JPH11283627A - Lithium secondary battery and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithium secondary battery of a high capacity, having a long cycle lifetime, and a method for manufacturing the same. SOLUTION: A lithium secondary battery comprises at least a negative electrode 301, a positive electrode 303 and an electrolyte 307, in which an oxidation/ reduction reaction of a lithium ion is used for charging/discharging. An electrode having active material which has at least an amorphous phase and 0.48 degree or more of a half-width of the peak at which a highest diffraction intensity appears at an X-ray diffraction angle 2θ in an X-ray diffraction chart representing the diffraction ray intensity at 2θ and which is composed mainly of a material including one or more elements selected from a group of cobalt, nickel, manganese and iron, is used as the negative electrode 301 and/or the positive electrode 303.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium secondary battery, a secondary battery thereof, and a manufacturing method. More specifically,
The present invention relates to a lithium secondary battery having a long life by suppressing an increase in electrode impedance due to expansion and contraction of an electrode active material generated by repeated charge and discharge of a secondary battery, and a method of manufacturing the same. In addition, the present invention relates to a high energy density lithium secondary battery in which the number of sites where lithium ions can be intercalated and deintercalated is increased to increase the capacity of a positive electrode and a negative electrode, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Recently, the amount of CO ₂ gas contained in the atmosphere is increasing, and it is predicted that the greenhouse effect will cause global warming. Thermal power plants convert thermal energy obtained by burning fossil fuels and the like into electric energy, but because it emits a large amount of CO ₂ gas, it has become difficult to construct a new thermal power plant. ing. Therefore, as an effective use of the power generated by generators such as thermal power plants, nighttime power is stored in secondary batteries installed in ordinary households, and this is used during the daytime when power consumption is high, and the load is leveled. The so-called road leveling has been proposed.

[0003] Further, for electric vehicles which are characterized in that they do not emit substances related to air pollution including CO _X , NO _X , CH and the like, development of secondary batteries with high energy density is expected. Furthermore, for the power supply of portable devices such as book-type personal computers, word processors, video cameras, and mobile phones, there is an urgent need to develop small, lightweight, and high-performance secondary batteries.

As a small, lightweight and high-performance secondary battery,
JOUNAL is an example of applying graphite intercalation compounds to the anode of secondary batteries
Since it was reported in OF THE ELECTROCHEMICAL SOCIETY 117, 222 (1970), for example, a carbon material was used as the negative electrode active material and lithium ion introduced into the intercalation compound was used as the positive electrode active material. The so-called "lithium ion battery", which is a rocking chair type secondary battery that intercalates and stores lithium ions, has been developed and put into practical use. In this lithium-ion battery, the carbon material as the host material, which can intercalate lithium ions as the guest material between layers, is used for the negative electrode, thereby suppressing the growth of lithium dendrites during charging and providing a long life in the charge-discharge cycle. Have achieved.

[0005] Since the above-mentioned lithium-ion battery can achieve a long-life secondary battery, proposals and studies for applying various carbon materials to the negative electrode have been actively made. JP
In 62-122066, the atomic ratio of hydrogen / carbon is less than 0.15, (00
2) A secondary battery using a carbon material having a plane spacing of 0.337 nm or more and a c-axis crystallite size of 15 nm or less as a negative electrode has been proposed. Also, JP-A-63-2172
In 95, a carbon material is used for the negative electrode, where the (002) plane spacing is 0.370 nm or more, the true density is less than 1.70 g / ml, and there is no exothermic peak at 700 ° C or more in differential thermal analysis in an air stream. Secondary batteries have been proposed. Electrochemical, Vol 57, p.
614 (1989) carbon fiber, 34th Battery Symposium Proceedings, p77 (1993) mesophase microspheres, 33rd Symposium Battery Speech, p217 (1992) natural graphite, 34th Battery Abstracts of the debates, p 77 (1993), graphite whiskers, and the 58th Annual Meeting of the Electrochemical Society of Japan, p 158 (1991), report fired furfuryl alcohol resins.

However, in a lithium ion battery using a carbon material as a negative electrode active material for storing lithium, the discharge capacity (deintercalation rate of lithium) that can be stably taken out during repeated charge / discharge depends on the theoretical capacity of the graphite intercalation compound. Nothing beyond that has yet been obtained. Ie 6 carbon atoms
Nothing exceeding the theoretical capacity of a graphite intercalation compound capable of storing one lithium atom per piece has yet been obtained. Therefore, a lithium ion battery using a carbon material as a negative electrode active material has a long cycle life, but does not reach the energy density of a lithium battery using metallic lithium itself as the negative electrode active material. If an attempt is made to intercalate a lithium amount greater than the theoretical capacity to the carbon material negative electrode of a lithium ion battery during charging, lithium metal grows in dendrite (dendritic) form on the carbon material negative electrode surface, and eventually Since repeated charge / discharge cycles lead to internal short circuit between the negative electrode and the positive electrode, a "lithium-ion battery" exceeding the theoretical capacity of the graphite negative electrode has not obtained a sufficient cycle life for practical use.

On the other hand, practical use of a high-capacity lithium secondary battery using metallic lithium as a negative electrode has been desired, but has not been realized. The reason is that the charge and discharge cycle life is extremely short. The main cause of the extremely short charge / discharge cycle life is that lithium metal reacts with impurities such as moisture in the electrolyte and organic solvents to form an insulating film on the electrode. Is generally considered to grow in dendrite (dendritic) form, causing an internal short circuit between the negative electrode and the positive electrode, leading to the end of life.

Further, when the above-mentioned lithium dendrite grows and the negative electrode and the positive electrode are short-circuited, the energy of the battery is consumed in a short time due to the short-circuit, and heat is generated, or the solvent of the electrolyte is consumed. Decomposition and generation of gas may increase the internal pressure or damage the battery.

The above-mentioned problems of the metal lithium anode are as follows.
In order to suppress the reaction between metallic lithium and the water or organic solvent in the electrolytic solution, a method using a lithium alloy composed of lithium, aluminum, or the like for the negative electrode has been proposed.
However, in this case, since the lithium alloy is hard and cannot be spirally wound, a spiral cylindrical battery cannot be manufactured, the cycle life is not extended as expected, and it is comparable to a battery using lithium metal as the negative electrode. At present, it has not been put to practical use in a wide range because energy density cannot be obtained.

JP-A-5-190171, JP-A-5-47381, JP-A-6
3-114057, JP-A-63-13264 proposes using various lithium alloys for the negative electrode, and JP-A-5-234585 proposes providing a metal powder on the lithium surface that does not easily produce lithium and an intermetallic compound. However, none of these methods can be a decisive method for dramatically extending the life of the negative electrode.

On the other hand, JOURNAL OF APPLIED ELECTROCHEMIS
STRY 22 (1992) 620-627 describes a high-energy-density lithium secondary battery that uses aluminum foil with an etched surface as the negative electrode, although its energy density is lower than that of a lithium primary battery. However, when the charge / discharge cycle is repeated up to the practical use range, the aluminum foil repeatedly expands and contracts, cracks are generated, the current collecting property is reduced and dendrite growth occurs, and the cycle life can be used at a practical level. No secondary battery has been obtained.

Under such circumstances, development of a negative electrode material having a longer life and a higher energy density than a carbon material negative electrode currently in practical use is eagerly desired.

Further, in order to realize a lithium secondary battery having a high energy density, it is essential to develop not only a negative electrode but also a positive electrode material. At present, lithium-ion is inserted (intercalated) into the intercalation compound as a positive electrode active material.
Transition metal oxides are mainly used, but have a theoretical capacity of 40
Only ~ 60% discharge capacity has been achieved. In particular, if a battery having a long cycle life is to be obtained as a battery for practical use, only a minimum amount of charge and discharge can be performed with respect to the theoretical capacity, which is contrary to the increase in capacity. This is, for example, the 34th Battery Symposium 2
Taking lithium cobalt oxide as an example from A04 (p39-40), when lithium cobalt oxide is charged and lithium is deintercalated, the crystal structure changes from monoclinic to hexagonal at around 3/4. Changes to At this time, since the C axis is extremely reduced, the reversibility of lithium is extremely deteriorated after the next discharge, and the cycle characteristics are deteriorated. It is known that the same phenomenon occurs in lithium nickel oxide and the like.

In order to suppress this structural change, for example,
In the 2nd session of the debate on batteries 2A08 (p47-48), part of lithium in lithium cobaltate was changed to sodium, potassium,
Substitution with copper or silver has been proposed, but has not been improved in utilization rate and cycle characteristics. In addition, addition of cobalt, manganese, aluminum and the like to lithium nickelate has been reported, but none of them has been able to suppress the change in crystal structure, improve the utilization factor and improve the cycle characteristics.

As can be understood from the above situation, lithium secondary batteries including lithium ion batteries (hereinafter, referred to as “lithium ion batteries”) utilizing lithium ions as guests for charge / discharge reactions.
In the present invention, a secondary battery utilizing the intercalation and deintercalation reactions by the oxidation-reduction reaction of lithium ions for the charge / discharge reaction at the electrode is used for lithium secondary batteries including a “lithium ion battery” using a carbon material for the negative electrode. It is strongly desired to develop a negative electrode and a positive electrode having a cycle life in a practical range and having higher capacities than the carbon material negative electrode and the transition metal oxide positive electrode which are currently in practical use.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a lithium secondary battery using a redox reaction of lithium ions for a charge / discharge reaction. An object of the present invention is to provide a secondary battery provided with an electrode having a high-capacity positive electrode active material or a negative electrode active material constituting a high-capacity positive electrode or negative electrode, and a method for manufacturing the same.

[0017]

SUMMARY OF THE INVENTION A first aspect of the present invention is a lithium secondary battery comprising at least a negative electrode, a positive electrode, and an electrolyte and utilizing the oxidation-reduction reaction of lithium ions for charge and discharge. 2θ in an X-ray diffraction chart obtained by taking diffraction line intensity with respect to X-ray diffraction angle 2θ having a phase
The half-value width of the peak at which the highest diffraction intensity appeared was 0.
At least 48 degrees, containing an amorphous phase and cobalt, nickel, manganese, and a material containing at least one element selected from iron as a component, an electrode having an active material, the negative electrode, And / or a lithium secondary battery used as the positive electrode.

In the second aspect of the present invention, at least a negative electrode, a positive electrode,
In a secondary battery composed of an electrolyte and utilizing the oxidation-reduction reaction of lithium ions for charge and discharge, the negative electrode contains (b) at least an amorphous phase, and the strongest diffraction intensity for 2θ appears in X-ray diffraction. The peak half width is 0.48
Degree or more, a material containing at least one or more selected from a metal element having an amorphous phase and carbon, and a material other than lithium in an electrode in which the active material is used during a charge and discharge reaction of a lithium battery. On the other hand, a lithium secondary battery is an electrode having a complex with a material that is electrochemically inactive as an active material.

According to the present invention, a material having an amorphous phase is prepared by applying physical energy to a crystalline material, and the material having the amorphous phase is used as a positive electrode active material and / or a negative electrode. A method for manufacturing a lithium secondary battery, wherein an electrode is formed using an active material, is provided.

In the present invention, the term "active material" is a general term for substances involved in the electrochemical reaction of charging and discharging in a battery (repetition of the reaction).

(Action) According to the present invention, a lithium secondary battery formed of at least a negative electrode, a positive electrode, and an electrolyte and utilizing the oxidation-reduction reaction of lithium ions for charge and discharge contains at least an amorphous phase, 2 in the X-ray diffraction chart obtained by taking the diffraction line intensity for the X-ray diffraction angle 2θ
The half-value width of the peak where the strongest diffraction intensity appears for θ is
0.48 degrees or more, containing an amorphous phase, and cobalt, nickel, manganese, by using an electrode using a compound consisting of at least one element selected from iron as an active material, the discharge capacity is large In addition, a lithium secondary battery having a long cycle life can be provided.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the first and second lithium secondary batteries according to the present invention, the specific form of the combination of electrodes is as follows. 1) X-ray diffraction angle 2θ having at least the amorphous phase
An active material in which the half-width of the peak at which the highest diffraction intensity appears for 2θ in the X-ray diffraction chart obtained by taking the diffraction line intensity is 0.48 degrees or more, having an amorphous phase and cobalt, A lithium secondary battery comprising, as a positive electrode, an electrode (a) having an active material, comprising a material containing at least one or more elements selected from nickel, manganese, and iron. 2) A lithium secondary battery using the electrode (a) as a negative electrode. 3) A lithium secondary battery using the above-mentioned electrode (a) for a positive electrode and a negative electrode, and different in active material composition between the positive electrode and the negative electrode. 4) It contains at least the amorphous phase and has 2θ by X-ray diffraction.
The half-value width of the peak at which the highest diffraction intensity appeared was 0.
At least 48 degrees, a material containing at least one or more selected from a metal element having an amorphous phase and carbon, and a material other than lithium at the electrode where the active material is used during a charge and discharge reaction of a lithium battery. A lithium secondary battery using, as a negative electrode, an electrode (b) having a complex with an electrochemically inert material as an active material. 5) A lithium secondary battery using the electrode (a) as a positive electrode and the electrode (b) as a negative electrode.

