JPH1167208A - Electrode for secondary battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for a lithium secondary battery and its manufacturing method capable of retarding the formation of dendrites without reducing the capacity of an electrode to realizing a high capacity lithium secondary battery, and easily applying to a battery production process. SOLUTION: An electrode plate for a lithium secondary battery is obtained by forming an active material layer 11 on a current collector 10 made of a copper foil, and the active material layer 11 is constituted with a lithium metal - lithium compound composite material in which many lithium metal particles 13 whose surfaces are covered with a lithium compound layer 12 containing lithium carbonate are compressed and densely filled so as not to have any gaps. The total thickness of the current collector 10 and the active material layer 11 is 80 μm, and the content of the lithium carbonate in the lithium compound layer 12 is 80 wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode plate for a secondary battery and a method of manufacturing the same, and more particularly to a lithium secondary battery having excellent charge / discharge cycle life and safety by suppressing generation of dendrite. And a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the demand for portable devices has been increasing, and small batteries such as dry batteries have become increasingly important as power sources. Among such small-sized batteries for general use, primary batteries such as manganese batteries and alkaline manganese batteries cannot be reused, and thus are discarded after use. Therefore, from the viewpoint of effective use of resources, it can be said that the rechargeable secondary battery is superior to these primary batteries.

Conventionally, nickel cadmium batteries and nickel-metal hydride batteries have been used as secondary batteries used in portable equipment because of their high overall performance. However, secondary batteries generally have a drawback that the electric capacity per unit volume is smaller than primary batteries, and increasing the capacity has been a permanent issue in battery development. Lithium secondary batteries have been studied to meet the demand for higher capacity density of such secondary batteries.

[0004] The lithium secondary battery has a feature that the electric capacity per volume is large and light as compared with the nickel cadmium battery and the nickel hydride battery which have been mainly used in the past. Very suitable as a battery for There are several types of such lithium secondary batteries, which are collectively referred to as lithium ion types that use a carbon-based material as the negative electrode active material and occlude and release lithium ions between various positive electrode active materials. Lithium secondary batteries have already been put to practical use and widely used.

Further, in order to increase the capacity of a lithium secondary battery, there is a method of using lithium metal instead of a carbon material as a negative electrode active material. According to this configuration, the secondary battery of the highest capacity class is used. Is realized. Actually, various types of lithium secondary batteries using lithium metal as the negative electrode active material have been manufactured in trials, and are shown to have higher capacity density than lithium ion type secondary batteries.

However, this type of battery has not been put to practical use yet mainly because of the problem derived from lithium dendrites (dendritic crystals) generated on the surface of the negative electrode when charge / discharge cycles are repeated. This is because it has not been resolved yet.

That is, when dendrite is generated on the surface of the negative electrode, the lithium metal is less likely to contribute to charge and discharge, so that there is a problem that the capacity of the battery is reduced and the cycle life is shortened. In addition, since the dendrite that has grown may cause a short circuit between the positive electrode and the negative electrode inside the battery and cause smoke or ignition of the battery, there is the greatest problem of lack of safety. In a battery system in which even a small amount of dendrite is generated by one charge / discharge, such an abnormality cannot be completely eliminated. Therefore, it is necessary to prevent the generation of dendrite. Has become a major challenge in the development of

As one method for solving such a problem, a lithium aluminum alloy is used as an electrode material,
In such a case, a method of favorably manufacturing an electrode made of a lithium aluminum alloy has been proposed (JP-A-4-337).
244 and JP-A-4-328276). In addition, there has been proposed a material in which the same kind of material is used as an electrode material and the electrode is further improved in terms of structure (see Japanese Patent Application Laid-Open No. 6-231755). According to these proposals, in any case, since a lithium aluminum alloy is used as an electrode material instead of lithium metal, generation of dendrites can be prevented or suppressed.

Further, as another solution, there has been proposed a method of manufacturing an electrode having an electrodeposited layer in which fine particles of a metal which can be alloyed with lithium and lithium ions are mixed on a metal lithium plate (Japanese Patent Laid-Open No. Hei 10 (1994) -207). No. 6-140027). According to this proposal, the formation of a large number of active sites by the electrodeposited layer causes the current to be dispersed, thereby alleviating local current concentration. This has an advantageous effect on the prevention of dendrite growth, and does not prevent dendrite growth. Can be suppressed. In addition, according to this proposal, since the alloy of lithium metal and another metal is only included in the electrodeposited layer, the capacity density of the electrode is reduced as compared with the case where a lithium aluminum alloy is used for the entire electrode. Can be reduced.

[0010]

However, when the above-mentioned conventional lithium aluminum alloy is used as an electrode material, a component of aluminum irrelevant to the operation as an active material is contained in the electrode in order to suppress the generation of dendrite. Because of the addition, the capacity per unit volume of the electrode decreases. Therefore, although the generation of dendrites is suppressed, the original purpose of achieving higher capacity cannot be sufficiently achieved. As described above, the method of using the lithium aluminum alloy as the electrode material has a problem that the effect of increasing the capacity density of the lithium metal electrode is reduced.

In the case of an electrode having the above-mentioned conventional metal lithium plate on which an electrodeposited layer in which fine particles of a metal capable of being alloyed with lithium and lithium ions are mixed is formed, the electrodeposited layer is formed on the electrode prior to assembling the battery. In the subsequent steps, it is necessary to keep the electrode in a wet state with the electrolytic solution in order to maintain the state of the lithium ions contained in the electrodeposited layer. It is difficult to adjust the position or the like due to wetness in the winding or laminating stage of the process, which causes a problem that the product yield is reduced. In addition, if an assembly process is performed such that the electrodes are in a wet state prior to battery assembly, the organic electrolyte containing a lithium salt used in a lithium secondary battery generally has a very high hygroscopicity, so that the moisture brought into the battery is reduced. In order to keep the battery performance low so as not to affect the battery performance, the dew point of the assembling environment must be kept extremely low, which causes a problem of increasing the manufacturing cost.

Accordingly, the present invention has been made in view of the above problems, and in order to commercialize a high capacity lithium secondary battery, it is possible to suppress the generation of dendrite without reducing the capacity of the electrode. Another object of the present invention is to provide a lithium secondary battery electrode which can be easily applied to a battery manufacturing process, and a method for manufacturing the same.

[0013]

Means for Solving the Problems To solve the above problems, the present inventor conducted experiments on the respective components of a lithium secondary battery using lithium metal for the negative electrode by using various materials to determine whether or not dendrite was generated. Then, a study was made to find the optimum material. As a result, it has been found that the above object can be achieved by the following electrode plate for a secondary battery according to the present invention.

That is, the electrode plate for a secondary battery according to claim 1 is a lithium metal-lithium compound composite material obtained by compressing a large number of lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate. It is characterized by being an active material.

In the electrode plate for a secondary battery according to the first aspect, a lithium metal-lithium compound composite formed by compressing a large number of lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate. By using the material as an active material, generation of dendrites is suppressed in almost all combinations of a positive electrode material and an electrolytic solution that can be used for a lithium secondary battery.

Although the mechanism by which the formation of dendrite is suppressed by such an electrode structure is not necessarily clear, the formation of dendrite by the use of an alloy of lithium and another metal as in the conventional method is not clear. It is considered that a novel lithium ion transport function was realized by a composite material of lithium and a lithium compound, which is different from the above-described one.

That is, in recent years, a lithium compound layer containing lithium carbonate is formed on the surface of a lithium electrode in a lithium secondary battery by reaction with an organic electrolyte or the like, and this lithium compound layer diffuses lithium ions relatively easily. In the electrode plate for a secondary battery according to claim 1, the lithium compound layer containing lithium carbonate forms a skeleton in a three-dimensional network. The function is expected to be used more actively. In addition, since the shape of the electrode plate is held by the skeleton of the three-dimensional mesh-like lithium compound layer, the shape of the electrode is not damaged, that is, no dendrite is generated. Therefore, it is considered that a favorable charge / discharge operation is performed by the electrode plate using the lithium metal-lithium compound composite material as an active material without generating dendrite.

According to a second aspect of the present invention, in the electrode plate for a secondary battery according to the first aspect, the lithium compound layer contains lithium fluoride in addition to lithium carbonate. By doing so, the generation of dendrite is favorably suppressed as in the case of the first aspect.
The lithium salt contained in the electrolyte of the lithium secondary battery contains fluorine as its composition, for example, LiCF
_{In the case of 3} SO ₃ , LiBF ₄ , LiPF ₆ , LiAsF _6, etc., the affinity between the lithium compound layer containing lithium fluoride and the electrolyte is increased, so that the diffusion rate of lithium ions is more rapid. Is obtained, so that the discharge current characteristics are further improved.

According to a third aspect of the present invention, in the electrode plate for a secondary battery according to the first aspect, the content of lithium carbonate in the lithium compound layer is 10 wt. )% And 90 wt% or less, the lithium compound layer containing lithium carbonate does not have a function as an active material, but its content relative to the entire lithium metal-lithium compound composite material is small. Therefore, the energy density of the electrode is not reduced unlike aluminum in a conventional lithium aluminum alloy. Therefore, a high capacity approximately the same as that of the lithium metal electrode having the highest capacity is realized.

The electrode plate for a secondary battery according to claim 4 is the electrode plate for a secondary battery according to claim 2, wherein the content of lithium carbonate in the lithium compound layer is 10 wt% or more of the lithium compound layer. 90 wt% or less,
The content of lithium fluoride in the lithium compound layer is
10 of the portion excluding lithium carbonate from the lithium compound layer
When the composition is not less than 100 wt% and not more than 100 wt%, the lithium compound layer containing lithium carbonate and lithium fluoride does not have a function as an active material, but their content with respect to the entire lithium metal-lithium compound composite material , The energy density of the electrode is not reduced unlike aluminum in a conventional lithium aluminum alloy. Therefore, a high capacity approximately the same as that of the lithium metal electrode having the highest capacity is realized.

In the electrode plate for a secondary battery according to claim 1 or 2, the lithium metal particles have a particle size of 0.1.
It is desirable to be within the range of μm to 10 μm.

