WO2004114443A1

WO2004114443A1 - Negative electrode material, negative electrode, nonaqueous secondary cell composed of the negative electrode and positive electrode

Info

Publication number: WO2004114443A1
Application number: PCT/JP2003/014033
Authority: WO
Inventors: Teruhiko Kusano; Kazuhiro Ogawa; Satoshi Yamasaki; Tsuyoshi Haga; Hisashi Satake; Kazuya Kuriyama; Shiro Mori; Yukiko Okano; Shenglong Wang; Hajime Kinoshita; Shizukuni Yata
Original assignee: Electric Power Development Co., Ltd.
Priority date: 2003-06-24
Filing date: 2003-10-31
Publication date: 2004-12-29
Also published as: TW200501484A; AU2003280702A1

Abstract

The invention relates to a negative electrode material, a negative electrode, and a nonaqueous secondary cell comprising the negative electrode and a positive electrode, particularly to a negative electrode material for nonaqueous secondary cells high in capacity and excellent in chargeability, the negative electrode, a positive electrode, and a nonaqueous secondary cell. The material is made of a polycyclic aromatic hydrocarbon produced by subjecting a raw material containing a main component of pitch to a thermal reaction, while specifically determining the specific atomic ratio between hydrogen and carbon, the specific area, and the particle size. The material of the positive electrode is also specified.

Description

Negative electrode material, negative electrode, non-aqueous secondary battery composed of the negative electrode and positive electrode

The present invention relates to a negative electrode material for a non-aqueous secondary battery and a method for producing the same, and in particular, comprises a negative electrode material capable of significantly improving the performance of a lithium secondary battery, a negative electrode, and the negative electrode and the positive electrode Non-aqueous field This relates to secondary batteries. Background art

In recent years, it has been related to power sources for small portable devices such as mobile phones, storage systems for late-night power, home-use decentralized power storage systems for storing power by photovoltaic power generation, and power storage systems for electric vehicles. Therefore, various types of high energy density batteries are being developed energetically. In particular, the market for lithium-ion batteries has expanded exponentially because of their high volume energy density exceeding 350 WhZl and their excellent reliability such as safety and cycle characteristics. I have.

Lithium ion batteries using L i C O_〇 _2, L i Mn ₂ 〇 ₄ lithium-containing transition metal oxide typified as the positive electrode uses a carbon-based materials typified by graphite as a negative electrode. At present, the capacity of lithium-ion batteries is being further increased, but the increase in capacity through the improvement of cathode oxides and anode carbon-based materials has almost reached its limit, exceeding 45 O WhZl. It is difficult to achieve energy density. Also, in order to meet the anticipated needs for upsizing, a reduction in material costs is also strongly desired.

In particular, ensuring the safety is the most important issue for increasing the energy density and increasing the size of batteries, and from this viewpoint, further improvements in the characteristics of the electrode materials are desired. Various graphite-based materials, carbon-based materials, etc. Materials and polycyclic aromatic conjugated structural materials (generally called low-temperature-treated carbon materials or polyacenic materials) have been developed. In particular, the polycyclic aromatic conjugated structural material obtained by heat-treating various raw materials at a relatively low temperature of about 550 to 1000 ° C is C ₆ Li (372 mAh / g), which is the theoretical capacity of graphite. It is receiving particular attention as a material that exceeds the standard.

Among them, a negative electrode material for a non-aqueous secondary battery from a polycyclic aromatic hydrocarbon obtained by subjecting a raw material mainly composed of petroleum and coal pitch to a thermal reaction has been proposed (JP-A-2000-2000). -251885 publication). Such a negative electrode material for a non-aqueous secondary battery has an atomic ratio of hydrogen / carbon in the range of 0.35 to 0.05 and a specific surface area by BET method of 5 On ^ Zg or less.

In the case of such a negative electrode material having an HZC ratio of 0.22, a capacity of 90 OmAh / g was obtained by lithium doping for 20 hours. In this regard, it is expected to be a material for solving the above-mentioned problems.

However, such a conventional negative electrode material for a non-aqueous secondary battery still needs to be improved in practical use. As described in Japanese Patent Application Laid-Open No. 2000-251885, polycyclic aromatic hydrocarbons often produce amorphous products after thermal reaction. Crushing is required. For example, graphite-based materials used in lithium-ion batteries are currently preferably 10 m or more, particularly 20 to 30 m. In such a case, a jet mill or a pole mill is usually used as a fine mill. However, when the above-mentioned material is treated with such a normal pulverizer, the material tends to increase in pore size and specific surface area as the material is crushed. It deteriorates the initial efficiency of doping and undoping of lithium as a material. Therefore, there is a need for a negative electrode material and a method for producing the same that do not increase the specific surface area relatively even if the material is sufficiently pulverized. Particularly, in the case of polycyclic aromatic hydrocarbon materials, pores formed by pulverization are required. It is desirable to minimize structural changes. There are many issues that need to be improved in the practical use of polycyclic aromatic hydrocarbon materials. Particularly, when this material is applied to non-aqueous secondary batteries, practical lithium batteries of up to about 8 hours can be used. The capacity (mAh) and the cycle characteristics at the doping rate become important, and further improvement of the capacity is desired from this viewpoint. Further, conventionally, the pitch-based carbon material is heated at a temperature of about 100 to 400 ° C. in the air or treated with an oxidizing solution such as nitric acid or sulfuric acid to obtain the pitch. It is often manufactured by infusibilizing (crosslinking) the whole or its surface and then heat-treating it in an inert atmosphere. The specific surface area of the polycyclic aromatic hydrocarbon obtained by this method was increased, and there was a problem in the initial efficiency and the like.

In addition, the capacity of the negative electrode using a polycyclic aromatic hydrocarbon and its secondary battery is remarkably improved as compared with a conventional commercial lithium ion battery, and a high capacity about twice that of a commercial battery can be obtained. However, even in the practical use of this battery, there is a problem to be improved in its charge receiving characteristics. From the viewpoint of battery design, a negative electrode and excellent charge receiving characteristics of the battery are desired.

In general lithium ion batteries, the thickness of both the positive electrode and the negative electrode is designed to be around 100 zm.In the case of a graphite negative electrode, the thickness of the electrode layer is about 80 to 120 m. The basis weight of graphite is about 1 Omg to ² Omg per cm ² . In the above-mentioned publication, the thickness of a negative electrode using polycyclic aromatic hydrocarbon obtained by subjecting a raw material mainly composed of pitch to a thermal reaction is 10 O ^ m, which is a conventional lithium ion battery. It is the same design as. However, when the polycyclic aromatic hydrocarbon is used as the negative electrode active material, sufficient design cannot be obtained with the same design as before, and the 8 hour rate (charging or discharging of the battery is completed in 8 hours) (Charging or discharging speed set as described above), there still remains a problem that the capacity deteriorates greatly with the progress of the cycle.

The amount of lithium that can be released from the positive electrode is defined as Cp (mAh), the amount of lithium pre-doped into the negative electrode is defined as Cn (mAh), and the mass of the multi-functional coal in the negative electrode is expressed as W ( g PT / JP2003 / 014033

B), the relationship of 50 <(: 11 / ^ ¥ ^ <800 <(Cn + Cp) is disclosed. That is, more than 5 OmAhZg is required for polycyclic aromatic hydrocarbons in the negative electrode. It is said that it is preferable to set the charge amount of the negative electrode to 80 OmAh / g or more with respect to the polycyclic aromatic carbon <toK element in the negative electrode. Various factors such as HZC, ratio table, positive electrode material, negative electrode mixture ratio, and m® of hydrocarbon are deteriorated: ^, capacity is not good, In the case of batteries that use polycyclic hydrocarbons as the negative electrode, it is desired to control the charge amount of the negative electrode appropriately.

Furthermore, Ta驟Keisumyi in the Richiumui on battery using the negative electrode material Ru preparative瞎material containing iodine, L i PF _6, Li electrostatic angle such as a lithium salt, such as BF _4? Quality material propylene carbonate and Echiru A non-aqueous solvent dissolved in a mixed solvent of methyl carbonate or a mixed solvent of propylene and one mixture of propylene glycol is one! Used for a¾. Normally, such lead materials are not so much restricted in relation to such movements, unlike graphite. However, in the case of using a mixed solvent containing propylene carbonate, the chargeability of the negative electrode containing a polycyclic aromatic hydrocarbon is poor (or lithium is slow), and it takes a long time to charge. There is.

The lithium-nickel composite oxide, which is known as a high-capacity MIE electrode material for two nonaqueous pond cells, has a layered rock salt structure, similar to the lithium-cobalt composite oxide, and is a high-capacity material exceeding 200 mAh / g. This complex oxide is characterized by the fact that N i ⁴⁺ generated during charging is unstable in the structure, and the structure in a highly charged state where lithium is extracted from the structure in a large amount is unstable. is there. Due to this, there is a problem that the onset temperature of oxygen desorption from the crystal lattice is low. For example, it has been reported that “the onset temperature of oxygen desorption of a charged lithium nickel composite oxide is lower than that of conventional lithium cobalt oxide” (Solid State Ionics, No. 3). / 4, 265 (1994)).

For these reasons, lithium-nickel composite oxide is used alone as the positive electrode active material. Although a high capacity battery can be obtained, there is a problem in thermal stability in a high charge state, and the safety as a battery cannot be sufficiently secured. For this reason, it has not been put to practical use in lithium-ion batteries.

As the conductive material of the positive electrode, acetylene black, Ketjen black, natural graphite, artificial graphite, and the like have been used alone or in combination. Acetylene black and Ketjen black have a large specific surface area and are suitable for imparting electron conductivity to the positive electrode. However, there is a disadvantage that it is difficult to increase the density of the positive electrode because it is very bulky. Natural graphite and artificial graphite, on the other hand, are not bulky, but have a specific surface area of less than 100 parts by mass with respect to 100 parts by mass of the positive electrode active material in order to provide sufficient electron conductivity. Is required, which causes a decrease in battery capacity. For this reason, a positive electrode material that can be suitably combined with a negative electrode material having a high capacity is also desired.

A first object of the present invention is to make use of the characteristics of polycyclic aromatic hydrocarbons and suppress the change in the pore structure even when a material made of polycyclic aromatic hydrocarbons is pulverized to a sufficiently fine diameter. An object of the present invention is to provide a negative electrode material having a small specific surface area and a method for producing the same.

A second object of the present invention is to provide a material made of polycyclic aromatic hydrocarbons having a uniform particle size, specifying a particle size distribution and defining the specific surface area within a predetermined range, or setting a raw material pitch to a naphthene pitch. By specifying a coal-based isotropic pitch, it is possible to obtain a high capacity (mAh) in a practical lithium doping time, and to provide a negative electrode material having excellent cycle characteristics. It is an object of the present invention to provide a method for producing a negative electrode material for a non-aqueous secondary battery in which the production of such a material is easy and the yield is high, and a negative electrode and a non-aqueous secondary battery using the same.

A third object of the present invention is to improve the charge receiving characteristics at the negative electrode from the viewpoint of battery design,

It is an object of the present invention to provide a negative electrode that has less capacity deterioration due to repeated cycling even at a charging rate of about 8 hours, and a nonaqueous secondary battery in which the charge amount of the negative electrode is appropriately controlled. TJP2003 / 014033

A fourth object of the present invention is to provide a non-aqueous secondary battery having stability, high capacity, and excellent cycle life. Disclosure of the invention

The present inventors have found that it is particularly advantageous to use a polycyclic aromatic hydrocarbon obtained by subjecting a raw material to a thermal reaction without subjecting it to infusibilization as a negative electrode material, by subjecting the raw material to a thermal reaction. The first problem was solved by finding that the use of a Nylon pole mill, etc., when finely pulverizing to an average particle size of 10 m or less, would minimize the increase in the amount of pores. It is.

Further, the present inventors crushed a polycyclic aromatic hydrocarbon obtained using pitch as a main raw material so as to have a predetermined particle size distribution, and obtained a desired atomic ratio of hydrogen and Z carbon, and a desired specific surface area. It was found that the use of such a material as the negative electrode material of a non-aqueous secondary battery improves the capacity (mAh) in practical doping time and excels in its cycle characteristics. It is a solution.

That is, the negative electrode material of the present invention is a material composed of a polycyclic aromatic hydrocarbon obtained by subjecting a raw material having pitch as a main component to a thermal reaction, and the atomic ratio of hydrogen Z carbon of the material is 0. It is in the range of 50 to 0.05, the specific surface area by the BET method is in the range of 0.1 to 50 m ² Zg, and the average particle size of the material is 10 zm or less.

The negative electrode material preferably has the following physical properties or structure.

The material has an average particle size in the range of 6 xm to 1. The element ratio of hydrogen and carbon in the above material is in the range of 0.40 to 0.15. The specific surface area of the above materials by the BET method is in the range of 0.1 to 30 m ² Zg. The above material has a diameter of 2 m or less at a volume integration of 10% in the particle size distribution, and a diameter of 10 m or less at the 90% volume integration. Further, the pore volume of the material in the range of. 20 to 5 OA measured at the BJH method is not more than 1 X 10- ³ cc / g. Further, the present inventors have found that when a polycyclic aromatic hydrocarbon having a specific structure obtained using naphthalene pitch as a main raw material is ground to a predetermined particle size or less, a conventional coal-based or petroleum-based pitch is used. That the desired hydrogen / carbon atomic ratio can be easily obtained, the desired specific surface area can be easily obtained, the true density is not less than a predetermined value, and It was found that the use of a suitable hydrocarbon material as a negative electrode material for a non-aqueous secondary battery improved the capacity in a practical doping time and also excelled in its cycle characteristics, and solved the second problem. .