Hereinafter, the electrode (a) used in each embodiment
And (b) will be described in detail. The electrode (a) has a characteristic by X-ray diffraction as described above, has an amorphous phase, and contains, as a component, a material containing at least one element selected from cobalt, nickel, manganese, and iron. , Having an active material, the above 1), 2), 3),
It is used for the positive electrode and / or the negative electrode of the lithium secondary battery in the form of 5). The material having an amorphous phase constituting such an active material is preferably at least selected from cobalt, nickel, manganese, and iron, which are reversible with respect to the charge / discharge reaction of a lithium battery, that is, cause a redox reaction of lithium ions. It is obtained by using a crystalline material containing one or more kinds of elements as a starting material and amorphizing it. When such an active material is used for a positive electrode or a negative electrode of a lithium secondary battery, sites where lithium ions can be intercalated and deintercalated are increased, and the active material functions as a high-capacity positive electrode active material or a negative electrode active material. .

When the crystalline material containing at least one element selected from the group consisting of cobalt, nickel, manganese, and iron is made amorphous, the active material is not charged during the charge / discharge reaction of the lithium battery. At the same time, add a material that is electrochemically inactive at the electrode used, or a material that is electrochemically inert to substances other than lithium at the electrode where the active material is used during the charge / discharge reaction of the lithium battery It is more preferable to combine them. Compound (composite) having amorphous phase finally obtained in this way
Reacted the above-mentioned electrochemically inactive material on the surface of the crystalline material as a starting material, and changed the crystalline portion of this crystalline material into another state, that is, disordered atomic arrangement. It is in an amorphous state. Further, in some cases, it is presumed that the electrochemically inactive material reacts with the amorphous material and diffuses into the amorphous material to change the crystalline material to another state.

The adoption of the above-described complexing increases the rate at which the crystalline material is made amorphous, and furthermore, the lithium ion intercalation in the finally obtained material (composite) having an amorphous phase. The point that the number of sites where the carrate and the deintercalate can be increased is further increased, and furthermore, if a conductive material is used as the electrochemically inactive material, a composite having an amorphous phase finally obtained is obtained. Around particles of a reversible material for lithium secondary batteries (a material comprising at least one element selected from cobalt, nickel, manganese, and iron) with the above-described electrochemically inactive material This is advantageous in that the conductivity of a reversible material for a lithium secondary battery can be improved.

As a crystalline material as a starting material for obtaining a material having an amorphous phase constituting the active material of the electrode (a), one selected from the above-mentioned cobalt, nickel, manganese, and iron A material containing more than one kind of element (including these metal elements), preferably a transition metal compound capable of electrochemically inserting or removing lithium ions, more preferably an oxide or nitride of a transition metal,
Oxides, nitrides, sulfides, hydroxide peroxides, and the like of sulfides, hydroxides, peroxides, and transition metals containing lithium are used. Further, an oxide or a peroxide of the above-mentioned transition metal containing an alkali metal other than lithium, or an oxide or a peroxide of the above-mentioned transition metal containing lithium may be used. Here, since a compound of cobalt, nickel, manganese, and iron expresses a high voltage of 4V class, a secondary battery using an electrode having an active material containing such a material as an essential component can have a high energy density. The feature is the point. Further, the compounds of cobalt, nickel, manganese, and iron are also advantageous in that they maintain reversibility even after repeated charging and discharging, and are long-life electrodes.

In such a material, in addition to cobalt, nickel, manganese, and iron, a transition metal element, for example, S which is an element partially having a d shell or an f shell,
c, Y, Lanthanoid, Actinoid, Ti, Zr, Hf, V, N
b, Ta, Cr, Mo, W, Tc, Re, Fe, Ru, Os, Rh, Ir, Pd, P
t, Cu, Ag, Au can be added. Here, depending on the composition of the material, a material having an amorphous phase finally obtained is selected and used as a positive electrode active material or a negative electrode active material. In particular, a material obtained from a material composed of only the above elements of cobalt, nickel, manganese, and iron is used as the negative electrode active material.

[0028] In addition, the charging of a lithium battery, which is preferably compounded with a material having an amorphous phase obtained from a crystalline material containing at least one element selected from the group consisting of cobalt, nickel, manganese, and iron. A material that becomes electrochemically inactive at the electrode where the active material is used during the discharge reaction, or electrochemically reacts with a material other than lithium at the electrode where the active material is used during the charge / discharge reaction of a lithium battery. Inert materials include the above cobalt,
It is a material having an element configuration and composition different from a material containing at least one element selected from nickel, manganese, and iron, and a metal, a carbon material, a compound containing a metal, or the like can be used.

Here, the electrochemically inactive material refers to a material that is charged or discharged (oxidized and reduced) in a battery (or an electrode).
Does not react with lithium ions (intercalate-deintercalate) at the electrode where the material is used, does not react with the electrolytic solution, does not change to another substance,
For example, the added metal does not change into an oxide or the like, that is, the added metal or the like does not directly participate in charge / discharge (a reaction other than an intercalate-deintercalate reaction of lithium does not occur during battery charge / discharge). Although having a performance, "a material that is electrochemically inactive during the charge / discharge reaction of a lithium battery" is a material that satisfies all of the above requirements in an electrode using the material, Further, “a material that is electrochemically inert to substances other than lithium during a charge / discharge reaction of a lithium battery” does not satisfy the above-described requirements in an electrode using the material, but satisfies the requirements and the respective requirements. Things,
It can be selected and used in consideration of the relationship between the electrode used and the potential of the material of the electrode serving as the counter electrode. And
Electrode having as active material a composite material of "a material that becomes electrochemically inactive during charge / discharge reaction of lithium battery" and a material composed of at least one element selected from cobalt, nickel, manganese, and iron (A) is a positive electrode, "a material that is electrochemically inert to substances other than lithium during a charge / discharge reaction of a lithium battery" and at least one element selected from cobalt, nickel, manganese, and iron The electrode (a) having, as an active material, a material obtained by compounding a material consisting of

A material which becomes electrochemically inactive at the electrode where the active material is used during the charge / discharge reaction of the lithium secondary battery, or the active material is used during the charge / discharge reaction of the lithium secondary battery As a metal used as a material which is electrochemically inert to a substance other than lithium in the electrode, a material having high conductivity is desirable. Further, a metal which does not react with the electrolytic solution during charging and discharging or does not dissolve in the electrolytic solution is preferable.

As the metal material which becomes electrochemically inactive in the electrode using the active material during the charge / discharge reaction of the lithium secondary battery, a metal material having a standard electrode potential is preferable. Preferred materials include magnesium, aluminum, manganese, zinc, chromium, iron, cadmium, cobalt, nickel, zinc, various alloys, and two or more composite metals of the above materials. The material can be selected and used in consideration of a material to be used (active material material).

The metal material which is electrochemically inactive with respect to substances other than lithium at the electrode using the active material during the charge / discharge reaction of the lithium secondary battery includes a standard electrode potential. Are preferred. Preferred materials include cobalt, nickel, tin, lead, platinum, silver, copper, gold, various alloys, and two or more composite metals of the above materials. Material).

Materials which become electrochemically inactive at the electrode where the active material is used during the charge / discharge reaction of the lithium secondary battery include amorphous carbon containing carbon black such as Ketjen black and acetylene black. And artificial graphite such as natural graphite, non-graphitizable carbon, and graphitizable carbon, and the like, which can be selected and used in consideration of a material (active material) used for an electrode serving as a counter electrode. Since carbon black such as acetylene black has a small primary particle size on the order of submicron, it is suitable for coating the surface of the active material. On the other hand, in the case of complexing with a crystalline material composed of at least one element selected from the above cobalt, nickel, manganese, and iron, in consideration of performing mechanical grinding, graphite having a large primary particle diameter is Since the weight of one particle increases, energy larger than that of carbon black can be obtained, so that mechanical gliding easily proceeds, which is more preferable.

The carbon material used as a material which is electrochemically inactive to substances other than lithium at the electrode using the active material during the charge / discharge reaction of the lithium secondary battery is Ketjen black. Considering the material (active material) used for the counter electrode, amorphous carbon including carbon black such as carbon black and acetylene black, artificial graphite such as natural graphite, non-graphitizable carbon, and easily graphitizable carbon, etc. Can be selected and used.

[0035] used as a material which is electrochemically inactive with respect to substances other than lithium at the electrode where the active material is used during the charge / discharge reaction of the lithium secondary battery;
As the compound containing a metal, a transition metal compound is preferable. Specifically, transition metal nitrates, acetates, halide salts, sulfates, organic acid salts, oxides, nitrides, sulfides,
Sulfate, thiocarbonate, hydroxide, alkoxide and the like can be used. As these transition metal elements, for example, Sc, Y, lanthanoid, actinoid, Ti, Zr, Hf,
V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, R
h, Ir, Ni, Pd, Pt, Cu, Ag, and Au. Especially,
Ti, V, Cr, Mn, Fe, Co, Ni, C
u is preferably used. Such a transition metal compound can be selected and used in consideration of a material (active material) used for an electrode serving as a counter electrode.

The metal-containing compound used as a material that is electrochemically inactive with respect to substances other than lithium at the electrode using the active material during the charge / discharge reaction of the lithium secondary battery includes: A material which electrochemically has a potential lower than the potential of the positive electrode is preferable. This is because when a material having an electrochemically lower potential with respect to the positive electrode potential, in other words, a material closer to the lithium electrode potential is used on the negative electrode side, lithium ions are reversibly intercalated and deintercalated. This is because you can car rate.
Specific examples include sulfides, oxides, and nitrides of titanium, copper, vanadium, molybdenum, iron, and the like containing or not containing lithium, and a material (active material) used for an electrode serving as a counter electrode is included. It can be selected and used with consideration.

On the other hand, the electrode (b) is made of a material containing at least one selected from a metal element having an amorphous phase having the above-described X-ray diffraction characteristics and carbon, and a lithium secondary battery. An electrode in which the active material is used during a discharge reaction has a complex with a material that is electrochemically inactive to a substance other than lithium as an active material, and lithium in the form of 4) or 5) above It is applied to the negative electrode of a secondary battery. The composite constituting the active material is preferably a crystalline material containing at least one selected from a metal element and carbon, and an electrode in which the active material is used during a charge / discharge reaction of a lithium secondary battery. In the above, a material which is electrochemically inactive with respect to substances other than lithium is simultaneously added to obtain a composite. In the composite having an amorphous phase finally obtained in this way, the above-mentioned electrochemically inactive material is replaced with the crystalline material as a starting material, as in the case described for the electrode (a). Reacts on the surface of the crystalline material to change the crystalline portion of the crystalline material into another state, that is, an amorphous state in which the atomic arrangement is disordered.

The adoption of the above-described complexing increases the rate at which the crystalline material is made amorphous, as in the case described in connection with the electrode (a). In a material (composite) having the above, the number of sites where lithium ions can be intercalated and deintercalated is increased, and furthermore, if a conductive material is used as the electrochemically inactive material, The obtained compound having an amorphous phase (composite) is advantageous in that the conductivity of a reversible material for a lithium secondary battery can be improved.

The electrode (b) was a negative electrode made of an active material containing a complex with a material which became electrochemically inert to substances other than lithium during the charge / discharge reaction of the lithium battery. Thus, unnecessary decomposition of the active material and formation of an unnecessary oxide film during the battery reaction are suppressed, and a charge / discharge reaction with good performance is performed.

As a crystalline starting material for obtaining a composite having an amorphous phase used for the electrode (b), preferably a carbon material capable of electrochemically inserting or removing lithium ions, an electrochemical reaction Metal that alloys with lithium at
A metal that does not alloy with lithium by an electrochemical reaction, a compound (metal material) that can intercalate and deintercalate lithium, or the like can be used.

Specifically, examples of the carbon material include carbon having a graphite skeleton structure, such as artificial graphite such as natural graphite, non-graphitizable carbon and graphitizable carbon. Al, Mg, Pb, K,
Na, Ca, Sr, Ba, Si, Ge, Sn, In and the like. Ni, Co, Ti, Cu, Ag, Au, W, Mo, F
e, Pt, Cr and the like. Examples of the compound capable of intercalating and deintercalating lithium ions include oxides, nitrides, hydroxides, sulfides, and sulfates of the above metals. As a specific example,
Lithium titanium oxide and lithium cobalt nitride (Li
3-xCoxN), lithium-cobalt vanadium oxide and the like.

In the electrode (b), during the charge / discharge reaction of a lithium battery for obtaining a composite having an amorphous phase, the electrode (negative electrode) using the active material electrochemically reacts with a substance other than lithium. The material which becomes inert in nature is a material having an elemental composition and composition different from that of the above-mentioned crystalline starting material, and is preferably a material other than lithium which is preferably used in the above-mentioned negative electrode of the active material of the electrode (a). A material which is electrochemically inactive can be appropriately selected and used in consideration of the potential of the material used for the counter electrode.

In particular, for the electrode (b), if a material capable of reversibly intercalating and deintercalating lithium ions is used as a material which is electrochemically inactive to substances other than lithium, the active material Since charge and discharge can be performed separately from the material, the charge and discharge capacity is not reduced, and an amorphous composite can be advantageously obtained. For example, there is a case where a complex is made amorphous by using tin, which is a material electrochemically inactive to substances other than lithium, and crystalline natural graphite.