In the electrode plate for a secondary battery according to claim 1 or 2, the lithium compound layer has a thickness of 10 n.
It is preferable that the diameter is in the range of m to 100 nm and is 1/10 or less of the particle diameter of the lithium metal particles.

Next, a method for manufacturing the electrode plate for a secondary battery according to the present invention will be described. For example, as a method for forming the electrode plate for a secondary battery according to the first aspect, a method in which lithium metal powder and lithium compound powder containing lithium carbonate are mixed and compression-molded is supposed first. However, in the secondary battery electrode plate according to the present invention, it is important that lithium ions are easily transported from lithium metal through the lithium compound layer. However, since the lithium metal and the lithium compound layer are not sufficiently bonded to each other and a boundary layer is formed at the interface that hinders the transport of lithium ions, an electrode plate for a secondary battery having the function aimed at by the present invention is realized. Have difficulty. Therefore, the present inventor conducted various experiments on the method of manufacturing the electrode plate for a secondary battery according to the present invention. As a result, the following method for producing an electrode plate for a secondary battery according to the present invention has been conceived.

That is, in the method for manufacturing an electrode plate for a secondary battery according to claim 7, the lithium metal layer containing lithium carbonate is reacted with a predetermined atmospheric gas by evaporating or spraying lithium metal in the processing chamber. First, a large number of lithium metal particles whose surfaces are covered by
And a second step of compressing a large number of lithium metal particles deposited on the current collector to form a lithium metal-lithium compound composite material as an active material on the current collector. Features.

Thus, in the method of manufacturing an electrode plate for a secondary battery according to claim 7, the evaporated or sprayed lithium metal is reacted with a predetermined atmospheric gas, and the surface is covered with a lithium compound layer containing lithium carbonate. After depositing a large number of lithium metal particles on the current collector, the large number of lithium metal particles deposited on the current collector are compressed to form a lithium metal-lithium compound composite material as an active material. Lithium ions are easily transported from the lithium metal through the lithium compound layer because the lithium metal and the lithium compound layer are sufficiently bonded and a boundary layer that prevents the transport of lithium ions is not formed at the interface. The electrode plate for a secondary battery according to claim 1 having a lithium ion transport function is realized.

Here, as an atmosphere gas for reacting with lithium metal to form a lithium compound layer containing lithium carbonate on the surface of lithium metal particles, C.sub.2 is used.
It is preferable to use O, CO ₂ , CH ₃ OH, C ₂ H ₅ (OH), (CH ₃ ) ₂ CO, or a mixed gas thereof.

[0027] Further, according to a method of manufacturing an electrode plate for a secondary battery according to claim 8, in the method of manufacturing an electrode plate for a secondary battery according to claim 7, the first step is performed in a processing chamber. Lithium metal is vaporized or sprayed to react with a predetermined atmospheric gas, and lithium metal particles whose surface is covered with a lithium compound layer containing lithium carbonate and lithium fluoride are deposited on a current collector. Thereby, the lithium metal and the lithium compound layer are sufficiently bonded to each other, and a boundary layer that hinders the transport of lithium ions is not formed at the interface. Therefore, lithium ions can easily pass from the lithium metal through the lithium compound layer. Faster when using an electrolyte that has a lithium ion transport function and a lithium salt containing fluorine as a composition dissolved in it. For a secondary battery electrode plate according to the claim 2 the diffusion rate of lithium ions is obtained it is realized.

Here, as atmosphere gases for forming a lithium compound layer containing lithium carbonate and lithium fluoride on the surface of lithium metal particles by reacting with lithium metal, CO, CO ₂ , CH ₃ OH, C ₂ H
It is preferable to use ₅ (OH) or (CH ₃ ) ₂ CO, or a mixed gas thereof to which F ₂ is added.

According to a ninth aspect of the present invention, in the method for manufacturing an electrode plate for a secondary battery according to the seventh aspect, the first step is performed in a processing chamber. A plasma region excited by discharge is provided, and lithium metal is vaporized or sprayed to react with plasma of a predetermined atmospheric gas, and lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate are formed on a current collector. By adopting the configuration of the deposition step, the lithium metal and the lithium compound layer are sufficiently bonded to form a boundary layer at the interface, which prevents the transport of lithium ions, as in the case of the seventh aspect. 3. The secondary battery according to claim 2, which has a lithium ion transport function in which lithium ions are easily transported from lithium metal through a lithium compound layer because there is no lithium ion. Pond electrode plates is achieved.

Here, CO, CO ₂ , CH ₃ OH, C ₃ OH and C ₃ are used as atmosphere gases for forming a lithium compound layer containing lithium carbonate on the surface of lithium metal particles by reacting with lithium metal in plasma. ₂ H
It is preferable to use ₅ (OH) or (CH ₃ ) ₂ CO or a mixed gas thereof, and this gas is used as He,
It is preferable to use a gas diluted with H ₂ , Ar, N ₂ or O ₂ or a mixed gas thereof, and to use a gas diluted with CH ₂ or C ₂ H ₄ or a mixed gas thereof with O _2. It is suitable.

According to a tenth aspect of the present invention, in the method for manufacturing an electrode plate for a secondary battery according to the seventh aspect, the first step is performed in a processing chamber. Providing a plasma region excited by discharge,
Lithium metal is vaporized or sprayed to react with a plasma of a predetermined atmospheric gas to deposit lithium metal particles having a surface coated with a lithium compound layer containing lithium carbonate and lithium fluoride on a current collector. with, even in the case of using the inert gas is not a gas that has a toxic or flammable as F ₂ for safety securing the ambient gas, as in the case of the claim 8, Lithium ions are easily transported from the lithium metal through the lithium compound layer because the lithium metal and the lithium compound layer are sufficiently bonded and a boundary layer that prevents the transport of lithium ions is not formed at the interface. When using an electrolyte that has a lithium ion transport function and in which a lithium salt containing fluorine as a composition is dissolved, more rapid Rechargeable battery electrode plate according to the claim 2 the diffusion rate of the Ion is obtained is realized.

Here, CO, CO ₂ , CH ₃ OH, C ₃ OH, and C ₃ are used as atmosphere gases for forming a lithium compound layer containing lithium carbonate on the surface of lithium metal particles by reacting with lithium metal in plasma. ₂ H
It is preferable to use CF ₄ , CHF _3, C ₂ F _6, or a mixed gas thereof in addition to ₅ (OH) or (CH ₃ ) ₂ CO or a mixed gas thereof. It is preferable to use a gas diluted with H ₂ , Ar, N ₂ or O ₂ or a mixed gas thereof, and to add CH ₄ or C ₂ H ₄ or a mixed gas thereof to CF ₄ , CHF ₃ or C ₂ F It is preferable to use a gas obtained by diluting a gas obtained by adding ₆ or a mixed gas thereof with O ₂ .

In the method for manufacturing an electrode plate for a secondary battery according to claim 7 or 8, the pressure of the atmosphere gas to be reacted with the lithium metal is 1.33 mPa to 0.133 P.
It is desirably within the range of a.

In the method for manufacturing an electrode plate for a secondary battery according to the ninth or tenth aspect, the pressure of the atmosphere gas to be reacted with the lithium metal is from 13.3 mPa to 13.3 P.
It is desirably within the range of a.

In the method for producing an electrode plate for a secondary battery according to any one of claims 7 to 10, the current collection when depositing the lithium metal particles whose surfaces are covered with the lithium compound layer on the current collector. Body temperature is -50 ° C to -10 ° C
Is desirably held within the range.

In the method for producing an electrode plate for a secondary battery according to any one of claims 7 to 10, the deposition rate when depositing lithium metal particles whose surface is covered with a lithium compound layer on a current collector. Is 0.1 μm / min to 10 μm
It is desirably within the range of m / min.

In the method for manufacturing an electrode plate for a secondary battery according to the ninth or tenth aspect, when a plasma region excited by discharge is provided in the processing chamber, the power density supplied for plasma generation is: it is preferably within a range of 0.1W / cm ² ~2W / cm ² of the area of the deposition region.

[0038]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. (First Embodiment) FIG. 1 is a sectional view showing an electrode plate for a lithium secondary battery according to a first embodiment of the present invention. As shown in FIG. 1, the electrode plate for a lithium secondary battery according to the present embodiment has a structure in which an active material layer 11 is formed on a current collector 10 made of a copper foil. A large number of lithium metal particles 13 whose surfaces are covered with a lithium compound layer 12 containing lithium carbonate are compressed and are composed of a lithium metal-lithium compound composite material densely packed without gaps. There is a feature of this embodiment.

Here, the current collector 10 made of a copper foil and the active material layer 1 made of a lithium metal-lithium compound composite material
1 has a total thickness of 80 μm.
The content of lithium carbonate in No. 2 was 80 wt%.

Next, a method of manufacturing the electrode plate for a lithium secondary battery shown in FIG. 1 will be described with reference to FIG. Here, FIG.
FIG. 1 is a schematic cross-sectional view showing a processing apparatus for forming an active material layer 11 made of a lithium metal-lithium compound composite material on a current collector 10.

This processing apparatus, as shown in FIG.
A processing chamber 20, a gas supply mechanism for supplying an atmospheric gas CO ₂ from a cylinder 21 filled with CO ₂ gas into the processing chamber 20 via an MFC (Mass Flow Controller) 22, and a processing chamber 2
A vacuum evacuation device 23 for evacuating the gas in the chamber 0 to the outside, a variable orifice 24 for adjusting the pressure in the processing chamber 20, a tantalum vapor deposition boat 26 on which lithium metal 25 as an evaporating substance is mounted, A power source 27 for vapor deposition for energizing the vapor deposition boat 26 to heat and evaporate the lithium metal 25 on the vapor deposition boat 26; a current collector holding mechanism 28 for retaining the current collector 10 facing the vapor deposition boat 26;
An openable / closable shutter mechanism 29 disposed between the vapor deposition boat 26 and the current collector holding mechanism 28 is provided as a main mechanism.

