JP2002373646A - Nonaqueous electrolyte secondary battery and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery energy density which is higher than a lithium ion battery and superior in charging and discharging cycle characteristics and safety. SOLUTION: This nonaqueous electrolyte secondary battery comprises a negative electrode containing a negative electrode active material, comprising a carbon material for storing and releasing lithium ions, metal lithium or lithium alloy precipitated on the carbon material, and a solid electrolyte interface(SEI).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a negative electrode active material, a method for producing the same, a non-aqueous electrolyte secondary battery using the same, and a method for producing the same.

[0002]

2. Description of the Related Art A battery using a non-aqueous electrolyte can be used at a high voltage of 3 V or more, so that the energy density of the battery can be increased. A typical example is a lithium-based battery. Metal lithium is the most basic metal and has a high theoretical capacity of 3860 mAh / g, making it an attractive negative electrode material.
However, when metallic lithium is used as the negative electrode, short-circuiting is likely to occur due to the generation of dendrites and the progress of pulverization with the cycle, and the cycle life is short.

[0003] Thereafter, the use of a solid polymer electrolyte improved the safety of lithium batteries, but the conductivity of the solid polymer electrolyte at room temperature was low. Only high temperatures of 60 ° C. or higher can be used. In addition, since the charge / discharge coulomb efficiency is poor, the amount of lithium charged as a reserve is 2 to the positive electrode capacity.
Three times more must be used.

On the other hand, lithium ion batteries using a carbon material capable of occluding and releasing lithium ions instead of metallic lithium have been put to practical use. Graphite is a typical carbon material, and its theoretical capacity when fully charged to LiC ₆ is 372 mAh / g. Although the theoretical capacity is much lower than that of lithium metal, the cycle life and safety are greatly improved.

The electrolyte salt of a conventional non-aqueous electrolyte secondary battery uses LiPF ₆ . During the initial charging process, a dense solid electrolyte interface containing LiF (SEI, Solid Electrolyte Int) is formed on the surface of the carbon material.
(hereinafter, abbreviated as “SEI”) layer, the growth of the passivation film was suppressed, and the cycle life was improved. The same applies to the case where metallic lithium is used as the negative electrode.
An SEI layer containing iF is formed.

However, in a non-aqueous electrolyte secondary battery using metallic lithium for the negative electrode, charge / discharge of 100% of the negative electrode capacity, that is, complete charge / discharge, is repeated, and all the lithium is eluted at the time of discharge. New SE
I was formed, and SEI was continuously deposited on the surface of the negative electrode. As a result, the SEI layer became thicker, and it became difficult for lithium ions to pass through the SEI layer, thereby lowering the charge / discharge efficiency. Conversely, if the negative electrode is not completely discharged, the SEI layer is formed only at the time of initial charge and no new SEI layer is formed thereafter, so that the SEI layer functions as a protective film, and the charge / discharge efficiency of the lithium metal negative electrode is improved. I do.

[0007]

In the conventional lithium ion battery, since a carbon material is used for the negative electrode, it is difficult to further increase the energy density. On the other hand, nonaqueous electrolyte secondary batteries using metallic lithium for the negative electrode have problems in terms of utilization, cycle life, and safety.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a non-aqueous battery having a higher energy density than lithium ion batteries, excellent charge / discharge cycle characteristics, and excellent safety. An object of the present invention is to provide an electrolyte secondary battery.

[0009]

According to a first aspect of the present invention, there is provided a non-aqueous electrolyte secondary battery, comprising: a carbon material for absorbing and releasing lithium ions; metallic lithium or a lithium alloy deposited on the carbon material; Interface (SEI)
And a negative electrode including a negative electrode active material configured to include:

Here, SEI (Solid Electr)
“Olyte Interphase” refers to a passivation film formed on the surface of lithium metal or carbon material when the initial charge of lithium metal or carbon material is performed in a non-aqueous electrolyte by reducing the solvent in the electrolyte. Edited by Masayuki Yoshio and Akiya Ozawa, "Lithium ion secondary batteries-materials and applications," Nikkan Kogyo Shimbun (1996). Then, the SE formed on the surface of metallic lithium or carbon material
I functions as a lithium ion conductive protective film, and the subsequent reaction between the metallic lithium or carbon material and the solvent is suppressed.