Next, the mechanism of the performance of the active materials of the electrodes (a) and (b) with respect to the charge / discharge reaction of the lithium secondary battery will be described in detail with reference to the drawings.

For example, in the case of a crystalline active material (interlayer compound), the active material has a structure in which crystal lattice atoms 1 are regularly arranged as shown in FIG. Intercalation is regularly performed between the layers composed of atoms (during battery discharge).

On the other hand, in the active material in the amorphous phase obtained by applying physical energy to the material of the crystalline active material used for the electrode (a) or (b), for example. Then, the atoms 2 in an irregular state appear as shown in FIG. 1C through the state shown in FIG. In this case, the number of sites capable of intercalating lithium ions increases, and the capacity becomes higher.

In the case of a positive electrode active material, especially in the case of a crystalline intercalation compound, when lithium ions are intercalated, the C-axis direction of the crystal structure of the positive electrode active material serving as a host generally extends. Conversely, when deintercalating is performed, the C-axis direction contracts. When charging and discharging are repeated as a secondary battery, the stress of expansion and contraction accumulates, and there is a problem that the battery life is shortened. When the amount of intercalation and deintercalation of lithium ions to the positive electrode active material is increased, the crystal structure changes, and the life is shortened even by the structural stress at this time. For this reason, when used as a practical battery, there is a restriction that the amount of intercalation and deintercalation of lithium ions into the positive electrode active material must be limited, which hinders an increase in capacity.

On the other hand, in the above-mentioned positive electrode active material containing an amorphous phase, the atomic arrangement of the active material is irregular, so that even if lithium ions are intercalated, the structural change of the positive electrode active material as a host occurs. Is less. That is, during repetition of battery charge and discharge, stress due to expansion and contraction due to the intercalation rate and deintercalation rate of lithium ions is small, and the life is extended.

A comparison between a secondary battery actually provided with the electrode (a) and / or (b) composed of an active material having an amorphous phase and a battery using a crystalline active material according to the present invention is as follows. In addition, the charge and discharge voltage characteristics of the battery are different. For example, a description will be given along an experiment using a positive electrode active material as an example.

Nickel hydroxide and lithium hydroxide are weighed so that the molar ratio of nickel to lithium is 1: 1 and uniformly mixed, then transferred to an electric furnace and calcined at 750 ° C. for 20 hours in an oxygen stream. In addition, crystalline lithium nickelate was used as a positive electrode active material. Polyvinylidene fluoride was further added to 20% by weight of acetylene black added to the positive electrode active material to obtain a positive electrode. For the counter electrode, a mesophase microsphere (artificial graphite) heat-treated at 2800 ° C. was used as a negative electrode active material. Lithium secondary batteries made using these materials (because this negative electrode active material is crystalline having a graphite skeleton structure, the voltage characteristics during charging and discharging also have a plateau region (a voltage region where the battery voltage becomes flat over time). ), The discharge characteristics were L-shaped, with a discharge curve having a plateau region near 4 V or less. That is, the positive electrode active material in the above experiment had two or more crystal phases, accompanied by a phase change during charge / discharge, and the crystal lattice changed continuously during discharge.

On the other hand, 80 wt% of the same crystalline lithium nickelate and 20 wt% of acetylene black as those prepared above were charged into a planetary ball mill, and 15 m
Using a stainless steel ball having a diameter of 4 m and a vessel having a diameter of 4 cm, mechanical grinding was performed under the conditions of a rotation speed of 4000 rpm and a mixing time of 1 hour. When the obtained composite of lithium nickelate and acetylene black was analyzed using an X-ray diffractometer, it was confirmed that the half width of each peak was increased and the peak was amorphous. Polyvinylidene fluoride was added to the composite of lithium nickelate and acetylene black having the amorphous phase in the same manner as in the above-mentioned crystalline lithium nickelate to obtain a positive electrode. As a counter electrode, mesophase microspheres (artificial graphite) heat-treated at 2800 ° C. as described above were used. When a battery manufactured using these is charged and discharged, a discharge curve of a lithium secondary battery using a composite of lithium nickelate having an amorphous phase and acetylene black is, for example, about 4 V as shown in FIG. From 2.5 V to a gradual curve without a plateau region. This is because the atomic arrangement in the positive electrode active material is irregular, so that even when lithium ions are intercalated, the structural change of the positive electrode active material serving as the host is small. The half width of the X-ray diffraction peak of the active material containing an amorphous phase used for the electrode (a) of the first lithium secondary battery of the present invention (FIG. 3 shows the half width of one peak as an example). Is a peak corresponding to the (003) plane or the (104) plane in the case of the positive electrode active material, and the half width is preferably 0.48 degrees or more.

In the case of the negative electrode active material used for the electrode (b) of the second lithium secondary battery of the present invention, for example, in the case of carbon, the peak corresponding to the (002) plane or the (110) plane has a half-value width. Is preferably 0.48 degrees or more, and when tin is used as the active material, the peak corresponding to the (200) plane, the (101) plane, and the (211) plane is preferably 0.48 degrees or more.

It is preferable that the half width of the material of the active material containing these amorphous phases is at least 10% larger than the half width of the crystalline material before it becomes amorphous. More preferably, it is larger by 20% or more.

The smaller the crystallite size of the active material is, the smaller the crystallinity of the active material is. In the case of the active material used in the present invention, the crystallite size calculated using the following Scherrer's formula is preferably 200 ° or less. In the case of a composite with an inert material, the temperature is preferably 400 ° or less. The size of the crystallite is preferably 50% or less, more preferably 2/3 or less, of the crystalline material of the starting material.

(*) Scherrer's formula: t = 0.9λ / Bcosθ t: crystallite size λ: wavelength of X-ray beam B: half-width of X-ray diffraction peak θ: diffraction angle

In the present invention, it is preferable that the active material having an amorphous phase constituting the electrode (a) or (b) is synthesized by applying physical energy to a crystalline material. More specifically, crystalline raw materials (cobalt,
A material containing at least one or more elements selected from nickel, manganese, and iron, or a material containing at least one or more elements selected from a metal element and carbon) by using a collision energy generated by applying a centrifugal force to the material. Then, in the solid-phase reaction method, the crystallinity of the raw material is made non-uniform, and the atomic arrangement of the crystalline active material is made irregular. According to this method, it is not necessary to perform a long-time treatment at a high temperature in order to advance the reaction of the raw material as in the method using baking, and the centrifugal force is applied to the raw material, and heat generated by collision energy or the like generated at that time. Thus, the reaction of the raw material can proceed, so that the synthesis reaction of the active material can proceed at room temperature. In this case, as a raw material used as a starting material, a material having a low decomposition temperature is preferable because the applied centrifugal force is small and the synthesis reaction can proceed in a short time.

In each of the electrodes (a) and (b), a material which is electrochemically inactive at the electrode using the active material during the charge / discharge reaction of the lithium battery as described above, or It is preferable to impart a physical energy by mixing a material that is electrochemically inactive to a substance other than lithium in an electrode using the active material during a charge / discharge reaction of a lithium battery. Furthermore, depending on the type of the raw material, for example, when the active material synthesis reaction is difficult to proceed as in the case of the nickel-based material in the case of the electrode (a), the ambient temperature of the container containing the raw material salt may be increased in advance, or the atmosphere may become more oxidizable. (For example, an oxygen atmosphere or the like) is preferable because the reaction speed is accelerated.

By using such a method, the synthesis can be performed at room temperature without the need for heating, the reaction time can be shortened, and the synthesis reaction can be performed at a low temperature, so that the active material containing an amorphous phase can be efficiently used. Can be synthesized.

However, in the case of synthesizing without heating at room temperature, impurities remain, and the impurities are decomposed during charging / discharging of the battery or react with lithium as an active material to lower the activity of lithium. Therefore, it is desirable to remove them. For example, if impurities are dissolved in a solvent such as water or an organic solvent, sufficient washing may be performed. Oxidation, reduction,
Alternatively, there is a method of heating and decomposing and removing under an inert gas atmosphere.

However, the heating in this case does not need to be at a high temperature (for example, 700 ° C. or higher) as in the case of synthesizing an active material, but may be any temperature at which impurities can be removed.

For example, starting materials are sodium permanganate or potassium permanganate and a lithium compound such as lithium iodide, and physical energy is applied to these materials at room temperature to synthesize the materials. This contains impurities such as sodium iodide and potassium iodide. However, these impurities are easily soluble in water, alcohol, etc.
It can be removed by washing.

When a material is obtained by applying physical energy to lithium acetate and manganese acetate, for example, acetate may remain as an impurity. By subjecting this material to a heat treatment at 200 ° C. in an oxygen stream, acetate as an impurity can be decomposed and removed.

By using the method as in the above two examples, it is possible to obtain a lithium manganese oxide having higher purity and excellent electrochemical reversibility. By giving more physical energy to the material synthesized in this way, it is possible to further advance the amorphousization, and it is also possible to make the material highly electrochemically active and highly reversible. .

The above method employed in the present invention applies physical energy and applies a centrifugal force to one or more types of raw materials so that the raw materials collide with each other and a reaction is caused by the collision energy or the like at that time. Mechanical grinding method or mechanical alloying method, which is equivalent to a method of mechanically pulverizing or mechanically mixing two or more types of materials to form an alloy (particularly, synthesizing an alloy using metals as raw materials) Case). Therefore, in the present invention, it is possible to apply a device used in a general mechanical gliding method or a mechanical alloy method, but the mixing reaction is performed by applying a centrifugal force to a raw material or the like and collision energy generated at that time, A general mechanical grinding method or a mechanical alloy can be used in order to form a composite by mixing with the above-mentioned electrochemically inactive material as needed, or to make a material containing an amorphous phase from crystalline. A method with elements that are more characteristic to the method is adopted.

Referring to FIGS. 4 and 5, a method for amorphizing a crystalline material using a mechanical grinding method in the manufacturing method of the present invention will be described. An example of a method of adding an electrochemically inactive material 206 to an electrode using an active material finally obtained during a charge / discharge reaction of a secondary battery to form a composite to form an amorphous material will be described.

FIG. 4 schematically shows an example of the configuration of an apparatus for performing mechanical gliding. FIG. 5 is a conceptual diagram of the apparatus of FIG. 4 when viewed from above.

The materials (crystalline raw material 205 and electrochemically inert material (20)) charged in the closed containers (102, 202) with the cooling jackets (103, 203)
6) Rotating (revolving) the main shafts (101, 201) causes the rings (104, 204), which are the medium, to rotate, and gives acceleration to the material charged into the device by the centrifugal force generated at this time. As a result, the materials collide with each other between the ring and the inner wall of the container, and by this repetition, the crystalline raw material (205) becomes amorphous and the raw material (205) becomes electrochemically inert with the material (206). Compounding proceeds. Finally, as shown in the example shown in FIG. 5, the surface of the active material (205) is made of a material (2
06) is uniformly coated, and at the same time, becomes a composite (207) containing an amorphous phase due to collision energy.

At this time, the degree of progress of the amorphization of the raw material and the compounding with the electrochemically inactive material changes depending on the conditions such as the material of the main shaft, the medium, the container and the like, the number of rotations, and the like. The atmosphere in the container can be changed to various atmospheres by changing the gas (106) introduced into the apparatus. For example, if an oxygen gas is introduced, an oxidizing atmosphere can be obtained, and if oxidation is to be suppressed, an inert gas such as an argon gas can be used.

In the above-mentioned example, in particular, in the preparation of the active material used for the electrode (a), it is also possible to perform mechanical grinding by charging only one kind of crystalline raw material. Also,
Two different types of crystalline raw materials can be charged and mixed.

The conditions of mechanical grinding include, for example, a) the type of the device, b) the material and shape of the container and medium of the device,
c) centrifugal force, d) time to apply centrifugal force, e) ambient temperature,
f) Determined by considering factors such as added materials.

A) Types of Apparatus The apparatus for performing mechanical gliding includes:
Apparatus capable of giving impact energy such as large centrifugal force to the raw material powder as shown in FIGS. 4 and 5 is preferable. Specifically, it is preferable to use a device capable of revolving the container itself containing the material, or a device capable of rotating the medium or the like in the container and rotating the material. For example, a planetary ball mill, a rolling ball mill, a vibrating ball mill, various pulverizers, a high-speed mixer, or the like can be used.

B) Material and Shape of Container and Medium of Apparatus The material of the container and medium of the apparatus is preferably a material having high wear resistance and corrosion resistance. If the container or the medium is shaved by a large centrifugal force or the like, it may cause contamination, which may adversely affect battery characteristics and the like. Further, as a material for mechanical grinding, an acid, an alkali, an organic solvent, or the like may be used, and therefore, a material having corrosion resistance is preferable. Specific examples of the material of the container and medium include ceramic, agate, stainless steel, and super hard (tungsten carbide). Further, as the shape of the medium, there are a ball, a ring, a bead and the like. The material of the container or the medium is selected based on the compatibility with the material used for mechanical grinding, productivity, and the like.

C) Centrifugal force Applying a centrifugal force causes mechanical gliding to proceed more quickly. However, in some cases, it is better not to apply too much depending on the material of the material to be subjected to mechanical gliding.
For example, when a material having a low melting point is used, if the centrifugal force is fast, the material may be melted by heat generated at that time. If melting is not appropriate, it is necessary to take measures such as adjusting the centrifugal force so that the melting point does not exceed the melting point, or cooling the container to lower the ambient temperature.