That is, the negative electrode material of the present invention is a material composed of a polycyclic aromatic hydrocarbon obtained by subjecting a raw material mainly composed of naphthylene pitch to a thermal reaction, and the hydrogen carbon atom of the material. The ratio is in the range of 0.50 to 0.05, the specific surface area by the BET method is in the range of 0.1 to 50 m ² Zg, and the average particle size of the material is 10 zm or less.

It is preferable that such a negative electrode material as a raw material containing a naphthalene pitch as a main component particularly has the following physical properties or structure.

The material has an average particle size in the range of 6 to 1 / m. The specific surface area of the above materials by the BET method is in the range of 0.1 to 30 m ² / g. In particular, it is preferable that the specific surface area of the above material by the BET method is in the range of 0.1 to 10 m ² Zg. The spacing d002 of the (002) plane of the above material by X-ray wide angle diffraction is less than 0.347 nm. The above material has an atomic ratio of hydrogen / carbon (H / C) in the range of 0.40 to 0.20, preferably in the range of 0.33 to 0.23, and the true density of the material is 1.

More preferably, it is 40 gZcm ³ or more.

Further, the present inventors have crushed polycyclic aromatic hydrocarbons obtained using coal-based isotropic pitch as a main raw material to a predetermined particle size or less, and obtained a desired hydrogen / carbon atomic ratio and a desired ratio table. It was found that the use of a non-aqueous secondary battery having an area and a true density exceeding a predetermined value as a negative electrode material improves the capacity in a practical doping time and has excellent cycle characteristics. It is a solution to the above problem. That is, the negative electrode material of the present invention is a material composed of a polycyclic aromatic hydrocarbon obtained by subjecting a raw material mainly composed of coal-based isotropic pitch to a thermal reaction. Has an atomic ratio in the range of 0.50 to 0.05, a specific surface area determined by the BET method in the range of 0.1 to 50 m ² / g, and an average particle diameter of the material is 10 × m or less.

It is preferable that the above-described negative electrode material, which is a raw material mainly composed of coal-based isotropic pitch, has the following physical properties or structure.

The material has an average particle size in the range of 6 m to 1 im. The specific surface area of the above material by the BET method is in the range of 0.1 to 30 m ² / g. The true density of the material is 1.45 gZcm ³ or more, and the atomic ratio of hydrogen to carbon (HZC) in the material is in the range of 0.25 to 0.18. The above material has a diameter of 2 m or less at a volume integration of 10% in the particle size distribution, and a diameter of 10 m or less at the 90% volume integration. The present inventors have solved the first and second problems by the following method for producing a negative electrode material.

That is, in a method for producing a negative electrode material for a non-aqueous secondary battery, a raw material containing pitch as a main component is subjected to a thermal reaction to generate a polycyclic aromatic hydrocarbon, which is powdered, and has an average particle diameter of 10 m. The atomic ratio of hydrogen / carbon is in the range of 0.5 to 0.05, the specific surface area by the BET method is in the range of 0.1 to 50 m ² / g, and the average particle size of the material is 10 m.

In such a production method, it is particularly preferable to subject the raw material to a thermal reaction without infusibilizing the raw material.

The inventors of the present invention have conducted various studies while paying attention to the above-described techniques, and as a result, the negative electrode manufactured with the negative electrode material having the above pitch having a specific basis weight or less has a charge characteristic of a non-aqueous secondary battery, It was found that the reliability of cycle characteristics was improved, and the third problem was solved.

That is, the negative electrode for a non-aqueous secondary battery of the present invention is obtained by thermally reacting a raw material containing pitch as a main component. A polycyclic aromatic hydrocarbon material obtained by subjecting the material to a hydrogen / carbon atomic ratio in the range of 0.50 to 0.05, and a specific surface area of 0 to 50% by the BET method. A negative electrode material having an average particle diameter of 10 m or less and a conductive material in a range of 1 to 50 m ² Zg, and a conductive material are molded with a binder. In the above-mentioned negative electrode, the basis weight of the negative electrode material is preferably 6 mg / cm ² or less. It is preferable that the density of the molding material is in the range of 0.85 to 1.3 g / cm ³ . It is preferable electric conductivity of the molding material is 10- ³ SZcm more. Further, the present inventors prepared a negative electrode material comprising a polycyclic aromatic hydrocarbon having a specific structure using the pitch as a raw material for the negative electrode, prepared a solvent for an electrolytic solution, etc. By controlling the voltage to a specific range, it was found that high capacity and charge acceptability could be improved, and the first to fourth problems were solved.

In particular, the present inventors have conducted intensive studies in order to solve the above problems, and as a result, have found that a negative electrode using a material composed of a polycyclic aromatic hydrocarbon having a specific structure and obtained using pitch as a main raw material. When a non-aqueous secondary battery is combined with a lithium nickel composite oxide having a specific composition as a positive electrode active material and a natural graphite having a specific physical property as a conductive material, a non-aqueous secondary battery has stability. The present inventors have found that a high-capacity non-aqueous secondary battery having excellent cycle characteristics can be obtained, and have reached the present invention.

That is, the non-aqueous secondary battery of the present invention is a non-aqueous secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte solution. a material consisting of aromatic hydrocarbons, with the range atomic ratio of hydrogen / carbon-containing of 0.50 to 0.05 of the material, BET method by specific surface area is 0.1 to 50 m ² Zg The negative electrode material has an average particle diameter of 10 m or less and a negative electrode formed by molding a conductive material with a binder. The positive electrode is a lithium composite metal oxide whose positive electrode active material contains Ni, and has a composition formula

L i _a N i _b Co _c A 1 _d 0 ₂ (l ≤ a ≤ 1.1, 0.5 ≤ b <0.9, 0.3 ≤ c 0.5, 0 <d≤0.15, b + c + d = l).

The negative electrode open potential at the time of charging of the negative electrode is preferably 10 OmV or less and 20 mV or more with respect to the lithium potential.

In such a negative electrode, a predetermined amount of lithium is pre-doped.

When the amount of lithium is defined as Cn (mAh) and the amount of lithium that can be released from the positive electrode active material in the initial charge is defined as the initial charge amount Cp (mAh), the negative electrode is doped with lithium of Cn + Cp (mAh). It is preferable to set the amount of Cn so that the above open potential is 10 OmV or less and 2 OmV or more with respect to the lithium potential. Assuming that the initial efficiency at the negative electrode when the amount of lithium of Cn + Cp (mAh) is doped is X and the amount of lithium absorbed into the positive electrode during the initial discharge is Cp 2 (mAh), the above Cp2 and (Cn + Cp) should satisfy the relationship of Cp 2Z (Cn + Cp) ≤x.

When the amount of lithium that can be released from the positive electrode active material in the initial charge of the positive electrode is defined as an initial charge amount Cp (mAh), and the amount of the positive electrode active material is defined as Wp (g), 180 <Cp / Wp S good.

Further, the non-aqueous locomotive includes a lithium salt containing at least ethylene carbonate and a chain carbonate as a solvent, and the ethylenic force containing 10% or more and 70% or less by volume percentage of the solvent. Is preferred.

.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the negative electrode material, the negative electrode, and the nonaqueous secondary battery including the negative electrode and the positive electrode according to the present invention will be described in detail. The nonaqueous secondary battery comprising the negative electrode material, the negative electrode, and the negative and positive electrodes according to the present invention is not limited to the following embodiments and examples.

The negative electrode material for a non-aqueous secondary battery according to the present invention is obtained by heat-treating a raw material containing pitch as a main component. PT / JP2003 / 014033

In particular, it comprises a polycyclic aromatic hydrocarbon (polycyclic aromatic conjugated structural material) obtained by subjecting it to a thermal reaction without being subjected to the infusibilizing treatment described below.

The pitch, which is the main component of the raw material, is not particularly limited as long as a negative electrode material having predetermined physical properties can be obtained. The pitch can be broadly divided into petroleum pitch and coal pitch. For example, examples of the petroleum pitch include a distillation residue of a raw material, a fluidized hornworm decomposing residue (eg, decant oil), potato oil from a thermal cracker, and ethylene tar obtained during naphtha cracking. Examples of coal-based pitch include straight pitch, which is a residue obtained by distilling coal, which is the oil obtained during carbonization of coal, and from which light components are discharged, or a mixture of this and anthracene oil, urea, etc. It is.

Further, as described later in detail, synthetic pitches such as naphthalene pitch synthesized by polycondensation of naphthalene are also known.

These pitches are currently inexpensive and produced in large quantities, and are mainly used for applications such as coke binders for steelmaking, impregnating materials for electrodes, raw materials for coke, raw materials for carbon fiber, and binders for molded carbon materials. However, the pitch used in the present invention is preferably a coal-based isotropic pitch, and such a pitch is optically isotropic when observed with a polarizing microscope.

On the other hand, as the anisotropic pitch, the crystallized pitch (mesophase pitch) is produced by combining heating of a certain isotropic pitch, solvent extraction, hydrogenation, etc., which is disadvantageous in cost. In the present invention, it is preferable to use a coal-based isotropic pitch as described later.

In addition, petroleum-based pitches often contain more sulfur as impurities than coal-based pitches, and synthetic pitches are disadvantageous in cost as well as crystallized pitches (mesophase pitches).

The raw material mainly composed of pitch used for the negative electrode material according to the present invention includes pitch For example, a conductive material such as a synthetic resin such as a phenol resin and graphite may be included in an amount not exceeding 50% by mass, more preferably not exceeding 30% by mass. Therefore, the “raw material containing pitch as a main component” in the present invention includes not only a raw material consisting of pitch alone but also such a pitch containing a mixture. However, in order to effectively obtain the negative electrode material according to the present invention, it is preferable to use a raw material consisting of the pitch alone.

The softening point of the raw material containing the pitch as a main component is preferably in the range of about 70 to 400 ° C, more preferably in the range of 100 to 350 ° C, and particularly preferably. Has a temperature in the range of 150 ° C. to 300 ° C. When the softening point of the pitch is lower than the above range, the yield of the desired thermal reaction product is reduced. On the other hand, when the softening point of the pitch is higher than the above range, the thermal reaction product is reduced. This also makes it difficult to obtain a desired negative electrode material. The negative electrode material for a non-aqueous secondary battery according to the present invention is obtained by thermally reacting the pitch, and the obtained hydrocarbon material has an element ratio of hydrogen / carbon of 0.50 to 0.05. The specific surface area by the BET method is in the range of 0.1 to 50 m ² // g.

The anode material according to the present invention has a hydrogen / carbon elementary ratio (hereinafter referred to as “H / C”) in the range of 0.50 to 0.05. Further, it is more preferably in the range of 0.40 to 0.15 as the negative electrode material. H / C is determined according to the raw material and the intended battery characteristics.However, if the H / C of the above materials exceeds 0.50, the polycyclic aromatic conjugated structure is not sufficiently generated in the negative electrode material. Therefore, when used as a negative electrode material, its capacity and efficiency are reduced. On the other hand, if the H / C of the above material is less than 0.05, carbonization proceeds excessively, and a sufficient capacity as a negative electrode material intended by the present invention cannot be obtained.

Further, when the raw material pitch contains the above-mentioned naphthalene pitch as a main component, the atomic ratio of hydrogen and Z-carbon (HZC) is 0.40 to 0.20, more preferably 0.33 to 0.23. It is better to be within the range of 0.23.

When the above atomic ratio (H / C) exceeds 0.33, the main polycyclic aromatic conjugate structure is not sufficiently formed in the negative electrode material, and therefore, it was used as a negative electrode material for a non-aqueous secondary battery. In such a case, a sufficient improvement in the maintenance rate of the cycle capacity cannot be seen. On the other hand, when the above-mentioned atomic ratio (H / C) is less than 0.23, the maintenance rate of the cycle capacity is increased, but the carbonization proceeds, and a high capacity cannot be obtained. Therefore, when the atomic ratio (HZC) of the material is in the range of 0.33 to 0.23, a high-capacity electrode material can be obtained, and a negative electrode material having an excellent cycle retention ratio can be obtained.

Further, when the raw material pitch is mainly composed of coal-based isotropic pitch, the hydrogen-Z carbon atomic ratio (HZC) is preferably in the range of 0.25 to 0.18.

When the above atomic ratio (H / C) exceeds 0.25, the main polycyclic aromatic conjugate structure was not sufficiently formed in the negative electrode material, and thus the material was used as a negative electrode material for non-aqueous secondary batteries. In such a case, a sufficient improvement in the maintenance rate of the cycle capacity cannot be seen. On the other hand, when the above atomic ratio (HZC) is less than 0.18, the maintenance rate of the cycle capacity increases, but the carbonization proceeds excessively and a high capacity cannot be obtained. Therefore, when the atomic ratio (HZC) of the material is in the range of 0.25 to 0.18, a high-capacity electrode material can be obtained, and a negative electrode material having an excellent cycle retention rate can be obtained.

