JPH0574457A - Negative electrode material and manufacture thereof, and nonaqueous electrolyte battery using it - Google Patents

Abstract

PURPOSE:To provide a nonaqueous electrolyte battery having a large discharge capacity and an excellent cycle characteristic by providing a negative electrode material doped with a large amount of lithium and a manufacturing method for the material. CONSTITUTION:The negative electrode of a nonaqueous electrolyte battery is made of graphitization-resistant carbon composed mainly of carbon, phosphorus and oxygen, or coke (readily graphitizable carbon). The phosphorus content of the carbon is 0.2 to 9.0wt.%. The negative electrode material has a peak at + or -100ppm in a <31>P nucleus solid NMR spectrum with reference to orthophosphoric acid and a peak of 135.0eV in a phosphorus atom 2(p) orbit spectum at XPS. The negative electrode material is manufactured by adding phosphoric acid or phosporus oxides, etc., to organic material or carbonaceous material, and baking this mixture. The nonaqueous electrolyte battery comprises the negative electrode material, a positive electrode containing Li, and electrolyte.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative electrode material comprising a compound containing carbon, phosphorus and oxygen as main components and doped with lithium and dedoped, and a method for producing the same. The present invention relates to a non-aqueous electrolyte battery.

[0002]

2. Description of the Related Art The electric capacity per unit weight of carbonaceous material is determined by the lithium doping amount. Therefore, in order to increase the charge / discharge capacity of a battery, the carbon material should be doped with lithium as much as possible. Is desirable (theoretically, the ratio of 1 Li atom to 6 carbon atoms is the upper limit).

Conventionally, as a carbonaceous material used for the negative electrode of this type of battery, an organic material is used, as described in, for example, JP-A-62-122066 or JP-A-62-90863. A carbonaceous material obtained by carbonization is known.

[0004]

However, in the above-mentioned carbonaceous material, the doping amount of lithium is insufficient, which is about half the theoretical value. Therefore, the present invention has been proposed for the purpose of further improving a carbonaceous material, and an object of the present invention is to provide a negative electrode material having a lithium doping amount much higher than those of conventional carbonaceous materials and a method for producing the same. ..

Another object of the present invention is to provide a non-aqueous electrolyte battery having a large discharge capacity and excellent cycle life characteristics.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies as to achieve the above-mentioned object, and as a result, it has been found that a specific compound composed of carbon, phosphorus and oxygen exhibits good characteristics as a negative electrode material. Came to obtain the knowledge of. And ³¹ P
By conducting structural analysis by nuclear-solid state NMR and XPS (X-ray photoelectron spectroscopy), the added phosphorus atom does not exist as an atom or a compound such as an oxide alone, and reacts with carbon or oxygen during the firing process. It was found that a compound having a bond such as carbon-phosphorus or carbon-oxygen-phosphorus was formed. This means that the effect of adding a phosphorus compound, which brings about an increase in the amount of lithium doped, is not a mere doping / de-doping of lithium with respect to a carbon material, but a special compound containing carbon, oxygen, and phosphorus as main components (hereinafter referred to as C-P-
It is called an O compound. ) Means that it is expressed.

The negative electrode material of the present invention is based on this finding.
Has been completed with the main components of carbon, phosphorus and oxygen.
The phosphorus content is 0.2 to 9.0% by weight.
, ³¹Ortholine in the P-nuclear-solid NMR spectrum
X-ray with a peak in the range of ± 100ppm based on acid
1s orbital spectrum of carbon atom in photoelectron spectroscopy
And the binding energy of carbon to carbon of 284.6 eV
When the phosphorus atom 2p orbital spectrum is 135 eV or less,
Characterized by mainly containing a compound having a lower peak
It is something.

Further, the production method of the present invention is characterized in that 0.2 to 32% by weight of phosphorus compound in terms of phosphorus is added to the organic material or the carbon material, and the mixture is baked in an inert atmosphere. is there. Furthermore, the non-aqueous electrolyte battery of the present invention contains carbon, phosphorus, and oxygen as main components and has a phosphorus content of 0.2 to 9.0% by weight, and has a ³¹ P nucleus-solid NMR spectrum based on orthophosphoric acid. ± 100
In the measurement of X-ray photoelectron spectroscopy, when the binding energy between carbon and carbon in the carbon atom 1s orbital spectrum is set to 284.6 eV, the phosphorus atom 2p orbital spectrum has a peak of 135 eV or less in the range of ppm. It is characterized by comprising a negative electrode containing the compound as a main component, a positive electrode containing Li, and a non-aqueous electrolyte.

The negative electrode material of the present invention is obtained by adding a phosphorus compound to an organic material or a carbon material and firing it in an inert atmosphere. The organic material or carbon material used as the starting material is arbitrary, but for example, by firing (00
2) Face spacing is 3.70Å or more, and true density is 1.70g.
Less than / cm ³ and 7 by differential thermal analysis in air flow
An organic material or a carbon material that does not have an exothermic peak at 00 ° C. or higher and is so-called non-graphitizable carbon is suitable.

The non-graphitizable carbon has a large lithium doping amount as compared with the conventional carbon material, and in combination with the effect of the addition of the phosphorus compound, the negative electrode having a lithium doping amount much higher than the conventional carbonaceous materials. It becomes possible to provide materials.

A furan resin composed of a furfuryl alcohol or furfural homopolymer or copolymer is preferable as the organic material used as the starting material of the non-graphitizable carbon. This is because the carbonaceous material obtained by carbonizing the furan resin has a (002) plane spacing of 3.70 Å or more, a true density of 1.70 g / cc or less, and a DTA having no oxidation exothermic peak at 700 ° C. or more, This is because it exhibits very good characteristics as a negative electrode material for batteries. ..

As another starting material for non-graphitizable carbon, one obtained by introducing a functional group containing oxygen (so-called oxygen cross-linking) into petroleum pitch having a specific H / C atomic ratio is also used as the furan resin. Similarly, it can be used because it exhibits excellent properties when carbonized. The petroleum pitch is tars obtained by high-temperature pyrolysis of coal tar, ethylene bottom oil, crude oil, etc., distillation consisting of asphalt (vacuum distillation, atmospheric distillation, steam distillation), thermal polycondensation, extraction, chemical polycondensation. And the like.

At this time, the H / C atomic ratio of petroleum pitch is important, and it is necessary to set the H / C atomic ratio to 0.6 to 0.8 in order to obtain non-graphitizable carbon. The specific means for introducing a functional group containing oxygen into these petroleum pitches is not limited, but for example, a wet method using an aqueous solution of nitric acid, mixed acid, sulfuric acid, hypochlorous acid, or an oxidizing gas (air, oxygen) is used. A dry method and further a reaction with a solid reagent such as sulfur, ammonium nitrate, ammonium persulfate, ferric chloride, etc. are used.