Further, pulverization due to pulverization of the material occurs simultaneously with the mechanical grinding, so that it is necessary to determine the conditions in consideration of this point.

Further, it is necessary to consider the ratio G between the centrifugal acceleration and the gravitational acceleration. Factors that determine G include the weight of the medium, the number of revolutions (the number of revolutions) of the apparatus, and the size of the container, as described below.

The centrifugal force refers to the force appearing on the center of the circle with respect to the object moving in a circle in the device a), and can be expressed by the following equation.

Centrifugal force F = W · ω ² · r W: weight of the object (weight of the medium, which depends on the medium of the device used), ω: angular velocity, r: radius of the container

The centrifugal acceleration a can be expressed by the following equation.

Centrifugal acceleration a = ω ² · r Therefore, G (the ratio of centrifugal acceleration to gravitational acceleration) can be expressed by the following equation.

G = a / g = ω ² · r / g A preferable range of G (ratio of centrifugal acceleration to gravitational acceleration) is 5 to 200 G, a more preferable range is 10 to 100 G, and a more preferable range is 10 to 50G. However, this range varies depending on the material selected as described above.

D) Time for applying the centrifugal force The time for applying the centrifugal force must be determined by linking to the above-mentioned materials of the apparatus and the container and the conditions of the centrifugal force. Amorphization and complexation of the active material with the above-described electrochemically inactive material are preferable because they proceed.

E) Atmosphere It is preferable to increase the ambient temperature because mechanical gliding also proceeds.

When the raw material is a salt, it is preferable to raise the ambient temperature in order to synthesize the active material. However, if the temperature rises due to the temperature rise due to the ambient temperature plus the heat generated during mechanical gliding, the amorphous material may return to the crystal in reverse.Therefore, the atmosphere temperature should be set in consideration of this point. Is preferred. Depending on the material, for example, in the case of a low melting point, it may be better to cool.

In addition, when mechanical grinding is performed, some materials are easily oxidized depending on the materials to be added. For example, when a metal is added. An inert gas atmosphere is preferable since oxidation can be suppressed by performing mechanical grinding in an inert gas atmosphere. Conversely, after the mechanical grinding is performed, the atmosphere of the apparatus is changed to an oxidizing atmosphere such as oxygen, and a predetermined amount of a lithium salt is added to the material after the mechanical grinding, and the mechanical grinding is performed again. It can be changed to a metal oxide. This makes it possible to reduce the amount of unnecessary metal other than the conductive auxiliary material after mechanical grinding, and to further increase the capacity.

As the atmosphere, an oxidizing atmosphere, a reducing atmosphere, an inert atmosphere and the like are preferable. As the oxidizing atmosphere, at least one gas selected from oxygen, ozone, air, water vapor, and ammonia gas is suitably used. Oxidation can be promoted by setting these gas atmospheres.

As the reducing atmosphere, hydrogen and a mixed gas of an inert gas and hydrogen are preferable. By setting these gas atmospheres, reduction can be promoted and oxidation can be suppressed.

As the inert gas atmosphere, at least one gas selected from argon gas, helium gas, and nitrogen gas is preferable. The use of such a gas atmosphere can suppress oxidation and promote nitridation.

In some cases, it is preferable to perform the oxygen plasma or nitrogen plasma treatment after the mechanical gliding treatment is completed, because oxidation and nitridation are further promoted.

F) Material to be added The crystalline raw material (starting material of the active material) is electrochemically inactive at the electrode which becomes the active material finally obtained during the charge / discharge reaction of the lithium battery as described above. (In the case of preparing the active material at the electrode (a)), or at the electrode finally obtained during the charge / discharge reaction of the lithium battery, the electrode other than lithium is electrochemically incompatible with the material other than lithium. An active material (in the case of preparing an active material at the electrodes (a) and (b)) is added and mixed together, and a centrifugal force is applied to perform mechanical grinding to promote amorphization.
These are suitable in that a chemically stable material can be obtained in the battery.

In particular, in mechanical grinding, in order to give a larger energy (E) to the powder, the energy varies depending on the weight of the medium used in the apparatus and the set number of revolutions as described in the section of c) centrifugal force. . Also,
As is clear from the equation of E = 1/2 mv ² , it is preferable to use a higher speed and a heavier powder for the powder. The former speed is determined by a device that performs mechanical grinding, and the powder weight is determined by the specific gravity and the particle size of the selected powder. However, as for the particle size, when coating the surface of an active material (a crystalline material that becomes a material having an amorphous phase), or when increasing the contact area with a crystalline material to advance mechanical grinding, etc. It is better that the particle diameter is smaller than that of the crystalline material. Specifically, the particle diameter of the crystalline material of the first component is preferably 1/3 or less, more preferably 1/5 or less. On the other hand, when the electrochemically inactive material is uniformly reacted to the inside of the crystalline material, or the two or more kinds of raw material salts are mixed and subjected to mechanical grinding, and the raw material salts are mixed and melted and reacted. In some cases, the larger the particle size, the more energy can be applied to the powder, so that the active material becomes amorphous and the raw material (starting material) of the active material is combined with the electrochemically inactive material. In some cases, it is preferable because the formation proceeds easily.

When the material to be added is a metal or a carbon material, the added material is uniformly dispersed on the surface or inside of the crystalline material of the raw material, so that the metal or the carbon material is simply added. This is preferable because the current collecting ability is improved as compared with the case where the material is mixed with a crystalline material. By mechanically grinding a crystalline material as a raw material of the active material together with a metal or a carbon material to obtain a positive electrode active material or a negative electrode active material whose surface is finally coated with a metal or a carbon material, in some cases, It is not necessary to add the conductive auxiliary to the active material, or the amount of addition can be reduced. In addition, if the surface of the active material is coated with a metal or carbon material, conductivity can be secured with a small amount, so that as a whole, the content of the conductive auxiliary in the electrode can be reduced,
The packing density of the active material is improved, and as a result, an electrode having a high energy density can be obtained.

Furthermore, when an active material containing an amorphous material is prepared by mechanical grinding, the number of sites where lithium ions can be intercalated and deintercalated is increased as compared with the crystalline material before mechanical grinding, and the capacity is increased. Since the size of the electrode becomes large, it is possible to increase the capacity of the electrode by adding a lithium compound or the like in advance during mechanical grinding so that lithium ions enter this site. Examples of the lithium compound to be added include hydroxides, nitrides, sulfides, carbonates, and alkoxides. In particular, since lithium nitride itself has ionic conductivity, even if it is not put into the above-mentioned site, it has conductivity and is suitable. In addition, in the case of adding a lithium compound, in order to make the lithium salt easily melt or decompose and enter the active material layer, under mechanical grinding conditions, for example, a condition such as imparting a centrifugal force or increasing the ambient temperature is selected. Is more preferred.

A material other than lithium becomes electrochemically inactive in an electrode using the active material during a charge / discharge reaction of a lithium battery or a material other than lithium in an electrode using the active material during a charge / discharge reaction of a lithium battery. When adding an electrochemically inactive material,
A larger amount is preferable because mechanical gliding easily progresses. However, an excessive increase in the addition amount causes a decrease in the active material packing density in the electrode and lowers the energy density. Specifically, the addition amount of the above-mentioned electrochemically inactive material is 1 to 50%.
Is more preferable, and more preferably 1 to 20%, and more preferably a range of 1 to 10% in which the increase in the active material utilization is larger than the decrease in the energy density, or the range of 1 to 10% when used as a substitute for the conductive auxiliary. .

On the other hand, in the embodiment of the lithium secondary battery of the present invention, the electrode (a) is added to the negative electrode for the counter electrode in the above mode 1).
Further, an electrode having a configuration other than the electrode (a) is used as the counter electrode of the configuration 2) or 4).

In the negative electrode for the counter electrode in the form 1), as the active material, a crystalline material that retains lithium before discharging, such as lithium metal or a carbon material in which lithium is intercalated Alternatively, a crystalline material including a transition metal oxide, a transition metal sulfide, and a lithium alloy can be used. In addition, amorphous carbon including carbon black such as crystalline or amorphous Ketjen black and acetylene black, artificial graphite such as natural graphite, non-graphitizable carbon, and easily graphitizable carbon can be used. In addition, amorphous vanadium pentoxide can be used.

In the positive electrode for the counter electrode in the form 2) or 4), a crystalline transition metal oxide, a transition metal sulfide, a lithium-transition metal oxide, or a lithium-transition metal sulfide is used as an active material. Is generally used. These transition metal elements include, for example, a partially d-shell or f-shell.
Sc, Y, lanthanoid, which is an element with a shell
Actinoid, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, M
n, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu,
Ag and Au are mentioned. In particular, the first transition metal series T
i, V, Cr, Mn, Fe, Co, Ni, Cu are preferred. In addition,
Amorphous vanadium pentoxide can also be used.

The materials of the positive and negative electrode active materials are as follows:
It is selected and used in consideration of the potential of the active material of the opposing electrode.

Electrode (a) using active material as described above
And (b), the production of other electrodes, and the secondary battery produced using this electrode.

(Electrode Configuration and Manufacturing Method) The electrodes (a) and (b) and the other electrodes in the secondary battery of the present invention were composed of a current collector, an active material, a conductive auxiliary agent, a binder and the like. Things. As a method for producing this electrode, a paste obtained by mixing an active material or other active material containing an amorphous phase as described above, a conductive auxiliary agent, a binder and the like with a solvent,
There is a method of coating on the surface of the current collector. As described above, when a highly conductive material such as a metal or a carbon material is used as an additive uniformly dispersed on the surface or inside of the active material, the conductive auxiliary material may not be added or may be included. The amount can be reduced. As a coating method, for example, a coater coating method, a screen printing method, or the like can be applied.

Examples of the conductive auxiliary agent used for the electrode include graphite, carbon black such as Ketjen black and acetylene black, and fine metal powder such as nickel and aluminum. Examples of the binder used for the electrode include polyolefins such as polyethylene and polypropylene, fluorine resins such as polyvinylidene fluoride and tetrafluoroethylene polymer, polyvinyl alcohol, cellulose, and polyamide.

It is preferable to use raw materials such as active materials and binders or electrodes which have been sufficiently dehydrated before being made into a battery.

The current collector of the electrode plays a role of efficiently supplying a current consumed by the electrode reaction at the time of charging / discharging or collecting the generated current. Therefore, as a material for forming the current collector of the electrode, a material having a high electric conductivity and being inactive in the battery reaction (even if a voltage is applied in the battery and charge / discharge (oxidation-reduction reaction) is performed), Material does not react, or does not react with the electrolytic solution).

Preferred materials for the current collector of the positive electrode include nickel, titanium, aluminum, stainless steel, platinum, palladium, gold, zinc, various alloys, and two or more composite metals of the above materials.

Preferred materials for the current collector of the negative electrode include:
Examples include copper, nickel, titanium, stainless steel, platinum, palladium, gold, zinc, various alloys, and two or more composite metals of the above materials. As the shape of the current collector, for example, a shape such as a plate shape, a foil shape, a mesh shape, a sponge shape, a fiber shape, a punching metal, and an expanded metal can be adopted.

(Shape and Structure of Battery) Specific shapes of the secondary battery of the present invention include, for example, a flat shape, a cylindrical shape, a rectangular parallelepiped shape, and a sheet shape. In addition, examples of the structure of the battery include a single-layer type, a multilayer type, and a spiral type. Among them, the spiral cylindrical battery has a feature that the electrode area can be increased by winding the separator between the negative electrode and the positive electrode with the separator interposed therebetween, and a large current can flow during charging and discharging. In addition, the rectangular or sheet-shaped battery has a feature that the storage space of a device configured to store a plurality of batteries can be effectively used.

Hereinafter, the shape and structure of the battery will be described in more detail with reference to FIGS. FIG. 6 is a sectional view of a single-layer flat (coin-shaped) battery, and FIG. 7 is a sectional view of a spiral cylindrical battery. These lithium batteries have a negative electrode, a positive electrode, an electrolyte / separator, a battery housing, and an output terminal.

6 and 7, reference numerals 301 and 401 denote negative electrodes, 303 and 408 denote positive electrodes, 305 and 405 denote negative electrode terminals (negative electrode caps), 306 and 406 denote positive electrode terminals (positive cans), and 307 and 407 denote separator terminals. Electrolyte, 310 and 410 are gaskets, 400 is a negative electrode current collector, 404 is a positive electrode current collector, 411 is an insulating plate, 412 is a negative electrode lead, 41
3 is a positive electrode lead, and 414 is a safety valve.

In the flat type (coin type) secondary battery shown in FIG. 6, a positive electrode 303 including a positive electrode material layer (active material layer) and a negative electrode 301 including a negative electrode material layer (active material layer) use at least an electrolytic solution. The stacked body is stacked via the held separator 307, and the stacked body is accommodated from the positive electrode side in a positive electrode can 306 as a positive electrode terminal, and the negative electrode side is covered with a negative electrode cap 305 as a negative electrode terminal. Then, a gasket 310 is arranged in another portion inside the positive electrode can.