The negative electrode material may contain other elements besides carbon and hydrogen as long as the effects of the present invention are not affected. For example, the negative electrode material may contain elements (oxygen, sulfur, nitrogen, etc.) other than carbon and hydrogen derived from the raw material. In order to prevent the characteristics of the negative electrode material from being impaired by such elements, it is desirable that the total mass of the other elements be suppressed to not more than 0.2%, more preferably not more than 10%, and still more preferably not more than 5%. . For this purpose, it is desirable to select a raw material having a small content of unnecessary elements or to select thermal reaction conditions under which unnecessary elements are easily released. In addition, sulfur can be easily reduced to 1% or less because naphthylene pitch is a synthetic pitch. PT / JP2003 / 014033

The negative electrode material for a non-aqueous secondary battery according to the present invention has a specific surface area by BET method in the range of 0.1 to 50 m ² Zg. Preferably, the specific surface area is in the range of 0.1 to 30 m ² / g. In particular, when the raw material is naphthalene pitch, the specific surface area is preferably in the range of 0.1 to 20 m ² / g, and particularly preferably in the range of 0.1 to 10 m ² / g.

If the specific surface area of the negative electrode material is too large, the initial efficiency of lithium doping and undoping is deteriorated, which is not practically preferable. If the specific surface area of the negative electrode material is less than the above range, lithium doping cannot be performed smoothly. The negative electrode material for a non-aqueous secondary battery according to the present invention is obtained by powdering the above-mentioned polycyclic aromatic hydrocarbon to have an average particle diameter of 10 m or less, and particularly, in the range of 6 m to 1 zm. Is desirable.

Usually, the negative electrode material for a non-aqueous secondary battery is formed by coating a conductive foil or the like as a mixed slurry of a polycyclic aromatic hydrocarbon and a resin pulverized to the above particle size. In this case, if the average particle size of the negative electrode material for a non-aqueous secondary battery is within the above range, a negative electrode having an appropriate thickness can be formed.

Further, the negative electrode material for a non-aqueous secondary battery according to the present invention has a particle diameter of 10% by volume in the particle size distribution is 2 m or less, and is pulverized so that the 90% diameter is 10 m or less. It is preferable to adjust the particle size distribution to the above range by classification. More preferably, the diameter of 10% is 2 zm or less, 1 / zm or more, and the diameter of 90% is 10 m or less, 6 zm or more. In particular, it is preferable when the raw material mainly contains coal-based isotropic pitch. When the diameter of the negative electrode material at a volume integration of 90% exceeds 10, the capacity decreases, and when the diameter of the 10% exceeds 2 m, the cycle deterioration tends to increase.

In addition, the negative electrode material is used to size the amorphous thermal reaction product to a predetermined particle size.The average particle size is 10 m or less, and the particle size is 1 m or less in the particle size distribution. It is preferable that the volume fraction of the compound be 1% or more. In particular, preferably, the average particle size is 10 m or less, and the volume fraction of the particle size of 1 m or less is 1 to 20%, more preferably 3 to 15%, particularly preferably 5 to 10%. It is desirable to be within the range.

Since the above-mentioned thermal reaction product has an irregular shape, it is crushed by a crusher such as a pole mill or a jet mill, and then, if necessary, classified to obtain a predetermined particle size. In general, graphite materials used for lithium-ion batteries with an average particle size of 10 m or less and a particle size of 1 or less and a volume fraction of 1% or more are unlikely to have lower initial charge / discharge efficiency and increase in electrode density. Use has been withheld. However, in the above-mentioned negative electrode material, although the mechanism is unknown, setting the above range improves the electrode density and the charge receiving characteristics. If the average particle size exceeds 10 m, the charge receiving characteristics will decrease. Also, if the volume fraction is less than 1% when the volume fraction is less than 1%, the electrode density is unlikely to increase, and the charge receiving characteristics are reduced. If the volume fraction exceeds 20%, it is difficult to fabricate an electrode described later. It becomes.

In the negative electrode material according to the present invention, the BJH method (B

The JH method is a calculation method generally used for the analysis of mesopores, and has been proposed by Barrett, Joyner, Ha1 enda, etc., and the calculation program is usually built in the pore distribution device. I have. ), The pore amount in the range of 2 OA to 5 OA is preferably 1 × 10 ⁻³ cc / g or less. In particular, it is preferred that the pore volume is less than 8 X 1 CT ⁴ c cZg. If pore volume is within the above range is less than 1 X 10- ³ c cZg, the specific surface area of the time the material is also rather the difficulty increases, the efficiency of de one blanking and Datsudoichipu in the initial increases, The capacity itself is sufficiently maintained.

When the above-mentioned raw material is mainly composed of naphthalene pitch, the negative electrode material preferably has a (002) plane spacing d 002 of less than 0.347 nm according to the X-ray wide-angle diffraction method. Compare within the above preferred HZC range (0.33-0.23) In this case, the interplanar spacing d 002 is smaller than that of polycyclic aromatic hydrocarbons obtained from general raw materials such as petroleum pitch, coal pitch, etc., and polycyclic aromatic hydrocarbons produced using naphthylene pitch There are characteristics in hydrocarbons.

The thermal reaction of the raw material containing the pitch as a main component is performed in an inert atmosphere (including vacuum) such as nitrogen or argon. The reaction temperature is also determined in consideration of various conditions other than the above-mentioned raw material type, properties, and temperature (heating rate, reaction time, reaction atmosphere, pressure, removal rate of gas components generated during the reaction outside the reaction system, etc.). The atomic ratio of hydrogen, hydrogen and carbon (H / C), and the specific surface area by BET method can be appropriately selected so as to be within the above range after pulverization.

The thermal reaction temperature is usually in the range of 550 to 750 ° C. When naphthalene pitch is used as a raw material, it is preferably in the range of 580 to 700 ° C, more preferably in the range of 600 to 680 ° C. When coal-based isotropic pitch is used as a raw material, the temperature is preferably in the range of 600 to 750 ° C, more preferably in the range of 620 to 720 ° C.

The yield of the desired hydrocarbon by the thermal reaction mainly depends on the softness point of the pitch and the solubility of quinoline, but is at least 60% or more, preferably 80% or more in the production method of the present invention. If the raw material, softening point and the like are appropriately selected within the above temperature range, a desired polycyclic aromatic hydrocarbon can be sufficiently obtained with a yield of 60% or more. If the raw material containing the pitch as a main component is thermally reacted in a temperature range of 550 to 750 ° C in an inert atmosphere, the thermal reaction product has an atomic ratio and a specific surface area of hydrogenocarbon in the above range from the thermal reaction product. A polycyclic aromatic hydrocarbon material can be obtained in a high yield.

Further, when a naphthylene pitch is the main component, the negative electrode material preferably has a true density of 1.40 g / cm ³ or more. In addition, when the main component of coal-based isotropic pitch, 1. 45 gZcm ³ or more, and more 1. preferably from 50 gZcm ³ or more. In order to obtain a sufficient capacity per volume, it is preferable to use 1.45 g / cm ³ or more. Next, a simple method for producing the negative electrode material for a non-aqueous secondary battery according to the present invention will be described. In the method for producing a negative electrode material according to the present invention, a polycyclic aromatic hydrocarbon is obtained by subjecting the above-described raw material having pitch as a main component to a thermal reaction without performing infusibilization.

Further, in the method for producing a negative electrode material according to the present invention using the above-described hydrocarbon as a main material, the hydrogen / carbon atomic ratio (H / C) of the material is within a predetermined range, and the specific surface area by the BET method is predetermined. It is manufactured so that the particle size and the particle size distribution take predetermined values.

The thermal reaction of the raw material containing the pitch as a main component is performed in an inert atmosphere (including vacuum) such as nitrogen or argon. The reaction temperature also takes into account various conditions other than the above-mentioned raw material type, properties and temperature (heating rate, reaction time, reaction atmosphere, pressure, removal rate of gas components generated during the reaction outside the reaction system, etc.). The atomic ratio of hydrogen and carbon (H / C), and the specific surface area by the BET method can be appropriately selected so as to be within the above ranges after pulverization.

The thermal reaction temperature is usually in the range of 600 to 750 ° C, more preferably in the range of 620 to 720 ° C, except that the above-mentioned naphthene pitch is the main component. is there.

If the raw material containing the pitch as a main component is thermally reacted in a temperature range of 600 to 75 ° C. in an inert atmosphere, the thermal reaction product can be used to obtain the above-mentioned atomic ratio of hydrogen and Z carbon and A polycyclic aromatic hydrocarbon material having a specific surface area can be obtained in a high yield.

Further, in the method for producing a negative electrode material according to the present invention, in order to simultaneously satisfy a specific HZC ratio and a specific specific surface area value, the thermal reaction temperature of the pitch raw material is controlled and the infusibilization treatment is not performed. For thermal reaction.

The specific surface area of the anode material generally decreases as the thermal reaction temperature increases, increasing the initial efficiency of lithium doping and undoping, but on the other hand, the capacity decreases sharply. You. Conventional polycyclic aromatic conjugated structural substances generally have a higher specific surface area than carbon-based materials and graphite-based materials, and most of them exceed 50 m ² Zg. In order to reduce the high specific surface area and increase the capacity, a technique of performing surface treatment again has been developed. However, in this case, a complicated operation is required, and an extra process is added in manufacturing, and the negative electrode material is added. This is practically disadvantageous because the manufacturing cost of the device is significantly increased.

The negative electrode material for a non-aqueous secondary battery according to the present invention is characterized in that the specific surface area is 50 m ² Zg or less while maintaining the range of the HZC ratio as described above. In the present invention, the pitch can be used as a raw material, and the specific surface area can be reduced to 5 Om ² Zg or less by one thermal reaction of the raw material pitch, and the reaction operation can be performed more easily.

Conventionally, when producing a hydrocarbon material from pitch raw material, the pitch must be 10 in air.

After heating at a temperature of about 0 to 400 ° C or by treating with an oxidizing liquid such as nitric acid or sulfuric acid to make the entire pitch or its surface infusible (crosslinking), an inert atmosphere Manufactured by heat treatment inside. On the other hand, in the production method of the present invention, the pitch is adjusted without infusibilizing treatment or surface oxidation treatment so that the reaction product simultaneously satisfies the above specific HZC ratio and specific specific surface area. Is subjected to a thermal reaction.

Furthermore, in the method for producing a negative electrode material according to the present invention, the main condition for determining its characteristics is the above-mentioned range of the thermal reaction temperature, but other secondary conditions are not particularly limited. There is no heating rate.

The heating rate is in the range of 10 to 100 ° C./hour, more preferably 50 to 500

° C / hour range. The heating rate does not need to be constant; for example, the temperature rises at a rate of 100 ° C up to a temperature of 300 ° C and 50 ° C from a temperature of 300 ° C to 65 ° C. The temperature can be raised at a rate of ° C / hour. The reaction time (peak temperature holding time) is about 1 to 50 hours. The pressure may be normal pressure, but the pressure may be reduced or increased.

In the method for producing a negative electrode material for a non-aqueous secondary battery according to the present invention, the heat reaction The resulting thermal reaction products are mostly obtained in an amorphous state. In order to use this as a material, the amorphous thermal reaction product is pulverized to a predetermined particle size, and the particle size is adjusted as necessary before use as a negative electrode material. That is, as described above, in order to adjust the particle size to a predetermined value of the average particle size and the volume integration in the particle size distribution, the thermal reaction product is powder-framed by a pulverizer such as a pole mill or a jet mill according to a conventional method, If necessary, it is classified and manufactured using a wind classifier.

Next, an embodiment of the negative electrode for a non-aqueous secondary battery according to the present invention will be briefly described.

Further, it is possible to assemble the battery in a state where lithium is previously doped in the above-mentioned anode material of the anode of the present invention, and further, after assembling the battery by a method such as bonding lithium metal on the anode. It is also possible to dope lithium into the negative electrode.

The negative electrode for a non-aqueous secondary battery according to the present invention is obtained by dispersing the above-described negative electrode material, conductive material, and the like in a resin binder and molding. The molding material for the electrode can be molded by a known method, taking into account the desired shape and characteristics of the non-aqueous secondary battery. In the present invention, the conductive material and the binder are not particularly limited, but concretely, the conductive material is exemplified by acetylene black, carbon black, Ketjen black, graphite, etc., and the binder is polyvinylidene fluoride. (PV d F), fluorine-based resins such as polytetrafluoroethylene; rubber-based materials such as fluororubber and SBR; polyolefins such as polyethylene and polypropylene; and acrylic resins.

The amount of the conductive material may be appropriately determined according to the type, particle size, shape, weight per unit area of the target electrode, strength, and the like of the negative electrode material of the present invention, and is not particularly limited. Usually, it is preferably about 1 to 20 parts by mass with respect to 100 parts by mass of the negative electrode material of the present invention.

The amount of the binder depends on the type, particle size, shape, purpose, and the like of the negative electrode material of the present invention. It may be determined appropriately according to the basis weight, strength, etc. of the electrode to be formed, and is not particularly limited, but is usually: 100 parts by mass of the negative electrode material of the present invention:! It is preferable that the amount be about 30 parts by mass.