For example, when oxygen is introduced into petroleum pitch by the above-mentioned method, the final carbonaceous material is obtained in a solid state without melting during the carbonization process (400 ° C. or higher),
It is similar to the formation process of non-graphitizable carbon.

The petroleum pitch having oxygen-containing functional groups introduced therein is carbonized by the above-mentioned method to be used as a negative electrode material. Regardless of the conditions for carbonization, the (002) plane spacing is 3.70 Å or more and the true density is 1.70g / cc or less and 700 with DTA
If a carbonaceous material satisfying the characteristic that it does not have an oxidation exothermic peak above 0 ° C. is obtained, a large amount of lithium doping per unit weight can be obtained. For example, by setting the oxygen content of the precursor obtained by oxygen-crosslinking petroleum pitch to 10% by weight or more, the (002) plane spacing can be set to 3.70Å or more. Therefore, the oxygen content of the precursor is preferably 10% by weight or more, and practically in the range of 10 to 20% by weight.

Further, the organic material for oxygen crosslinking is H
Since the / C atomic ratio may be 0.6 to 0.8, it can be used by performing a preheat treatment such as pitching. Examples of such a starting material include phenol resins, acrylic resins, vinyl halide resins, polyimide resins, polyamideimide resins, polyamide resins, conjugated resins, certrene, anthracene, triphenylene, pyrene, perylene, pentaphene, pentacene, and other condensed polycondensates. Ring hydrocarbon compounds, other derivatives (for example, carboxylic acids thereof, carboxylic anhydrides, carboxylic acid imides, etc.), various pitches mainly composed of a mixture of each compound, acenaphthylene, indole, isoindole, quinoline, isoquinoline, quinoxaline, Phthalazine, carbazole, acridine,
Fused heterocyclic compounds such as phenazine and phenanthridine,
The derivative etc. are mentioned.

Alternatively, as a starting material, an organic material or a carbon material which is heat-treated at 700 ° C. or lower and baked to form coke may be used. Here, coke means
It is a carbon material that is graphitized when heat-treated at about 3000 ° C., that is, easily graphitizable carbon, and is advantageous in terms of packing density as compared with the above non-graphitizable carbon.

That is, in a cylindrical practical battery made by winding a spiral electrode, the electrode area must be increased in order to charge and discharge at a high rate, but the electrode must be filled with more active material. I have to. However, since the carbon material has a smaller true density than the oxide-based active material, the capacity increase due to the phosphorus addition effect in the carbon material having a higher true density, such as coke (true density of about 2.0 g / cm ³ ). If achieved, it is expected that the capacity can be further increased as compared with the case where phosphorus is contained in non-graphitizable carbon.

Typical examples of the organic material as a starting material for the graphitizable carbon include coal and pitch. Pitch can be obtained by distillation (vacuum distillation, atmospheric distillation, steam distillation, etc.), thermal polycondensation, extraction, chemical polycondensation, etc. from tars, asphalt, etc. obtained by high-temperature pyrolysis of coal tar, ethylene bottom oil, crude oil, etc. There are also those obtained by operation, and other pitches produced during carbonization of wood.

Further, as the polymer compound raw material, there are polyvinyl chloride resin, polyvinyl acetate, polyvinyl butyrate, 3,5-dimethylphenol resin and the like.

These raw materials have a maximum of 400 during carbonization.
It exists in a liquid state at about ℃, and when kept at that temperature, the aromatic rings are condensed, polycyclic, and become in a layered orientation, and at a temperature of about 500 ℃ or more, a solid carbon precursor, that is, semi-coke, is formed. Form. Such a process is called a liquid-phase carbonization process and is a typical formation process of graphitizable carbon.

The above-mentioned raw materials such as coal, pitch, and polymer compounds are naturally subjected to the above-mentioned liquid phase carbonization process when carbonized. In addition, condensed polycyclic hydrocarbon compounds such as naphthalene, phenanthrene, anthracene, triphenylene, pyrene, perylene, pentaphene, pentacene, and other derivatives (for example, carboxylic acids thereof,
Carboxylic anhydrides, carboxylic acid imides, etc.), mixtures of the above compounds, condensed heterocyclic compounds such as acenaphthylene, indole, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, phenanthridine, and their derivatives. Etc. can also be used as a raw material.

When a carbonaceous material is obtained by using the above raw material organic material, for example, after carbonizing at 300 to 700 ° C. in a nitrogen stream, the temperature rising rate is 1 to 20 ° C. per minute in the nitrogen stream, and the reached temperature is 900 to The firing may be performed under the conditions of 1500 ° C. and a holding time of 0 to 5 hours at the ultimate temperature. Of course, the carbonization operation may be omitted in some cases. In the present invention, before the firing of the raw material organic material, or after carbonizing the raw material organic material to some extent, by adding and firing a phosphorus compound, carbon, phosphorus, oxygen as the main component, the lithium doping amount Can be obtained.

Examples of phosphorus compounds include phosphorus oxides such as phosphorus pentoxide, oxo acids such as orthophosphoric acid and salts thereof, and phosphorus oxides and phosphoric acids are preferred from the viewpoint of ease of handling. is there. In particular, when a raw material that becomes coke (graphitizable carbon) after firing is used, a phosphorus oxide such as phosphorus pentoxide is suitable.

In the present invention, at the time of production, 0.2 to 32% by weight, preferably 1.0 to 15% by weight of phosphorus based on the raw material of the C--P--O compound, that is, the organic material or the carbon material.
A phosphorus compound is added at a ratio of wt% to obtain C
-The proportion of phosphorus remaining in the P-O compound is 0.2 to 9.
It is 0% by weight, preferably 0.3 to 5.0% by weight. In particular, when non-graphitizable carbon is used after firing, C-P-O
0.2 to 15% by weight in terms of phosphorus based on the raw material of the compound,
Preferably, the phosphorus compound is added in a proportion of 0.5 to 7% by weight, and the proportion of phosphorus remaining in the obtained C-P-O compound is preferably 0.2 to 5.0% by weight.

If the addition amount of the phosphorus compound is less than the above range and the proportion of phosphorus in the C--P--O compound is too small,
The effect of increasing the doping amount of lithium cannot be expected so much. On the contrary, if the addition amount of the phosphorus compound is too large, CP
Even if the proportion of phosphorus in the —O compound is too high, the elemental phosphorus increases and C that substantially participates in the doping of lithium.
There is a possibility that the proportion of the —P—O compound decreases, and the characteristics deteriorate.