First, a lithium metal 25 as an evaporation substance is placed on a tantalum evaporation boat 26 in the processing chamber 20.
And a current collector 10 made of a copper foil having a thickness of 20 μm is fixed downward on the bottom surface of the current collector holding mechanism 28 so as to face the lithium metal 25 on the evaporation boat 26.

Subsequently, a CO ₂ gas as an atmospheric gas is supplied from the cylinder 21 into the processing chamber 20. At this time, the flow rate of the atmosphere gas CO ₂ is controlled to 10 sccm by the MFC 22. The pressure in the processing chamber 20 is maintained at 13.3 mPa by the evacuation device 23 and the variable orifice 24.

Subsequently, power is supplied to the evaporation boat 26 by the evaporation power supply 27, and the lithium metal 25 on the evaporation boat 26 is turned on.
Is heated and evaporated. Then, the evaporated lithium metal is reacted with a CO ₂ gas as an atmosphere gas to cover the surface of the lithium metal particles 13 with the lithium compound layer 12 containing lithium carbonate and to form the lithium compound layer containing lithium carbonate. A large number of lithium metal particles 13 whose surfaces are covered with 12 are deposited on the current collector 10.

At this time, by controlling the time of the open state of the shutter mechanism 29, a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate are deposited on the current collector 10. Thickness, ie, the thickness of the deposited layer of the lithium metal-lithium compound composite material is 1
It is controlled to be 00 μm.

Next, the current collector 10 on which a large number of lithium metal particles 13 whose surface is covered by the lithium compound layer 12 containing lithium carbonate is deposited, is placed in a processing chamber 20.
After being taken out from the container, the entire thickness of the current collector 10 and the deposited layer of the lithium metal-lithium compound composite material is compressed from 120 μm to 80 μm using a roll press device, and densely packed without gaps. State.
Then, this is punched into a rectangle to form an electrode plate for a lithium secondary battery.

Thus, the lithium compound layer 12 containing 80% by weight of lithium carbonate as shown in FIG.
Lithium metal particles 13 whose surface is coated with
Is compressed and the active material layer 11 made of a lithium metal-lithium compound composite material densely filled without gaps is provided.
Is formed on a current collector 10 made of copper foil, and has a thickness of 8
An electrode plate for a lithium secondary battery of 0 μm is manufactured.

When the cross section of the electrode plate for a lithium secondary battery manufactured by using such a manufacturing method was examined by an X-ray microanalyzer, it was found that the lithium metal particles 13 and the lithium compound layer 12 containing lithium carbonate were not. No particular impurity layer was present at the interface, and it was confirmed that a good interface was formed.

Next, the characteristics of the electrode for a lithium secondary battery using the electrode plate for a lithium secondary battery according to this embodiment will be described.

The electrode plate for a lithium secondary battery shown in FIG. 1 is used as a negative electrode plate, and is opposed to a positive electrode plate of the same size via a separator made of a polypropylene film having pores. As this positive electrode plate, LiC for lithium batteries is used.
Acetylene black and PTFE (polytetrafluoroethylene) resin powder were mixed at 10 wt% each with oO ₂ powder,
Add N-methylpyrrolidone, knead well, and add
A coating is applied to an aluminum foil of μm so that the thickness after drying is 200 μm, then dried and pressed. As the electrolytic solution, a solution obtained by dissolving 1 mol / l of LiClO ₄ as a lithium salt in a 1: 1 mixed solvent of ethylene carbonate and dimethyl carbonate is used.
Thus, a lithium secondary battery glass cell A using the electrode plate for a lithium secondary battery according to the present embodiment as a negative electrode plate was produced.

The lithium secondary battery glass cell A
For comparison, the following three types of lithium secondary battery glass cells BD were prepared.

That is, in Comparative Example 1, the thickness was 20 μm
An alloy foil containing 50% by weight of lithium and aluminum was formed on a current collector made of a copper foil, and pressed into contact so that the total thickness became 80 μm. The electrode plate was used as a negative electrode plate, and a lithium secondary battery glass cell B was prepared in which the other positive electrode plate, electrolyte, and the like were exactly the same as the above lithium secondary battery glass cell A.

In Comparative Example 2, the thickness was 20 μm.
An alloy foil composed of 80% by weight of lithium and 20% by weight of aluminum was formed on a current collector composed of a copper foil, and pressed into contact so that the total thickness became 80 μm. A lithium secondary battery glass cell C was prepared in which the electrode plate for use was used as a negative electrode plate, and the other positive electrode plates, electrolyte, and the like were exactly the same as the above lithium secondary battery glass cell A.

In Comparative Example 3, the thickness was 20 μm.
Forming a lithium metal foil on the current collector made of copper foil,
After being pressed into contact so that the entire thickness becomes 80 μm, the resulting plate was punched out into a rectangular shape and used as an electrode plate for a lithium secondary battery as a negative electrode plate. A lithium secondary battery glass cell D exactly the same as the battery glass cell A was produced.

A cycle test was performed on these four types of lithium secondary battery glass cells A to D by supplying a charge / discharge current having a current density of 1.5 mA / cm ² in a voltage range of 2.7 V to 4.2 V, and a battery capacity was determined. Was measured, and after the cycle test, it was decomposed and examined for the presence or absence of dendrite formation. The following results were obtained.

1. The lithium secondary battery glass cell A using the electrode plate for a lithium secondary battery according to the present embodiment as a negative electrode plate has a capacity of 98% or more of the initial capacity of the lithium secondary battery glass cell D of Comparative Example 3, No capacity reduction occurred even after more than 500 cycles. Further, as a result of the decomposition inspection after the cycle test, no generation of dendrites was observed inside.

2. In the glass cell B of the lithium secondary battery of Comparative Example 1, the capacity was slightly reduced even after 500 cycles. In addition, as a result of the decomposition inspection after the cycle test, no generation of dendrites was observed inside. However, the battery capacity was 50%, which is the same as the ratio of the active material to the initial capacity of the lithium secondary battery glass cell D of Comparative Example 3.

3. The lithium secondary battery glass cell C of Comparative Example 2 showed a capacity of 80% of the initial capacity of the lithium secondary battery glass cell D of Comparative Example 3, but the charge / discharge capacity gradually decreased after the start of the test, and was around 300 cycles. Caused an internal short circuit. In addition, as a result of the decomposition inspection after the cycle test, formation of dendrite was observed inside.

4. In the lithium secondary battery glass cell D of Comparative Example 3, the charge / discharge capacity rapidly decreased every cycle after the start of the test, and an internal short circuit occurred in 30 cycles. Further, as a result of the decomposition investigation after the cycle test, generation of a large amount of dendrite was observed inside.

From these results, the lithium secondary battery glass cell A using the electrode plate for a lithium secondary battery according to the present embodiment as a negative electrode plate has the highest capacity lithium secondary battery using a lithium metal plate as the negative electrode plate. It was found that the capacity was substantially the same as that of the secondary battery glass cell D, and that no dendrite was generated. Further, since the electrode plate for a lithium secondary battery according to the present embodiment is handled in a dry state similarly to the electrode plates for lithium secondary batteries of Comparative Examples 1 to 3, the electrodeposition layer described as one of the prior arts It was confirmed that there was no difficulty in handling due to the electrode being in a wet state, which could be a concern when using a battery, and that a normal battery assembly process could be applied.

Next, the optimum range of the particle size of the lithium metal particles 13 in the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the electrode plate for a lithium secondary battery shown in FIG. 1, a large number of lithium metal particles 13 whose surfaces are covered with a lithium compound layer 12 containing lithium carbonate are compressed and densely packed without gaps. Material layer 1 from lithium metal-lithium compound composite material filled in
However, since the change in the particle size of the lithium metal particles 13 is expected to change the characteristics of the electrode plate for a lithium secondary battery, the particle size of the lithium metal particles 13 is variously changed. An experiment was conducted to clarify the optimum range.

The lithium metal 2 described with reference to FIG.
By changing various conditions at the time of heating and evaporating 5, a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate are collected into the current collector 10.
It is possible to variously change the particle size of the lithium metal particles 13 when deposited on the top. That is, mainly, the pressure of the atmospheric gas CO ₂ when heating and evaporating the lithium metal 25, the vapor deposition boat 26 on which the lithium metal 25 as the evaporating substance is mounted, and the current collector holding mechanism for fixing the current collector 10 to the bottom portion 2
By changing the conditions of the distance from the metal plate 8 and the temperature of the vapor deposition boat 26, the particle size of the lithium metal particles 13 after compression by the roll press device could be changed in the range of 0.01 μm to 20 μm.

In this range, electrode plates for lithium secondary batteries in which the particle diameters of the lithium metal particles 13 are variously different were prepared, and further, the lithium secondary battery glass cells using the electrode plates for lithium secondary batteries as negative electrodes were prepared. Was fabricated, and the change in capacity with respect to the discharge current was investigated. As a result, when the particle size of the lithium metal particles 13 is within the range of 0.1 μm to 10 μm, the decrease in the discharge capacity when the discharge current is increased is smaller than when the discharge current is outside this range, and the load current characteristics It was confirmed that an excellent lithium secondary battery could be realized.

Next, the optimum range of the lithium carbonate content of the lithium compound layer 12 in the electrode plate for a lithium secondary battery according to the present embodiment will be described.

In the electrode plate for a lithium secondary battery shown in FIG. 1, the content of lithium carbonate in the lithium compound layer 12 covering the surface of the lithium metal particles 13 is 80%.
However, when the content of lithium carbonate in the lithium compound layer 12 changes, a change in the characteristics of the electrode plate for a lithium secondary battery is expected. Therefore, the content of lithium carbonate in the lithium compound layer 12 is reduced. Experiments were conducted with various changes to clarify the optimum range.

The lithium metal 2 described with reference to FIG.
By changing various conditions at the time of heating and evaporating 5, a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate are collected into the current collector 10.
It is possible to variously change the content of lithium carbonate in the lithium compound layer 12 when depositing on the lithium compound layer 12.