Regarding SEI, "The film formed on the surface of the carbon negative electrode causes irreversible capacity, but plays an important role in the reversibility of charge and discharge. That is, a stable film is formed. Is believed to deactivate the carbon surface, suppress the decomposition of the electrolyte, and allow insertion of lithium.Such a surface coating exhibits lithium ion conductivity, but does not exhibit electron conductivity, SEI
(Solid Electrolyte Interph
ase). Schematic illustrations of the surface coating formed on the graphite negative electrode are shown in FIGS. The surface of the carbon negative electrode is covered with an oxide or a lithium salt that is a reaction product with an electrolytic solution or the like. When a good SEI is formed, the Coulomb efficiency after the second charge / discharge becomes almost 100%. Further, as shown in FIGS. 3, 6, and 10, a solvent co-insertion model in which solvated lithium is occluded between layers and undergoes reductive decomposition to cause decomposition products remaining between layers to function as SEI. Proposed. In this model, the coating is formed on the inner carbon surface. ("Battery handbook,
3rd edition ", P261-262, Maruzen (2001, 2
Month)).

According to the first aspect of the present invention, a non-aqueous electrolyte secondary battery having a large reversible capacity, a large discharge capacity, and a high energy density can be obtained as compared with a conventional lithium ion-inserted carbon material. In addition, since the negative electrode active material of the present invention hardly generates dendrites as compared with a metal lithium negative electrode, a nonaqueous electrolyte secondary battery having a charge and discharge Coulomb efficiency close to 100% can be obtained.

[0013] The SEI layer is obtained by acting on the organic electrolyte during the charging process of the carbon material, or by coating with a similar composition. The SEI layer is composed of a mixture of an organic substance and an inorganic salt. For example, LiPF ₆ / ethylene carbonate (EC) + diethyl carbonate (D
EC) system, LiF, Li ₂ CO ₃ ,
(CH ₂ OCO ₂ Li) ₂ , CH ₃ CH ₂ OCO ₂ Li
Is generated. SE on the surface of carbon material electrochemically
In order to form the I layer, a reduction current may be applied to a potential at which lithium ions are inserted into the carbon material. In other words, before depositing lithium, the carbon material may be charged and discharged at least once in the same manner as in a conventional lithium ion battery.

After the carbon-based active material is fully charged, the LI
C (Lithium Intercalation Co
A composite negative electrode active material in which metallic lithium is deposited on the surface of a carbon active material in a mounds state may be used.

In the process of depositing lithium, the diffusion of lithium ions is rate-determining, so that dendrites are easily generated. SEI
On the surface of the carbon material on which the layer is formed, lithium ions are desolvated or exchanged with lithium ions in the SEI layer, and insertion of lithium into the carbon layer and deposition reaction of metallic lithium occur. Since the lithium deposition reaction rate is suppressed, relatively uniform metallic lithium is deposited.

The obtained negative electrode active material includes:
(1) a structure in which a metal lithium or lithium alloy layer is deposited on a carbon material and an SEI layer is provided thereon, (2)
A structure including a mixed layer containing metallic lithium or a lithium alloy and SEI on a carbon material; (3) metallic lithium or a lithium alloy and SE on a carbon material;
A structure in which a mixed layer containing I and a metal lithium or lithium alloy layer is provided thereon may be used.

According to a second aspect of the present invention, in the non-aqueous electrolyte secondary battery according to the first aspect, a polymer electrolyte layer is provided on a surface of a negative electrode active material comprising lithium metal or a lithium alloy and SEI. It is characterized by having.

According to the second aspect of the present invention, since the fine pulverization of lithium due to charge / discharge can be suppressed and an internal short circuit caused by lithium fine powder can be avoided, the non-aqueous liquid having a long charge / discharge cycle life and excellent safety can be obtained. An electrolyte secondary battery can be obtained.

The polymer electrolyte includes a solid type (for all solid state batteries) and a gel type. In the embodiment of the present invention, the base polymer of the gel electrolyte uses a polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) copolymer, but other single or mixed system, cross-linked polymer or copolymer Or a derivative polymer may be used. For example, polyethylene oxide (PEO), polypropylene oxide (PPO), polyacrylonitrile (PA
N), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyvinylidene fluoride (PVd
F), polymethyl acrylate, polyisoprene, and the like. According to a third aspect of the present invention, in the nonaqueous electrolyte secondary battery according to the first or second aspect, the lithium alloy is an alloy of lithium and an alkali metal or an alkaline earth metal.

According to the third aspect of the present invention, the potential of the obtained lithium alloy is lower than the potential for inserting lithium ions into the carbon material, the activity of lithium is suppressed, and the potential of the nonaqueous electrolyte secondary battery is reduced. The charge and discharge efficiency is improved. For example, a trace amount of an alkali or alkaline earth metal source is preferably obtained from those ions which are present in the electrolytic solution in advance.