Basically, the phosphorus compound is added to the carbonaceous material to form a C--P--O compound, but the amount of remaining phosphorus becomes smaller, resulting in As a result, the lithium doping amount does not increase so much. Therefore, it is preferable to add the phosphorus compound from the starting material as much as possible. Especially, coke after firing (graphitizable carbon)
In this case, the upper limit temperature for adding the phosphorus compound is 70
It is 0 ° C, and even if it is added to a material processed at a temperature higher than that, phosphorus is contained to some extent.
There is no effect on dedoping. This suggests that the C—P—O bond site in the bulk, which may be formed by the reaction between the raw material and the phosphorus compound in the firing process, is involved in lithium doping / dedoping.

The C--P--O compound obtained by firing is ground and classified to be used as a negative electrode material. This grinding may be performed before or after firing or during the temperature rising process. When the above-mentioned C-P-O compound is used as the negative electrode of a non-aqueous electrolyte battery, the positive electrode preferably contains a sufficient amount of Li, for example, the general formula LiMO ₂ (where M is at least Co or Ni). A mixed metal oxide represented by 1), an intercalation compound containing Li, and the like are preferable, and LiCoO _{2 is} particularly preferable.
Good properties are exhibited when the above is used.

Since the non-aqueous electrolyte battery of the present invention is aimed at achieving a high capacity, the positive electrode has a negative electrode C in a steady state (for example, after repeating charging and discharging about 5 times).
It is necessary to contain Li corresponding to a charge / discharge capacity of 250 mAH or more per 1 g of the —P—O compound, and it is desirable to include Li corresponding to a charge / discharge capacity of 300 mAH or more.
It is more preferable to contain Li corresponding to a charge / discharge capacity of 0 mAH or more. Note that Li does not necessarily have to be entirely supplied from the positive electrode material, and the point is that Li corresponding to a charge / discharge capacity of 250 mAH or more per 1 g of the C—P—O compound is charged in the battery system.
Should exist. The amount of Li is determined by measuring the discharge capacity of the battery.

The non-aqueous electrolytic solution is prepared by appropriately combining an organic solvent and an electrolyte, and any organic solvent and electrolyte can be used as long as they can be used in a battery of this type. For example, organic solvents such as propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, methylethyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1 , 3-dioxolane, 4 methyl 1,3 dioxofuran, diethyl ether, sulfolane, methylsulfolane, acetonitrile,
Examples include propionitrile, anisole, acetic acid ester, butyric acid ester, and propionic acid ester.

As the electrolyte, LiClO ₄ , LiAs
F ₆ , LiPF ₆ , LiBF ₄ , LiB (C
₆ H ₅ ) ₄ , CH ₃ SO ₃ Li, CF ₃ SO ₃ Li, L
iCl, LiBr, etc.

[0032]

[Function] By adding a phosphorus compound to an organic material or a carbon material and calcining in an inert atmosphere, carbon containing carbon, phosphorus or oxygen as a main component-phosphorus or carbon-
A compound with an oxygen-phosphorus bond is formed. In particular, it has a peak in the range of ± 100 ppm on the basis of orthophosphoric acid in the ³¹ P nucleus-solid NMR spectrum, and has a carbon-carbon binding energy of 284.6 eV in the carbon atom 1s orbital spectrum measured by X-ray photoelectron spectroscopy. , The phosphorus atom 2p orbital spectrum of the compound having a peak of 135 eV or less has a large lithium doping amount as compared with the conventional carbonaceous material. A water electrolyte secondary battery becomes possible.

[0033]

EXAMPLES The present invention will be described below with reference to specific examples, but it goes without saying that the present invention is not limited to these examples. First, the method for measuring the negative electrode capacity, ³¹ P nucleus-solid state NMR spectrum and X-ray photoelectron spectroscopy spectrum used in this example will be described.

Capacitance measuring method Materials such as C-O-P compound obtained after firing were crushed in a mortar, classified to 38 µm or less by a mesh, and evaluated by a test cell. In the preparation of the test cell, first, the classified powder was preheated immediately before preparation of the negative electrode mix in an Ar atmosphere under the conditions of a temperature rising rate of about 30 ° C./minute, an ultimate temperature of 600 ° C., and an ultimate temperature holding time of 1 hour. Then, polyvinylidene fluoride in an amount corresponding to 10% by weight was added as a binder, dimethylformamide was mixed as a solvent, and the mixture was dried to prepare a negative electrode mix. Then, 37 mg thereof was molded into a pellet having a diameter of 15.5 mm together with a Ni mesh as a current collector to prepare a working electrode. The structure of the test cell is as follows.

<Cell configuration> Coin cell (diameter 20 mm, thickness 2.5 mm) Counter electrode: Li metal separator: Polypropylene porous membrane Electrolyte: Propylene carbonate and 1,2-
Dimethoxyethane mixed solvent (volume ratio 1: 1) in Li
ClO ₄ dissolved at a ratio of 1 mol / l.

Current collector: Copper foil

For the test cell having the above configuration, CP-
The capacity per 1 g of O compound was measured. It should be noted that the working electrode is doped with lithium (charging: strictly speaking, in this test method, the process of doping with the C-P-O compound is discharging, not charging, but for convenience, this doping is done according to the actual conditions in the actual battery. The process is referred to as charging and the dedoping process is referred to as discharging.) In the current density of 0.53 mA / cm ² , charging for 1 hour and resting for 2 hours are repeated, and the equilibrium potential during the rest is 3 mV (Li / Li ⁺ ). I went to. The discharge (de-doping process) was repeated at a current density of 0.53 mA / cm ² for 1 hour of discharge / 2 hours of rest, and the terminal voltage of 1.5 V was used as the cutoff voltage.

It has been known that the amount of discharged electricity obtained by this method is smaller than the amount of charged electricity of any material, and this electric capacity which is not discharged is called capacity loss for convenience. In a practical battery, the value of this capacity loss is also important for evaluating the negative electrode material.

< ³¹ P Nuclear-Solid High-Resolution NMR Measurement Method> A powder sample and the same weight of KCl were mixed, packed in a sample tube, sealed, and measured under the following conditions. ³¹ P nucleus-solid high-resolution NMR measurement condition device JEOL GSX270 (solid probe: GSH27T6) measurement nucleus ³¹ P measurement frequency 109.25 MHz measurement mode MASGHD reference substance diammonium hydrogen phosphate (1.
6ppm) Sample tube rotation speed about 5000Hz Measurement temperature Room temperature Diluent KCl (2 to 3 times)

<XPS (X-ray Photoelectron Spectroscopy)> Using a powder sample, phosphorus atom, 2p orbital spectrum was measured under the following conditions. XPS (X-ray Photoelectron Spectroscopy) measurement conditions Device SSI M-PROBE Measurement vacuum at 1 × 10 ^-9 torr After evacuation, introduce argon gas and measure at 2 × 10 ^-7 torr Neutralization electron 2.0 eV pass Energy 50 eV Photoelectron uptake angle 35 ° Charge uniformization Ni mesh Standard carbon-carbon bond 284.6 eV Waveform processing Gaussian 80% + Lorentzi
an 20%

<Standard Compound> Since it is difficult to consider the presence of an alkyl chain in a carbon material heat-treated at high temperature, it is appropriate to consider that the terminal to which phosphorus is bound is a benzene ring.
The chemical shift value of NMR and the binding energy of XPS were compared with the measured value of the aromatic phosphorus compound to identify the existing state of phosphorus.