In the present invention, the negative electrode can be formed on one side or both sides of the current collector. In this case, the current collector to be used is not particularly limited, and examples thereof include copper foil, stainless steel foil, and titanium foil. Further, a material on which an electrode can be formed on a metal foil or in a gap between the metals, for example, an expanded metal or a mesh may be used.

The basis weight of the negative electrode material in the negative electrode according to the present invention is 6 mg Zcm ² or less, preferably 5 mg Zcm ² or less, and 2 mg Zcm ² or more. If the weight per unit area in the present invention the formation of the negative electrode on one surface of for example copper foil, the mass of the negative electrode material-containing Murrell present invention per Fukyokumen 1 cm ^2, the case of forming the negative electrode on both sides of a copper foil, This is the mass of the negative electrode material contained on each side.

In the present invention, by setting the basis weight of the negative electrode material to 6 mg Zcm ² or less, the charge receiving characteristics can be improved. If the basis weight is too small, the volume ratio of the current collector, the separator and the like in the battery increases, and the battery capacity tends to decrease.

Here, the charge receiving characteristic will be described. In a non-aqueous secondary battery using the negative electrode of the present invention, for example, when a lithium-based electrolytic solution described later is used, the negative electrode is doped with lithium during charging, and the negative electrode potential decreases. If the lithium potential is reached and the lithium doping beyond that is continued at the same rate, the negative electrode will be below the lithium potential and in some cases lithium metal will deposit on the negative electrode. The charge acceptability is the easiness of doping until the negative electrode reaches the lithium potential.If the charge acceptability is poor, even if the active material has the ability to dope a large amount of lithium, its capacity is reduced. It cannot be fully utilized in battery design.

Therefore, when the basis weight of the negative electrode material exceeds 6 mg Z cm ² , the charge doping ability is poor, so that the lithium doping ability of the negative electrode material cannot be utilized and the battery capacity decreases. In addition, the capacity deterioration accompanying the cycle increases due to the deposition of lithium metal on the negative electrode.

The molding density (or molding layer density) of the negative electrode according to the present invention is not particularly limited, but is preferably in a range of about 0.85 to 1.3 gZcm ³ , and the H / C , $ Standing distribution, amount of conductive material and amount of binder. The molded electric conductivity (or the electric conductivity of the formed layer) of the negative electrode of the present invention is not particularly limited, but is preferably 10 ³ S / cm or more, more preferably 5 × 10 5 It is in the range of ^{3 to} 1 × 10 ^DS / cm. For example, when the electric conductivity is low, the charge acceptability is deteriorated.

In the negative electrode material of the negative electrode according to the present invention, it is possible to assemble the battery in a state in which lithium is previously doped, and further, by attaching a lithium metal on the negative electrode, the battery can be assembled. It is also possible to dope the above negative electrode material with lithium after assembly.

The non-aqueous secondary battery according to the present invention includes a negative electrode, a positive electrode, a separator, and a non-aqueous electrolyte as basic elements.

The above-described negative electrode material is used for the negative electrode for a non-aqueous secondary battery according to the present invention, and the positive electrode is not particularly limited as long as it is a positive electrode material capable of absorbing and releasing lithium. In order to obtain a secondary battery, for example, known lithium composite cobalt oxide, lithium composite nickel oxide, lithium composite manganese oxide, or a mixture thereof, and further, one or more different metal elements are added to these oxides A system or the like can be used. Further, manganese, vanadium, metal oxides such as iron, disulphide compounds, polyacene-based material, it is also possible to use a like activated carbon, in particular, L i CO0 terms of volume _{_{2, L i N i x Co}} y _{_{0 2, L i N i x}} Mn y 〇 ₂ lithium composite oxide and the like are preferable.

Further, the positive electrode in the nonaqueous secondary battery according to the present invention preferably contains a lithium composite oxide containing Ni as a positive electrode active material, and is further represented by the following composition formula: It is preferable to include a lithium nickel composite oxide as the positive electrode active material.

a) Composition formula L i _a N i _b C o _c A 1 _cl 0 ₂

(Where l≤a≤l.1, 0.5≤b <0.9, 0.3≤c <0.5, 0 <d≤

0.15, b + c + d = l) ".

A indicating the atomic ratio of L i is in the range of l≤a≤l.1. If a deviates from this range, the cycle characteristics will be reduced, or the capacity of the active material will be significantly reduced.

B, which indicates the atomic ratio of Ni, is in the range of 0.5 ≦ b <0.9. When b is 0.9 or more, the capacity of the active material increases, but the thermal stability decreases and the safety of the battery decreases. On the other hand, when it is less than 0.5, the capacity of the active material decreases.

Indicates the atomic ratio of Co. Is in the range 0.3≤c <0.5. When C is more than 0.5, the thermal stability is improved and the safety of the battery is improved, but the capacity of the active material is reduced. On the other hand, if it is less than 0.3, the capacity of the active material is increased, but the thermal stability is reduced and the safety of the battery is also reduced.

D, which represents the atomic ratio of A1, is in the range of 0 <d≤0.15. When d exceeds 0.15, the capacity of the active material decreases. Further, when A1 is not contained, the capacity of the active material is increased, the thermal stability is reduced, and the safety of the battery is also reduced.

The average particle size of the positive electrode active material is not particularly limited, and may be the same as that of a known active material. The average particle size of the positive electrode active material is in the range of 1 to 60 m, preferably

It is in the range of 5 to 40 zm, more preferably in the range of 10 to 30 m. In this specification, the “average particle size” means a central particle size in a volume particle size distribution obtained by a dry laser diffraction measurement method.

Although the specific surface area of the positive electrode active material is not particularly limited, it is usually not more than lm ² Zg, and more preferably in the range of 0.2 to 0.7 m ² Zg. In the present specification, “specific surface area” indicates a value measured by a BET method using nitrogen gas. The conductive material in the positive electrode of the nonaqueous secondary battery according to the present invention has a specific surface area of 10%.

It is preferable to include natural graphite of 0 m ² / g or more. This reduces the amount of such graphite Sufficient electron conductivity can be imparted even when used in a large amount, and the battery capacity is also improved. In addition, the electrode density can be easily controlled even during roll pressing after electrode application, and a high-density positive electrode can be obtained. Furthermore, it can be used in combination with a conductive material having a high specific surface area, such as acetylene black or Ketjen black, depending on the type of the active material. The amount of the conductive material used in the positive electrode is 100 parts by mass or less, preferably 2 to 7 parts by mass, when the positive electrode active material is 100 parts by mass.

In the lithium composite oxide according to the present invention, the amount of lithium that can be released from the positive electrode active material in the initial charge of the battery is Cp (mAh), and the amount of the positive electrode active material contained in the positive electrode is Wp (g). , 180, and Cp / Wp are preferable. ± L i N i 0 ₂ As _{¾ϋ, L i N i X C} o y 〇 _{_{2, L i N i x Mn}} y 0 2 , etc. of the lithium composite oxide containing N i especially good Mashiiku, sex lithium composite oxides from the perspective including _{_{L i N i x C o y}} 0 2, L i N i x Mn y 0 2 or N i with the addition of ¾¾¾ containing these reduction compounds are particularly preferred.

The above CpZWp force of 180 or less: ^, the negative electrode of the present invention has a capacity of 2 to 3 times @ ¾ of graphite used for lithium ion batteries. There is a problem in terms of cost, due to the increased thickness of the car.

The two nonaqueous pond of the present invention has the above-mentioned 3IE electrode, a negative electrode, and a nonaqueous motive, and the negative electrode open potential at the time of charging is 10 OmV or less and 2 OmV or more with respect to the lithium potential.

The negative electrode opening consideration during charging is the negative electrode opening when the battery is fully charged as determined by the charge. For example, after charging to 4.2 V with a current of 0.2 CA, apply a constant ¾E of 4.2 V for 0 hours. After charging for 8 hours with a constant current and constant voltage, with no current flowing to the battery The opening potential is defined as 25 ° C, and the opening time is defined as the potential after one hour, because the opening potential varies depending on the temperature and the temperature. The opening of the negative electrode during charging can be controlled by adjusting the active material balance of the positive electrode and the negative electrode, and the pre-doping amount. However, the potential between the lithium gold IS illumination electrode and the negative electrode may be measured.

The negative electrode opening during charging ^ t position exceeds 10 OmV with respect to lithium potential, Since lithium has not been doped, it is difficult to attain the high capacity which is the object of the present invention. When the voltage is less than 20 mV, the capacity is deteriorated due to the cycle because the temperature is close to the lithium doping capacity limit of the negative electrode.

In the non-aqueous secondary battery of the present invention, the negative electrode is preferably predoped with lithium to the negative electrode material.

The pre-doping amount _Cn (mAh) is the amount of lithium Cp (mAh) that can be released from the positive electrode active material in the initial charge, and the negative electrode opening when Cn + Cp (mAh) lithium is doped. It is desirable to say that the frank position is 10 OmV or less and 2 OmV or more with respect to the lithium potential. The amount of lithium C p (mAh) that can be released from the positive electrode active material during the initial charge is the amount released from the positive electrode during the first charge, specifically, the charge amount of the first battery, This is the amount of charge up to the electric charge where ± 電 ^ is determined.

In the present invention, the initial efficiency of the negative electrode when Cn + Cp (mAh) lithium is doped is X, the amount of lithium that can be released from the positive electrode active material in the initial charge is Cp (mAh), and the positive electrode in the initial discharge is When the amount of lithium stored in the battery is C p 2 (mAh), it is preferable to set a positive electrode so that C p 2 / (C n + C p) ≦ x. Regarding the initial efficiency X of the negative electrode, an electrochemical cell using the negative electrode as the working electrode, lithium metal as the counter electrode and the reference electrode is assembled, and C n + C p ( mAh) I: [^ After doping with lithium (mAh / g), 脱 (for example, 0.25 mA / cm ² ) escapes to 2 V with respect to the lithium metal potential. It can be measured by one tap. Further, the amount of lithium C p 2 (mAh) stored in the positive electrode in the initial stage is the amount of lithium that can be used by the positive electrode in the initial charge state of ± ί.

Regarding the amount of lithium Cp2 (mAh) stored in the positive electrode in the early stage Ma, the positive electrode was used as a non-aqueous electrode, and an electrode using lithium metal as a counter electrode and a reference electrode was assembled.リチウム! T (e.g., 0.25 mA / cm ² ) after discharging lithium in a specific capacity (mAh / g) corresponding to C p (mAh) calculated in advance in the electric horn Can be measured by undoping up to 3 V with respect to the lithium metal potential. C When p 2 / (C n + C p)> x, the battery capacity obtained tends to decrease. The method of pre-doping the negative electrode in the two non-aqueous batteries according to the present invention is not particularly limited. For example, before electrochemical charging, an electrochemical system using lithium metal as a counter electrode is assembled, and the key is removed. During aqueous transfer, a method of pre-doping a predetermined amount of lithium, and a method of bonding lithium metal to a negative electrode impregnated with a whip are available.

Also, in order to perform lithium pre-doping after the battery ast, a lithium source such as lithium metal and a negative electrode are bonded to each other by a method such as laminating them, and moving the battery inside the battery. It is the ability to predope lithium by injecting waves. Among them, as one example of a simple predoving method, there is a method in which a lithium metal foil is adhered to a negative electrode, a battery is ALX, and a lithium solution is poured into the battery to predope lithium. At this age, after the completion of lithium pre-doping, gaps are formed in the lithium metal part, and internal removal tends to increase. At this age, the thickness of the rice cake

0.2 Awake

There is a case in which the gap generated after the completion of the pre-doping of lithium is eliminated by pressing the gap between the battery and the internal pressure of the battery.

It is also possible to stop playing again after the completion of pre-doping. A typical example of an e-book of 0.2 or less is an aluminum-resin laminate film of π, which is also possible in the present invention.

As the non-aqueous whip narrowed in the present invention, a known non-aqueous electrolyte containing a lithium salt is used. The type of the electrolytic solution is appropriately determined according to the type of the positive electrode material, the properties of the negative electrode material, the use conditions such as the charging voltage, and the like. As the electrolyte, for example,

_{L i PF 6, L i BF} 4, L i C 1_Rei ₄ lithium salt propylene carbonate Natick bets such as ethylene force one Poneto, Jechiruka one Poneto, Jimechiruka one port ne one Bok, methylation E chill carbonate, Jimetokishe Tan, a-butyrolactone, methyl acetate

And those dissolved in one or more organic solvents such as methyl formate are preferred. Good.

In particular, for non-aqueous drama II, a mixed solvent containing ethylene carbonate (hereinafter referred to as EC) is preferable. The ^ fraction of EC in the mixed solvent containing EC is preferably 10 to 70%, more preferably 15 to 60%, and still more preferably 20 to 50%. EC rate less than 10%: ^ decreases charging acceptability, exceeds 70% :! ^ Has a high freezing point of EC of 39 ° C and is segregated at low temperature, and the emission of ffi- 10 ° C or less in the battery is remarkably reduced.

Examples of the solvent used in combination with the EC include a linear carbonate, for example, ethyl methyl carbonate (EMC), getyl carbonate (DEC), and dimethyl carbonate. Wear. What is a chain carbonate?