That is, mainly, the pressure of the atmosphere gas CO ₂ when heating and evaporating the lithium metal 25, the vapor deposition boat 26 on which the lithium metal 25 as the evaporating substance is mounted, and the current collector 10.
The content of lithium carbonate in the lithium compound layer 12 ranges from 0.5 wt% to 95 wt% by changing the conditions of the distance from the current collector holding mechanism 28 for fixing the bottom surface to the current collector holding mechanism 28 and the temperature of the evaporation boat 26. Was able to change.

Then, within this range, electrode plates for lithium secondary batteries having various contents of lithium carbonate in the lithium compound layer 12 were prepared, and the lithium secondary battery electrode plates were used as negative electrode plates. A battery glass cell was fabricated, and a change in capacity with respect to a discharge current was investigated. As a result, when the content of lithium carbonate in the lithium compound layer 12 is within the range of 10 wt% to 90 wt%, the decrease in discharge capacity when the discharge current is increased is smaller than when the content is outside this range, It was confirmed that a lithium secondary battery having excellent load current characteristics could be realized.

Next, the optimum range of the thickness of the lithium compound layer 12 containing lithium carbonate in the electrode plate for a lithium secondary battery according to the present embodiment will be described.

In the electrode plate for a lithium secondary battery shown in FIG. 1, a large number of lithium metal particles 13 whose surfaces are covered with a lithium compound layer 12 containing lithium carbonate are compressed and densely packed without gaps. Material layer 1 from lithium metal-lithium compound composite material filled in
Although the thickness of the lithium compound layer 12 changes, it is expected that the characteristics of the electrode plate for a lithium secondary battery change. Therefore, the thickness of the lithium compound layer 12 is variously changed. An experiment was conducted to clarify the optimum range.

The lithium metal 2 described with reference to FIG.
By changing various conditions at the time of heating and evaporating 5, a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate are collected into the current collector 10.
It is possible to variously change the thickness of the lithium compound layer 12 when depositing on it.

That is, mainly, the pressure of the atmospheric gas CO ₂ when heating and evaporating the lithium metal 25, the vapor deposition boat 26 on which the lithium metal 25 as the evaporating substance is mounted, and the current collector 10.
The thickness of the lithium compound layer 12 was able to be changed in the range of 10 nm to 1 μm by changing each condition of the distance from the current collector holding mechanism 28 for fixing the layer to the bottom portion and the temperature of the evaporation boat 26. .

Then, within this range, electrode plates for lithium secondary batteries having various thicknesses of the lithium compound layer 12 were prepared, and further, the lithium secondary battery glass cells using the electrode plates for lithium secondary batteries as negative electrodes were prepared. Was fabricated, and the change in capacity with respect to the discharge current was investigated. As a result, the thickness of the lithium compound layer 12 is in the range of 10 nm to 100 nm, and
It was confirmed that when the discharge current was 0 or less, the decrease in discharge capacity when the discharge current was increased was smaller than that when the discharge current was outside this range, and a lithium secondary battery having excellent load current characteristics could be realized.

Next, the types of atmospheric gases used for producing the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the method of manufacturing the electrode plate for a lithium secondary battery described with reference to FIG. 2, a large number of lithium metal particles 13 whose surface is covered with a lithium compound layer 12 containing lithium carbonate are collected by the current collector 10. CO ₂ gas is used as an atmosphere gas for reacting with the evaporated lithium metal when depositing on the top, but the uniformity of the lithium metal particles 13 is different due to the change of the kind of the atmosphere gas. Since changes in the characteristics of the electrode plate for a lithium secondary battery due to the above are expected, experiments were conducted to clarify the optimal gas type by changing the type of atmosphere gas in various ways.

Using various gases that can be used as atmosphere gases, the gas was reacted with the evaporated lithium metal, and a large number of lithium metal particles 13 whose surfaces were covered with the lithium compound layer 12 containing lithium carbonate were compressed. Active material layer 1 made of lithium metal-lithium compound composite material
1 is formed on the current collector 10 to prepare an electrode plate for a lithium secondary battery, and further, a glass cell for a lithium secondary battery using this electrode plate for a lithium secondary battery as a negative electrode plate is manufactured, and a capacity with respect to discharge current is produced. The changes were investigated.

As a result, CO, C were used as atmosphere gases.
O ₂ , CH ₃ OH, C ₂ H ₅ (OH), (CH ₃ ) ₂ C
It was confirmed that when any gas of O or a mixture of some of these gases was used, a decrease in the discharge capacity when the discharge current was increased was small, and a lithium secondary battery having excellent load current characteristics could be realized. Was done. When these gases are used as atmospheric gases, they react with the evaporated lithium metal to form a lithium compound layer 1 containing lithium carbonate.
Numerous lithium metal particles 1 whose surface is coated with 2
3 is deposited on the current collector 10, the lithium metal particles 1
It is considered that, because of excellent uniformity of No. 3, an electrode plate for a lithium secondary battery having uniform characteristics was formed.

Of these gases, CH ₃ OH, C
It was confirmed that when any one of ₂ H ₅ (OH) and (CH ₃ ) ₂ CO was used alone or partially mixed, more excellent current characteristics could be obtained. However, these gases are at room temperature,
Since it is a liquid under normal pressure, when used as an atmospheric gas, it is necessary to heat the entire gas supply system, leading to an increase in manufacturing equipment costs. It is preferable to use CO and CO ₂ .

Next, the pressure of the atmospheric gas used for producing the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the method of manufacturing an electrode plate for a lithium secondary battery described with reference to FIG. 2, a large number of lithium metal particles 13 whose surface is covered with a lithium compound layer Atmosphere gas C which reacts with evaporated lithium metal when deposited on
The pressure of O ₂ is maintained at 13.3 mPa.
Since there is a difference in the uniformity of No. 3 and a change in the characteristics of the electrode plate for a lithium secondary battery due to the difference is expected, the range of the optimal gas pressure is clarified by variously changing the pressure of the atmosphere gas. An experiment was conducted to

Using CO ₂ as an atmospheric gas, it was reacted with lithium metal evaporated under various pressures to compress a large number of lithium metal particles 13 whose surfaces were covered with a lithium compound layer 12 containing lithium carbonate. An active material layer 11 made of a lithium metal-lithium compound composite material is formed on the current collector 10 to produce an electrode plate for a lithium secondary battery. A secondary battery glass cell was fabricated, and the change in capacity with respect to the discharge current was investigated.

As a result, the pressure of the atmospheric gas CO ₂ was 1.
It was confirmed that, when the discharge current was in the range of 33 mPa to 0.133 Pa, a decrease in discharge capacity when the discharge current was increased was small, and a lithium secondary battery having excellent load current characteristics could be realized. Atmospheric gas CO ₂ pressure is 1.33 mPa ~
When it is within the range of 0.133 Pa, the uniformity of the lithium metal particles 13 when depositing a large number of lithium metal particles 13 whose surfaces are covered with the lithium compound layer 12 containing lithium carbonate on the current collector 10 is increased. This is considered to be due to the fact that an electrode plate for a lithium secondary battery having uniform characteristics is formed because of its excellent properties.

Further, instead of CO ₂ gas, CO, CH ₃ OH, C ₂ H ₅ (OH), (C
A similar experiment was performed using any gas of H ₃ ) ₂ CO or a mixture of some of these gases. In this case, the same result as that obtained when the CO ₂ gas was used was obtained.

Next, the temperature of the current collector 10 used for producing the electrode plate for a lithium secondary battery according to the present embodiment will be described.

In the method of manufacturing an electrode plate for a lithium secondary battery described with reference to FIG. 2, a large number of lithium metal particles 13 whose surface is covered with a lithium compound layer 12 containing lithium carbonate are collected by the current collector 10. A change in the uniformity of the lithium metal particles 13 is observed due to a change in the temperature of the current collector 10 when it is deposited thereon, and a change in the characteristics of the electrode plate for a lithium secondary battery due to the difference is expected. Body 1
Experiments were conducted to clarify the optimum temperature range of the current collector 10 by changing the temperature of 0 in various ways.

In the above manufacturing method, the temperature of the current collector 10 is changed variously, and the lithium metal-lithium compound in which a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate is compressed. An active material layer 11 composed of a composite material is formed on the current collector 10 to produce an electrode plate for a lithium secondary battery, and a glass cell for a lithium secondary battery using the electrode plate for a lithium secondary battery as a negative electrode plate is further prepared. It was fabricated and the change in capacity with respect to the discharge current was investigated.

As a result, when the temperature of the current collector 10 is maintained at a constant temperature between -50 ° C. and -10 ° C., the decrease in the discharge capacity when the discharge current is increased is small, and the load current characteristics It was confirmed that an excellent lithium secondary battery could be realized. A large number of lithium metal particles 13 whose surface is covered with a lithium compound layer 12 containing lithium carbonate are deposited on the current collector 10 maintained at a constant temperature within a temperature range of −50 ° C. to −10 ° C. It is considered that, since the uniformity of the lithium metal particles 13 is excellent, an electrode plate for a lithium secondary battery having uniform characteristics is formed.

Next, on the current collector 10 of a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate when the electrode plate for a lithium secondary battery according to the present embodiment is manufactured. Next, the deposition rate on the substrate will be described.

In the method of manufacturing an electrode plate for a lithium secondary battery described with reference to FIG. 2, a large number of lithium metal particles 13 whose surface is covered with a lithium compound layer 12 containing lithium carbonate are collected by the current collector 10. Since the uniformity of the lithium metal particles 13 is different due to the change of the deposition rate when depositing on the top, and the property of the electrode plate for the lithium secondary battery is expected to change due to the difference, the deposition rate is variously changed. Then, an experiment was performed to clarify the optimum deposition rate range.

In the above manufacturing method, the deposition rate of a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate is changed variously, and the active material layer made of the lithium metal-lithium compound composite material is changed. 11 is formed on the current collector 10 to prepare an electrode plate for a lithium secondary battery, and further, a glass cell for a lithium secondary battery using this electrode plate for a lithium secondary battery as a negative electrode plate is manufactured, and the capacity with respect to discharge current is produced. The changes were investigated.