The fact that the aromatic phosphorus compound can be used as a standard compound was confirmed by simulating by molecular orbital calculation or the like that the increase in the number of benzene rings bonded to the phosphorus compound has no effect. Table 1 shows the chemical shift value in the ³¹ P nucleus-solid state NMR spectrum and the binding energy in the XPS-P (2p) spectrum of each phosphorus compound.

[0043]

[Table 1]

Experiment 1 This experiment is an example of studying non-graphitizable carbon.

<Preliminary Experiment 1> First, using furan resin as an organic material, the effect of addition of phosphorus was investigated. Figure 1
Is a furfuryl alcohol resin (polymerization catalyst: maleic anhydride) 1200 ° C. fired body (hereinafter, abbreviated as PFA-C) is added with phosphoric acid during firing, and the continuous chargeable / dischargeable capacity of a battery using this as a negative electrode It shows that the addition of phosphoric acid at the time of firing is very effective in expanding the charge / discharge capacity.
The added phosphorus remained in the obtained C-P-O compound depending on the added amount, as shown in FIG. The amount of phosphorus was determined by inductively coupled plasma optical emission spectroscopy.

Further, PFA-C is 700 in DTA.
No exothermic peak above ℃, (002)
The interplanar spacing also shows a large value of 3.85 Å, but even if phosphoric acid is added during firing into PFA-C,
And, as shown in FIG. 4, there is almost no change in these characteristics. For example, even if 10 wt% of phosphoric acid is added, the exothermic peak in DTA is about 680 ° C., and the (002) plane spacing is 3.70 Å or more. there were.

<Preliminary Experiment 2> First, petroleum pitch (H / C
Atomic ratio of 0.6 to 0.8) is oxidized, and the oxygen content is 15.
A carbon precursor of 4% by weight was prepared, and various phosphorus compounds [orthophosphoric acid, phosphoric anhydride (phosphorus pentoxide), various phosphates] were added thereto, and then 500 ° C in a nitrogen atmosphere,
Heat treated for hours.

Then, the precursor after the heat treatment is pulverized by a mill, charged in a crucible, and heated in a nitrogen atmosphere at a heating rate of 5 ° C./min, a maximum attainable temperature of 1100 ° C., and a holding time at the maximum attainable temperature of 1 It was fired under the condition of time. After cooling, it was ground in a mortar, classified to 38 μm or less with a mesh, and evaluated by a test cell according to the above-mentioned capacity measuring method.

As a result, the discharge capacity was improved by adding any of the phosphorus compounds, but the effect of addition was anhydride> phosphoric acid>
The order was monobasic acid salt> dibasic acid salt. FIG. 5 is a characteristic diagram showing the relationship between the amount of phosphorus compound (phosphorus pentoxide and orthophosphoric acid) added to the carbon precursor and the discharge capacity.
In the case of orthophosphoric acid, the discharge capacity was maximized by adding about 5% by weight, and thereafter became almost constant. On the other hand, phosphorus pentoxide reached its maximum at about 10% by weight, and thereafter the discharge capacity rather decreased. Comparing orthophosphoric acid and phosphorus pentoxide, it can be said that the latter is more effective.

Table 2 shows discharge capacities when typical phosphorus compounds are added.

[0051]

[Table 2]

When used as the negative electrode of a non-aqueous electrolyte battery, the (002) plane spacing determined by X-ray diffraction and the temperature of the exothermic peak appearing in the DTA curve in an air atmosphere are closely related to the battery characteristics. Is considered to have. Then, it was investigated what kind of changes appeared in the (002) interplanar spacing and DTA peak temperature by the addition of the phosphorus compound, and how these changes corresponded to the characteristics.

The respective results are shown in FIG. 6 and FIG.
It was estimated that the amount of change in each parameter due to the addition of the phosphorus compound was not so large, that the improvement in the characteristics and the change in these parameters did not correspond uniquely, and that the contribution of another factor was large.

Further, it was examined how much phosphorus remained when the phosphorus compound was added. The measurement of the residual amount of phosphorus is the same as in the preliminary experiment 1 above. The result is shown in FIG. As the amount of phosphorus compound added increases, the amount of phosphorus remaining in the C-P-O compound naturally increases, but the remaining amount of phosphorus tends to be saturated at about 3% by weight. Was given.

Therefore, the amount of remaining phosphorus is 0.2-5.
It can be said that the content is preferably wt% and more preferably 0.5 to 3 wt%.

Further, an attempt was made to analyze the existing state of residual phosphorus, which is important for investigating the cause of the effect of the addition of the phosphorus compound. The measurement sample is petroleum pitch (H
/ C atomic ratio of 0.6 to 0.8) and the oxygen content is 1
10% phosphorus pentoxide was added to the carbon precursor of 5.4% by weight.
After being added in an amount of 10% by weight, the mixture was heat-treated at 500 ° C. for 5 hours in a nitrogen stream, and the precursor after the heat treatment was pulverized in a mill and charged into a crucible, and the temperature rising rate was 5 ° C. in a nitrogen stream. / Min, the maximum ultimate temperature is 800, 1100, 1300 ° C under the condition that the holding time at the maximum ultimate temperature is 1 hour.
The presence state of phosphorus was analyzed by ³¹ P nucleus-solid high resolution NMR and XPS (X-ray photoelectron spectroscopy) measurement using the above-mentioned four kinds that were calcined as above.

FIG. 9 shows the analysis result of ³¹ P nucleus-solid high resolution NMR, and FIG. 10 shows the XPS (phosphorus atom, 2p orbital) spectrum. First, as a result of NMR, the main peak of phosphorus pentoxide is found at 0 ppm and the side band is found at about ± 50 ppm at a firing temperature of 500 ° C., and a considerable amount remains. In addition, peaks are found at about −10 ppm and about 20 ppm as shoulders of the main peak. A peak is also seen at about 40 ppm.

Next, at 800 ° C., the peak of phosphorus pentoxide disappears and the main peak is at about -10 ppm.
The peak at 500 ° C. is small but remains. Next, at 1100 ° C, the main peak remained unchanged and the intensity was 80%.
Considering the fact that it is almost the same as 0 ° C., it is considered that the residual amounts of phosphorus are also substantially equal. Other peaks are absent except that a sideband-like rise is observed on both sides of the main peak.

