPF ₆ was dissolved at a concentration of 1 M in a mixed solvent containing EC and DEC at a volume ratio of 1: 2 (EC: DEC) was used.
The conditions of the charge / discharge test were as follows.
In the first charge / discharge, the battery is charged at a current density of 1 mA / cm ² until the voltage (potential difference between the reference electrode and the test electrode) becomes 0.01 V, and the voltage is maintained at 0.01 V and the constant voltage for 24 hours. The battery was charged and then discharged at a current density of 1 mA / cm ² until the voltage reached 1.5 V. The discharge capacity at this time was defined as the initial discharge capacity.
The second and subsequent charge / discharge cycles are performed by charging at a current density of 1 mA / cm ² until the voltage becomes 0.01 V and discharging at a current density of 1 mA / cm ² until the voltage becomes 1.5 V. The transition of the discharge capacity was measured. The cycle number at which the discharge capacity was able to maintain 80% of the initial discharge capacity was defined as the cycle life, and the evaluation was performed.

(Pore distribution measurement by _{N 2} adsorption method)
To the negative electrode active material obtained was subjected to pore distribution measurement by N ₂ adsorption method in the above method. Specifically, 0.2-0.5 g of the negative electrode active material sample was collected in a 1/2 inch cell, and firstly, as a pretreatment, a temperature was about 200 ° C. for about 15 hours by a vacuprep manufactured by Shimadzu Corporation-Micromeritics Co., Ltd. After performing degassing treatment by drying under reduced pressure, the measurement was performed using Tristar II3020 manufactured by Shimadzu Corporation-Micromeritics Co., Ltd. The resulting adsorption-desorption isotherm is shown in FIG. Thus, the slope a and the slope a ′ in the desorption isotherm were obtained.

(Structural observation inside the active material)
The test electrode obtained in Example 1 was sliced by an ion milling method, and then observed by TEM to confirm that silicon oxide particles were dispersed in the negative electrode active material. I got The resulting image is shown in FIG. The device used was JEM-200CX manufactured by JEOL Ltd., and the accelerating voltage was 200 kV.

(Composition analysis)
O / Si (atomic molar ratio) in the negative electrode active material obtained in Example 1 was calculated based on elemental composition analysis. The specific method of elemental composition analysis is to first determine the content of silicon atoms in the active material by alkali melting-ICP emission spectroscopy and the content of oxygen atoms by inert gas melting-infrared absorption, respectively. Next, the atomic molar ratio was calculated from this content ratio. As a result, a result was obtained in which silicon atoms were contained at a ratio of 25.7% by weight and oxygen atoms were contained at a ratio of 25% by weight, and O / Si (atomic molar ratio) was calculated to be 2.0.

  In the following Examples and Comparative Examples, only portions different from Example 1 will be described, and other synthesis and evaluation procedures are performed in the same manner as in Example 1, and thus description thereof will be omitted. In each case, as in Example 1, it was confirmed that the silicon-containing particles were dispersed in the amorphous carbon.

(Example 2)
A negative electrode active material was obtained in the same manner as in Example 1, except that 3.8 g of sucrose powder was used instead of ascorbic acid powder.

(Example 3)
The mixed powder of silicon and silicon dioxide was plasma-heated under the following conditions to obtain a silicon oxide powder. Silicon was a commercially available powder of about 5 μm, and silicon dioxide was a commercially available powder of about 4 μm. The mixed powder was prepared by mixing silicon and silicon dioxide at a molar ratio of 3: 1 (silicon: silicon dioxide). In the plasma heating, an area of 8000 ° C. was present in the plasma heating apparatus, and the mixed powder was dropped from above the area by a feeder and passed through the area. After passing through the above-mentioned region, the mixed powder vaporized by heating was quenched and precipitated. The obtained silicon oxide powder had an average primary particle size of 14 nm, a BET specific surface area of 268 m ² / g, and x of SiOx was 0.70.
4.0 g of ascorbic acid powder was added to 1.5 g of this silicon oxide powder, and dry-mixed in an agate mortar for 5 minutes. Next, ethanol was added to the obtained mixed powder using a dropper and kneaded for 30 minutes to obtain an ethanol-containing mixture. At the time of stiffening, ethanol was appropriately added as the ethanol evaporated. This ethanol-containing mixture was shaped into a dumpling to obtain a dumpling-like ethanol-containing mixture. This ethanolic mixture containing dumplings was put in an alumina mortar, allowed to stand on a hot plate at 150 ° C. for 1 hour, dried and solidified. The obtained dumpling-like solid was held at 1000 ° C. for 3 hours in an Ar atmosphere and fired. The obtained dumpling-like fired product was pulverized in an agate mortar, and the pulverized product obtained through the pulverization was sieved through a 20 μm sieve to remove coarse particles to obtain a negative electrode active material.