According to a fourth aspect of the present invention, in the nonaqueous electrolyte secondary battery according to any one of the first to third aspects, the surface of the current collector on which the negative electrode active material is not provided is insulative. According to the invention of claim 4, it is possible to avoid the generation of lithium dendrite due to the current concentration at the edge of the negative electrode and the influence of the current collector, and to provide a long charge-discharge cycle life and excellent safety. A water electrolyte secondary battery can be obtained.

According to a fifth aspect of the present invention, in the non-aqueous electrolyte secondary battery according to any one of the first to fourth aspects, an inorganic salt which does not generate LiF on the surface of the negative electrode is used as an electrolyte salt of the non-aqueous electrolyte. It is characterized by the following.

According to the fifth aspect of the invention, it is possible to prevent excessive deposition of LiF on the surface of the carbon material, and to improve the Coulomb efficiency of the negative electrode.

In a conventional battery using a metal lithium anode, the metal lithium anode does not discharge to 100% of its capacity, that is, does not completely discharge. Therefore, the LiF layer has an effect of protecting bulk lithium. ,
In order to discharge 100% of lithium, new LiF is generated in each charging process, so that the Coulomb efficiency of charging and discharging is reduced. In addition, if excessive LiF is deposited on the surface of the carbon material, it prevents insertion and release of lithium ions into and from the carbon material. Further, it also affects the film properties of the metal lithium layer.

In the present invention, an electrode which does not produce LiF
As the decomposing salt, for example, LiClO ₄Elemental fluorine such as
Use electrolyte salt that does not contain.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a non-aqueous electrolyte secondary battery according to any one of the first to fifth aspects, wherein SEI is provided on a carbon material that absorbs and releases lithium ions, In the state where the carbon material is in a charged state, lithium metal or a lithium alloy is electrically deposited on the carbon material to obtain a negative electrode active material.

According to the invention of claim 6, after the carbon material is fully charged, a uniform lithium metal or lithium alloy layer is generated, and the reversible capacity of the obtained negative electrode active material is larger than that of the conventional carbon material. Become. In addition, the negative electrode active material of the present invention can be manufactured by a simple method, and further, conventional lithium ion battery manufacturing equipment and steps can be used.

[0028] The invention of claim 7 relates to a method of manufacturing a non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein a negative electrode containing a carbon material that occludes and releases lithium ions, And a positive electrode provided with a positive electrode active material containing the compound, wherein the negative electrode is in an overcharged state.

According to the seventh aspect of the present invention, in a simple method,
A layer containing lithium metal and SEI or a lithium alloy and SEI may be provided on the negative electrode active material.

When the negative electrode is in an overcharged state, preliminary charge and discharge without depositing lithium on the negative electrode are performed at least once,
Thereafter, the negative electrode is preferably set in an overcharged state.

In this case, a negative electrode provided with a polymer electrolyte on the surface of a carbon material may be used. This polymer electrolyte layer is desirably coated directly on the surface of the carbon base material, but in some cases, the formed metallic lithium and SEI
Alternatively, the surface of a layer containing a lithium alloy and SEI may be coated.

In the non-aqueous electrolyte secondary battery, the polymer electrolyte layer may be provided on the surface of the negative electrode active material or the surface of the electrode, or may be coated on the surface of the separator in contact with the negative electrode. By providing a polymer electrolyte layer on the surface of the negative electrode active material or the surface of the electrode, growth of lithium dendrite and diffusion of finely divided lithium can be prevented.

As the lithium alloy, an alloy of lithium and an alkali metal or an alkaline earth metal may be used. In this case, it is preferable that an alkali metal or alkaline earth metal source is previously contained in the electrolyte.

In the method for producing the negative electrode of the nonaqueous electrolyte secondary battery of the present invention, the surface of the precharged and discharged carbon material may be coated with a polymer electrolyte. After removing the gas generated in the initial stage of charging, the surface of the carbon material is coated with the polymer electrolyte, and then lithium is uniformly deposited. At this time, a supporting salt containing fluorine may be used. According to this method, a uniform SEI layer is formed.