At 1300 ° C., the position and shape of the main peak are the same as at 1100 ° C., but it is considered that the strength is reduced and the residual amount of phosphorus is also reduced. From the above results, 800 ℃
It is considered that the main peaks that exist thereafter are derived from the compound formed by the reaction between the carbon material and phosphorus during firing. About this −
The peak at 10 ppm is − (C ₆ H ₅ ) ₃ P for the standard compound.
8.9 ppm, or (C ₆ H ₅ O) ₂ P (= O) (OH) -12.
7 ppm was the closest, but the peak was broad and could not be clearly distinguished.

Here, looking at the phosphorus atom 2p orbital binding energies of the XPS of the phosphorus compound narrowed down by NMR, there is a difference of about 4 eV, and the oxidation states are greatly different, so it is easy to distinguish in XPS. all right.

Next, the results of XPS will be described. Figure 1
The XPS spectrum of No. 0 is further subjected to waveform processing (curve fitting) in FIG. 11, and the compounds and P / C atomic ratios identified thereby are shown in Table 3.

[0062]

[Table 3]

The P / C atomic ratio greatly decreased from 500 ° C. to 800 ° C., which corresponds to the disappearance of the phosphorus pentoxide peak in the NMR spectrum. Moreover, although it does not change up to 1100 ° C., it decreases greatly again at 1300 ° C. As a compound, (C ₆ H ₅ O) ₂ P (= O) (OH) was most abundant at 500 ° C, and (C ₆ H ₅ )
The presence of ₃ P was not recognized. As the calcination temperature rises, it becomes a compound in which carbon and phosphorus are directly bonded, and eventually phosphorus itself is reduced to (C ₆ H ₅ ) ₃ P and further to P (element). confirmed.

From the XPS results, at 500 ° C. (C
_{Since 6} H ₅ ) ₃ P is not present, it is about −10 in NMR.
It was found that the ppm peak was derived from (C ₆ H ₅ O) ₂ P (= O) (OH).

In the industrial production method of phosphorus, 1100-1
From the fact that carbon reacts with oxygen of phosphoric acid at 400 ° C to remove and reduce oxygen in the form of carbon monoxide gas,
Since it can be seen that phosphorus is more easily reduced on the surface,
It was confirmed by XPS that the composition did not change even if the firing temperature was changed, while the reduction of phosphorus occurred on the outermost surface from the result of NMR which is bulk information.

From the above results, the above-mentioned negative electrode material is mainly a compound having a carbon-oxygen-phosphorus bond in its internal composition, and its surface composition is further reduced in addition to the carbon-oxygen-phosphorus bond. It can be proved that it is a special compound consisting of a compound having a phosphorus bond.

Based on the above preliminary experiments, a phosphorus compound was added to an organic material or a precursor in which the oxygen content of petroleum pitch was increased, and a non-aqueous electrolyte secondary battery was assembled using a fired body. I investigated its characteristics.

<Study with Petroleum Pitch> A petroleum pitch appropriately selected from the range of H / C atomic ratio of 0.6 to 0.8 was crushed and subjected to oxidation treatment in an air stream to obtain a carbon precursor. The quinoline insoluble matter of this carbon precursor (JIS centrifugal method: K24
25-1983) was 80%, and the oxygen content (by organic elemental analysis) was 15.4% by weight.

Phosphorus pentoxide (P ₂ O ₅ ) was added to this carbon precursor.
6 wt% was added, and the mixture was kept at 500 ° C. for 5 hours in a nitrogen stream, then heated to 1100 ° C. and heat-treated for 1 hour. Using the C—P—O compound thus obtained, the following battery was constructed.

The above C--P--O compound was crushed in a mortar, classified by a sieve, and used as 390 mesh or less. To 1 g of this powder, 100 mg of polyvinylidene fluoride as a binder was added, made into a paste using dimethylformamide, applied on a stainless steel net, and dried at 5 tons /
The pressure was applied at a pressure of cm ² . This was punched out and used as a negative electrode, and the net active material at this time was 32.4 mg.

On the other hand, the positive electrode is made of LiNi as an active material._0.2
Co_o.8O₂Using LiNi _0.2Co_o.8O₂9
1g of graphite powder 6g, polytetrafluoroethyl
Add 3g of ren and mix well, then take 1g of that
Put in mold and 2 ton / cm ²Compression with pressure
Then, a disk-shaped electrode was obtained.

Using the above positive electrode and negative electrode, 1% of propylene carbonate and 1,2-dimethoxyethane was used as an electrolytic solution.
LiClO ₄ in 1: 1 (volume ratio) mixed solvent 1 mol / l
The coin-shaped battery (Example 1) was obtained by dissolving polypropylene
Was prototyped. The battery was constructed so that the positive electrode >> negative electrode was obtained, with the amount of active material used as the electrochemical equivalent, and the negative electrode was regulated.

A coin-type battery (Comparative Example 1) was manufactured in the same manner as in Example 1 except that phosphorus pentoxide was not added.

First, discharge curves were drawn for Example 1 and Comparative Example 1. The result is shown in FIG. In the figure, the solid line shows the discharge curve of Example 1, and the broken line shows the discharge curve of Comparative Example 1. From FIG. 12 as well, it was found that the addition of the phosphorus compound and the firing were significantly superior in terms of capacity.

Next, the cycle characteristics of Example 1 and Comparative Example 1 were examined. In the charge / discharge test, the current density was 0.53 mA / cm ² for both charging and discharging, and the discharge cutoff voltage was set to 1.5V.
The result is shown in FIG. In addition, in FIG. 13, the line a represents the cycle characteristics when Example 1 was charged at 360 mAH / g,
Line b shows the cycle characteristics when Comparative Example 1 was charged at 360 mAH / g, and line c shows the cycle characteristics when Comparative Example 1 was charged at 320 mAH / g.

In Example 1, good cycle characteristics are exhibited even when charged at 360 mAH / g, but in Comparative Example 1, the life is very short. Further, in Comparative Example 1, when the battery is charged at 320 mAH / g, the cycle characteristics are good, but the discharge capacity is small.

<Study with Novolac Phenolic Resin> 10 g of novolac phenolic resin powder (product name XPGA 4552B, manufactured by Gunei Chemical Co., Ltd.) was added with 10 g of pure water and 1 g of ethanol, and the mixture was moistened. An acid aqueous solution (500 mg) was added and mixed well. This was held at 500 ° C. for 5 hours in a nitrogen atmosphere, then heated to 1200 ° C., and heat-treated for 1 hour. The physical properties of the obtained compound are as follows.