(Example 4)
As in Example 1, 1.5 g of hydrophilic silicon dioxide powder (commercially available, average primary particle size: 12 nm, BET specific surface area: 302 m ² / g, x = 2.0 of SiOx) and silicon powder (commercially available, average primary A silicon oxide powder was obtained by mixing a particle diameter of 40 nm, a BET specific surface area of 60 m ² / g, and SiOx (x = 0.024) of 0.075 g. 4.0 g of ascorbic acid powder was added to the obtained silicon oxide powder, and dry-mixed in an agate mortar for 5 minutes. Next, 25 g of pure water was added to the mixed powder, and crushing and mixing were performed using a ZrO ₂ ball with a planetary ball mill to prepare a slurry. The slurry was filtered under reduced pressure to remove ZrO ₂ balls, and the filtered slurry was transferred to a metal container so that the thickness became 5 mm or less, allowed to stand at 80 ° C. for 10 hours, and dried. The obtained dried product was transferred to an alumina mortar, allowed to stand on a hot plate at 150 ° C. for 1 hour, and further dried and solidified. The obtained solid was held at 1000 ° C. for 3 hours in an Ar atmosphere and fired. The obtained calcined product was pulverized in an agate mortar, and the pulverized product obtained by the pulverization was sieved through a 20 μm sieve to remove coarse particles to obtain a negative electrode active material.

(Example 5)
As in Example 1, 1.5 g of hydrophilic silicon dioxide powder (commercially available, average primary particle size: 12 nm, BET specific surface area: 302 m ² / g, x = 2.0 of SiOx) and silicon powder (commercially available, average primary A silicon oxide powder was obtained by mixing a particle diameter of 40 nm, a BET specific surface area of 60 m ² / g, and SiOx (x = 0.024) of 0.075 g. 4.0 g of ascorbic acid powder was added to the obtained silicon oxide powder, and dry-mixed in an agate mortar for 5 minutes. Next, this mixed powder was added to a solution prepared by dissolving 3.0 g of a solid resol-based phenol resin in 26 g of ethanol, and crushed and mixed by a planetary ball mill using ZrO ₂ balls to prepare a slurry. . The slurry is filtered under reduced pressure to remove the ZrO ₂ balls, the filtered slurry is transferred to a metal container so that the thickness becomes 5 mm or less, and the slurry is heated and dried at 80 ° C. C. for 1 hour to solidify. The obtained solid was transferred to an alumina mortar, and kept at 1000 ° C. for 3 hours in an Ar atmosphere and fired. The obtained calcined product was pulverized in an agate mortar, and the pulverized product obtained by the pulverization was sieved through a 20 μm sieve to remove coarse particles to obtain a negative electrode active material.

(Example 6)
A negative electrode active material was obtained in the same manner as in Example 5, except that 5.2 g of a liquid resol-based resin was used instead of the solid resol-based phenol resin.

(Comparative Example 1)
A negative electrode active material was obtained in the same manner as in Example 1 except that the liquid used for stiffening was replaced by pure water and a mixture of ethanol and ethanol at a weight ratio of 1: 2.

(Comparative Example 2)
Instead of hydrophilic silicon dioxide powder (commercially available, average primary particle size 12 nm, BET specific surface area 302 m ² / g, x of SiOx = 2.0), hydrophilic silicon dioxide powder (commercially available, average primary particle size 33 nm) And a BET specific surface area of 49 m ² / g, x of SiOx = 2.0), except that a negative electrode active material was obtained in the same manner as in Example 1.

(Comparative Example 3)
A negative electrode active material was obtained in the same manner as in Example 3, except that the liquid used for the stiffening was a mixture of ethanol and pure water at a weight ratio of 1: 1 instead of ethanol.

(Comparative Example 4)
A negative electrode active material was obtained in the same manner as in Example 5, except that the filtered slurry was transferred to a metal container so that the thickness became about 40 mm instead of being transferred to a thickness of 5 mm or less.