R 1— 0— CO— 0— R 2, where Rl and R 2 have the same or different alkyl groups, and may be alkyl groups in which the hydrogen has been replaced with a halogen of fluorine group. ^ When R1 and R2 are alkyl groups, those having 1 to 4 carbon atoms are preferably used.

The concentration of the electrolyte is not particularly limited, but may be 0.5 to 2mo 1

A range of about Z liters is practical. Of course, it is preferable to use an electrolyte having a water content of 100 ppm or less. In this specification, the term “non-aqueous electrolyte” means a concept including a non-aqueous electrolyte and an organic electrolyte, and also includes a concept including a gel and a solid electrolyte. It is. The shape and size of the non-aqueous pond according to the present invention are not limited to those that are not knee-shaped, and can be any shape such as a cylindrical type, a square type, a film battery, and a box type, depending on the intended use. What is necessary is just to measure the thing of the size.

Hereinafter, examples and comparative examples of the non-aqueous secondary battery material according to the present invention, and a method for producing the same will be shown to further clarify features of the present invention.

(Example 1)

1) Coal-based isotropic pitch (softening point 280 ° C) 1000 g in stainless steel dish TJP2003 / 014033

The dish was placed in an electric furnace (effective size in the furnace: 300 × 300 × 300 mm) and subjected to a thermal reaction. The thermal reaction was performed in a nitrogen atmosphere, and the nitrogen flow rate was 10 liter / min. During the thermal reaction, the temperature is raised from room temperature to a temperature of 635 ° C (furnace temperature) at a rate of 100 ° C / hour. After the temperature was raised, the temperature was maintained at the same temperature for 4 hours, then cooled to a temperature of 60 ° C by natural cooling, and the reaction product was taken out of the electric furnace. The resulting product did not retain the shape of the raw material, and was an amorphous insoluble infusible solid. The heat reaction temperature and yield were 804 g, and the yield was 80.4% by mass.

The obtained product was pulverized by a jet mill to obtain a negative electrode material having an average particle diameter of 5.5 m and particles of 1 m or less having a volume fraction of 7%. Using this negative electrode material, elemental analysis (measurement device: PE2400 Series II, CHNS / 0 manufactured by PerkinElmer Inc.) and specific surface area by BET method (measurement device: Easa Ionics Co., Ltd.) N〇VA 1200 ”). As a result, H / C was 0.26, and the specific surface area was 24 m ² Zg. The elemental analysis and the measurement of the specific surface area in the following examples are performed by the above-mentioned instruments.

2) 90 parts by weight of the above negative electrode material, 5 parts by weight of acetylene black, 7 parts by weight of polyvinylidene fluoride (PVdF), and N-methyl-2-pyrrolidone (NMP) were mixed to obtain a negative electrode mixture slurry. This slurry was applied to one surface of a copper foil having a thickness of 14, dried, and pressed to obtain a negative electrode having a thickness of 6 (mixture layer thickness of 49 m) and a density of 1.0 gZcm ³ .

3) Using the above negative electrode as a working electrode, metallic lithium as a counter electrode and a reference electrode, and an electrolytic solution (a solvent obtained by mixing ethylene carbonate and getyl carbonate in a volume ratio of 50:50 to a concentration of lmo1 / liter in a solvent mixed with a volume ratio of 50:50). (A solution in which PF ₆ was dissolved) was used to prepare an electrochemical cell in an argon dry box. Then, the charge receiving characteristics of the negative electrode were evaluated.

The charge acceptance characteristics of the negative electrode are evaluated in the second cycle, and the doping of lithium in the second cycle is 16 OmA / g until it reaches lmV with respect to the lithium potential. Then, undoping was performed at a rate of 16 OmAZg to 2 V with respect to the lithium potential, and the capacity was evaluated based on the obtained undoping amount. The results are shown in Table 1.

(Example 2, Comparative Example 1)

Example 2 and Comparative Example 1 were the same as Example 1 except that the average particle size of the material obtained in 1) of Example 1 and the volume fraction of particles of 1 m or less were changed as shown in Table 1. Prototyping and evaluation were performed in the same manner.

table 1

From the results in Table 1, it can be seen that the average particle size of the nonaqueous secondary battery negative electrode material exceeds 10; m even when the volume fraction of particles of 1 / m or less is 1% or more as in Comparative Example 1. In addition, it can be seen that the charge receiving characteristics are inferior to those of the example. Also, in the negative electrode or the non-aqueous secondary battery using the negative electrode material for a non-aqueous secondary battery in which the volume fraction of particles of 1 m or less is less than 1% as in Example 2, the charge receiving characteristics are as in Example 1. It turns out that it is slightly inferior.

Negative electrode material for a nonaqueous secondary battery according to the present invention, a hydrogen / elemental ratio of carbon is in the range of 0.50乃optimum 0.05, the range of the specific surface area is 0.1 to 50 m ² Zg by the BET method In addition, since the above-mentioned materials have an average particle size of 10 / m or less, the materials have high capacity and excellent charge-receiving characteristics.

(Example 3)

• Manufacturing method of negative electrode material

In the same manner as in Example 1, the product obtained from the coal-based isotropic pitch was To make a powder with a particle size of about 100 zm. Elemental analysis of this powder and specific surface area by BET method were performed. As a result, H / C was 0.22, and the specific surface area was 26 m ² / g. Also was 1 X 10_ ⁴ c cZg following order was determined pore volume of 20 to 5 OA ranges by the BJH method in the calculation software provided the equipment.

Next, the above powder was ground with a nylon pole mill for 18 hours to obtain a negative electrode material having an average particle diameter of 3 m. The specific surface area by the BET method by measurement of the same is 14. 4m ² / g, a pore volume of 20 to 5 OA by the BJH method is filed at 1. 48X 10 one ⁴ cc / g / this.

(Reference example 1)

In the same manner as in Example 2, except that the alumina-made pole mill was ground, a 4 m powder was obtained by grinding for 6 hours. According to the above measurement, the specific surface area by the BET method was 26.4 m ² Zg, and the pore amount of 20 to 5 OA by the BJH method was 1.44 × 10 ³ cc / g. Although the particle size was larger than that of Example 2, the specific surface area was large. It that has become pores due to the difference in milling methods Ri our increased compared to Example 2, pores of 20 to 5 OA by the BJH method 10- ³ c cZg more.

As described above in Reference Example 1, the negative electrode material for a non-aqueous secondary battery according to the present invention has an average particle diameter of 10 or less and is in the range of 20 A to 50 A in the BJH method. pore volume is less than 10- ³ c cZg, be ground polycyclic aromatic hydrocarbon material to a sufficient small diameter, the pore structure change is suppressed, it is a child of the specific surface area small.

(Example 4)

1000g of coal-based isotropic pitch (softening point 280 ° C) is placed in a stainless steel dish, and this dish is placed in an electric furnace (effective size in the furnace: 30 OmmX 30 OmmX 300mm) to allow thermal reaction. Provided. The thermal reaction is performed in a nitrogen atmosphere, and the nitrogen flow rate is 1 _m

PCT / JP2003 / 014033

It was 0 liter Z minutes. In the thermal reaction, the temperature rises at a rate of 100 ° CZ for temperatures up to 400 ° C. . After the temperature was raised, the temperature was maintained at the same temperature for 12 hours, and then cooled to a temperature of 60 ° C by natural cooling, and the reaction product was taken out of the electric furnace. The obtained product did not retain the shape of the raw material, and was an amorphous insoluble infusible solid. The yield was 79.4% by mass.

The resulting material was coarsely ground to a particle size of 5 mm or less by a shearing mill, and then ground to an average particle size of about 4 xm using a jet mill to obtain a negative electrode material. Elemental analysis of the obtained negative electrode material, specific surface area by BET method, true density (using 1-butanol as solvent), and particle size distribution (measurement machine: Shimadzu Corporation “S ALD 2000 J”) were measured. . The results are shown in Table 2 below.

Next, 90 parts by mass of the negative electrode material powder, 5 parts by mass of acetylene black powder as a conductive agent, and 5 parts by mass of PVdF as a binder were mixed with NMP as a solvent to obtain a negative electrode mixture slurry. This slurry was applied to one surface of a copper foil having a thickness of 18; zm, dried, and pressed to obtain an electrode having a thickness of 50 m and a density of lg / cm ³ .

The electrode obtained above was used as the working electrode, metallic lithium was used as the counter electrode and the reference electrode, and 1 mo 1 ZL was added to a solvent obtained by mixing ethylene force ponate and getyl carbonate in a 1: 1 (volume ratio) electrolyte. An electrochemical cell was prepared in an argon dry box using a solution of Li PF ₆ dissolved at a concentration. Doping lithium is carried out in 1 MAZ cm ² constant current until the 1 mV with respect Lithium potential, further a constant voltage application lmV respect Lithium potential, and 8 hours doping combined. After a pause of 10 minutes, dedoping was performed at a constant current of ImA / cm ² to 2 V with respect to the lithium potential. After a pause of 10 minutes, doping and undoping were performed in the same manner as above, and a total of 10 cycles were performed. The results are shown in Table 2 below.

(Example 5) A thermal reaction was performed in the same manner as in Example 4 except that the thermal reaction temperature of the coal-based isotropic pitch raw material was set at 680 ° C to obtain an insoluble infusible solid. The yield was 79.5% by mass. Table 2 shows the results of measuring the HZC, specific surface area, true density, and average particle size of this material in the same manner as in Example 3.

Next, an electrode was produced in the same manner as in Example 4, and the doping amount and the undoping amount of lithium were measured for 10 cycles. Table 2 shows the results of the initial capacity and the 10-cycle capacity.

(Example 6)

A thermal reaction was carried out in the same manner as in Example 4 except that the thermal reaction temperature of the coal-based isotropic pitch raw material was set at 660 ° C to obtain an insoluble infusible solid. The yield was 79.4% by mass. Table 2 below shows the results of measuring the HZC, specific surface area, true density, and average particle size of this material in the same manner as in Example 4.

Next, an electrode was produced in the same manner as in Example 4, and the doping amount and the undoping amount of lithium were measured for 10 cycles. Table 2 shows the results of the initial capacity and the 10-cycle capacity. '' (Example 7)

A thermal reaction was performed in the same manner as in Example 4 except that the thermal reaction temperature of the coal-based isotropic pitch raw material was set at 64 ° C. to obtain an insoluble infusible solid. The yield was 84.3% by mass. The H / 'C, specific surface area, true density and average particle size of this material were measured in the same manner as in Example 4 and the results are shown in Table 2 below.

(Reference example 2)

A thermal reaction was performed in the same manner as in Example 3 except that the thermal reaction temperature of the coal-based isotropic pitch raw material was set at 62 ° C., to obtain an insoluble infusible solid. The yield was 81.3% by mass. Three

The HZC, specific surface area, true density, and average particle size of this material were measured in the same manner as in Example 4, and the results are shown in Table 2 below.

(Reference example 3)

A thermal reaction was performed in the same manner as in Example 4 except that the thermal reaction temperature of the coal-based isotropic pitch raw material was set at 580 ° C, to obtain an insoluble infusible solid. The yield was 82.5% by mass. Table 2 shows the results of measuring the H / C, specific surface area, true density, and average particle size of this material in the same manner as in Example 4.

(Reference example 4)

A thermal reaction was carried out in the same manner as in Example 4 except that the thermal reaction temperature of the coal-based isotropic pitch raw material was set at 740 ° C, to obtain an insoluble infusible solid. The yield was 79.2% by mass. Table 2 shows the results of measuring the HZC, specific surface area, true density, and average particle size of this material in the same manner as in Example 4.

Next, an electrode was produced in the same manner as in Example 4, and the doping amount and the undoping amount of lithium were measured for 10 cycles. Table 2 shows the results of the initial capacity and the 10-cycle capacity. Example 4 Example 5 Example 6 Example 7 Reference example 2 Reference example Thermal reaction temperature (to 700 680 660 640 620 580

0.18 0.21 0.23 0.25 0.28 0.3 Specific surface area (OnVs) 17 19 20 20 22 28 True density (s / cm ^s ) 1.63 1.61 1.55 1.50 1. 9 1. Average particle size (ym 3. 8 3. 9 4. 0 3. 9 4.0) 3. Initial capacity (mAli / s) 618 644 688 736 727 680

10 cycle capacity

583 597 616 642 618 548 (mAhXg)

Cycle capacity X true density

950 961 955 963 921 773 (mAh / cm ¹ )

In order to comprehensively determine the capacity per mass, volume, and cycle characteristics, comparing the capacity per volume obtained by multiplying the capacity at the 10th cycle by the true density, when H / C is 0.25 to 0.18, was 950mAh / cm ^³ ~97 OmAhZcm ^3, when the H / C exceeds 0.25, the initial capacity is increased, the volumetric capacity is reduced. If it is less than 0.18, the initial capacity itself will be reduced.

Therefore, it is understood from the relationship with Examples 4 to 7 and Reference Examples 2 to 4 that the range of H / C is more preferably 0.25 to 0.18.