In the spiral cylindrical secondary battery shown in FIG. 7, the positive electrode (active material) formed on the positive electrode current collector 404
A positive electrode 408 having a layer 403 and a negative electrode 402 having a negative electrode (active material) layer 401 formed on a negative electrode current collector 400
Are opposed to each other via a separator 407 holding at least an electrolytic solution, and form a multilayer body having a cylindrical structure wound in multiple layers. The laminate having the cylindrical structure is accommodated in a positive electrode ring 406 as a positive electrode terminal. In addition, a negative electrode cap 405 as a negative electrode terminal is provided on the opening side of the positive electrode can 406, and a gasket 410 is disposed in another portion inside the negative electrode can. The stacked body of the electrodes having the cylindrical structure is separated from the positive electrode cap side via the insulating plate 411. For the positive electrode 408, the positive electrode lead 413
Through the positive electrode can 406. Also negative electrode 402
About the negative electrode cap 40 via the negative electrode lead 412.
5 is connected. A safety valve 414 for adjusting the internal pressure inside the battery is provided on the negative electrode cap side.

As described above, the active material layer of the negative electrode 301, the active material layer of the positive electrode 303, the active material layer 401 of the negative electrode 402, and the active material layer 403 of the positive electrode 408 have the above-mentioned 1) to
5) An electrode (a) made of an active material having an X-ray diffraction characteristic and having an amorphous phase and / or
Or (b) and optionally electrodes (a) and (b)
Other electrodes are used.

In the following, an example of a method of assembling the battery shown in FIGS. 6 and 7 will be described. (1) Negative electrode (301, 402) and molded positive electrode (306, 40)
8), the separator (307, 407) is sandwiched therebetween and assembled into the positive electrode can (306 or 406). (2) After injecting the electrolyte, the negative electrode cap (305 or 405) and the gaskets (310, 410) are assembled. (3) The battery is completed by caulking the above (2).

It should be noted that the above-described lithium battery material preparation,
And the assembly of the battery, in dry air from which moisture has been sufficiently removed,
Or it is desirable to carry out in a dry inert gas.

The members other than the electrodes constituting the secondary battery as described above will be described.

(Separator) The separator has a role of preventing a short circuit between the negative electrode and the positive electrode. In some cases, it has a role of holding an electrolytic solution. The separator must have pores through which lithium ions can move, and must be insoluble and stable in the electrolytic solution. Therefore, as the separator, for example, a nonwoven fabric such as glass, polyolefin such as polypropylene or polyethylene, a fluororesin, or a material having a micropore structure is suitably used. Further, a metal oxide film having fine pores or a resin film in which a metal oxide is compounded can be used. In particular, when a metal oxide film having a multilayered structure is used, the dendrite hardly penetrates, which is effective in preventing a short circuit. When using a fluororesin film that is a flame retardant material, or glass that is a nonflammable material, or a metal oxide film,
Security can be further improved.

(Electrolyte) The electrolyte can be used in the secondary battery of the present invention in the following three ways. (1) A method used as it is. (2) A method of using as a solution dissolved in a solvent. (3) A method in which a gelling agent such as a polymer is added to a solution to be used as an immobilized one.

In general, an electrolytic solution obtained by dissolving an electrolyte in a solvent is used by being retained in a porous separator.

The conductivity of the electrolyte as a value at 25 ° C. is preferably 1 × 10 ⁻³ S / cm or more, more preferably 5 × 1 ⁻³ S / cm.
It must be 0 ^-3 S / cm or more.

In a lithium secondary battery in which the negative electrode active material is lithium, the electrolyte may be, for example, H ₂ SO ₄ , HCl, HNO ₃
Such as acid, lithium ion (Li ⁺ ) and Lewis acid ion (B
F ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , BPh ₄ ⁻ (Ph:
Phenyl group)), and mixed salts thereof. Further, salts composed of cations such as sodium ion, potassium ion, tetraalkylammonium ion and Lewis acid ions can also be used. It is desirable that the salt is sufficiently dehydrated and deoxygenated by heating under reduced pressure.

Examples of the solvent for the electrolyte include acetonitrile, benzonitrile, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, dimethylformamide, tetrahydrofuran, nitrobenzene, dichloroethane, diethoxyethane, 1,2-dimethoxyethane, chlorobenzene, and the like. γ-butyrolactone, dioxolan, sulfolane, nitromethane, dimethylsulfide, dimethylsulfoxide, dimethoxyethane, methyl formate, 3-methyl-2-oxazolidinone, 2-methyltetrahydrofuran, 3-propylsydnone, sulfur dioxide, phosphoryl chloride, thionyl chloride ,
Sulfuryl chloride or a mixture thereof can be used.

The solvent may be dehydrated with, for example, activated alumina, molecular sieve, phosphorus pentoxide, calcium chloride, or the like, or may be distilled in an inert gas in the presence of an alkali metal to remove impurities and dehydrate. Good to do.

Further, in order to prevent the electrolyte solution from leaking, it is preferable to gel the electrolyte solution. As the gelling agent, it is desirable to use a polymer that absorbs the solvent of the electrolytic solution and swells. As such a polymer, polyethylene oxide, polyvinyl alcohol, polyacrylamide and the like are used.

(Insulation Packing) Gasket (310, 41)
As the material of 0), for example, a fluorine resin, a polyamide resin, a polysulfone resin, and various rubbers can be used. As a method for sealing the battery, a method such as glass sealing tube, adhesive, welding, soldering, or the like is used in addition to "caulking" using insulating packing as shown in FIGS. Various organic resin materials and ceramics are used as the material of the insulating plate in FIG.

(Outer Can) The outer can of the battery was a positive electrode can (3
06, 406) and a negative electrode cap (305, 405). As a material for the outer can, stainless steel is preferably used. In particular, a titanium clad stainless steel plate, a copper clad stainless steel plate, a nickel plated steel plate and the like are frequently used.

Since the positive electrode can (306) in FIG. 6 and the positive electrode can (408) in FIG. 7 also serve as the battery housing (case), the above stainless steel is preferable. However, when the cathode or anode can does not double as the battery housing, the material of the battery case is not only stainless steel but also metal such as zinc, plastic such as polypropylene, or composite material of metal or glass fiber and plastic. Is mentioned.

(Safety Valve) The lithium secondary battery is provided with a safety valve as a safety measure when the internal pressure of the battery increases. Although not shown in FIG. 7, as the safety valve, for example, rubber, a spring, a metal ball, a burst foil, or the like can be used.

[0126]

The present invention will be described below in more detail with reference to examples.

First, a method for preparing an active material containing an amorphous phase in the lithium secondary battery of the present invention will be described with reference to FIGS. I will explain. 8 to 1
The height of the vertical peak of the X-ray diffraction profile of No. 1 indicates a relative level. The intensity (cps) is omitted.

Example 1 Nickel hydroxide and lithium hydroxide were weighed and uniformly mixed so that the molar ratio of nickel to lithium was 1: 1 and then placed in an electric furnace in an oxygen atmosphere at 750 ° C. for 20 hours. It was calcined to obtain lithium nickelate.
X-ray diffraction analysis (Cu-Kα) of this lithium nickelate
From the results, it was found that the crystal state was attributed to a hexagonal crystal (FIG. 8A). The average particle diameter of the lithium nickelate was 13 μm as determined by laser particle size distribution measurement. Next, an average particle diameter of 1 μm
m nickel simply mixed, the same X
Line diffraction analysis was performed (FIG. 8 (b)). From these results, respective peaks attributed to lithium nickelate and nickel were observed.

On the other hand, 50% by weight of lithium nickelate and 50% by weight of nickel in the above crystalline state were mixed in a planetary ball mill container.
(Container diameter: 4 cm), the rotation speed of the drive motor was set to 3700 rpm so as to take 15 G, and the diameter was 1 cm.
Using a 5 mm stainless steel ball, mechanical gliding was performed for 1 hour or 2 hours. The obtained material was subjected to X-ray diffraction analysis in the same manner as described above (FIG. 8).
(C), (d)), for example, the peak (2) of the (003) plane
Focusing on (θ = around 19 °), it was found that the peak intensity was lower than before the treatment with the planetary ball mill and changed to a broad peak. Specifically, the ratio between the X-ray diffraction intensity and the half width at 1850 cps / degree before the mechanical grinding processing was reduced to 300 cps / degree by performing the mechanical grinding processing for 1 hour (FIG. 8). (C) / Intensity is omitted in the drawing). Further, if mechanical gliding treatment is performed for 1 hour, the peak disappears, so that the ratio between the X-ray diffraction intensity and the half width cannot be calculated (FIG. 8 ( d)). That is, the peak becomes broad by changing the conditions of the planetary ball mill, such as changing from crystalline to amorphous, further increasing the mixing time, increasing the centrifugal force, etc. It can be seen that the peak is no longer observed and it becomes completely amorphous. Also, due to mechanical gliding, the peak of the added nickel metal decreased in intensity when the mixing time was prolonged, but remained after 2 hours (FIG. 8 (d) / dots ●).

From the above analysis, it is recognized that the active material obtained by the method of the present invention is essentially completely different from that having a structure obtained by simply mixing lithium nickelate and nickel metal.

The degree of amorphization of the active material (mixing lithium nickelate and nickel for 2 hours / profile shown in FIG. 8D) obtained in the above-described example was further measured by the small-angle X-ray scattering method. As a result, a non-uniform density fluctuation was observed from the scattering angle and the scattering intensity, and it was found that the film was amorphous. Further, from the results of reflection high-energy electron diffraction (RHEED) analysis, a weak ring pattern was observed when the above-described lithium nickelate and nickel were mixed for 1 hour, and a halo pattern was observed when mixing for 2 hours. It turned out that it was amorphous.

In the case of a material prepared by a quenching method, a solution reaction method, or the like, which is generally used to make a crystalline material amorphous, the arrangement of the atomic structure is irregular even in a short period (micro). On the other hand, in the method of the present invention, which is characterized in that physical energy such as centrifugal force is applied by using a crystalline material as a starting material, instead of having a completely irregular atomic structure, it is not microscopically. The difference is that the atomic structure leaves a regular part in a short period.

The material thus obtained has electron conductivity because the amorphous material has a short period and the atomic structure has regularity. Therefore, an active material having a longer charge / discharge capacity and a longer cycle life than an amorphous active material obtained by a quenching method or the like can be obtained.

As a result of XMA analysis of the lithium nickelate after the above-mentioned mechanical gliding, it was observed that the surface of the lithium nickelate particles was coated with nickel.

(Example 2) Amorphous carbon (acetylene black) was used in place of nickel of Example 1 above, and lithium nickelate 80% by weight and acetylene black 20 were used.
The wt% was mixed in a planetary ball mill. The mixing conditions were as follows: the diameter of the container was 4 cm;
It was set to 00 rpm, and mechanical grinding was performed for 1 hour using a stainless steel ball having a diameter of 15 mm. X-ray diffraction analysis was performed on the material before and after the mechanical grinding in the same manner as in Example 1. This result (FIG. 9)
(A), (b)) For example, (003) plane and (104)
Focusing on the peak of the surface, the planetary ball mill mixing
Peak intensity ratio before (mechanical gliding) ((00
3) plane / (104) plane) 1.5 (Fig. 9 (a)) 2.8
(FIG. 9B), it can be seen that the peak of the (003) plane has grown greatly, indicating that the layered structure has developed. In addition, the half width of the (104) plane was widened, and the tailings of other peaks were also large. That is, it was found that the amorphous state progressed by mechanical grinding with a planetary ball mill. Further, the carbon peak due to the added acetylene black disappeared due to the mechanical gliding (FIG. 9).
(A) / dots ● (Example 3)).

Example 3 Cobalt oxide and lithium carbonate were weighed so that the molar ratio of cobalt to lithium was 1: 1 and then dry-mixed.
It was fired at 850 ° C. The obtained lithium cobaltate was pulverized in a pulverizer so as to have an average particle size of 15 μm (laser type particle size distribution measuring device). A planetary ball mill (container diameter 23c) was prepared by adding 50 wt% of titanium having an average particle diameter of 3 μm to this lithium cobalt oxide.
In (m), the number of revolutions was set to 200 rpm, and the mixing time was changed from 0 to 1 hour. X-ray diffraction analysis was performed on each material before and after the mechanical grinding in the same manner as in Example 1. The results are shown in FIGS. 10 (b) and 10 (c). In addition, the X-ray profile of lithium cobaltate alone used at the same time is shown for reference (FIG. 10A).

In FIG. 10, the peak of lithium cobalt oxide had already disappeared one hour after mixing. That is, it was found that the crystalline lithium cobalt oxide (FIGS. 10A and 10B) was changed to amorphous by mechanical grinding (FIG. 10C). However, it was also found that titanium was changed to titanium oxide due to mixing in the atmosphere. Therefore, it is inappropriate to use this as it is as an active material, but it can be seen that amorphousization is progressing. Further, if the atmosphere is made non-oxidizing, oxidation of titanium can be suppressed, and it can be used as an active material.