As a result, the deposition rate of a large number of lithium metal particles 13 whose surfaces were covered with the lithium compound layer 12 containing lithium carbonate was increased from 0.1 μm / min to 10 μm.
It was confirmed that when the deposition rate was maintained at a constant rate of m / min, a decrease in the discharge capacity when the discharge current was increased was small, and a lithium secondary battery having excellent load current characteristics could be realized. When a large number of lithium metal particles 13 whose surface is covered with the lithium compound layer 12 containing lithium carbonate are deposited while maintaining the deposition rate within a range of 0.1 μm / min to 10 μm / min. In addition, since the uniformity of the lithium metal particles 13 is excellent, it is considered that an electrode plate for a lithium secondary battery having uniform characteristics is formed.

(Second Embodiment) FIG. 3 is a sectional view showing an electrode plate for a lithium secondary battery according to a second embodiment of the present invention. The same components as those of the electrode plate for a lithium secondary battery shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In the first embodiment, FIG.
When producing a lithium secondary battery glass cell using a lithium secondary battery electrode plate as a negative electrode plate as shown in the following, LiClO ₄ is used as a lithium salt dissolved in the electrolytic solution. In recent years, lithium salts containing fluorine in the composition, for example, L
iBF ₄ , LiPF ₆ , LiN (CF ₃ SO ₃ ) ₂ , L
iB (C ₆ H ₅ ) ₄ , LiAsF _{6 and the} like are often used.

It is expected that the state in which these lithium salts are present in the organic electrolyte is considerably complicated, and the mechanism is not necessarily clear, but is important in the first embodiment. When fluorine is contained as a composition element also in the lithium compound layer 12 that plays a role, the affinity with an electrolyte in which a lithium salt containing fluorine is dissolved is increased, and the like. It is empirically expected that a rapid diffusion rate of lithium ions can be obtained, and as a result, a battery having excellent discharge current characteristics can be realized.

Therefore, in the present embodiment, the first
In the embodiment, the lithium compound layer 15 contains fluorine. Accordingly, the electrode plate for a lithium secondary battery according to the present embodiment has a structure in which the active material layer 14 is formed on the current collector 10 made of a copper foil as shown in FIG. 14 is a lithium metal-lithium compound in which a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium fluoride in addition to lithium carbonate are compressed and densely packed without gaps. The feature of the present embodiment lies in that it is composed of a composite material.

Here, the current collector 10 made of a copper foil and the active material layer 1 made of a lithium metal-lithium compound composite material
4 has a total thickness of 80 μm, and the lithium compound layer 1 has a thickness of 80 μm.
5, the content of lithium carbonate was 80 wt%,
Further, the content of lithium fluoride is 20% by weight.

Next, a first method for manufacturing the electrode plate for a lithium secondary battery shown in FIG. 3 will be described with reference to FIG. Here, FIG. 4 is a schematic sectional view showing a processing apparatus for forming an active material layer 14 made of a lithium metal-lithium compound composite material on the current collector 10. The same components as those of the processing apparatus shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

This processing device, as shown in FIG.
Although it has substantially the same mechanism as the processing apparatus according to the first embodiment shown in FIG. 2 above, in addition to the cylinder 21 filled with CO ₂ gas and the MFC 22 for controlling the flow rate, F ₂ gas The cylinder 2 is provided with a filled cylinder 31 and an MFC 32 for controlling the flow rate thereof.
1, 31 to CO ₂ gas via MFCs 22 and 32
It is characterized in that a mixed gas to which _two gases are added is supplied into the processing chamber 20.

First, a lithium metal 25 as an evaporating substance is placed on a tantalum evaporation boat 26 in the processing chamber 20.
And a current collector 10 made of a copper foil having a thickness of 20 μm is fixed downward on the bottom surface of the current collector holding mechanism 28 so as to face the lithium metal 25 on the evaporation boat 26.

Subsequently, the MFC2 is supplied from the cylinders 21 and 31.
CO ₂ and F ₂ in the processing chamber 20 via
Is supplied. At this time, the flow rates of the mixed gas of CO ₂ and F ₂ are controlled by the MFCs 22 and 32, respectively, so that the mixing ratio of CO ₂ and F ₂ becomes 80:20, and the flow rate of the whole mixed gas becomes 10 sccm. The pressure in the processing chamber 20 is maintained at 13.3 mPa by the evacuation device 23 and the variable orifice 24.

Subsequently, power is supplied to the deposition boat 26 by the deposition power source 27, and the lithium metal 25 on the deposition boat 26 is turned on.
Is heated and evaporated. Then, the heated and evaporated lithium metal is reacted with CO ₂ gas and F ₂ gas as atmosphere gases, and the surface of the lithium metal particles 16 is covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride, A large number of lithium metal particles 16 whose surfaces are covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride are collected by the current collector 10.
Deposit on top.

At this time, the time of the open state of the shutter mechanism 29 is adjusted, and a large number of the lithium metal particles 16 whose surface is covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride are collected by the current collector 10. It is controlled so that the thickness deposited thereon, that is, the thickness of the deposited layer of the lithium metal-lithium compound composite material is 100 μm.

Next, the current collector 10 on which a large number of lithium metal particles 16 whose surface is covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride is deposited.
Is taken out of the processing chamber 20, and the total thickness of the current collector 10 and the deposited layer of the lithium metal-lithium compound composite material is reduced from 120 μm to 8 using a roll press device.
It is compressed until it becomes 0 μm, and it is in a state where it is densely filled without gaps. And punch this into a rectangle,
An electrode plate for a lithium secondary battery.

Thus, as shown in FIG. 3, in addition to lithium carbonate 80 wt%, lithium fluoride 20 wt%
% Of the lithium metal particles 16 whose surfaces are covered by the lithium compound layer 15 containing a lithium metal-containing compound material, and the active material layer 14 made of a lithium metal-lithium compound composite material densely packed without gaps is formed of a copper foil. An electrode plate for a lithium secondary battery having a thickness of 80 μm and formed on a current collector 10 made of is manufactured.

In the first manufacturing method, F ₂ gas is used as an atmosphere gas in order to make the lithium compound layer 15 contain lithium fluoride.
_{(2) Since the} gas shows severe corrosiveness to metals, it is necessary to manufacture manufacturing equipment using materials with excellent corrosion resistance.Because of its strong toxicity, high-sensitivity leak detection equipment and exhaust gas elimination Installation of facilities etc. is obliged,
There is a problem that it is a gas that is difficult to handle and significantly increases the cost of manufacturing equipment.

In order to avoid this problem, it is conceivable to use an inert gas containing a fluorine atom such as CF ₄ as the atmospheric gas. However, the first manufacturing method using the processing apparatus shown in FIG. In the method, whether lithium fluoride can be contained in the lithium compound layer 15 even if an inert gas containing a fluorine atom other than the F ₂ gas is used,
Even if it could be included, its amount was very small.

Thus, the present inventor conducted experiments on various methods. As a result, even when an inert gas such as CF ₄ was used as an atmosphere gas, lithium fluoride was used as the lithium compound layer 1.
As a method that can be favorably contained in No. 5, a second manufacturing method of an electrode plate for a lithium secondary battery using a plasma reaction described below has been conceived.

Next, a second method for manufacturing the electrode plate for a lithium secondary battery shown in FIG. 3 will be described with reference to FIG. Here, FIG. 5 is a schematic sectional view showing a plasma processing apparatus for forming an active material layer 14 made of a lithium metal-lithium compound composite material on the current collector 10. Note that FIG.
The same reference numerals are given to the same components as those of the processing device shown in FIG.

As shown in FIG. 5, the plasma processing apparatus has substantially the same mechanism as the processing apparatus used in the first manufacturing method shown in FIG. 4, but is filled with F ₂ gas. Cylinder 31 and MFC controlling its flow rate
Cylinder 33 filled with CF ₄ gas instead of 32
And a MFC 34 for controlling the flow rate thereof. A mixed gas obtained by adding CF ₄ gas to CO ₂ gas from the cylinders 21 and 33 via the MFCs 22 and 34 is provided in the processing chamber 20.
It is designed to be supplied inside. In addition to this, an induction coil 35 for generating a plasma region of the atmospheric gas between the deposition boat 26 and the current collector holding mechanism 28,
It is characterized in that an RF power supply 36 for supplying RF (high frequency) power of 13.56 MHz to the induction coil 35 is provided as a new mechanism.

First, in the same manner as in the first manufacturing method, the tantalum evaporation boat 2 in the processing chamber 20 is used.
A current collector made of a copper foil having a thickness of 20 μm is mounted on the bottom surface of a current collector holding mechanism 28, with a lithium metal 25 as an evaporating substance mounted on the vapor deposition boat 6 and facing the lithium metal 25 on the evaporation boat 26. Fix 10 downward.

Subsequently, the MFC2 is supplied from the cylinders 21 and 33.
CO ₂ and CF into the processing chamber 20 via
Supply the mixed gas of ₄ . At this time, CO ₂ gas and C
The flow rate of the F ₄ gas is controlled by the MFCs 22 and 34, respectively, so that the mixing ratio of CO ₂ and CF ₄ is 80:20, and the flow rate of the entire mixed gas is 10 sccm. The pressure in the processing chamber 20 is maintained at 133 mPa by the evacuation device 23 and the variable orifice 24.

Subsequently, the induction coil 35 is supplied from the RF power source 36.
Is supplied with RF power of 13.56 MHz to generate a plasma region of the atmospheric gas between the vapor deposition boat 26 and the current collector holding mechanism 28. In addition, power is supplied to the evaporation boat 26 by the evaporation power source 27 to heat and evaporate the lithium metal 25 on the evaporation boat 26. Then, the heated and evaporated lithium metal is reacted with plasma of CO ₂ and CF ₄ as atmosphere gas, and the surface of the lithium metal particles 16 is covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride, A large number of lithium metal particles 16 whose surfaces are covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride are deposited on the current collector 10.

At this time, the time of the open state of the shutter mechanism 29 is adjusted, and a large number of the lithium metal particles 16 whose surface is covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride are collected. It is controlled so that the thickness deposited thereon, that is, the thickness of the deposited layer of the lithium metal-lithium compound composite material is 100 μm.