(002) Interplanar spacing 3.75 A True density 1.60 g / cm ³ DTA exothermic peak 631 ° C. Phosphorus content about 0.8 wt% ³¹ P Nuclear-solid peak NMR at −11 ppm Chemical shift by XPS Surface composition / abundance ratio of phosphorus (C ₆ H ₅ O) ₂ P (= O) (OH) /17.7% (C ₆ H ₅ ) ₂ P (= O) (OH) /35.9% (C _{6 H 5) 3 P = O} /26.0% (C 6 H 5) 3 P /20.4%

Using the C—P—O compound powder thus obtained as a negative electrode active material, a battery (Example 2) having the same structure as that of Example 1 was produced as a prototype. The net negative electrode active material is 32.
It was 5 mg. As a result of performing a charge / discharge cycle test with various charge / discharge capacities, it was found that stable charge / discharge can be performed at a charge amount of 360 mAH / g or less.

Therefore, the discharge curve when charging / discharging at 360 mAH / g is shown by the solid line in FIG.

Next, a battery (Comparative Example 2) was prepared in exactly the same manner as in Example 2 except that phosphoric acid was not added to the novolac type phenol resin powder, and a charge / discharge cycle test was conducted at various charge / discharge capacities. It was As a result, stable charging / discharging was possible only at a charging amount of about 210 mAH / g at most.

The discharge curve when charged at 210 mAH / g is shown by the broken line in FIG.

Experiment 2 In this experiment, the effect of phosphorus content in graphitizable carbon was investigated.

<Preliminary Experiment> Acenaphthylene (C ₁₂ H ₈ :
Wako Junyaku Co., Ltd. reagent) as raw material, raw material state and 200-
P ₂ O ₅ was added to the one heat-treated at 650 ° (constant amount of addition: 5% by weight), and a change in capacity with respect to the heat treatment temperature (for convenience, referred to as an addition temperature) was examined. In addition, regarding the phosphorus content, inductively coupled plasma optical emission spectroscopy (IC
Quantitation was performed according to P).

Here, the sample was prepared as follows. That is, after the temperature of acenaphthylene was raised to the addition temperature, the temperature was once lowered, pulverized, P ₂ O ₅ was added and mixed,
The temperature was raised again to the addition temperature. Then, after holding for 1 hour, carbonize at 530 ° C., and further calcination at 1100 ° C.
A sample that passed 90 mesh was used as a sample. The heating rate was 100 ° C./hour until carbonization and 5 ° C./minute during firing.

FIG. 15 shows changes in capacity and capacity loss with respect to the addition temperature, and FIG. 16 shows changes in phosphorus content. The capacity was almost constant up to the addition temperature of 430 ° C., but thereafter decreased, and at 600 to 700 ° C., the capacity was about the same as that without P ₂ O ₅ added. On the other hand, as is clear from FIG. 16, the phosphorus content decreases at the addition temperature of 300 ° C. or higher. However, considering together with FIG. It has been found that a large effect can be obtained on the expansion of.

<Study with acenaphthylene> 25 g of acenaphthylene (C ₁₂ H ₈ : reagent manufactured by Wako Pure Chemical Industries, Ltd.) was heated to 430 ° C. at 100 ° C./hour in a nitrogen stream, then cooled and ground to obtain a sample. P ₂ O ₅ was added to and mixed with the obtained sample, and the mixture was held at 430 ° C. for 1 hour and then heated to 530 ° C. to obtain a solid precursor. This was further crushed, heated to 1100 ° C., heat-treated for 1 hour, and cooled to obtain a powder sample.

The amount of P ₂ O ₅ added was 3% by weight (Example A),
5% by weight (Example B), 10% by weight (Example C), 15
Wt% (Example D), 20 wt% (Example E),
The phosphorus content, capacity and capacity loss were measured. Quantitation of phosphorus in the powder sample was performed by ICP. In addition, the plane spacing (d002) of the (002) diffraction peak which is a structural parameter
And the crystallite thickness (Lc002) were measured by the powder X-ray diffraction method, and the true density was also measured.

A powder sample (Comparative Example A) was prepared in exactly the same manner as in Examples A to E except that P ₂ O ₅ was not added to acenaphthylene, and the capacity, d002, Lc002 and true density were measured. Table 4 summarizes the above results.
Is.

[0090]

[Table 4]

FIG. 17 shows the change of the capacity with respect to the phosphorus content, and FIG. 18 shows the change of the phosphorus content with the addition amount of P ₂ O ₅ . Furthermore, the charge-discharge curves at the time of measuring the capacities of Comparative Example A and Examples A to E are shown in FIGS. 19 to 24, respectively.
Here, the solid line shows the closed circuit voltage at the time of energization, and ○ and △
The mark indicates the equilibrium potential after the rest.

Next, using the powder samples of Example D and Comparative Example A, a cell for a cycle test was prepared and evaluated.
The cell manufacturing method and test conditions are shown below. For the negative electrode,
A molded electrode was prepared in the same manner as in the capacity test method using a C-O-P compound powder sample as an active material. LiCoO ₂ was used as an active material for the positive electrode, and 6 g of graphite and 3 g of polytetrafluoroethylene were added to 91 g of the LiCoO ₂ and thoroughly mixed, and 1 g of the graphite was placed in a mold and a pressure of 2 ton / cm ² was applied. Then, compression molding was performed to obtain a disk-shaped electrode.

Using the above positive electrode and negative electrode, 1% of propylene carbonate and 1,2-dimethoxyethane was used as an electrolytic solution.
A coin-type battery was prototyped by using LiPF ₆ dissolved in a 1: 1 (volume ratio) mixed solvent at a ratio of 1 mol / l and using polypropylene nonwoven fabric as a separator. This battery uses the amount of active material used as the electrochemical equivalent
>> It is configured to be the negative electrode, and the negative electrode is regulated.

The charge / discharge cycle test was carried out under the conditions that 320 mAh was charged per 1 g of the negative electrode active material, and discharge was performed up to a cutoff of 2.5V. The results are shown in FIG. 25. The better cycle characteristics were shown when phosphorus was contained.

Next, using the samples of Examples A to E, the presence state of phosphorus was analyzed by ³¹ P nucleus-solid high resolution NMR and XPS measurement. For Example C, in order to see the change in the firing process, in addition to the 1100 ° C fired product, 500 ° C
The measurement was also performed on the calcined product and the calcined product at 1300 ° C.
26 shows the NMR spectra of Examples A to E, FIG. 27 shows the XPS spectra, and Table 5 shows a summary of the composition of each compound.