As described above, the negative electrode material according to the present invention is made of a polycyclic aromatic hydrocarbon obtained by subjecting a raw material mainly containing coal-based isotropic pitch to a thermal reaction. The atomic ratio of the hydrogen Z carbon is in the range of 0.25 to 0.18, the specific surface area by the BET method is in the range of 0.1 to 50 m ² Zg, and the true density is 1.45 g Z cm ³ As described above, since the average particle size is 10 zm or less, a high capacity per mass and per volume can be obtained with a practical doping time, and a non-aqueous secondary battery with excellent cycle characteristics can be provided. Can be. Further, the method for producing a negative electrode material for a non-aqueous secondary battery according to the present invention is characterized in that the raw material containing the above-mentioned coal-based isotropic pitch as a main component is subjected to a thermal reaction without being subjected to infusibilization treatment, and is subjected to polycyclic aromatic carbonization. Since hydrogen is obtained, the production of the negative electrode material is simple and the yield can be improved.

(Example 8)

Coal-based isotropic pitch (softening point 280 ° C) 100 Og is put into a stainless steel dish, and this dish is placed in an electric furnace (effective size in furnace: 30 OmmX 30 OmmX 30 Omm) and heat It was subjected to the reaction. The thermal reaction is performed in a nitrogen atmosphere, and the nitrogen flow rate is 1

0 liter / min. In the thermal reaction, the temperature rises at a temperature rise rate of 10 OZ hours up to a temperature of 400 ° C, and rises to a temperature of 680 ° C (in-furnace temperature) at a temperature rise rate of 50 ° CZ for temperatures of 400 ° C or more. After the temperature was raised, the temperature was maintained at the same temperature for 12 hours, and then cooled to a temperature of 60 ° C by natural cooling, and the reaction product was taken out of the electric furnace. The obtained product did not retain the shape of the raw material, and was an amorphous insoluble infusible solid. 79.5 quality yield %.

The obtained material was coarsely ground to a particle size of 5 mm or less by a shearing mill, and then ground to an average particle size of about 4 m using a jet mill to obtain a negative electrode material. Elemental analysis was performed on the obtained negative electrode material. The hydrogen / carbon atomic ratio (HZC) was 0.21. In addition, the specific surface area and the particle size distribution were measured by the BET method. The results are shown in Table 3 below. The true density (using 1-butanol as a solvent) was measured (measuring machine: Shimadzu "SALD 2000 J"). As a result, it was 1.61 g / cm ³ .

Next, 90 parts by mass of the above-described negative electrode material powder, 5 parts by mass of acetylene black powder as a conductive agent, and 5 parts by mass of PVdF as a binder were mixed with N-methylpyrrolidone (NMP) as a solvent. A slurry was obtained. This slurry was applied to one side of a copper foil having a thickness of 18 zm, dried, and pressed to obtain an electrode having a thickness of 50 μm and a density of 1 gZcm ³ .

The electrode obtained above was used as the working electrode, metallic lithium was used for the counter electrode and the reference electrode, and 1 mo 1 ZL was added to a solvent obtained by mixing ethylene force ponate and getylcapone ponate at a ratio of 1: 1 (volume ratio) as the electrolyte. An electrochemical cell was prepared in an argon dry box using a solution of Li PF ₆ dissolved at a concentration. Doping lithium is carried out in 1 MAZ cm ² constant current until 1 m V relative Lithium potential, further a constant voltage application 1 mV with respect Lithium potential, and 8 hours doping combined. After a pause of 10 minutes, undoping was performed to a lithium potential of 2 V with a constant current of ImA / cm ² . After a pause of 10 minutes, doping and undoping were performed in the same manner as above, and a total of 10 cycles were performed. Table 3 shows the results of the initial capacity and the 10-cycle capacity.

(Example 9)

A negative electrode material having an average particle size of 4 zm and a particle size distribution different from that of Example 8 was obtained using an air classifier in Example 8. The specific surface area and particle size distribution of this material were compared with those of Example 8. P2003 / 014033

It measured by the same method. The results are shown in Table 3 below.

Next, an electrode was produced in the same manner as in Example 8, and the doping amount and the undoping amount of lithium were measured for 10 cycles. Table 3 below shows the results for the initial capacity and 10 cycle capacity.

(Reference Example 5)

A negative electrode material having an average particle size of 4 zm and a particle size distribution different from that of Example 8 was obtained using an air classifier in Example 8. The specific surface area and particle size distribution of this material were measured in the same manner as in Example 8. The results are shown in Table 3 below.

Although the diameter of 10% of the volume integration of such a material is within the desired range, the diameter of 90% is 10.6 m, which is beyond the range of 10 xm or less in the embodiment. There was a drop.

(Reference Example 6)

A negative electrode material having an average particle size of 4 m and a particle size distribution different from that of Example 8 were obtained using an air classifier in Example 8. The specific surface area and particle size distribution of this material were measured in the same manner as in Example 8. The results are shown in Table 3 below.

Although the 90% diameter of the material is within the desired range, the 10% diameter is 2.2 xm, which is less than the range of 2 m or less in Example 8. There was down. Table 3

As described above, with reference to Reference Examples 5 and 6, the negative electrode materials of Examples 8 and 9 have, in addition to the requirements of Examples 4 to 7, a diameter of 2 m where the volume integral in the particle size distribution is 10%. Since the diameter of 90% is 10 zm or less, a high capacity can be obtained in a practical doping time, and a nonaqueous secondary battery excellent in cycle characteristics can be provided. Further, in the method for producing a negative electrode material for a non-aqueous secondary battery according to the present invention, a polycyclic aromatic hydrocarbon is obtained by subjecting the raw material containing the pitch as a main component to a thermal reaction without infusibilizing the raw material. Therefore, the production of the negative electrode material is simple and the yield can be improved.

(Example 10)

, Manufacturing method of negative electrode material

The naphthylene pitch (softening point: 287 ° C) 60 was placed in a magnetic dish, and this dish was placed in a small cylindrical furnace (core tube inner diameter: 10 Omm) and subjected to thermal reaction. The thermal reaction was performed in a nitrogen atmosphere, and the nitrogen flow rate was 0.5 liter / minute. The thermal reaction is performed at a temperature of 100 ° C, and the temperature in the core tube is changed from room temperature to a predetermined thermal reaction temperature (630 ° C, 640 ° C, 650 ° C, 686 ° C). C, and 70 ° C). After the temperature was raised, the temperature was maintained at the same temperature for 4 hours, then cooled to a temperature of 60 ° C by natural cooling, and the dishes were taken out of the furnace. The obtained polycyclic aromatic hydrocarbon material did not keep the shape of the raw material, and was an amorphous insoluble infusible solid. The thermal reaction temperature and yield are summarized in Table 4 below. -Negative electrode manufacturing method

Each hydrocarbon material at each thermal reaction temperature obtained above using a pole mill The material was pulverized to an average particle size of about 5 / m to obtain a negative electrode material. The obtained negative electrode material was subjected to X-ray wide-angle diffraction (measurement machine: Mac science XMP-3 X-ray source Cu—Κα (1 • 54Α)), elemental analysis, and measurement of specific surface area by BET method. The results are shown in Table 1 below.

Next, 88 parts by mass of the above negative electrode material powder, 5 parts by mass of acetylene black, 7 parts by mass of PVdF, and N-methyl-2-pyrrolidone (NMP) were mixed to obtain a negative electrode mixture slurry. This slurry was applied to one side of a copper foil having a thickness of 14 im, dried, and pressed to obtain an electrode having a thickness of 80 m.

• Evaluation of the capacity of the anode in the obtained negative electrode

The negative electrode obtained above was used as the working electrode, metallic lithium was used as the counter electrode and the reference electrode, and the solvent was a mixture of ethylene force monoponate and getyl carbonate in a 3: 7 (volume ratio) mixture. the concentration of liter have use a solution of L i PF _6, an electrochemical cell was prepared in an argon dry box. Doping of lithium was performed at a rate of 16 OmAZg until the potential became lmV with respect to the lithium potential, and a constant voltage of lmV was applied with respect to the lithium potential. The doping was completed in a total of eight hours. Next, the operation of undoping up to 2 V with respect to the lithium potential at a rate of 16 OmAZg was repeated twice, and the capacity was evaluated by the second undoping amount. The results are shown in Table 4.

Table 4

(Reference Example 7)

The raw material is coal-based isotropic pitch (softening point 280 ° C), thermal reaction temperature is 615 ° C, A thermal reaction was carried out in the same manner as in Example 10 except that the temperature was changed to 65O 0 C, to obtain an amorphous insoluble infusible solid. Table 5 summarizes the thermal reaction temperature and yield. Further, the powder frame was formed in the same manner as in Example 10, and the physical properties were measured. Thereafter, an electrode was formed and the capacity was evaluated. Table 5 shows the results.

Table 5

(Reference Example 8)

The same thermal reaction as in Example 10 was carried out except that the raw material was petroleum-based isotropic pitch (softening point: 225 ° C) and the thermal reaction temperature was 615 ° C, 650 ° C. A fixed insoluble infusible solid was obtained. Table 6 summarizes the thermal reaction temperature and yield. Further, the powder was ground in the same manner as in Example 10, and the physical properties were measured. Thereafter, an electrode was prepared, and the capacity was evaluated. Table 6 shows the results.

Table 6

As a result, as shown in Example 10, a negative electrode material can be obtained at a higher yield when using naphthylene pitch as a raw material than when using petroleum pitch or coal pitch as a raw material. In addition, it can be seen that the value of H / C with respect to the thermal reaction temperature is relatively high, and that d002 is low. In addition, the capacity has been greatly improved compared to the case where petroleum pitch and coal pitch are used as raw materials.

(Example 11)

100 g of naphthalene pitch (softening point: 287 ° C: manufactured by Mitsubishi Gas Chemical Company) is placed in a stainless steel dish, and the dish is placed in an electric furnace (effective size in furnace: 300 mm × 300 mm). mm x 30 O mm) and subjected to a thermal reaction. Thermal reaction is performed under nitrogen atmosphere The nitrogen flow rate was 10 l / min. In the thermal reaction, the temperature is raised at a rate of 100 ° CZ for temperatures up to 400 ° C, and at a temperature of 400 ° C or higher, the temperature is raised at a rate of 60 ° C / hour until the temperature reaches 670 ° C (furnace temperature). After the temperature was raised, the temperature was maintained at the same temperature for 4 hours, then cooled to 60 ° C by natural cooling, and the reaction product was taken out of the electric furnace.

The obtained product did not retain the shape of the raw material, and was an amorphous insoluble infusible solid. The yield was 82%.

The obtained material was ground to an average particle size of about 5 m using a pole mill to obtain a negative electrode material. The obtained negative electrode material was subjected to elemental analysis and measurement of specific surface area, density, and particle size distribution by a BET method. The results are shown in Table 7 below.

Next, 90 parts by mass of the negative electrode material powder, 5 parts by mass of acetylene black powder as a conductive agent, and 5 parts by mass of PVdF as a binder were mixed with N-methyl-2-pyrrolidone (NMP) as a solvent. Thus, a negative electrode mixture slurry was obtained. The slurry was applied to one side of a copper foil having a thickness of 18 m, dried, and pressed to obtain an electrode having a thickness of 50 m and a density of 1 gZcm ³ .

The electrode obtained above was used as the working electrode, metallic lithium was used as the counter electrode and the reference electrode, and a solvent of ethylene carbonate and getyl carbonate mixed at a ratio of 1: 1 (volume ratio) was used as the electrolyte to a concentration of 1 mo 1ZL. using a solution of L i PF _6, an electrochemical cell was prepared in an argon dry box. Lithium doping is performed at a constant current of 20 OmA / g per negative electrode active material until the potential of lithium becomes lmV, and a constant voltage of lmV is applied to the lithium potential for a total of 8 hours. did. After a pause of 10 minutes, dedoping was performed at a constant current of 20 OmAZg per negative electrode active material to 2 V with respect to the lithium potential. After a 10-minute pause, doping and undoping were performed in the same manner as above, and a total of 10 cycles were performed. The results are shown in Table 7 below.

(Example 12)

Example 11 was repeated except that the thermal reaction temperature of the naphthalene pitch material was changed to 660C. A thermal reaction was performed in the same manner as in Example 11 to obtain an insoluble infusible solid. The yield was 83% by mass. Table 7 shows the results of measuring the HZC, specific surface area, true density, and average particle size of this material in the same manner as in Example 11.

Next, an electrode was produced in the same manner as in Example 11, and the doping amount and the undoping amount of lithium were measured for 10 cycles. Table 7 below shows the results of the initial capacity and the 10-cycle capacity.

(Example 12)

A thermal reaction was performed in the same manner as in Example 11 except that the thermal reaction temperature of the naphthalene pitch raw material was changed to 63 ° C. in Example 11 to obtain an insoluble infusible solid. The yield was 83% by mass. Table 7 below shows the results of measuring the HZC, specific surface area, true density, and average particle size of this material in the same manner as in Example 11.

(Reference Example 9)

Except that the thermal reaction temperature 6 8 5 ^D C naphthoquinone evening Renpitchi raw material in the same manner as in Example 1 1 was thermally reacted to give the insoluble and infusible solid. The yield was 83% by mass. The H / C, specific surface area, true density and average particle size of this material were measured in the same manner as in Example 11 and the results are shown in Table 7 below. HZC was 0.22. Next, an electrode was produced in the same manner as in Example 11, and the doping amount and undoping amount of lithium were measured for 10 cycles. Table 7 shows the results of the initial capacity and the 10-cycle capacity.