[0035]

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view showing a sectional structure of a negative electrode according to the present invention. In FIG. 1, reference numeral 1 denotes a copper current collector, 2 denotes a carbon material, 3 denotes a layer containing metallic lithium and SEI (hereinafter referred to as a layer) , Li / SEI layer). In addition, Li / SE
A similar structure is obtained when a lithium alloy is used in place of lithium (Li) in the I layer. 1A shows a state in which a carbon material 2 is attached to a current collector 1, and FIG.
On metal lithium and SEI or lithium alloy and S
The state provided with the layer containing EI is shown.

In the present invention, as the carbon material, a single carbon material capable of occluding and releasing lithium ions, such as soft carbon and hard carbon, including graphite, and a composite material thereof can be used. As the physical form of the carbon material, any form such as a powder form, a fibrous form, and a non-woven fabric can be used.

FIG. 2 shows an example of a process for providing a Li / SEI layer on a carbon material. In FIG. 2, symbols 2 and 3 indicate the same as in FIG. 1, and 4 indicates lithium in the electrolyte. Ion, 5 is the SEI layer, 6 is lithium in the SEI layer, 7 is lithium in the carbon material, 8 is the lithium layer,
9 is a polymer electrolyte layer.

FIG. 2A shows a state in which the new carbon material 2 is in contact with the electrolyte. Next, when electricity is supplied in the direction in which the carbon material 2 is charged, as shown in FIG. 2B, an SEI layer 5 is formed on the carbon material 2 and lithium 6 exists in the SEI layer 5. When charging is further continued, lithium 7 is occluded in the carbon material 2 as shown in FIG. 2c. When charging is further continued, as shown in FIG.
Li / SEI layer 3 is formed on carbon material 2. As shown in FIG. 2E, the Li / SEI layer may have a structure in which the lithium layer 8 is formed in contact with the carbon material 2 and the SEI layer 5 is further formed thereon. FIG. 2f
Shows a state in which a polymer electrolyte layer is provided on the surface of the Li / SEI layer 3 shown in FIG. 2D.

In the process shown in FIG. 2, a lithium layer is electrically generated in advance, or a conventional positive electrode active material (LiCoO ₂ , LiNiO ₂ ) having an equivalent amount of electricity (reversible chargeable / dischargeable amount of electricity). ₂ , LiMn ₂ O ₄ and their transition metal substitutes), and the SEI layer may be formed on the carbon surface by at least one precharge / discharge at a shallow depth where metal lithium is not deposited.

FIG. 3 shows that a polymer electrolyte layer is first formed on a carbon material, and then Li / SE is formed during overcharging of the carbon material.
FIG. 3 shows an example of a process for forming the I layer. Symbols 2 to 9 in FIG. 3 indicate the same as those in FIG. 2, and 10 is lithium in the polymer electrolyte layer. First, as shown in FIG. 3B, on the surface of the carbon material 2 as shown in FIG.
The polymer electrolyte layer 9 is formed, and then the carbon material 2 provided with the polymer electrolyte layer 9 is brought into contact with the electrolyte. Next, when electricity is supplied in the direction in which the carbon material 2 is charged, FIG.
As shown in FIG. 3, an SEI layer 5 is formed between the carbon material 2 and the polymer electrolyte layer 9, lithium 6 exists in the SEI layer 5, and lithium 10 also exists in the polymer electrolyte layer 9. Exists. When charging is further continued, lithium 7 is occluded in the carbon material 2 as shown in FIG. 3d. When charging is further continued, as shown in FIG.
Li / SEI layer 3 is formed between and Li / SEI layer 9. As shown in FIG. 3F, the Li / SEI layer may have a structure in which the lithium layer 8 is formed in contact with the carbon material 2 and the SEI layer 5 is further formed thereon.

The present invention can be applied to a non-aqueous electrolyte secondary battery with a limited negative electrode. A negative electrode-limited battery means that the reversible capacity (mAh) of the positive electrode active material is equal to the reversible capacity (m
Ah), a battery larger than the sum of the irreversible capacity (mAh) of the carbon material and the amount of electricity for lithium deposition (mAh). Here, the reversible capacity of the carbon material indicates the lithium ion storage / release capacity. For example, in the case of graphite, 372 m
Ah / g. In this way, a battery that limits the negative electrode is manufactured, the carbon material is fully charged in the charging process, and a metal lithium layer is deposited thereon. Thereafter, a non-aqueous electrolyte secondary battery in which the capacities of the positive electrode and the negative electrode are balanced is obtained.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

Example 1 A non-aqueous electrolyte secondary battery of Example 1 was manufactured according to the following procedure. FIG. 4 is a diagram showing a cross section of an electrode portion of the produced nonaqueous electrolyte secondary battery. In FIG. 4, symbols 1, 2 and 3 indicate the same as those in FIG. Denotes a positive electrode mixture layer containing a positive electrode active material, 13 denotes a separator, and 14 denotes a polymer electrolyte layer. The positive electrode current collector 11 is made of aluminum foil, Li _0.5 CoO ₂ is used as the positive electrode active material, and the solid or gel type can be used as the polymer electrolyte layer 14.