[0096]

[Table 5]

As a result, even if the amount of P ₂ O ₅ added increases, the NM
The main peak of R was about -10 ppm. On the other hand, X
In the PS spectrum, in addition to the compound in which the benzene ring and phosphorus were bonded, elemental phosphorus or a component having a lower binding energy (component having an electron-rich bond than the element) was present. The component with lower binding energy than elemental phosphorus is
Usually, compounds of phosphorus and other metals are mentioned, but the constituent elements are carbon, oxygen, phosphorus and some hydrogen, and other metals do not exist. Therefore, this phenomenon can be considered as follows. That is, a low binding energy means an excess of electrons, which can be considered to be influenced by the donation of electrons. Since such a phenomenon did not occur in the non-graphitizable carbon containing phosphorus, the graphitizable carbon has a more developed graphite structure, and the effect of the π electron is a part of the elemental phosphorus. It is considered that the peak shifted and appeared as a component with low binding energy in the spectrum. (This peak is indicated as electron-rich P because it is attributed to the electron-rich element phosphorus.) This phenomenon can be said to be a characteristic of graphitizable carbon such as coke containing phosphorus.

FIG. 28 shows an NMR spectrum for changes in the firing process, FIG. 29 shows an XPS spectrum, and Table 6 shows the composition of each compound.

[0099]

[Table 6]

From the NMR spectrum, at 500 ° C., the main peak of phosphorus pentoxide was found at 0 ppm and the side band was found at about ± 50 ppm, and a considerable amount remained. In addition, peaks are found at about −10 ppm and about 20 ppm as shoulders of the main peak. Also, about -30pp
A peak is also seen at m. Next, at 1100 ° C., about −
The main peak appears at 10 ppm, and the other peaks disappear, except that a rise like a side band is observed.

Finally, at 1300 ° C., the position and shape of the main peak are the same as those at 1100 ° C., but it is considered that the strength is reduced and the residual amount of phosphorus is also reduced. This peak at about -10 ppm is (C ₆ H
_{5) -8.9ppm} or (C ₆ H ₅ O of _{3 P) 2 P (= O} ) of (OH) -
12.7 ppm was the closest, but the peak was broad and could not be clearly distinguished.

On the other hand, in the XPS spectrum, P ₂ O ₅ was the most at 500 ° C., (C ₆ H ₅ O) ₂ P (= O) (OH) was also present, and (C ₆ H ₅ ) ₃ The presence of P was not recognized. 1100 ° C
In (C ₆ H _{5) 3} is P was present also recognized the, intermediate in the course of its production _{(C 6 H 5 O) 2} P (= O) (OH) or (C ₆ H _{5) 3} P It was found that there is a process in which = O is present and phosphorus is gradually reduced.

From the XPS results, at 500 ° C. (C
_{Since 6} H ₅ ) ₃ P is not present, it is about −10 in NMR.
The ppm peak was found to be (C ₆ H ₅ O) ₂ P (= O) (OH) ₂ . In the industrial manufacturing method of phosphorus, 1100 to 140
From the fact that carbon reacts with oxygen of phosphoric acid at 0 ° C to remove oxygen in the form of carbon monoxide and reduce it, it can be seen that phosphorus is more easily reduced on the surface. It was confirmed by XPS that phosphorus was reduced on the outermost surface even if the firing temperature was changed.

From the above results, in the negative electrode material of this example, the internal composition was mainly a compound having a carbon-oxygen-phosphorus bond, and the surface composition was further reduced in addition to the carbon-oxygen-phosphorus bond. It was proved to be a special compound consisting of a compound having a carbon-phosphorus bond.

<Study with Petroleum Coke> Next, a similar experiment was conducted using petroleum coke instead of acenaphthylene. That is, petroleum coke was crushed to 200 mesh or less, and 10 g thereof was mixed with 1 g of P ₂ O ₅ and then heat-treated under the same conditions as in Example A.
A powder sample (Example F) was obtained by firing at 0 ° C. for 1 hour. Then, the phosphorus content, the capacity, and the capacity loss of the obtained sample were measured.

On the other hand, heat treatment was carried out in the same manner as in Example F except that P ₂ O ₅ was not added to petroleum coke to obtain a powder sample (Comparative Example B). Then, the phosphorus content, the capacity, and the capacity loss of the obtained sample were measured. The above results are summarized in Table 7. In addition, charge and discharge curves at the time of measuring the capacities of Example F and Comparative Example B are shown in FIGS. 30 and 31, respectively. In addition,
Here again, the solid line shows the closed circuit voltage when energized.
The mark indicates the equilibrium potential after the rest.

[0107]

[Table 7]

Further, using the powder samples of Example F and Comparative example B, cells similar to those of Example D and Comparative example A were prepared and cycled. The charge / discharge cycle test was performed by charging 320 mAh per 1 g of the negative electrode active material and cutting off at 2.5 V.
It was carried out under the condition of discharging up to. The results are shown in FIG. 32, and it can be seen that phosphorus is contained to exhibit better cycle characteristics.

Next, for the sample of Example F, ³¹ P nucleus-
The result of having analyzed the existing state of phosphorus by solid high-resolution NMR and XPS measurement is shown. Chemical shift of peak in ³¹ P nucleus-solid NMR spectrum: −11 ppm Surface composition (abundance ratio) of phosphorus by −11: (C ₆ H ₅ O) ₂ P (═O) (OH) 12.9% :( C ₆ H ₅ ) ₂ P (= O) (OH) 15.5%: (C ₆ H ₅ ) ₃ P = O 23.0%: (C ₆ H ₅ ) ₃ P 22.3%: P 7.5% : P with electron-rich bond 18.7%

The specific embodiments to which the present invention is applied have been described above, but the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. ..

[0111]

As is apparent from the above description, phosphatization
Compound, and carbon containing carbon, phosphorus and oxygen as main components
Forms phosphorus or compounds with carbon-oxygen-phosphorus bonds
By doing so, a negative electrode material having a large lithium doping amount
Can be provided. That is, the negative electrode material of the present invention
Has an internal composition (C₆H_FiveO)₂P (= O) (O
H) but the surface composition is (C₆H_FiveO)₂P (= O)
(OH) and further reduced (C₆H_Five)₂P (= O)
(OH), (C₆H_Five)₃P = O, (C₆H _Five)₃P?
It is a special compound consisting of And this special structure
Increase lithium doping only by having
That is the effect.

Further, according to the production method of the present invention, a negative electrode material having excellent characteristics can be produced by a simple operation, and a negative electrode material such as a lithium secondary battery can be produced without increasing the production cost or degrading the productivity. A suitable negative electrode material can be manufactured. Furthermore, in the non-aqueous electrolyte battery of the present invention, since a negative electrode material having a large lithium doping amount is used, it is possible to realize a charge / discharge capacity that exceeds the theoretical value when graphite is used as the negative electrode, and It is possible to provide a battery having excellent cycle characteristics. The use of this material enables a non-aqueous electrolyte secondary battery having a large charge / discharge capacity.

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing the relationship between the charged amount of phosphoric acid and the amount of electricity that can be continuously charged / discharged in the obtained polyfurfuryl alcohol fired product.

FIG. 2 is a characteristic diagram showing a relationship between a phosphoric acid charging amount and a phosphorus residual rate in a polyfurfuryl alcohol resin fired body.