(Reference Example 10)

A thermal reaction was performed in the same manner as in Example 11 except that the thermal reaction temperature of the naphthalene pitch raw material was set to 595 ° C, to obtain an insoluble infusible solid. The yield was 83% by mass. Table 7 shows the results of measuring the HZ specific surface area, true density, and average particle size of this material in the same manner as in Example 11. H / C was 0.36. Next, an electrode was produced in the same manner as in Example 11, and the doping amount and the undoping amount of lithium were measured for 10 cycles. Table 7 shows the results for the initial capacity and 10-cycle capacity.

(Reference Example 11)

Coal-based isotropic pitch (softening point 280 ° C) 10 Og is put in a stainless steel dish, and this dish is placed in an electric furnace (effective furnace size: 30 OmmX 30 OmmX 30 Omm) and heat reaction occurs Was served. The thermal reaction was performed in a nitrogen atmosphere, and the flow rate of nitrogen was 10 liter / min. In the thermal reaction, the temperature is raised at a rate of 100 ° C / hour up to a temperature of 400 ° C, and at a temperature of 400 ° C or higher, the temperature is raised at a rate of 50 ° CZ for a temperature of 660 ° C (furnace temperature). After the temperature was raised, the temperature was maintained at the same temperature for 4 hours, then cooled to a temperature of 60 ° C by natural cooling, and the reaction product was taken out of the electric furnace. The obtained product did not retain the shape of the raw material, and was an amorphous insoluble infusible solid. The yield was 78% by mass.

££ 0 10 / £ 00Ζάΐ / 13ά £ WI contract OAV

As described above, from the reference examples and examples, the negative electrode material for a non-aqueous secondary battery according to the present invention is based on polycyclic aromatic hydrocarbons obtained by subjecting a raw material mainly containing naphthalene pitch to a thermal reaction. The atomic ratio of hydrogen / carbon is in the range of 0.33 to 0.23, the specific surface area by the BET method is in the range of 0.1 to 30 m ² Zg, and the true density is 1.4 O g / cm ³ As described above, the average particle size is 10 m or less, so that a high capacity per mass and per volume can be obtained in a practical doping time, and a non-aqueous secondary battery with excellent cycle characteristics is provided. be able to. In addition, the method for producing a negative electrode material for a non-aqueous secondary battery according to the present invention is a method for producing a polycyclic aromatic hydrocarbon by subjecting the above-mentioned raw material containing naphthylene pitch to a thermal reaction without infusibilizing the raw material. Therefore, the production of the negative electrode material is simple and the yield can be improved.

(Example 14)

The negative electrode material powder obtained in the same manner as 1) of Example 1 (having an average particle size of 5.5 urn,

Particles of 1 nm or less have a volume fraction of 7%, H / C = 0.26, and a specific surface area of 24 m ²

/ g), acetylene black as a conductive material, polyvinylidene fluoride (PVdF) as a binder, and N-methylpyrrolidone (NMP) as a solvent, to obtain a negative electrode mixture slurry.

At this time, the compounding ratio (mass ratio) of the negative electrode material powder, acetylene black as the conductive material, and the binder was set to be negative electrode material: acetylene black: binder = 88: 7: 7. The slurry was applied to one side of a copper foil having a thickness of 14 m, dried, and pressed to obtain a negative electrode. Table 8 shows the thickness and the basis weight of the negative electrode mixture layer. Next, the negative electrode obtained above was used as a working electrode, metallic lithium was used as a counter electrode and a reference electrode, and ethylene carbonate and ethyl methyl carbonate were used as electrolytes.

: The mixed solvent 7 volume ratio to the concentration of lmo 1ZL with a solution of L i PF _6, an electrochemical cell was produced in an argon dry box, it was assessed charge acceptance of the negative electrode. The charge acceptability of the negative electrode is evaluated in the second cycle, and the lithium doping in the second cycle is 16 16πιΑ / g, followed by undoping up to 2 V with respect to the lithium potential at a rate of 16 OmAZg, and the discharge capacity obtained was evaluated. The results are shown in Table 8 below.

(Examples 15 to 16, and Reference Example 12)

An electrode was produced in the same manner as in Example 14. Table 8 shows the molding material layer thickness and the basis weight of the negative electrode mixture. In addition, we continued to evaluate charging acceptability. Table 8 shows the results.

Table 8

As is evident from the above results, when the basis weight is 6 mg / cm ² or less, it is understood that good charge receiving characteristics can be obtained.

Examples 17 to 19, Reference example 13

... 1) cathode material _{_{L i N i 0 8 C o}} 0 2 0 2 89. 5 parts by mass of acetylene black click 4.5 parts by weight were mixed PVdF6 0 parts by mass and NMP, positive electrode composite slurry - Got. Next, the slurry was applied to both surfaces of a 20 im-thick aluminum foil serving as a current collector, dried, and pressed to obtain a positive electrode.

2) The negative electrode of the present invention (Examples 14 to 16) and the reference negative electrode (Reference Example 12) were opposed to the positive electrode obtained by the above method via a separator, to produce a battery. Here, the positive electrode was coated and used so that the basis weight was adjusted so that the active material weight ratio of the positive electrode and the negative electrode would be the same. Electric angle军液is ethylene carbonate and E chill methyl carbonate 3: 7 mixed solvent of a volume ratio to the concentration of 1 mo 1Z liters using a solution of L i PF _6. 3) Next, the battery prepared above was charged to 4.2 V with a current of 0.2 CmA, and thereafter, constant-current constant-voltage charging in which a constant voltage of 4.2 V was applied was performed for 8 hours. Subsequently, a cycle of discharging to 2.0 V at a constant current of 0.2 CmA was repeated 100 times. Table 9 shows the results.

Table 9

While basis weight batteries using the negative electrode is 6MgZcm ² below was maintained 78% or more of the initial capacity, the capacity of the battery using the comparison anode mass per unit area is more than 6 MGZ cm ² was reduced to 50% I was

(Examples 20, 21 and Reference Example 14)

Negative electrode material powder obtained in the same manner as 1) of Example 1 (particles having an average particle size of 5.5 rn, 1 Hm or less have a volume fraction of 7%, H / C = 0.26, and a specific surface area of Was mixed with 90 parts by mass of 24 m ² / g), 5 parts by mass of acetylene black as a conductive material, 5 parts by mass of PVdF as a binder, and NMP as a solvent to obtain a negative electrode mixture slurry. It was applied to one surface of a copper foil having a thickness of 14 xm The slurry was dried, by performing the press to obtain a negative electrode having a thickness of ^{49 / xm (52 X 32mm 2} ).

_{_{_{L iNi 0. 8 Co 0.}}} 15 A1 0. 05 89. 5 Quality of O ₂ * ^, mixed 6 quality and NMP of 4. 5 m-PVdF acetylene black, to obtain a positive electrode slurry. Next, the slurry was applied to a 2 cm thick aluminum foil serving as a current collector, dried and pressed to obtain a thickness of 67 67ηΐΐΚΌΊΕ (50 × 30 mm ² ).

Next, the negative electrode obtained above was used as a working electrode, metallic lithium was used as a counter electrode and a reference electrode, and ethylene glycol and ethyl methyl carbonate were used as electrolytes. : Using a solution of L i PF ₆ to a concentration of 1 mo 1ZL the mixed solvent 1 volume ratio, the lithium predetermined amount in the negative electrode [Cn (mAh)] was pre-doped. Subsequently, after the above-mentioned pre-doped negative electrode: the IE electrode is opposed to each other via a separator (porous polyethylene: 54 × 34 mm ² ), a 1: 1 # ratio of ethylene force and jettyreca as a liquid is used. in after dragon the solution dissolve the i PF ₆ in «the Imo 1 / liter mixed solvent, the thickness of 1 lmm aluminum 'transliteration effect laminate film

(Aluminum layer: 0.02 mm) was used as a sample, and a battery was obtained by vacuum sealing with ET (0.1 ^ J ±). The reference electrode (lithium metal) is attached to T.).

Next, the battery prepared above was charged to 4.2 V with a current of 10 mA, and then a constant current constant voltage charge of applying a constant voltage of 4.2 V was performed for 8 hours (the charge amount at this time was Cp ( mAh)). After charging, the battery was allowed to stand for 1 hour with no current flowing, and the position of the negative electrode was measured. The voltage was then increased to 2.0 V at a constant current of 10 mA. Table 10 below summarizes the lithium pre-doping amount Cn, the initial charge amount (lithium released from the positive electrode during initial charging *) Cp, and the opening amount of the negative electrode. Separately, using lithium metal as the counter electrode and the reference, at night, Li MoPF ₆ was dissolved in the solvent of 1 mo 1 noritr in a mixture of ethylene carbonate and getyl carbonate at a ratio of 1: 1. The values of X and C p 2 measured using the solution are also shown.

Table 10

However, in the battery shown in Reference Example 14 in Table 10, a flat portion was observed at the initial stage of discharge, and deposition of lithium metal was confirmed. (Examples 22 and 23 and Reference Example 15)

With the positive movement thickness of 54, a battery was prepared in the same manner as in Male Example 20, and the negative electrode opening position and the flow rate were measured. The lower pre-doping amount Cn, the initial charge amount (lithium M released from the positive electrode during the initial charge) Cp, the opening position of the negative electrode, the method amount, and so on. The value of p2 is also shown.

Table 11

In the case of Reference Example 15 in which the negative electrode release potential exceeds 10 OmV, sufficient capacity cannot be obtained, and from Examples 20 to 23, the negative electrode release potential during charging is set to 10 OmV or less and 2 OmV or more to achieve high capacity. A battery is obtained.

(Example 24)

(1). Anode material powder obtained in the same manner as in 1) of Example 1 (particles having an average particle size of 5.5 m or less 1 m are volume fraction 7% H / C = 0.26 and ratio 90 parts by mass having a surface area of 24 mVg), 5 parts by mass of acetylene black as a conductive material, 5 parts by mass of polyvinylidene fluoride (PVdF) as a binder, and N-methyl-2-pyrrolidone (NMP) as a solvent were mixed. Thus, a negative electrode mixture slurry was obtained. The slurry was applied to one side of a copper foil having a thickness of 14 m, dried, and then pressed to obtain a 94 m-thick negative electrode (mixture layer thickness: 80 zm).

(2). Using the negative electrode as the working electrode, lithium metal as the counter electrode and the reference electrode, and an electrolytic solution (concentration of lmo 1Z liter in a solvent in which ethylene force ionate and ethyl methyl carbonate are mixed at a volume ratio of 50:50). L i solution of PF ₆₎ to have use of the electrochemical ^ "fe Le prepared in an argon dry box, Hakamen charge ¾Λ of the negative electrode did. Charging at the negative electrode The 性 λ property faces I in the second cycle, and the doping of lithium in the second cycle is performed with a current of 160 mAZg until the potential of lithium becomes 1 mV, and then the 16 OmAZg Dedoping was performed at a speed up to 2 V with respect to the lithium potential. Table 12 shows the results.

(Bell row 25, ex. 16-18)

When the solvent of the whip in (2) of Difficult Example 24 was changed to that shown in Table 12, a battery was produced in the same manner as in Example 24, and the same surface as in Difficult Example 24 was performed. The results are shown in Table 1.

Table 12

In the table, EC is ethylene carbonate, PC is propylene carbonate, and DEC is getylcapone. When the five types of electrolytes shown in these Examples and Reference Examples were left in an atmosphere at a temperature of 0 ° C., solidification was observed in the electrolyte solution of Reference Example 16.

(Example 26)

1). First, the lithium nickel composite oxide as _{_{_{L iNi 0. 80 Co 0.}}} 15 A1 0. 05 0 2, and a high specific surface area of natural graphite (BET method specific surface area = 25 Og / m ²⁾ as a conductive agent Dry mixed. The resulting mixture was uniformly dispersed in NMP in which PVdF as a binder was dissolved, to prepare Slurry 1-1. Next, the slurry 1 was applied to both surfaces of an aluminum foil serving as a current collector, dried, and pressed to obtain a positive electrode. The density of the obtained positive electrode was 3. OgZcm ³ . The mass ratio of solids in the positive electrode is Nickel composite oxide: high specific surface area natural graphite: prepared so that PVdF = 92: 5: 3. In this example, application area of the positive electrode (Wl XW2) is a 53 X 32 mm ^2. In addition, the electrode is provided with a current collector where no active material is applied.

2). Coal-based isotropic pitch (softening point 280 ° C) was pulverized with a coffee mill to obtain a pitch material with a particle size of 1 mm or less. 1000 g of the pitch powder was placed in a stainless steel dish, and the dish was placed in an electric furnace (effective size in furnace: 30 OmmX 30 OmmX 30 Omm) and subjected to a thermal reaction. The thermal reaction was performed in a nitrogen atmosphere, and the flow rate of nitrogen was 10 liter / minute. In the thermal reaction, the temperature is raised from room temperature to a temperature of 680 ° C (furnace temperature) at a rate of 100Z hours. After the temperature was raised, the temperature was maintained at the same temperature for 12 hours, and then cooled to a temperature of 60 ° C by natural cooling, and the reaction product was taken out of the electric furnace. The obtained product did not retain the shape of the raw material, and was an amorphous insoluble infusible solid. The yield was 801 g, and the yield was 80.1% by mass.