Regarding the negative electrode active materials of Examples 1 to 6 and Comparative Examples 1 to 4, the slope a and the slope a ′ in the desorption isotherm, the average primary particle diameter of the silicon oxide particles in the active material, the value of x in SiOx, and the first time Table 1 shows the discharge capacity and the cycle life. Observation of the structure inside the active material confirmed that silicon oxide particles were dispersed in all the active materials. As an example in which the slope a is negative and the slope a ′ is positive, but the absolute value of the slope a ′ is smaller than the absolute value of the slope a, the adsorption / desorption isotherm in the pore distribution measurement by the N ₂ adsorption method in Example 5 is shown. As shown in FIG. FIG. 9 shows an adsorption / desorption isotherm in the pore distribution measurement by the N ₂ adsorption method of Comparative Example 4 as an example in which the slope a is positive.

  In Examples 1, 2, 4, 5, 6 and Comparative Examples 1 and 4, there was no significant difference in the average primary particle diameter of the silicon oxide particles in the active material, the value of x in SiOx, and the initial discharge capacity. In Comparative Example 2 and Comparative Example 2, there is no significant difference in the value of x of SiOx and the initial discharge capacity, but the cycle a of Examples 1, 2, 4, 5, and 6 in which the slope a is minus is larger than the cycle life of Examples 1, 2, 4, 5, and 6. The cycle life of Comparative Examples 1, 2, and 4 was low. In Example 3 and Comparative Example 3, there is no significant difference in the average primary particle diameter of the silicon oxide particles in the active material, the value of x in SiOx, and the initial discharge capacity, but the slope a is negative. The cycle life of Comparative Example 3, in which the slope a was positive, was lower than that of Comparative Example 3.

  Although the embodiments have been described above, the embodiments are not limited to these, and various changes can be made within the scope of the invention described in the claims. Further, the embodiment can be variously modified in the implementation stage without departing from the scope of the invention. Furthermore, various inventions can be formed by appropriately combining a plurality of components disclosed in the above embodiments.

  Although several embodiments of the present invention have been described, these embodiments are provided by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Silicon oxide particle, 2 ... Carbonaceous material, 100 ... Negative electrode, 101 ... Negative electrode collector, 102 ... Negative electrode mixture layer, 200 ... Non-aqueous electrolyte secondary battery, 201 ... Wound electrode group, 202 ... 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 secondary battery, 301: stacked 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 unit cell, 402 adhesive tape, 403 battery pack, 404 printed wiring board, 405 Thermistor, 406: protection circuit, 407: conducting terminal, 408: positive lead, 409: positive connector, 410: negative lead, 411: negative connector, 412: wiring, 413: wiring, 414a: positive wiring 414b ... wiring on the minus side, 415 ... wiring, 416 ... protection sheet, 417 ... storage container, 418 ... lid

Claims (8)

Silicon oxide particles composed of silicon and silicon oxide, or silicon oxide, and having a composition formula represented by SiOx (0.1 ≦ x ≦ 2) and a carbonaceous material;
The average primary particle size of the silicon oxide particles is 3 nm or more and 50 nm or less,
In the type II desorption isotherm in the pore distribution measurement by the N ₂ adsorption method, the first measurement point where P / P ₀ was larger than 0.5 and the first measurement point where P / P ₀ was smaller than 0.7 were connected. An active material for a non-aqueous electrolyte battery in which the slope a of the straight line is negative. In the desorption isotherm, the slope a ′ of a straight line connecting the first measurement point where P / P ₀ is larger than 0.3 and the first measurement point where P / P ₀ is smaller than 0.5 is positive, and inclination a 'of the non-aqueous electrolyte battery active material according to size than I請 Motomeko 1 the absolute value of the absolute value of the slope a. The active material for a non-aqueous electrolyte battery according to claim 1, wherein the silicon oxide particles are dispersed in the carbonaceous material. Active material for a nonaqueous electrolyte battery according to any one of Ah Ru請 Motomeko 1 to 3 of particles the silicon oxide particles made of silicon dioxide. A current collector, and an electrode mixture layer formed on one or both surfaces of the current collector,
An electrode for a non-aqueous electrolyte battery, wherein the electrode mixture layer contains the active material for a non-aqueous electrolyte battery according to claim 1, a conductive agent, and a binder. An exterior material, a positive electrode housed in the exterior material, a negative electrode housed in the exterior material through a separator, spatially separated from the positive electrode, and a non-electrode filled in the exterior material. And a water electrolyte,
A non-aqueous electrolyte battery comprising the non-aqueous electrolyte battery electrode according to claim 5.   A battery pack comprising one or more nonaqueous electrolyte batteries according to claim 6. A vehicle comprising the battery pack according to claim 7.