Example 4 Manganese dioxide and lithium nitrate were weighed so that the molar ratio of manganese to lithium was 1: 1 and then dry-mixed, and then fired in a high-temperature electric furnace at 800 ° C. in an oxygen atmosphere. The lithium manganate thus obtained was pulverized in a pulverizer so as to have an average particle diameter of 13 μm (laser type particle size distribution analyzer). Aluminum having an average particle diameter of 1 μm is added to the lithium manganate in an amount of 50 w.
After adding t%, planetary ball mill (container diameter 23 cm)
, The revolution speed was set to 150 rpm, and the mixing time (mechanical grinding time) was changed from 0 to 2 hours to perform the mechanical grinding. The materials before and after the mechanical grinding were evaluated by X-ray diffraction in the same manner as in Example 1. The results are shown in FIGS.
(D). The X-ray profile of the lithium manganate alone used at the same time is shown for reference (FIG. 11A).

From FIG. 11, it can be seen that the peak intensity ratio at around 19 ° belonging to the (111) plane is greatly reduced by one hour of mixing (FIG. 11C). It was found that the shape was collapsed and the amorphization was further advanced (FIG. 11D).

The results obtained in Examples 1 to 4 above were mainly observed in the preparation of the positive electrode active material used for the electrode (a) of the present invention. It is recognized that the same effect is obtained, and a negative electrode active material containing an amorphous phase can be obtained.

Example 5 Natural graphite having an average particle diameter of 5 μm (crystalline having a crystallite size of 1700 °) and an average particle diameter of 1 μm
After adding 20 wt% of copper powder, the container of planetary ball mill
(Container diameter: 23 cm) and revolved at 300 rpm
m, and the mechanical gliding was performed while changing the mixing time from 0 to 2 hours. When X-ray diffraction analysis was performed on the material before and after the mechanical grinding in the same manner as in Example 1, it was observed that the X-ray diffraction peak corresponding to the (002) plane decreased with the mixing time.
That is, it was found that the crystalline material changed from crystalline to amorphous similarly to the active material. It was found from the results of small-angle X-ray scattering analysis and reflection high-energy electron diffraction that the film was amorphous.

Next, examples of the lithium secondary battery of the present invention will be described.

Example 6 In this example, a lithium secondary battery having the cross-sectional structure shown in FIG. 6 was manufactured.

In the following, with reference to FIG. 6, a description will be given of the procedure for manufacturing each component of the battery and the assembly of the battery.

(1) Preparation procedure of positive electrode 303 Nickel hydroxide, cobalt hydroxide, and lithium hydroxide were mixed at a molar ratio of 0.4: 0.1: 0.5, and then, at 800 ° C. for 20 hours in an electric furnace under an oxygen atmosphere. Heat treatment was performed to prepare a lithium-cobalt nickel oxide. When this was analyzed with an X-ray diffractometer, the half width was 0.17 and the crystallite size was 6
It was 80 degrees. The average particle size measured using a laser type particle size distribution analyzer was 12 μm.

Next, 90 wt% of this lithium-cobalt nickel oxide and 5 wt% of aluminum having an average particle size of 2 μm were used.
% And 5 wt% of acetylene black were placed in a container having a structure shown in FIGS. 4 and 5 (diameter of the container was 10 cm), and the atmosphere in the container was examined with an argon gas so as to be an inert atmosphere. Then, at room temperature, the number of revolutions is 5 so that 15G is added.
Mechanical grinding was performed at 20 rpm, mixing time (mechanical grinding time) for 2 hours, and stainless steel as the material of the medium (104, 204). When the material before and after the mechanical grinding was analyzed by X-ray diffraction (Cu-Kα) in the same manner as in Example 1, the material had an X-ray profile belonging to a hexagonal crystal having a sharp peak before the mechanical grinding. But,
For example, it was found that the peak of the (003) plane near 19 ° decreased, and the other peaks also became broad and changed from crystalline to amorphous. At this time, the half width was 0.65, and the crystallite size was 150 °. In addition, when measured using the X-ray small angle scattering method or the like, uneven density fluctuation was observed from the scattering angle and the scattering intensity.

Subsequently, the above-prepared lithium-cobalt nickel oxide was used as a positive electrode active material, and 5 wt% of polyvinylidene fluoride powder was added thereto, and the mixture was added and mixed with N-methylpyrrolidone to obtain a paste. . The paste was applied on an aluminum foil and dried, and then dried under reduced pressure at 150 ° C. to produce a positive electrode 303.

(2) Preparation procedure of negative electrode 301 As a negative electrode active material, 95 wt% of natural graphite having an average particle diameter of 5 μm was used.
% Was added to an N-methylpyrrolidone solution in which 5% by weight of polyvinylidene fluoride was dissolved to form a paste.
This paste is applied to a copper foil and dried to produce a carbon negative electrode 301.
I got

(3) Preparation of Electrolyte Solution 307 A solvent was prepared by mixing ethylene carbonate (EC) and dimethyl carbonate (DMC) from which water had been sufficiently removed. Next, 1 M (mol / l) of lithium tetrafluoroborate dissolved in this mixed solvent was used as an electrolyte.

(4) Separator 307 A polyethylene microporous separator was used.

(5) Battery assembly A separator 30 containing an electrolyte between the positive electrode 303 and the negative electrode 301
7 was inserted into a positive electrode can 306 made of titanium clad stainless steel.

Next, an insulating packing made of polypropylene
310 and a negative electrode cap 305 made of a stainless steel material clad with titanium were covered and caulked to produce a lithium secondary battery.

Example 7 70% by weight of lithium-cobalt-nickel oxide and 30% by weight of nickel having an average particle size of 1 μm used in the preparation step of the active material of Example 6 were
The container was placed in the container shown in FIGS. 4 and 5 (the diameter of the container was 10 cm), and the atmosphere in the container was examined with argon gas so as to be an inert atmosphere. Then, using a device having the structure shown in FIGS.
m, mechanical gliding was performed using stainless steel as the material of the medium (104, 204). Here, mixing is performed by mechanical grinding in the same manner as in Example 6, except that the mixing time (mechanical grinding time)
Was changed (0 minute to 120 minutes), and the materials having different mixing times were analyzed by X-ray diffraction (Cu-Kα) in the same manner as in Example 1. The evaluation results are shown in Table 1 below. The evaluation result was standardized by the value at each mixing time with respect to the value at the mixing time of 0 minute, with the value at the mixing time of 0 minute as 100.

[0154]

[Table 1]

As is evident from Table 1, when the mixing time of the mechanical gliding becomes longer, the X-ray diffraction intensity decreases and the half width increases. Finally, it was found that the diffraction intensity did not appear as in the 120th minute of mechanical gliding, and the crystal changed from amorphous to amorphous. Since the positive electrode active material treated for each mechanical gliding mixing time has a different degree of amorphization, it is presumed that when a battery is used, the charge / discharge capacity and the charge / discharge curve will differ.

(Example 8) A negative electrode prepared according to the following procedure was used instead of the negative electrode of Example 6.

95% by weight of natural graphite having an average particle diameter of 5 μm used in Example 6 and 5% by weight of copper powder having an average particle diameter of 1 μm
Was placed in a planetary ball mill container (container diameter: 23 cm), and the atmosphere in the container was checked with argon gas so that the atmosphere became an inert atmosphere. Thereafter, mechanical grinding was performed using a stainless steel ball having a diameter of 12 mm so that the revolution speed was 400 rpm, the mixing time (mechanical grinding time) was 2 hours, and the rotation speed was 75 G. The material before and after the mechanical grinding was changed to X in the same manner as in Example 1.
Analysis by line diffraction showed that the carbon peaks observed in the material before mechanical grinding had disappeared and changed from crystalline to amorphous. Since the X-ray diffraction peak disappeared, neither the half width nor the crystallite size could be determined.

Using the material after mechanical grinding as the negative electrode active material, a negative electrode was prepared in the same manner as in Example 6.
A lithium secondary battery was produced in the same manner as in Example 6, except that this negative electrode was used.

(Example 9) A secondary battery was manufactured in the same manner as in Example 6, except that the positive electrode manufactured in the following procedure was used instead of the positive electrode of Example 6.

Manganese dioxide and lithium nitrate were mixed at a ratio of 1: 1.
And mixed into a planetary ball mill container (container diameter: 23 cm). At this time, the atmosphere of this container was left as the atmosphere. Thereafter, mechanical grinding was performed using zirconia balls having a revolution of 480 rpm and a diameter of 10 mm so as to cover 111 G. The temperature of the powder material after the execution was about 300 ° C., and it was observed that the temperature was increased by the energy due to the centrifugal force.

The material subjected to mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1. As a result, a slightly broad peak was obtained, but an X-ray profile attributed to lithium-manganese oxide was obtained. That is,
The lithium-manganese oxide was able to be synthesized at room temperature without passing through the firing step. Further, the crystal grain size at this time was calculated using Scherrer's formula.
Å, and it was found that the amorphous state of the lithium-manganese oxide produced by the calcination method was advanced as compared with 550 °. The half width was 0.6.

After using this lithium-manganese oxide as a positive electrode active material and adding 5 wt% of acetylene black,
Except for this, the cathode was produced in the same manner as in Example 6. Subsequently, a lithium secondary battery was produced in the same manner as in Example 6 using this positive electrode.

(Example 10) A positive electrode produced by the following procedure was used instead of the positive electrode of Example 6.

An average particle diameter of 12 μm prepared in Example 6
Of 95% by weight of lithium-cobalt nickel oxide and 5% by weight of acetylene black in a planetary ball mill container
(Container diameter: 23 cm), and the atmosphere in the container was examined with argon gas so that the atmosphere became an inert atmosphere. Thereafter, the revolution was set to 200 rpm so that 20 G was applied, and mechanical grinding was performed using alumina balls having a diameter of 15 mm and mixing time (mechanical grinding time) for 3 hours. The material before and after the mechanical grinding was analyzed by an X-ray diffractometer in the same manner as in Example 1. As a result, the material having an X-ray profile belonging to a hexagonal crystal having a sharp peak before the mechanical grinding was found to be, for example, 19 mm. The full width at half maximum of the peak near the (003) plane increases, especially at (104) near 44 °.
The half width of the peak of the plane increased more than that of the (003) plane, and the peak ratio of (003) / (104) became larger when mechanical grinding was performed. The other peaks were also broad, and it was found that the peak changed from crystalline to crystalline including amorphous. At this time (104)
The half width of the surface was 0.55.

Using this lithium-cobalt nickel oxide as a positive electrode active material, a positive electrode was produced in the same manner as in Example 6. Hereinafter, a lithium secondary battery was produced in the same manner as in Example 6, except that these positive electrodes were used.

(Example 11) A positive electrode produced by the following procedure was used instead of the positive electrode of Example 6.

First, manganese dioxide and lithium nitrate were mixed at a molar ratio of 1: 1 and then fired at 800 ° C. for 10 hours in an electric furnace in an air atmosphere to obtain lithium manganese oxide.
The average particle size measured by using a laser type particle size distribution analyzer was 15 μm.

Next, this lithium manganese oxide 90 wt.
% And 10 wt% of aluminum powder having an average particle size of 2 μm
Was placed in a planetary ball mill container (container diameter: 4 cm), and the atmosphere in the container was checked with argon gas so that the atmosphere became an inert atmosphere. After that, the rotation speed of the drive motor was set to 2600 rpm so as to take 10 G, and the diameter was 15 m.
Using a stainless steel ball of m, mechanical grinding was performed for 2 hours of mixing time (mechanical grinding time).

The material before and after the mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1. As a result, a material having an X-ray profile belonging to a hexagonal crystal having a sharp peak before the mechanical grinding was obtained. The half width of the peak of the (111) plane near 19 ° increases, and particularly, the half width of the peak of the (400) plane near 44 ° increases more than that of the (111) plane, and (40).
The peak ratio of (0) / (111) was larger when mechanical gliding was performed. The half width is 0.5
Met. The other peaks were also broad, indicating that the conversion from crystalline to amorphous progressed. Also, Scher
The crystal particle diameter calculated using the rr equation is 190 °,
It was found that amorphization was advanced as compared with 460 ° before mechanical grinding was performed.

Using this lithium-cobalt nickel oxide as a positive electrode active material, a positive electrode was produced in the same manner as in Example 6. Subsequently, Example 6 was repeated except that these positive electrodes were used.
In the same manner as in the above, a lithium secondary battery was produced.

(Example 12) Instead of the negative electrode of Example 6, a negative electrode produced by the following procedure was used.

The natural graphite having an average particle diameter of 5 μm and the titanium powder having an average particle diameter of 3 μm used in Example 6 were 3 wt%.
Was placed in an apparatus having the configuration shown in FIGS. 4 and 5, and the atmosphere in the container was examined with an argon gas so that the atmosphere became an inert atmosphere. After that, using the apparatus shown in FIGS. 4 and 5, the medium (104, 400) was rotated at 730 rpm at room temperature and mixing time (mechanical gliding time) for 3 hours.
Mechanical gliding was performed using stainless steel as the material of 204). The material before and after the mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1. As a result, it was found that the carbon peaks observed before the mechanical gliding had disappeared, and the material changed from crystalline to amorphous. Since the X-ray diffraction peak disappeared, neither the half width nor the crystallite size could be determined.

Using this carbon material as a negative electrode active material, a negative electrode was produced in the same manner as in Example 6. Subsequently, a lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used.

(Example 13) A negative electrode produced by the following procedure was used instead of the negative electrode of Example 6.