First, a negative electrode was prepared by mixing 90 wt% of graphite as a carbon material and 10 wt% of PVdF,
Was added to form a paste. The paste was applied to both surfaces of a copper foil as a current collector, dried, passed through a hot press roller, further dried at 150 ° C. under vacuum, and NMP was evaporated. This was designated as negative electrode A.
The thickness of the obtained negative electrode was 162 μm, and the porosity was 30%.

Next, the surface of the negative electrode was coated with a polymer. P
VdF-HFP copolymer was converted to tetrahydrofuran (TH
F) (1 g PVdF-HFP / 30 ml TH)
F), a solution was prepared by adding a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) as plasticizers in a ratio of 1.5 ml to 1 g of PVdF-HFP. Next, this solution was coated on the surface of the above-mentioned negative electrode A by the DPA method, and a spontaneous film was formed.
By drying in vacuum at a temperature of 500 ° C., PVdF
A negative electrode including the -HFP copolymer was obtained. This was designated as negative electrode B.

Subsequently, an SEI layer and a metal lithium layer were formed on the negative electrode A. Lithium is replenished from the opposite electrode. As the counter electrode, a transition metal oxide for a real battery (for example, LiCoO ₂ ) may be used. Here, metallic lithium is used. Therefore, a four-electrode cell composed of the negative electrode A, two metal lithium electrodes and a reference electrode was assembled, and 1 mol / l LiPF ₆ / EC + DEC (1:
Using 1), preliminary charge / discharge and charge / discharge cycle tests were performed.

In the pre-charging and discharging, charging was completed at 0.0 V to prevent deposition of metallic lithium, and discharging was performed up to 1.5 V. By performing such preliminary charging and discharging three times, a stable SEI layer is formed on the surface of graphite.

Subsequently, the charged amount of electricity was reduced to 1 g of graphite.
400 to 500 mAh per hour, and a metal lithium layer was formed on the surface of graphite. In this way, a negative electrode having a Li / SEI layer on the surface of graphite was produced, and this was designated as negative electrode C.

It should be noted that the charged Li
_0.5 loading when using CoO ₂ is in accordance with the amount of graphite to be _{used, Li} 0.5 CoO ₂ reversible charge and discharge capacity of graphite per 1g 400~500mAh
It was adjusted to be.

On the other hand, it is desirable to prepare a battery in a discharged state in consideration of handling in mounting. LiCoO ₂ may be used as the discharge state positive electrode active material. in this case,
The filling amount of the positive electrode active material is 400 to 5 per gram of graphite.
00 mAh. The formation of the SEI and the formation of the metal lithium layer on the surface of the negative electrode can be realized by the same pre-charge / discharge and main charge / discharge processes as described above. The depth of the pre-charging was such that the amount of charged electricity was 372 mAh or less per 1 g of graphite, and the depth of charge in the present charge / discharge cycle was 400 to 500 mAh per 1 g of graphite.

Next, a charge / discharge cycle test was performed.
Using the negative electrode C, EC + DEC (vo
1: 1), LiPF ₆ and LiCl as supporting salts
The influence of the electrolyte salt on the charge-discharge cycle characteristics was examined using O ₄ . The conditions of the charge / discharge cycle were as follows. The charging is performed at a constant current of a current density of 0.5 mA / cm ^{2 and} for a time corresponding to the charging capacity (for example, 8.7 hours for 400 mAh and 10.9 hours for 500 mAh).
The discharge was performed at a constant current of a current density of 1.0 mA / cm ² to a cutoff voltage of 1.5 V.

FIG. 5 shows the relationship between the number of charge / discharge cycles and the discharge capacity.
FIG. 6 shows the relationship between the number of charge / discharge cycles and the Coulomb efficiency of charge / discharge. From the results of FIGS. 5 and 6, in all cases, the use of LiClO ₄ as the supporting salt showed more excellent characteristics. Although not shown in FIG. 6, in the conventional nonaqueous electrolyte secondary battery using the metal lithium anode, the Coulomb efficiency was 90% or less regardless of the number of charge / discharge cycles.