Next, as in the case of the first manufacturing method, the current collector 10 on which a large number of lithium metal particles 16 whose surfaces are covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride is deposited. Is taken out of the processing chamber 20, and then, using a roll press device,
The entire thickness of the current collector 10 and the deposited layer of the lithium metal-lithium compound composite material is compressed from 120 μm to 80 μm so as to be densely packed without any gap. Then, this is punched into a rectangle to form an electrode plate for a lithium secondary battery.

Thus, even if an inert CF ₄ gas having no toxicity or flammability is used, as shown in FIG.
Lithium carbonate 80wt% and lithium fluoride 20wt%
A large number of the lithium metal particles 16 whose surfaces are covered by the lithium compound layer 15 containing is compressed, and the active material layer 14 made of the lithium metal-lithium compound composite material densely packed without gaps is made of copper foil. An electrode plate for a lithium secondary battery having a thickness of 80 μm formed on the current collector 10 is manufactured.

The cross section of the electrode plate for a lithium secondary battery manufactured by using the first and second manufacturing methods is indicated by X.
When examined by a line microanalyzer, in any case, no particular impurity layer was present at the interface between the lithium metal particles 16 and the lithium compound layer 15 containing lithium carbonate and lithium fluoride, and a favorable interface was observed. It was confirmed that it was formed.

Next, the characteristics of the electrode for a lithium secondary battery using the electrode plate for a lithium secondary battery according to the present embodiment will be described.

The electrode plate for a lithium secondary battery shown in FIG. 3 is used as a negative electrode plate, and is opposed to a positive electrode plate of the same size via a separator made of a polypropylene film having pores. As this positive electrode plate, LiC for lithium batteries is used.
Acetylene black and PTFE resin powder were mixed at 10 wt% each with oO ₂ powder, N-methylpyrrolidone was added and kneaded well, and then applied to a 20 μm-thick aluminum foil so that the thickness after drying was 200 μm. Dry,
Use what was pressed. As the electrolytic solution, a solution prepared by dissolving 1 mol / l of LiPF ₆ as a lithium salt in a 1: 1 mixed solvent of ethylene carbonate and dimethyl carbonate is used. Thus, a lithium secondary battery glass cell using the electrode plate for a lithium secondary battery according to the present embodiment as a negative electrode plate was produced.

Then, as in the case of the first embodiment, the lithium secondary battery glass cell was supplied with a current density of 1.5 mA / cm in a voltage range of 2.7 V to 4.2 V.
A charge / discharge current of ² was applied to perform a cycle test to measure the battery capacity. After the cycle test, the battery was decomposed and examined for the generation of dendrites. The following results were obtained.

That is, the lithium secondary battery glass cell using the lithium secondary battery electrode plate according to the present embodiment as a negative electrode plate is similar to the lithium secondary battery glass cell A in the first embodiment. It has been found that the battery has the same high capacity as the highest capacity lithium secondary battery glass cell using a lithium metal plate as the negative electrode plate, and that no dendrite is generated. In addition, since the electrodes were handled in a dry state, there was no difficulty in handling due to the electrodes being in a wet state, and it was confirmed that a normal battery assembly process could be applied.

Further, in the active material layer 14 made of the lithium metal-lithium compound composite material of the electrode plate for a lithium secondary battery according to the present embodiment, the lithium compound layer 15 covering the surface of the lithium metal particles 16 is made of lithium carbonate. In addition to containing lithium fluoride, the diffusion rate of lithium ions is more rapid due to an increase in the affinity with the electrolyte in which the lithium salt LiPF ₆ containing fluorine is dissolved, and the like. It is possible to obtain
Compared with the lithium secondary battery glass cell A in the first embodiment, the decrease in the discharge capacity when the discharge current was increased was smaller, and more excellent load current characteristics were realized.

In this embodiment, since LiPF ₆ is used as the lithium salt in the electrolyte, the electrolyte is more flame-retardant than the lithium secondary battery glass cell A in the first embodiment. As a result, the safety of the battery is improved.

The lithium salt in the electrolyte was LiP
Instead of F ₆ , for example, LiBF ₄ , LiN (CF ₃ S
Even when O ₃ ) ₂ , LiB (C ₆ H ₅ ) ₄ , LiAsF _6, or the like is used, the above-described effects can be similarly obtained.

Next, the optimum range of the particle size of the lithium metal particles 16 in the electrode plate for a lithium secondary battery according to the present embodiment will be described.

In the electrode plate for a lithium secondary battery shown in FIG. 3, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride are compressed to form gaps. The active material layer 14 is composed of a lithium metal-lithium compound composite material that is densely packed so that the characteristics of the lithium secondary battery electrode plate change due to the change in the particle size of the lithium metal particles 16. Therefore, an experiment was conducted to clarify the optimum range by changing the particle size of the lithium metal particles 16 in various ways.

In the first and second manufacturing methods described with reference to FIGS. 4 and 5, by changing various conditions at the time of heating and evaporating the lithium metal 25, the lithium metal containing lithium carbonate and lithium fluoride is changed. When a large number of lithium metal particles 16 whose surfaces are covered with the compound layer 15 are deposited on the current collector 10, the particle size of the lithium metal particles 16 can be variously changed.

That is, mainly, the pressure of the mixed gas of CO ₂ and CF ₄ , which is the atmosphere gas when heating and evaporating the lithium metal 25, the vapor deposition boat 26 on which the lithium metal 25 as the evaporating substance is mounted, and the current collector 10. The particle size of the lithium metal particles 16 can be changed in the range of 0.01 μm to 20 μm by changing the conditions of the distance from the current collector holding mechanism 28 that fixes the bottom surface portion and the temperature of the evaporation boat 26. did it.

In this range, electrode plates for lithium secondary batteries in which the particle diameters of the lithium metal particles 16 are variously different were produced, and further, the lithium secondary battery glass cells using the electrode plates for lithium secondary batteries as negative electrodes were prepared. Was fabricated, and the change in capacity with respect to the discharge current was investigated. As a result, when the particle size of the lithium metal particles 16 is in the range of 0.1 μm to 10 μm, the decrease in the discharge capacity when the discharge current is increased is smaller than when the discharge current is outside this range, and the load current characteristics It was confirmed that an excellent lithium secondary battery could be realized.

Next, the optimum range of the content of lithium carbonate and lithium fluoride in the lithium compound layer 15 in the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the electrode plate for a lithium secondary battery shown in FIG. 3, the content of lithium carbonate and lithium fluoride in the lithium compound layer 15 covering the surface of the lithium metal particles 16 is as follows: Although the content of lithium chloride was 20 wt%, changes in the content of lithium carbonate and lithium fluoride in the lithium compound layer 15 would change the characteristics of the electrode plate for a lithium secondary battery. Experiments were carried out to clarify the optimum ranges by changing the contents of lithium carbonate and lithium fluoride in various ways.

In the first and second manufacturing methods described with reference to FIGS. 4 and 5, by changing various conditions at the time of heating and evaporating the lithium metal 25, the lithium metal containing lithium carbonate and lithium fluoride is changed. It is possible to variously change the content of lithium carbonate and lithium fluoride in the lithium compound layer 15 when depositing a large number of the lithium metal particles 16 whose surfaces are covered with the compound layer 15 on the current collector 10. .

That is, mainly, the pressure of the mixed gas of CO ₂ and CF ₄ , which is the atmosphere gas when heating and evaporating the lithium metal 25, the evaporation boat 26 on which the lithium metal 25 as the evaporating substance is mounted and the current collector 10 The lithium carbonate content in the lithium compound layer 15 is adjusted to 0.5 wt. % To 95 wt%, and the content of lithium fluoride could be changed in the range of 0.5 wt% to 100 wt% of the portion of the lithium compound layer 15 excluding lithium carbonate.

In this range, electrode plates for lithium secondary batteries having various contents of lithium carbonate and lithium fluoride in the lithium compound layer 15 were prepared.
Further, a lithium secondary battery glass cell using the electrode plate for a lithium secondary battery as a negative electrode plate was manufactured, and a change in capacity with respect to a discharge current was investigated. As a result, lithium carbonate in the lithium compound layer 15 is 10 wt% to 90 wt%.
And the content of lithium fluoride is 10 wt% of the portion of the lithium compound layer 15 excluding lithium carbonate.
It is confirmed that when the content is within the range of 100 wt%, the decrease in discharge capacity when the discharge current is increased is smaller than that when the discharge current is outside this range, and a lithium secondary battery having excellent load current characteristics can be realized. Was.

Next, the optimum range of the thickness of the lithium compound layer 15 containing lithium carbonate and lithium fluoride in the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the electrode plate for a lithium secondary battery shown in FIG. 3, a large number of lithium metal particles 16 whose surfaces are covered by a lithium compound layer 15 containing lithium carbonate and lithium fluoride are compressed to form gaps. The active material layer 14 is composed of a lithium metal-lithium compound composite material that is densely packed so that the thickness of the lithium compound layer 15 changes, thereby changing the characteristics of the electrode plate for a lithium secondary battery. Therefore, an experiment was carried out to clarify the optimum range by changing the thickness of the lithium compound layer 15 in various ways.

In the first and second manufacturing methods described with reference to FIGS. 4 and 5, by changing various conditions at the time of heating and evaporating the lithium metal 25, the lithium metal containing lithium carbonate and lithium fluoride is changed. It is possible to variously change the thickness of the lithium compound layer 15 when depositing a large number of the lithium metal particles 16 whose surfaces are covered with the compound layer 15 on the current collector 10.

That is, the pressure of the mixed gas of CO ₂ and CF ₄ , which is the atmosphere gas when heating and evaporating the lithium metal 25, the evaporation boat 26 on which the lithium metal 25 as the evaporating substance is mounted, and the current collector 10 The thickness of the lithium compound layer 15 was able to be changed in the range of 10 nm to 1 μm by changing each condition of the distance from the current collector holding mechanism 28 for fixing the layer to the bottom portion and the temperature of the evaporation boat 26. .