Crystalline tin powder 97 having an average particle diameter of 10 μm
wt% and 3 wt% of Ketjen Black were placed in a planetary ball mill container (container diameter: 23 cm), and the atmosphere in the container was inspected with argon gas so that the atmosphere became an inert atmosphere. Then, the revolving speed is set to 200r so that it takes 20G.
The mechanical gliding was performed at a mixing time (mechanical gliding) of 2 hours using a stainless steel ball having a diameter of 15 mm set at pm. When the material before and after the mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1, the peak corresponding to the (200) plane was reduced, the half width was 0.49, and the crystallite size was 250 °.
there were.

Thereafter, a negative electrode was prepared in the same manner as in Example 6 except that the material after mechanical grinding was used. Subsequently, a lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used.

(Example 14) A negative electrode produced by the following procedure was used instead of the negative electrode of Example 6.

Crystalline silicon powder 90 having an average particle diameter of 5 μm
wt%, acetylene black 5wt%, average particle size 1μ
5 wt% of copper powder was placed in a planetary ball mill container (container diameter: 23 cm), and the atmosphere in the container was inspected with argon gas so as to be an inert atmosphere. Then 4
Set the revolution speed to 300 rpm so that it takes 5G,
Using a stainless steel ball having a diameter of 10 mm, mechanical grinding was performed for 2 hours of mixing time (mechanical grinding time). When the material before and after mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1, it was found that the silicon peak disappeared and the material became amorphous. Here, since the X-ray diffraction peak disappeared, the half width,
Both crystallite size could not be determined.

Thereafter, a negative electrode was produced in the same manner as in Example 6 except that the material after mechanical grinding was used. Subsequently, a lithium secondary battery was produced in the same manner as in Example 1 except that this negative electrode was used.

(Example 15) A positive electrode produced by the following procedure was used instead of the positive electrode of Example 6.

An average particle diameter of 12 μm prepared in Example 6
Was placed in a planetary ball mill container (container diameter: 23 cm), and the atmosphere in the container was examined with argon gas so as to be an inert atmosphere. Thereafter, the number of revolutions is increased to 30 so that 45G is applied.
Using a stainless steel ball having a diameter of 10 mm set at 0 rpm, mechanical grinding was performed for 4 hours of mixing time (mechanical grinding time). When the material before and after the mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1, the material having an X-ray profile belonging to a hexagonal crystal having a sharp peak before the mechanical grinding was, for example, 19 mm. The half-value width of the peak near the (003) plane increases,
The half width of the peak on the (104) plane near 4 ° is (003)
And (003) / (104)
The peak ratio became larger when mechanical gliding was performed. The (104) plane had a half width of 0.57 and a crystallite size of 180 °. The other peaks were also broad, indicating that the material had changed from crystalline to amorphous.

Using the thus obtained lithium-cobalt nickel oxide as a positive electrode active material, acetylene black 5
After adding wt%, a positive electrode was prepared in the same manner as in Example 6 except for this. Subsequently, a lithium secondary battery was produced in the same manner as in Example 6, except that this positive electrode was used.

(Example 16) A negative electrode produced by the following procedure was used instead of the negative electrode of Example 6.

Only natural graphite having an average particle diameter of 5 μm used in Example 6 was used in a planetary ball mill container (container diameter 23c).
m), and the atmosphere in the container was inspected with argon gas so that the atmosphere became an inert atmosphere. Thereafter, mechanical grinding was performed for 3 hours using a zirconia ball having a revolution of 480 rpm and a diameter of 10 mm so that the mixing speed (mechanical grinding time) was 3 hours. The material before and after the mechanical grinding was analyzed by X-ray diffraction in the same manner as in Example 1. As a result, the carbon peak observed before the mechanical gliding disappeared in the material after the mechanical grinding, and changed from crystalline to amorphous. I understand.

Using this carbon as a negative electrode active material, a negative electrode was produced in the same manner as in Example 6. Subsequently, as the positive electrode, a positive electrode produced in the same manner as in Example 6 except that the lithium-cobalt nickel oxide prepared in Example 6 and acetylene black and polyvinylidene fluoride were used. Subsequently, a lithium secondary battery was produced in the same manner as in Example 6, except that the negative electrode and the positive electrode were used.

(Example 17) A lithium-cobalt nickel oxide 90w having an average particle diameter of 12 µm produced in Example 6
t%, 5 wt% of aluminum having an average particle diameter of 1 μm, and 5 wt% of acetylene black were placed in a planetary ball mill container (container diameter: 23 cm), and the atmosphere in the container was examined with argon gas so that the atmosphere became an inert atmosphere. Then, changing the conditions of the planetary ball mill, such as the number of revolutions from 0 to 600 rpm, the mixing time (mechanical gliding time) from 0 to 5 hours, the material of the ball (stainless steel, zirconia ball, alumina ball) and the ball diameter (5 to 15 μm). Mechanical gliding. The materials before and after the mechanical grinding were analyzed by X-ray diffraction in the same manner as in Example 1 to evaluate the crystallinity, and the half width ((003) plane) and crystallite size of each material were determined.

Further, a lithium secondary battery was produced in the same manner as in Example 6, except that the material after mechanical grinding was used for a positive electrode.

Comparative Example 1 In this example, 90 wt% of crystalline lithium-cobalt nickel oxide having an average particle diameter of 12 μm, 5 wt% of aluminum having an average particle diameter of 2 μm, and 5 wt% of acetylene black prepared in Example 6 were mixed. 5 wt% of poly (vinylidene fluoride) powder was added to the resulting mixture (assuming this as 95 wt%), and the mixture was added and mixed with N-methylpyrrolidone to obtain a paste. The paste was applied on an aluminum foil and dried, and then dried under reduced pressure at 150 ° C. to produce a positive electrode. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this positive electrode was used.

Comparative Example 2 In this example, 95% by weight of crystalline lithium-cobalt nickel oxide having an average particle diameter of 12 μm prepared in Example 6 and 5% by weight of acetylene black were mixed. %) And 5 wt% of polyvinylidene fluoride powder were added and mixed in N-methylpyrrolidone to obtain a paste. The paste was applied on an aluminum foil and dried, and then dried under reduced pressure at 150 ° C. to produce a positive electrode. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this positive electrode was used.

Comparative Example 3 In this example, manganese dioxide and lithium nitrate used in the preparation of the positive electrode of Example 4 were mixed at a molar ratio of 1: 1 and then fired and pulverized in the air to obtain a material 95.
5% by weight of acetylene black was added to 5% by weight, and 5% by weight of poly (vinylidene fluoride) was added thereto (assuming 95% by weight), and the mixture was added and mixed in N-methylpyrrolidone to prepare a paste. After coating and drying on an aluminum foil, it was dried at 150 ° C. under reduced pressure to prepare a positive electrode. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this positive electrode was used.

Comparative Example 4 In this example, the average particle size was 15 μm.
90 wt% of crystalline lithium-manganese oxide and 10 wt% of aluminum having an average particle diameter of 2 μm, and 5 wt% of poly (vinylidene fluoride) are added to the mixture (assuming 95 wt%) and added to N-methylpyrrolidone. After mixing to prepare a paste, the paste was applied on an aluminum foil and dried, and then dried at 150 ° C. under reduced pressure to produce a positive electrode. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this positive electrode was used.

Comparative Example 5 In this example, the crystalline natural graphite 95w having an average particle diameter of 5 μm used in the preparation of the negative electrode of Example 6 was used.
5% by weight of polyvinylidene fluoride was added to a mixture of t% and 5% by weight of copper having an average particle diameter of 1 μm (95% by weight), and the mixture was added and mixed in N-methylpyrrolidone to prepare a paste. The paste was applied on an aluminum foil and dried, and then dried under reduced pressure at 150 ° C. to produce a negative electrode. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used.

Comparative Example 6 In this example, the crystalline natural graphite 97w having an average particle diameter of 5 μm used in the preparation of the negative electrode of Example 6 was used.
5% by weight of polyvinylidene fluoride was added to a mixture of 3% by weight of titanium having an average particle diameter of 3 μm and 3% by weight of titanium, and the mixture was added and mixed in N-methylpyrrolidone to prepare a paste. A negative electrode was produced in the same manner as in Example 6. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used.

Comparative Example 7 In this example, the crystalline tin powder 97 having an average particle diameter of 10 μm used in the preparation of the negative electrode of Example 13 was used.
wt% and 3 wt% of Ketjen Black are mixed (assuming that it is 95 wt%), 5 wt% of polyvinylidene fluoride is added, and the mixture is added and mixed in N-methylpyrrolidone to prepare a paste. Thus, a negative electrode was produced in the same manner as in Example 6. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used.

Comparative Example 8 In this example, 90 wt% of crystalline silicon powder having an average particle diameter of 5 μm and 5 wt% of acetylene black used in Example 14 and copper powder 5 having an average particle diameter of 1 μm were used.
A paste was prepared by adding 5 wt% of poly (vinylidene fluoride) to N-methylpyrrolidone with respect to the mixture obtained by mixing with the wt%, and using this paste, a negative electrode was produced in the same manner as in Example 6. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used. .

(Comparative Example 9) 5 wt% of polyvinylidene fluoride powder was added to the natural graphite having an average particle diameter of 5 μm used in Example 6 (assuming that it was 95 wt%), and the mixture was added to N-methylpyrrolidone and mixed. To obtain a paste. This paste was applied on a copper foil and dried, and then dried at 150 ° C. under reduced pressure to prepare a negative electrode. A lithium secondary battery was fabricated in the same manner as in Example 6, except that this negative electrode was used.

The performance of the lithium secondary batteries (Examples 6, 8 to 16, and 17) obtained as described above was evaluated. The performance evaluation was performed on the discharge capacity of the battery, the cycle life, and the irreversible capacity at the first cycle obtained in the charge / discharge cycle test.

The cycle test conditions were as follows: a cycle consisting of charging and discharging of 1 C (current of one time of capacity / time) and a 30-minute rest time was based on the electric capacity calculated from the positive electrode active material.
Cycle. The battery charge / discharge test was performed by HJ-1
06M was used. The charge / discharge test was started from charging, the battery capacity was defined as the amount of discharge in the third cycle, and the cycle life was defined as the number of cycles less than 60% of the battery capacity. The charge cutoff voltage is 4.5V and the discharge cutoff voltage is 2.
Set to 5V. The irreversible capacity in the first cycle was a capacity that could not be discharged with respect to a charge amount of 100% at the end of one cycle.

Table 2 shows Examples 6 and 8 for each comparative example.
It summarizes the performance evaluation of the lithium secondary batteries manufactured in 10, 11, and 15. However, the evaluation results regarding the cycle life and the discharge capacity are described by standardizing the value of the example and the value of the comparative example as 1.0.

[0200]

[Table 2]

From the results shown in Table 2 above, in the secondary battery using the material which was made amorphous by performing mechanical grinding on the crystalline material as the positive electrode active material, the active material without the mechanical grinding (crystalline) was used. 11 to 32% improvement in discharge capacity and cycle life of 50 to 150%
% Could be improved.

The nickel-based positive electrode active material has a larger irreversible capacity in the first cycle (capacity that could not be discharged with respect to a charged amount of 100%) than the positive electrode active materials such as cobalt and manganese in the second cycle. The balance of the capacity ratio between the positive electrode and the negative electrode thereafter was lost, and this was one of the causes of a decrease in charge / discharge capacity and a decrease in cycle life. But,
The irreversible capacity could be reduced by 10 to 45% by using the positive electrode active material which was made amorphous by mechanical grinding. As a result, a cycle life was improved, and a battery having a large discharge capacity could be obtained.

Table 3 shows the characteristics of the lithium secondary battery manufactured using the lithium-manganese oxide synthesized by the mechanical gliding method in Example 9 as a positive electrode, and the lithium secondary battery of Comparative Example 3 manufactured using the firing method. The values are normalized for secondary batteries.

[0204]

[Table 3]

As is clear from Table 3, the result of Example 4 in which mechanical grinding was performed was improved by 16% in discharge capacity and 40% in cycle life as compared with the conventional firing method. Also, the irreversible capacity in the first cycle could be reduced by 20%, and excellent results were obtained as compared with the firing method of the comparative example. It has been found that by performing mechanical grinding, it becomes possible to synthesize a positive electrode active material that had to be fired at a high temperature for a long time at room temperature.

Table 4 summarizes the performance evaluation of a lithium secondary battery using a negative electrode produced by subjecting a negative electrode active material to mechanical grinding. The discharge capacity and cycle life were normalized with respect to the results of the untreated comparative example.

[0207]

[Table 4]

[0208] From Table 4, it can be seen that by performing mechanical grinding on the negative electrode active material, the discharge capacity can be improved by 10 to 30% and the cycle life can be improved by 30 to 80% over the untreated comparative example. It was found that the performance was improved.

FIG. 12 shows the relationship between the half width of each secondary battery and the battery discharge capacity in Example 17 (the case where the mixing time is 0 is 1.0). From this result, it was found that the half width was almost constant at 0.48 degrees or more. Therefore, it was found that the half width of the active material was better than 0.48 degrees. In addition, even between 0.25 and 0.48 degrees, it can be seen that the discharge capacity is increased as compared with the case where the half width of the crystal is 0.17 degrees, and the mechanical gliding conditions are mild and the amorphous state has not advanced much. Also, it was found that the discharge capacity was more effective than using the crystalline active material as it was.