FIG. 3 is a characteristic diagram showing a temperature change of a DTA peak depending on a charged amount of phosphoric acid in a polyfurfuryl alcohol resin fired body.

FIG. 4 is a characteristic diagram showing changes in d ₀₀₂ depending on the charged amount of phosphoric acid in a polyfurfuryl alcohol resin fired product.

FIG. 5 is a characteristic diagram showing the relationship between the addition amount and the discharge capacity when orthophosphoric acid and phosphorus pentoxide are added to oxygen-crosslinked petroleum pitch.

FIG. 6 is a characteristic diagram showing changes in d ₀₀₂ due to the addition of a phosphorus compound in an oxygen-crosslinked petroleum pitch fired product.

FIG. 7 is a characteristic diagram showing a temperature change of a DTA peak due to the addition of a phosphorus compound in an oxygen-crosslinked petroleum pitch fired product.

FIG. 8 is a characteristic diagram showing the relationship between the amount of phosphorus compound added and the amount of residual phosphorus in an oxygen-crosslinked petroleum pitch fired product.

FIG. 9 is a ³¹ P nucleus-solid state NMR spectrum.

FIG. 10 is a phosphorus atom 2p orbital spectrum obtained by XPS.

11 is a diagram in which the spectrum of FIG. 10 is subjected to waveform processing.

12 is a characteristic diagram showing discharge curves of Example 1 and Comparative Example 1. FIG.

13 is a characteristic diagram showing cycle characteristics of Example 1 and Comparative Example 1. FIG.

14 is a characteristic diagram showing discharge curves of Example 2 and Comparative Example 2. FIG.

FIG. 15 is a characteristic diagram showing the relationship between the addition temperature of phosphorus pentoxide and the capacity and capacity loss in acenaphthylene.

FIG. 16 is a characteristic diagram showing the relationship between the phosphorus pentoxide addition temperature and phosphorus content in acenaphthylene.

FIG. 17 is a characteristic diagram showing the relationship between the phosphorus content and the capacity and capacity loss in acenaphthylene.

FIG. 18 is a characteristic diagram showing the relationship between the added amount of phosphorus pentoxide and the phosphorus content in acenaphthylene.

19 is a characteristic diagram showing a charge / discharge curve of Comparative Example A. FIG.

FIG. 20 is a characteristic diagram showing a charge / discharge curve of Example A.

21 is a characteristic diagram showing a charge / discharge curve of Example B. FIG.

22 is a characteristic diagram showing a charge / discharge curve of Example C. FIG.

FIG. 23 is a characteristic diagram showing a charge / discharge curve of Example D.

FIG. 24 is a characteristic diagram showing a charge / discharge curve of Example E.

25 is a characteristic diagram showing cycle characteristics of batteries using Example D and Comparative Example A. FIG.

FIG. 26 is a characteristic diagram showing a difference in ³¹ P nucleus-solid state NMR spectrum depending on the amount of phosphorus pentoxide added to acenaphthylene.

FIG. 27 is a characteristic diagram showing a difference in XPS spectrum depending on the amount of phosphorus pentoxide added to acenaphthylene.

FIG. 28 is a characteristic diagram showing the difference in ³¹ P nucleus-solid state NMR spectra depending on the firing temperature after the addition of phosphorus pentoxide in acenaphthylene.

FIG. 29 is a characteristic diagram showing a difference in XPS spectrum depending on a firing temperature after adding phosphorus pentoxide to acenaphthylene.

FIG. 30 is a characteristic diagram showing a charge / discharge curve of Example F.

31 is a characteristic diagram showing a charge / discharge curve of Comparative Example B. FIG.

32 is a characteristic diagram showing cycle characteristics of batteries using Example F and Comparative Example B. FIG.

Claims (9)

[Claims] 1. A main component of carbon, phosphorus and oxygen, wherein the content of phosphorus is 0.2 to 9.0% by weight, and within a range of ± 100 ppm on the basis of orthophosphoric acid in a ³¹ P nucleus-solid state NMR spectrum. It has a peak and has a carbon-to-carbon binding energy of 284.6 in the carbon atom 1s orbital spectrum measured by X-ray photoelectron spectroscopy.
When eV is set, the phosphorus atom 2p orbital spectrum is 13
A negative electrode material mainly composed of a compound having a peak of 5 eV or less. 2. The compound has a (002) plane spacing of 3.70 Å or more and a true density of less than 1.7 g / cm ³ , and has an exothermic peak at 700 ° C. or more in a differential thermal analysis in an air stream. The negative electrode material according to claim 1, wherein the negative electrode material is a compound that does not have the compound. 3. The negative electrode material according to claim 1, wherein the compound is a coke obtained by adding phosphorus pentoxide to a carbon material or an organic material that has been heat-treated at 700 ° C. or lower and calcining the coke. 4. A main component of carbon, phosphorus, and oxygen, which is characterized by adding 0.2 to 32% by weight of a phosphorus compound in terms of phosphorus to an organic material or a carbon material, and firing in an inert atmosphere. Method for producing negative electrode material. 5. An organic material or a carbon material has a (002) plane spacing of 3.70 Å or more, a true density of less than 1.7 g / cm ³ , and a differential thermal analysis of 700 ° C. or more in an air stream when fired. The method for producing a negative electrode material according to claim 4, wherein the negative electrode material is an organic material or a carbon material, which is a carbonaceous material having no exothermic peak. 6. The negative electrode material according to claim 4, wherein the organic material or carbon material is an organic material or carbon material which becomes a coke by being heat-treated at 700 ° C. or lower, and the phosphorus compound is phosphorus pentoxide. Manufacturing method. 7. A main component of carbon, phosphorus and oxygen, and a phosphorus content of 0.2 to 9.0% by weight, in the ³¹ P nucleus-solid state NMR spectrum, ±± based on orthophosphoric acid.
It has a peak in the range of 100 ppm, and when the carbon-to-carbon bond energy of the carbon atom 1s orbital spectrum is 284.6 eV in X-ray photoelectron spectroscopy measurement,
A non-aqueous electrolyte battery comprising a negative electrode mainly composed of a compound having a peak of a phosphorus atom 2p orbital spectrum of 135 eV or less, a positive electrode containing Li, and a non-aqueous electrolyte. 8. The compound has a (002) plane spacing of 3.70 Å or more and a true density of less than 1.7 g / cm ³ , and has an exothermic peak at 700 ° C. or more in a differential thermal analysis in an air stream. The non-aqueous electrolyte battery according to claim 7, wherein the non-aqueous electrolyte battery is a compound that does not have the compound. 9. The non-aqueous electrolyte battery according to claim 7, wherein the compound is a coke obtained by adding phosphorus pentoxide to a carbon material or an organic material that has been heat-treated at 700 ° C. or lower and firing the coke. ..