The obtained product material was pulverized with a Jet 1, mill and classified to an average particle size of 6 m to obtain a negative electrode material. Elemental analysis (measurement device: PE2400 Series II, CHNSZO, manufactured by PerkinElmer, Inc.) and specific surface area by BET method (measurement device: NOVAl 200J, manufactured by QANTACHROME, Inc.) The atomic ratio (H / C) of hydrogen / Z carbon was 0.22, and the specific surface area was 18 m ² / g.

After the above negative electrode material and acetylene black as a conductive agent were dry-mixed, slurry 2 was prepared by uniformly dispersing in a NMP in which PVDF as a binder was dissolved. Next, the slurry 12 was applied to both surfaces of a copper foil serving as a current collector, dried, and pressed to obtain a negative electrode. The solid content ratio (mass ratio) in the negative electrode was adjusted to be negative electrode material: acetylene black: PVdF = 92: 3: 5.

Coated area of the negative electrode (Wl XW2) is a 55X 34 mm ^2. In addition, the electrode is provided with a current collector to which the active material is not applied. Further, slurry 2 was applied only on one side by the same method as above, and a single-sided electrode was produced. The one-sided electrode is an electrode described later It is located outside in the stack.

3). Nine positive electrodes and ten negative electrodes (two inner electrodes on one side) obtained in the above 1) and ² ) were alternately laminated via a separator (porous polyethylene: 56 X 35 mm ² ). An electrode laminate was produced. At this time, a lithium metal foil is adhered to the surface of the negative electrode (200 mAh per gram of the negative electrode active material), and the negative electrode is pre-doped after the electrolyte injection in the following 4).

4). The positive and negative electrode lugs of the obtained electrode laminate were welded to tabs (positive electrode: aluminum, negative electrode: nickel), and ethylene carbonate and getyl carbonate were used as electrolytes in a 1: 1 ratio. after impregnated with solution prepared by dissolve the L i PF ₆ in mixed solvent to a concentration of 1 mo 1 / L in a volume ratio of aluminum one thickness 0. 1 lmm榭脂laminating one Tofi Lum (aluminum layer: 0. 02mm) as an exterior body, and vacuum-sealed under reduced pressure (0.1 atm) to obtain a battery.

5) After charging this battery to 4.2V with a current of 200mA, perform constant-current constant-voltage charging of applying a constant voltage of 4.2V for a total of 8 hours, followed by 2.0V at a constant current of 200mA. Until discharge. The capacity of the obtained battery was 102 OmAh.

(Reference Example 19)

A positive electrode was prepared and pressed in the same manner as in Example 25-1) except that the conductive agent for the positive electrode was acetylene black. The density of the obtained positive electrode was 2.7 gZ cm ³ . Except for this, it was manufactured in the same manner as in Example 1. The resulting battery capacity was 92 OmAh.

(Reference Example 20)

A battery was prototyped in the same manner as in Example 26 except that the negative electrode active material was graphitized mesocarbon microphone opening beads in Example 26 and no pre-doping was performed. Battery evaluation is

After charging to 4.2 V with a current of 128 mA, a constant current and constant voltage charge of applying a constant voltage of 4.2 V is performed for a total of 8 hours, followed by a discharge at a constant current of 128 mA to 2.5 V did. The capacity of the obtained battery was 70 OmAh. (Reference Example 21)

The positive electrode active material and L i Co_〇 ₂ in Example 26, was fabricated battery in the same manner as in Example 26. For battery evaluation, after charging to 4.2 V with a current of 136 mA, constant-current constant-voltage charging applying a constant voltage of 4.2 V was performed for a total of 8 hours, followed by 2.0 at a constant current of 136 mA. Discharged to V. The capacity of the obtained battery was 780 mAh.

Above, from the results of Example 26 and Reference Example 19 to 21, according to a non-aqueous secondary batteries according to the present invention, the positive electrode, (a) the composition formula _{_{L i a N i b C o}} c A 1 _d 〇 ₂ (l≤a≤l.1, 0.5 ≤b <0.9, 0.3 ≤c <0.5, 0 <d≤0.15, b + c + d = l) (B) at least a natural surface area of 100 m ² Zg or more by a BET method, and the negative electrode is obtained by thermally reacting a raw material mainly composed of pitch. Since the hydrogen and the atomic ratio of hydrogen and carbon (H / C) are 0.05-0.35 and the specific surface area by the BET method is 5 Om ² Zg or less, the polycyclic aromatic hydrocarbon is contained. Non-aqueous secondary batteries are stable, have high capacity, and have excellent cycle life. Industrial applicability

As described above, the present invention relates to a negative electrode material, a negative electrode thereof, and a non-aqueous secondary battery using the same. Particularly, the present invention relates to a non-aqueous secondary battery having high capacity and excellent charge acceptability. And a non-aqueous secondary battery that is practically used for distributed power storage systems for home use and power storage systems for electric vehicles.

Claims

The scope of the claims

1. A material consisting of polycyclic aromatic hydrocarbons obtained by subjecting a raw material mainly composed of pitch to a thermal reaction, wherein the atomic ratio of hydrogen to Z carbon is 0.50 to 0.05. The negative electrode material for a non-aqueous secondary battery has a specific surface area determined by the BET method in the range of 0.1 to 50 m ² Zg and an average particle size of the material of 10 m or less.

2. The negative electrode material according to claim 1, wherein the average particle size of the material is in the range of 6 to 1.

3. The material according to claim 1 or 2, wherein the material has a diameter of 2m or less at a volume integration of 10% in the particle size distribution and a diameter of 10Aim or less at the 90%. Negative electrode material.

4. The negative electrode material according to claim 1, wherein the element ratio of hydrogen and Z carbon in the material is in a range of 0.40 to 0.15.

5. The negative electrode material according to claim 4, wherein a specific surface area of the above material by a BET method is in a range of 0.1 to 30 m ² Zg.

6. negative electrode material according to paragraph 4 of claims pore volume of the material in the range of. 20 to 50 A as measured by the BJH method is not more than 1 X 10- ³ c cZg.

7. The negative electrode material according to claim 1, wherein the pitch is mainly a naphthalene pitch.

8. The negative electrode material according to claim 7, wherein a distance d002 between (002) planes of the above-mentioned material by X-ray wide-angle diffraction is less than 0.3347 nm.

9. The negative electrode material according to claim 7, wherein the material ratio of hydrogen / carbon in the material is in a range of 0.40 to 0.20.

10. The negative electrode material according to claim 7, wherein the material has an average particle diameter in the range of 6 zm to 1 m.

11. The negative electrode material according to claim 7, wherein the specific surface area of the above material by the BET method is in the range of 0.1 to 30 m ² / g.

12. The negative electrode material according to claim 10, wherein the specific surface area of the above material by the BET method is in the range of 0.1 to 10 m ² Zg.

13. The claim 7, wherein the hydrogen / carbon atomic ratio (HZC) of the material is in the range of 0.33 to 0.23 and the true density of the material is 1.40 g / cm ³ or more. Or the negative electrode material according to item 8.

14. The negative electrode material according to claim 1, wherein the pitch is mainly composed of coal-based isotropic pitch.

15. The negative electrode material according to claim 14, wherein the material has an average particle diameter in a range of 6 m to 1 m.

16. The material according to claim 14 or 15, wherein the diameter at 10% volume integration in the particle size distribution is 2m or less and the diameter at 90% is 10m or less in the particle size distribution. Negative electrode material.

17. Claims wherein the true density of the above material is 1.45 gZ cm ³ or more, and the hydrogen / carbon atomic ratio (H / C) of the above material is in the range of 0.25 to 0.18. Item 16. The negative electrode material according to item 14 or 15.

18. The negative electrode material according to claim 17, wherein a specific surface area of the above material by a BET method is in a range of 0.1 to 30 m ² / g.

19. In a method for producing a negative electrode material for a non-aqueous secondary battery, a raw material containing pitch as a main component is subjected to a thermal reaction to generate polycyclic aromatic hydrocarbons, which are then pulverized, and the average particle size is 10 m or less. and then, in the range of atomic ratio 0.5 to 0.05 hydrogen atoms, and with a specific surface area by the BET method is in the range of 0.1 to 50 m ² Zg, the average particle size of the material is below 10 / zm A method for producing a negative electrode material for a non-aqueous secondary battery to be manufactured as follows.

20. The method for producing a negative electrode material according to claim 19, wherein the raw material is subjected to a thermal reaction without being infusibilized.

21. A material comprising a polycyclic aromatic hydrocarbon obtained by subjecting a raw material containing pitch as a main component to a thermal reaction, wherein the hydrogen / carbon atomic ratio of the material is 0.50 to 0.05. The negative electrode material, which has a specific surface area of 0.1 to 50 m ² Zg by the BET method and an average particle size of the material of 10 / m or less, and a non-conductive material formed with a binder, Aqueous negative electrode for secondary batteries.

22. The negative electrode according to claim 21, wherein the basis weight of the negative electrode material is 6 mgZcm ² or less.

23. The negative electrode according to claim 21, wherein the density of the molding material is in a range of 0.85 to 1.3 g / cm ³ .

24. The negative electrode according to claim 21 or 22, wherein the density of the molding material is in the range of 0.85 to 1.3 gZcm ³ .

25. negative electrode according to the second items 1 to 23, wherein the claimed electric conductivity of the molding material is 10- ³ SZ cm or more.

26. The negative electrode according to any one of claims 21 to 23, wherein the pitch of the negative electrode material is mainly composed of coal-based isotropic pitch.

27. Polycyclic aromatic hydrocarbons obtained by subjecting pitch-based raw materials to a thermal reaction in a nonaqueous secondary battery equipped with a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte containing a lithium salt Including polycyclic aromatic hydrocarbons with an atomic ratio of hydrogen / carbon of 0.50 to 0.05 and a specific surface area by BET method of 50 m ² / g or less. In addition, a non-aqueous secondary battery using a negative electrode containing a negative electrode material having an average particle diameter of 10 m or less.

28. The non-aqueous secondary battery according to claim 27, wherein the hydrogen / carbon atomic ratio of the material is 0.35 to 0.05.

29. The nonaqueous secondary battery according to claim 27, wherein the negative electrode is formed by dispersing the negative electrode material and a conductive material in a binder and molding the negative electrode material and a conductive material.

30. The non-aqueous secondary battery according to claim 27, wherein the positive electrode is a material capable of electrochemically occluding and releasing lithium.

31. The non-aqueous secondary battery according to claim 30, wherein the positive electrode active material in the positive electrode is a lithium composite oxide containing Ni.

32. The positive electrode is a lithium composite metal oxide whose positive electrode active material contains Ni, and has a composition formula of L i _a N i _b C o _c A 1 _d 〇 ₂ (l≤a≤1.1, 0. 5 ≤ b <0.9, 0.3 ≤ c <0.5, 0 <d ≤ 0.15, b + c + d = l) 31. The non-aqueous secondary battery according to any one of items 27 to 30.

33. The non-aqueous secondary battery according to claim 32, wherein the positive electrode includes natural graphite having a specific surface area of at least 100 m ² Zg by a BET method.

34. The non-aqueous secondary battery according to claim 33, wherein the natural graphite is contained in an amount of 2 to 10 parts by mass with respect to 100 parts by mass of the composite oxide.

35. The nonaqueous two-battery battery according to claim 30, wherein the negative electrode open potential at the time of charging of the negative electrode is 10 OmV or less and 20 mV or more with respect to the lithium potential.

36. In the above negative electrode, a predetermined amount of lithium is pre-doped, Assuming that the amount of lithium is Cn (mAh) and the amount of lithium that can be released from the positive electrode active material during the initial charge is the initial charge amount Cp (mAh), the amount of Cn + Cp (mA) when the negative electrode is doped with lithium 36. The non-aqueous secondary battery according to claim 35, wherein the amount of Cn is provided so that the open potential is 10 OmV or less and 2 OmV or more with respect to the lithium potential.

37. Let X be the initial efficiency at the negative electrode when the amount of lithium of Cn + Cp (mA) is doped, and Cp 2 (mAh) be the amount of lithium absorbed into the positive electrode during initial discharge. 37. The nonaqueous secondary battery according to claim 35 or claim 36, wherein 2 and (Cn + Cp) satisfy a relationship of Cp2 (Cn + Cp) ≤x.

38. When the amount of lithium that can be released from the positive electrode active material in the initial charge at the 3IE electrode is defined as the initial charge Cp (mAh) and the amount of the positive electrode active material is defined as Wp (g), 180 <CpZWp. 37. The non-aqueous 2¾kH pond according to claim 35 or 36, wherein the pond is a tree.

39. The non-aqueous electrolyte contains at least ethylene carbonate and a chain carbonate as a solvent, and a lithium salt containing 10% or more and 70% or less by volume of the ethylene force component in the solvent. The non-aqueous 2 ^ ¾ according to any one of claims 27 to 31 of the claim