Further, FIG. 13 shows the relationship between the crystallite size of each secondary battery and the battery discharge capacity in Example 17 (1.0 when the mixing time is 0 is 1.0). From this result, it was found that the discharge capacity was constant when the crystallite size was 200 ° or less. Therefore, it was found that the crystallite size is preferably 200 ° or less. Even when the crystallite size is large, similar to the result of the half width in FIG.
It was found that the discharge capacity was larger than that in the case of crystalline, and that there was an effect of mechanical gliding.

As described above, it has been found that by employing the secondary battery of the present invention, a lithium secondary battery having a long cycle life and a high capacity can be obtained.

Note that, other than the positive electrode active materials used in the examples, the present invention is not limited thereto, and various positive electrode active materials such as lithium-cobalt oxide and lithium-vanadium oxide can be employed. Also for the negative electrode active material, other than those used in the examples, the present invention is not limited to this, and carbon such as artificial graphite, a metal alloying with lithium such as aluminum, a metal not alloying with lithium, and a lithium ion. Various negative electrode active materials such as compounds capable of intercalating and deintercalating can also be employed.

The electrolytes of Examples 6, 8 to
Although one type was used up to 17, the present invention is not limited to this.

[0214]

As described above, according to the present invention,
In a lithium secondary battery formed from at least a negative electrode, a positive electrode, and an electrolyte and utilizing the oxidation-reduction reaction of lithium ions for charging and discharging, a lithium secondary battery containing at least an amorphous phase and having a diffraction line intensity with respect to an X-ray diffraction angle 2θ was taken. The half-width of the peak at which the strongest diffraction intensity with respect to 2θ in the line diffraction chart appears is 0.48 degrees or more, contains an amorphous phase, and is at least one selected from cobalt, nickel, manganese, and iron By using an electrode using a compound consisting of the above elements as an active material, a lithium secondary battery having a large discharge capacity and a long cycle life can be provided.

[Brief description of the drawings]

1 (a) to 1 (c) are schematic diagrams showing a process of changing a starting material from crystalline to amorphous by the method of the present invention.

FIG. 2 is a diagram showing an example of a discharge curve of a lithium secondary battery using the positive electrode active material of the present invention.

FIG. 3 is a diagram for explaining a half width.

FIG. 4 is a diagram schematically showing an example of an apparatus for performing mechanical gliding.

FIG. 5 is a diagram schematically illustrating an example of an apparatus for performing mechanical gliding.

FIG. 6 is a cross-sectional view of a single-layer flat battery.

FIG. 7 is a sectional view of a spiral cylindrical battery.

FIG. 8 is a chart showing an X-ray diffraction profile of an active material obtained when the mechanical grinding conditions are changed.

FIG. 9 is a chart showing an X-ray diffraction profile of an active material obtained when mechanical grinding conditions are changed.

FIG. 10 is a chart showing an X-ray diffraction profile of an active material obtained when mechanical grinding conditions are changed.

FIG. 11 is a chart showing an X-ray diffraction profile of an active material obtained when mechanical grinding conditions are changed.

FIG. 12 is a diagram showing a relationship between a half width of an active material and a discharge capacity in an example of the present invention.

FIG. 13 is a diagram showing a relationship between a crystallite size and a discharge capacity in an example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crystal lattice atom 2 Irregular atom 101,201 Main axis 102,202 Closed vessel 103,203 Cooling jacket 104,204 Medium (ring) 105 Cooling water 106 Various gases 107,108 Opening / closing valve 205 Active material (crystalline) 206 Electricity Chemically inactive material 207 Composite of active material and electrochemically inactive material (including amorphous) 301, 401 Negative electrode active material 303, 403 Positive electrode active material 305, 405 Negative cap (negative electrode) Terminal) 306, 406 Positive electrode can (positive electrode terminal) 307, 407 Separator holding electrolyte 310, 410 Insulation packing 400 Negative current collector 404 Positive current collector 411 Insulating plate 412 Negative lead 413 Positive lead 414 Safety valve

Claims (44)

[Claims] 1. A lithium secondary battery comprising at least a negative electrode, a positive electrode, and an electrolyte and utilizing a redox reaction of lithium ions for charging and discharging, having at least an amorphous phase and a diffraction line intensity with respect to an X-ray diffraction angle 2θ. Is an active material having a peak at which the highest diffraction intensity with respect to 2θ in the X-ray diffraction chart obtained is 0.48 degrees or more, having an amorphous phase and cobalt, nickel, manganese, A lithium secondary battery including, as a negative electrode and / or a positive electrode, an electrode including an active material and containing, as a component, a material containing at least one element selected from iron. 2. The lithium secondary battery according to claim 1, wherein an electrode having an active material containing the compound having an amorphous phase as a component is used as a positive electrode. 3. The lithium secondary battery according to claim 1, wherein an electrode having an active material containing the compound having an amorphous phase as a component is used as a negative electrode. 4. An electrode having an active material containing a compound having an amorphous phase as a component is used for each of a positive electrode and a negative electrode, and the active material has a different composition between the positive electrode and the negative electrode. The lithium secondary battery according to claim 1. 5. The lithium secondary battery according to claim 2, wherein the positive electrode contains lithium in a battery discharge state. 6. The lithium secondary battery according to claim 3, wherein the negative electrode contains lithium when the battery is charged. 7. The method according to claim 1, wherein the active material is a material containing at least one element selected from the group consisting of cobalt, nickel, manganese, and iron, and an electrode in which the active material is used during a charge / discharge reaction of a lithium battery. 2. The lithium secondary battery according to claim 1, wherein the lithium secondary battery is a composite with a chemically inert material, and the electrode having the active material is a positive electrode. 8. A material in which the active material contains at least one element selected from the group consisting of cobalt, nickel, manganese, and iron, and lithium in an electrode in which the active material is used during a charge / discharge reaction of a lithium battery. The lithium secondary battery according to claim 1, wherein the lithium secondary battery is a composite with a material that is electrochemically inactive with respect to other substances, and the electrode having the active material is a negative electrode. 9. The crystallite size of the active material is 200 °
The lithium secondary battery according to claim 1, wherein: 10. The lithium secondary battery according to claim 1, wherein the X-ray diffraction intensity of the (003) plane of the active material is at least twice the X-ray diffraction intensity of the (104) plane. . 11. The lithium secondary battery according to claim 1, wherein the battery voltage at the time of constant current discharge changes in a curve with respect to the discharge capacity, and there is no plateau region. 12. The lithium secondary battery according to claim 1, wherein the open voltage with respect to the storage capacity has no plateau region. 13. A secondary battery comprising at least a negative electrode, a positive electrode, and an electrolyte and utilizing a redox reaction of lithium ions for charge and discharge. The half-width of the peak at which the highest diffraction intensity appears is 0.48 degrees or more, and a material containing at least one selected from a metal element having an amorphous phase and carbon, and a charge / discharge reaction of a lithium battery A lithium secondary battery comprising, as an active material, a complex with a material which is electrochemically inert to a substance other than lithium in an electrode in which the active material is used. 14. The half-value of a peak at which the positive electrode has at least an amorphous phase and in which an X-ray diffraction chart obtained by taking a diffraction line intensity at an X-ray diffraction angle 2θ shows the highest diffraction intensity at 2θ. An active material having a width of 0.48 degrees or more, having an amorphous phase and containing, as a component, a material containing at least one element selected from cobalt, nickel, manganese, and iron. 14. The lithium secondary battery according to claim 13, wherein: 15. The lithium secondary battery according to claim 13, wherein the positive electrode contains lithium in a battery discharged state. 16. The lithium secondary battery according to claim 13, wherein the negative electrode contains lithium when the battery is charged. 17. The method according to claim 13, wherein a crystallite size of the active material in the negative electrode is 200 ° or less.
The lithium secondary battery according to the above. 18. A material containing a metal element having an amorphous phase, which is alloyed with lithium at the time of lithium deposition by an electrochemical reaction, wherein Al, Mg, Pb, K, Na, Ca, Sr, Ba,
14. The lithium secondary battery according to claim 13, wherein the secondary battery is at least one metal material selected from the group consisting of Si, Ge, Sn, and In. 19. The method according to claim 19, wherein the material containing a metal element having an amorphous phase does not alloy with lithium at the time of deposition of lithium by an electrochemical reaction, wherein Ni, Co, Ti, Cu, Ag, Au,
14. The lithium secondary battery according to claim 13, wherein the lithium secondary battery is at least one metal material selected from the group consisting of W, Mo, Fe, Pt, and Cr. 20. The lithium secondary battery according to claim 13, wherein the carbon material having an amorphous phase is made of carbon having a graphite skeleton structure. 21. A material having an amorphous phase is prepared by applying physical energy to a crystalline material, and the material having the amorphous phase is used as a positive electrode active material and / or a negative electrode active material. A method for manufacturing a lithium secondary battery, comprising forming an electrode. 22. The method according to claim 21, wherein the crystalline material is a crystalline material containing at least one element selected from cobalt, nickel, manganese, and iron. 23. A material having an amorphous phase by mixing a material which is electrochemically inactive at an electrode using the active material during a charge / discharge reaction of a lithium battery with the crystalline material. 22. The method for producing a lithium secondary battery according to claim 21, wherein the prepared material having an amorphous phase is used as a positive electrode active material. 24. The lithium secondary battery according to claim 23, wherein a metal whose standard electrode potential is low is used as a material which is electrochemically inactive in an electrode using the active material during a charge / discharge reaction of the lithium battery. Manufacturing method of secondary battery. 25. The method for manufacturing a lithium secondary battery according to claim 23, wherein a carbon material is used as a material that is electrochemically inactive in an electrode using the active material during a charge / discharge reaction of the lithium battery. 26. A transition metal compound is used as a material which is electrochemically inactive in an electrode using the active material during a charge / discharge reaction of the lithium battery.
The method for producing the lithium secondary battery according to the above. 27. A material which is electrochemically inactive to a substance other than lithium at an electrode using the active material during a charge / discharge reaction of a lithium battery, is mixed with the crystalline material to form an amorphous material. 22. The method for producing a lithium secondary battery according to claim 21, wherein a material having a solid phase is prepared, and the material having an amorphous phase is used as a negative electrode active material. 28. A metal having a noble standard electrode potential is used as a material which is electrochemically inactive with respect to substances other than lithium in an electrode using the active material during a charge / discharge reaction of the lithium battery. A method for manufacturing a lithium secondary battery according to claim 27. 29. The lithium secondary battery according to claim 27, wherein a carbon material is used as a material which is electrochemically inactive to a substance other than lithium in an electrode using the active material during a charge / discharge reaction of the lithium battery. Manufacturing method of secondary battery. 30. The lithium according to claim 27, wherein a transition metal compound is used as a material that is electrochemically inactive to a substance other than lithium at an electrode using the active material during a charge / discharge reaction of the lithium battery. A method for manufacturing a secondary battery. 31. The method for manufacturing a lithium secondary battery according to claim 27, wherein a transition metal compound is used as a material that is electrochemically inert to substances other than lithium during the charge / discharge reaction of the lithium battery. 32. The method for manufacturing a lithium secondary battery according to claim 21, wherein the physical energy is given to the crystalline material by centrifugal force received from a rotating body. 33. The method for manufacturing a lithium secondary battery according to claim 21, wherein a heat treatment is performed after the physical energy is applied to the crystalline material. 34. The method for manufacturing a lithium secondary battery according to claim 21, wherein heat treatment is performed simultaneously when the physical energy is applied to the crystalline material. 35. The method for manufacturing a lithium secondary battery according to claim 21, wherein the method of applying the physical energy to the crystalline material includes rotating a container containing the crystalline material. 36. An atmosphere for applying the physical energy to the crystalline material includes an oxidizing atmosphere, a reducing atmosphere,
Or an inert gas atmosphere.
2. The method for producing a lithium secondary battery according to 1. 37. An oxidizing atmosphere for applying the physical energy to the crystalline material includes oxygen, ozone, air,
The method for manufacturing a lithium secondary battery according to claim 36, wherein the method is formed of at least one gas selected from water vapor and ammonia gas. 38. The lithium secondary battery according to claim 36, wherein the reducing atmosphere for applying the physical energy to the crystalline material is hydrogen, or a mixed gas of an inert gas and hydrogen. Production method. 39. An inert gas atmosphere for applying physical energy to the crystalline material is at least one kind of gas selected from argon gas, helium gas, and nitrogen gas. 36. The method for producing a lithium secondary battery according to 36. 40. The method for producing a lithium secondary battery according to claim 21, wherein after applying physical energy to the crystalline material, oxygen plasma or nitrogen plasma treatment is further performed. 41. The method for manufacturing a lithium secondary battery according to claim 21, wherein the material after the application of the physical energy is cooled. 42. The method for producing a lithium secondary battery according to claim 33, wherein the material after the heating is cooled. 43. The crystalline material before changing the half width of the (003) plane or (104) plane of the X-ray diffraction peak of the prepared material having an amorphous phase to amorphous. 22. The method for manufacturing a lithium secondary battery according to claim 21, wherein the half value width of the material is increased by 10% or more. 44. The crystallite size of the prepared material having an amorphous phase is reduced to 50% or less of the crystallite size of the crystalline material before being changed to amorphous. 22. The method for manufacturing a lithium secondary battery according to claim 21, wherein the method is varied.