Then, within this range, electrode plates for lithium secondary batteries having different thicknesses of the lithium compound layer 15 were prepared, and further, the lithium secondary battery glass cells using the electrode plates for lithium secondary batteries as negative electrode plates were prepared. Was fabricated, and the change in capacity with respect to the discharge current was investigated. As a result, the thickness of the lithium compound layer 15 is in the range of 10 nm to 100 nm, and is 1/1 times the particle size of the lithium metal particles 16.
It was confirmed that when the discharge current was 0 or less, the decrease in discharge capacity when the discharge current was increased was smaller than that when the discharge current was outside this range, and a lithium secondary battery having excellent load current characteristics could be realized.

Next, the types of atmospheric gases used for producing the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the first manufacturing method described with reference to FIG. 4, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride are formed on the current collector 10. A mixed gas of CO ₂ and F ₂ is used as an atmosphere gas to react with the evaporated lithium metal when depositing on the lithium metal particles.
Since the difference in the uniformity of No. 6 is observed and the change in the characteristics of the electrode plate for a lithium secondary battery is expected due to the difference, the type of the atmosphere gas is variously changed to clarify the optimum gas type. Was conducted.

Using various gases which can be used as atmospheric gases, the lithium gas is reacted with the evaporated lithium metal to form a lithium compound layer 1 containing lithium carbonate and lithium fluoride.
5 lithium metal particles 1 coated on the surface
An active material layer 14 made of a lithium metal-lithium compound composite material in which 6 is compressed is formed on the current collector 10 to produce an electrode plate for a lithium secondary battery. A lithium secondary battery glass cell used as a plate was produced, and a change in capacity with respect to a discharge current was investigated.

As a result, CO, C were used as atmosphere gases.
O ₂ , CH ₃ OH, C ₂ H ₅ (OH), (CH ₃ ) ₂ C
In the case of a gas obtained by adding F ₂ to a gas of any of O or a mixture of some of them, a decrease in discharge capacity when the discharge current is increased is small, and a lithium secondary gas having excellent load current characteristics is obtained. It was confirmed that a battery could be realized. When these gases are used as atmosphere gases, they react with the evaporated lithium metal to form a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride. It is considered that since the lithium metal particles 16 are excellent in uniformity when deposited on the electrode plate, an electrode plate for a lithium secondary battery having uniform characteristics is formed.

Also, in the second method for manufacturing the electrode plate for a lithium secondary battery described with reference to FIG. 5, a large number of the surfaces covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride are also provided. When depositing the lithium metal particles 16 on the current collector 10, a mixed gas of CO ₂ and CF ₄ is used as an atmosphere gas to react with the evaporated lithium metal. Similarly to the above, a change in the uniformity of the lithium metal particles 16 is observed due to the change in the type of the atmospheric gas, and a change in the characteristics of the electrode plate for the lithium secondary battery due to the difference is expected. Experiments were conducted to determine the optimal gas type with various changes.

That is, by using various gases that can be used as atmospheric gases, the plasma is reacted with the evaporated lithium metal, and the surface is coated with a lithium compound layer 15 containing lithium carbonate and lithium fluoride. The active material layer 14 made of the lithium metal-lithium compound composite material in which the lithium metal particles 16 of the
The electrode plate for a lithium secondary battery was formed by forming the electrode plate on a lithium secondary battery. Further, a glass cell for a lithium secondary battery using the electrode plate for a lithium secondary battery as a negative electrode plate was prepared, and a change in capacity with respect to a discharge current was investigated. .

As a result, CO, CO
₂ , CH ₃ OH, C ₂ H ₅ (OH), (CH ₃ ) ₂ CO
CF ₄ , CH 2
In the case of using any gas of F ₃ , C ₂ F ₆ or a mixed gas thereof, the above gas is used as He, H ₂ ,
In the case of using any gas of Ar, N ₂ , O ₂ or a gas diluted with a mixed gas thereof, CH ₄ , C ₂ H ₄
CF ₄ , CH 2
When a gas obtained by diluting any of F ₃ , C ₂ F ₆ or a mixed gas thereof with O ₂ is used, a decrease in discharge capacity when the discharge current is increased is small, and the load current characteristics It was confirmed that an excellent lithium secondary battery could be realized. When these gases are used as atmosphere gases, the plasma is reacted with the evaporated lithium metal to collect a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride. It is considered that since the lithium metal particles 16 are excellent in uniformity when deposited on the electric body 10, an electrode plate for a lithium secondary battery having uniform characteristics is formed.

Next, the pressure of the atmosphere gas used when producing the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the first manufacturing method described with reference to FIG. 4, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride are formed on the current collector 10. The pressure of the mixed gas of CO ₂ and F ₂ , which is the atmospheric gas to be reacted with the evaporated lithium metal when depositing on the
However, since the uniformity of the lithium metal particles 16 is changed due to a change in the pressure of the atmosphere gas, and a change in the characteristics of the electrode plate for a lithium secondary battery due to the difference is expected, the atmosphere gas is maintained. Experiments were carried out to clarify the optimum range of the gas pressure by changing the pressure in various ways.

A mixed gas of CO ₂ and F ₂ was used as an atmospheric gas, reacted with the lithium metal evaporated under various pressures, and a large number of lithiums whose surfaces were covered with the lithium compound layer 15 containing lithium carbonate were used. An active material layer 14 made of a lithium metal-lithium compound composite material in which metal particles 16 are compressed is formed on the current collector 10 to produce an electrode plate for a lithium secondary battery. Was fabricated as a negative electrode plate, and a change in capacity with respect to discharge current was investigated.

As a result, the atmosphere gases CO ₂ and F ₂
Pressure of the mixed gas with 1.33 mPa to 0.133 P
It was confirmed that, when the discharge current was within the range of a, a decrease in the discharge capacity when the discharge current was increased was small, and a lithium secondary battery having excellent load current characteristics could be realized. When the pressure of the mixed gas of CO ₂ and F ₂ is in the range of 1.33 mPa to 0.133 Pa, a large number of lithium metal particles whose surfaces are covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride It is considered that when depositing 16 on the current collector 10, the uniformity of the lithium metal particles 16 is excellent, so that an electrode plate for a lithium secondary battery having uniform characteristics is formed.

Furthermore, instead of a mixed gas of CO ₂ and F ₂ , CO, CO ₂ , CH ₃ OH, C ₂
H ₅ (OH), using (CH _{3) 2} CO either gas or gas plus F ₂ to these gases mixed with several (except a mixed gas of CO ₂ and F ₂₎ In a similar experiment, the same result as that obtained when a mixed gas of CO ₂ and F ₂ was used was obtained.

In the second manufacturing method described with reference to FIG. 5, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride are collected by a current collector. The pressure of a mixed gas of CO ₂ and CF ₄ , which is an atmosphere gas for reacting with the evaporated lithium metal when depositing on the metal 10, is 133 m.
Although the pressure was maintained at Pa, an experiment was performed to clarify the optimum range of the gas pressure by changing the pressure of the atmosphere gas in various ways as in the case of the first manufacturing method.

Using a mixed gas of CO ₂ and CF ₄ as an atmosphere gas, it is reacted with lithium metal evaporated under various pressures, and a large number of lithium particles whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate. An active material layer 14 made of a lithium metal-lithium compound composite material in which metal particles 16 are compressed is formed on the current collector 10 to produce an electrode plate for a lithium secondary battery. Was fabricated as a negative electrode plate, and a change in capacity with respect to discharge current was investigated.

As a result, the atmosphere gases CO ₂ and CF
₄ and the pressure of the mixed gas is 13.3 mPa to 13.3 P
It was confirmed that, when the discharge current was within the range of a, a decrease in the discharge capacity when the discharge current was increased was small, and a lithium secondary battery having excellent load current characteristics could be realized. CO ₂ and CF ₄
When the pressure of the gas mixture containing the lithium metal particles is in the range of 13.3 mPa to 13.3 Pa, a large number of lithium metal particles 16 whose surfaces are covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride are collected by the current collector. It is considered that since the lithium metal particles 16 are excellent in uniformity when deposited on the electrode 10, an electrode plate for a lithium secondary battery having uniform characteristics is formed.

Further, instead of a mixed gas of CO ₂ and CF ₄ , a mixed gas of CO ₂ and CF ₄ is used as an atmosphere gas, either He, H ₂ , Ar, N ₂ , O ₂ or When a similar experiment was performed using a gas diluted with these mixed gases, CO, CO ₂ , CH ₃ OH, C _{2
H 5 (OH), (CH} 3) 2 in any of the gas or mixed gas thereof of CO CF _4, CHF _3, or the gas or gas plus a mixed gas of C ₂ F ₆ (however, (Except for a mixed gas of CO ₂ and CF ₄ ), or the same gas was used as He,
When a similar experiment is performed using any gas of H ₂ , Ar, N ₂ , or O ₂ or a gas diluted with a mixed gas thereof, any one of CH ₄ , C ₂ H ₄ , or any of these gases is used. Even when a similar experiment was performed using a gas obtained by diluting a mixed gas of any one of CF ₄ , CHF ₃ , and C ₂ F ₆ or a gas obtained by adding a mixed gas thereof with O ₂ , CO ₂ and CO ₂ were mixed. The same results as in the case of using a mixed gas with CF ₄ were obtained.

Next, the temperature of the current collector 10 used when manufacturing the electrode plate for a lithium secondary battery according to this embodiment will be described.

In the first and second manufacturing methods described with reference to FIGS. 4 and 5, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride are provided. Current collector 10
A change in the uniformity of the lithium metal particles 16 is observed due to a change in the temperature of the current collector 10 when it is deposited thereon, and a change in the characteristics of the electrode plate for a lithium secondary battery due to the difference is expected. Experiments were performed to determine the optimal temperature range of the current collector 10 by changing the temperature of the body 10 in various ways.