It is considered that the influence of the supporting salt is due to the interaction with the lithium layer formed on the surface of the negative electrode. LiP
In the case of F ₆ , an inactive LiF layer is generated at the stage of charging up to lithium deposition, causing a decrease in Coulomb efficiency of charging and discharging. Further, when charge and discharge are repeated, LiF is deposited on the surface of the negative electrode, thereby inhibiting insertion and release of lithium ions into the graphite layer. Therefore, as shown in FIG.
A decrease in discharge capacity was observed as the number of charge / discharge cycles progressed.

Compared with LiPF ₆ , LiClO _{4 is} based on LiF
It was found that the discharge capacity and the Coulomb efficiency of charge / discharge were almost stable irrespective of the number of charge / discharge cycles, since a dense film as described above was not generated.

[0056]

The nonaqueous electrolyte secondary battery according to the present invention has a higher capacity and higher energy density than conventional lithium ion batteries because of the added capacity of metallic lithium. Since the metal lithium layer is discharged 100%, it has the same safety characteristics as a conventional lithium ion battery in a discharged state.

Further, since the SEI layer is formed in advance on the carbon material, precipitation of dendritic metal lithium can be suppressed. Furthermore, since the generation and diffusion of finely divided lithium can be avoided by coating the surface of the negative electrode with the polymer electrolyte, cycle life and safety can be significantly improved.

Since a non-fluorinated electrolyte salt is used, the coulomb efficiency of charging and discharging the metal lithium layer is improved in the case of 100% discharge, and the life of the non-aqueous electrolyte secondary battery can be extended. .

[Brief description of the drawings]

FIG. 1 is a schematic view showing a cross-sectional structure of a negative electrode according to the present invention.

FIG. 2 shows an example of a process for providing a Li / SEI layer on a carbon material.

FIG. 3 is a diagram illustrating another example of a process including a Li / SEI layer on a carbon material.

FIG. 4 is a diagram showing a cross section of an electrode portion of a non-aqueous electrolyte secondary battery.

FIG. 5 is a diagram showing the relationship between the number of charge / discharge cycles and discharge capacity.

FIG. 6 is a diagram showing the relationship between the number of charge / discharge cycles and the Coulomb efficiency of charge / discharge.

[Explanation of symbols]

 2 Carbon material 3 Li / SEI layer 5 SEI layer 8 Lithium layer 9 Polymer electrolyte layer

Continued on front page F-term (reference) 5H017 AA03 AS02 DD05 5H029 AJ05 AJ12 AK03 AL06 AL12 AM03 AM05 AM07 AM16 BJ12 BJ13 CJ16 CJ28 DJ07 HJ12 5H050 AA07 AA15 BA17 CA08 CB07 CB12 DA03 DA04 DA13 FA04 FA18 GA18 HA12

Claims (7)

[Claims] 1. A negative electrode comprising a negative electrode active material, comprising: a carbon material that stores and releases lithium ions; metallic lithium or a lithium alloy deposited on the carbon material; and a solid electrolyte interface (SEI). Non-aqueous electrolyte secondary battery characterized by the above-mentioned. 2. A metal lithium or lithium alloy,
The non-aqueous electrolyte secondary battery according to claim 1, wherein a polymer electrolyte layer is provided on a surface of the negative electrode active material including SEI. 3. The non-aqueous electrolyte secondary battery according to claim 1, wherein the lithium alloy is an alloy of lithium and an alkali metal or an alkaline earth metal. 4. The negative electrode including a negative electrode active material and a current collector, wherein the surface of the current collector on which the negative electrode active material is not provided is insulative. The non-aqueous electrolyte secondary battery according to the above. 5. The non-aqueous electrolyte secondary battery according to claim 1, wherein an inorganic salt that does not generate LiF on the surface of the negative electrode is used as an electrolyte salt of the non-aqueous electrolyte. 6. A negative electrode active material, wherein SEI is provided on a carbon material that occludes and releases lithium ions, and while the carbon material is in a charged state, metallic lithium or a lithium alloy is electrically precipitated on the carbon material. The method for producing a non-aqueous electrolyte secondary battery according to claim 1, wherein: 7. The battery according to claim 1, further comprising: a negative electrode including a carbon material capable of inserting and extracting lithium ions; and a positive electrode including a positive electrode active material including lithium, wherein the negative electrode is in an overcharged state. 6. The method for producing a non-aqueous electrolyte secondary battery according to any one of items 1 to 5.