In the first and second manufacturing methods, the temperature of the current collector 10 is changed variously, and the surface of the current collector 10 is covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride. An active material layer 14 made of a lithium metal-lithium compound composite material in which a large number of the lithium metal particles 16 are compressed is formed to produce an electrode plate for a lithium secondary battery. A lithium secondary battery glass cell used as a negative electrode plate was manufactured, and a change in capacity with respect to a discharge current was investigated.

As a result, in any case, when the temperature of the current collector 10 is maintained at a constant temperature between -50 ° C. and -10 ° C., the discharge capacity decreases when the discharge current increases. It has been confirmed that a lithium secondary battery having small load current characteristics and excellent load current characteristics can be realized. -50 ° C
A large number of lithium metal particles 16 whose surfaces are covered by a lithium compound layer 15 containing lithium carbonate and lithium fluoride are deposited on a current collector 10 maintained at a constant temperature within a temperature range of -10 ° C. It is considered that since the uniformity of the lithium metal particles 16 is excellent, an electrode plate for a lithium secondary battery having uniform characteristics is formed.

Next, when preparing the electrode plate for a lithium secondary battery according to the present embodiment, on the current collector 10 of a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate. Next, the deposition rate on the substrate is described.

In the first and second manufacturing methods described with reference to FIGS. 4 and 5, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride are provided. Current collector 10
Since the uniformity of the lithium metal particles 16 is different due to the change of the deposition rate when depositing on the top, and the change of the characteristics of the electrode plate for the lithium secondary battery due to the difference is expected, the deposition rate is variously changed. Then, an experiment was performed to clarify the optimum deposition rate range.

In the first and second manufacturing methods, the deposition rate of a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate and lithium fluoride is changed variously, −
An active material layer 14 made of a lithium compound composite material is formed on the current collector 10 to produce an electrode plate for a lithium secondary battery,
Further, a lithium secondary battery glass cell using the electrode plate for a lithium secondary battery as a negative electrode plate was manufactured, and a change in capacity with respect to a discharge current was investigated.

As a result, in any case, the deposition rate of a large number of lithium metal particles 16 whose surfaces were covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride was increased from 0.1 μm / min to 10 μm / min. It was confirmed that when the deposition rate was maintained at a constant rate, the decrease in discharge capacity when the discharge current was increased was small, and a lithium secondary battery having excellent load current characteristics could be realized. While maintaining a constant deposition rate within this deposition rate range of 0.1 μm / min to 10 μm / min, a large number of lithium metal particles 16 whose surfaces are covered with the lithium compound layer 15 containing lithium carbonate and lithium fluoride. It is presumed that the excellent uniformity of the lithium metal particles 16 when depositing the lithium secondary battery leads to the formation of an electrode plate for a lithium secondary battery having uniform characteristics.

Next, a description will be given of the power supplied for generating plasma when the electrode plate for a lithium secondary battery according to this embodiment is manufactured.

According to the second manufacturing method described with reference to FIG.
RF plasma power of 56 MHz is supplied to generate a plasma region of the atmosphere gas, and the plasma of the atmosphere gas is reacted with the evaporated lithium metal, and the surface is coated with a lithium compound layer 15 containing lithium carbonate and lithium fluoride. Many lithium metal particles 16 are deposited on the current collector 10, but the power density supplied for plasma generation at this time changes, so that the lithium metal particles 1
6, a change in the characteristics of the electrode plate for a lithium secondary battery is expected, and thus the power density supplied for plasma generation is variously changed, and the optimum power density is obtained. An experiment was performed to determine the range.

In the second manufacturing method, the RF power source 3
6 to form an active material layer 14 made of a lithium metal-lithium compound composite material on the current collector 10 by changing the power density when the RF power is supplied to the induction coil 35 to generate the plasma of the atmospheric gas. Thus, an electrode plate for a lithium secondary battery was produced, and a glass cell for a lithium secondary battery using the electrode plate for a lithium secondary battery as a negative electrode plate was produced, and a change in capacity with respect to a discharge current was investigated.

[0169] As a result, RF as the power density supplied to the plasma generation becomes constant power density of between 0.1 W / cm ² of 2W / cm ² with respect to the area of the deposition region
It has been confirmed that when power is supplied, a decrease in the discharge capacity when the discharge current is increased is small, and a lithium secondary battery having excellent load current characteristics can be realized. This 0.1W /
An RF power is supplied so as to have a constant power density within a power density range of ² cm ^{2 to 2} W / cm ² to generate a plasma region of the atmospheric gas, and the lithium compound layer 15 containing lithium carbonate and lithium fluoride generates the plasma region. It is considered that when depositing a large number of lithium metal particles 16 whose surface is coated, the uniformity of the lithium metal particles 16 is excellent, so that an electrode plate for a lithium secondary battery having uniform characteristics is formed. Can be

In the first embodiment, a large number of lithium metal particles 16 whose surfaces are covered with a lithium compound layer 15 containing lithium carbonate are collected using the processing apparatus shown in FIG. In the second embodiment, the lithium compound layer containing lithium carbonate and lithium fluoride is deposited using the processing apparatus shown in FIG. 4 or the plasma processing apparatus shown in FIG. Although a large number of lithium metal particles 16 whose surfaces are covered with 15 are deposited on the current collector 10, a plasma processing apparatus similar to the plasma processing apparatus shown in FIG. A large number of lithium metal particles 16 whose surface is covered with a lithium compound layer 15 containing lithium carbonate may be deposited on the current collector 10 by using It is a function.

The atmosphere gas used in this case is C
O, CO ₂ , CH ₃ OH, C ₂ H ₅ (OH), (C
It is preferable to use any gas of H ₃ ) ₂ CO or a mixed gas thereof, and to use this gas as He, H ₂ , A
It is preferable that the gas be any of r, N ₂ , and O ₂ or a gas diluted with a mixed gas thereof.
It is preferable that the gas be a gas obtained by diluting any of C ₄ and C ₂ H ₄ or a mixed gas thereof with O ₂ .

Other conditions such as the particle size of lithium metal particles, the content of lithium carbonate in the lithium compound layer, the thickness of the lithium compound layer containing lithium carbonate,
The pressure of the atmospheric gas, the temperature and the deposition rate of the current collector when depositing a large number of lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate on the current collector are respectively the same as those in the first embodiment. In this case, the power density to be supplied for generating the plasma of the atmospheric gas is the same as that in the second manufacturing method of the second embodiment.

Further, in the first and second embodiments, the evaporated lithium metal particles and the atmosphere gas or the atmosphere gas using the processing apparatus or the plasma processing apparatus shown in FIG. 2, FIG. 4, or FIG. Although the plasma is reacted, instead of such evaporation of the lithium metal particles, the lithium metal particles may be sprayed, and the sprayed lithium metal particles may react with the atmosphere gas or the plasma. . Also in this case, similarly to the first and second embodiments, a large number of lithium metal particles whose surfaces are covered with lithium carbonate or a lithium compound layer containing lithium carbonate and lithium fluoride are used as a current collector. An active material layer deposited on and formed of a lithium metal-lithium compound composite material can be formed.

[0174]

As described above, according to the electrode plate for a secondary battery and the method of manufacturing the same according to the present invention, the following effects can be obtained.

That is, according to the electrode plate for a secondary battery according to the first aspect, a lithium metal-lithium compound composite formed by compressing a large number of lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate. By using the material as an active material, a novel lithium ion transport function is realized by a composite material of lithium and a lithium compound, and the shape of the electrode plate is held by a three-dimensional network-like skeleton of a lithium compound layer. Therefore, in most combinations of the positive electrode material and the electrolytic solution that can be used for a lithium secondary battery, it is possible to realize a battery that suppresses generation of dendrites and performs a favorable charge / discharge operation. Further, since the electrode is handled in a dry state, it is possible to obtain an electrode having no difficulty in handling.

According to the electrode plate for a secondary battery according to the second aspect, since the lithium compound layer contains lithium fluoride in addition to lithium carbonate, it is possible to favorably suppress the generation of dendrite. In addition, when the lithium salt contained in the electrolyte contains fluorine as its composition, the affinity between the lithium compound layer containing lithium fluoride and the electrolyte increases, so that the lithium ions more rapidly form lithium ions. Since the diffusion speed can be obtained, the discharge current characteristics can be further improved as compared with the case where the electrode plate for a secondary battery according to claim 2 is used.

According to the electrode plate for a secondary battery according to the third aspect, the content of lithium carbonate in the lithium compound layer is not less than 10% by weight and not more than 90% by weight of the lithium compound layer, thereby constituting an active material. Since the content of lithium carbonate in the entire lithium metal-lithium compound composite material is small, the energy density of the electrode is not reduced unlike aluminum in a conventional lithium aluminum alloy, and the lithium metal electrode having the highest capacity is used. The same high capacity as in the case of can be realized.

According to the electrode plate for a secondary battery according to claim 4, the content of lithium carbonate in the lithium compound layer is not less than 10 wt% and not more than 90 wt% of the lithium compound layer, and the content of lithium fluoride is not more than 10 wt%. 10 wt% or more and 100 w of the portion where lithium carbonate is removed from the lithium compound layer
When the content is not more than t%, the content of lithium carbonate in the entire lithium metal-lithium compound composite material constituting the active material is small, so that the energy density of the electrode is reduced as in aluminum in a conventional lithium aluminum alloy. This is not required, and the same high capacity as that of the lithium metal electrode having the highest capacity can be realized.

Further, according to the electrode plate for a secondary battery according to claim 5, the particle diameter of the lithium metal particles is 0.1 μm to 10 μm.
By being within the range of m, a decrease in the discharge capacity when the discharge current is increased is relatively small, and a lithium secondary battery having excellent load current characteristics can be realized.

According to the electrode plate for a secondary battery according to claim 6, the lithium compound layer has a thickness of 10 nm to 100 n.
m, and 1 / the particle size of the lithium metal particles.
When it is 10 or less, a decrease in discharge capacity when the discharge current is increased is relatively small, and a lithium secondary battery having excellent load current characteristics can be realized.

According to the method for manufacturing an electrode plate for a secondary battery according to claim 7, the evaporated or sprayed lithium metal is reacted with a predetermined atmospheric gas, and the surface is covered with a lithium compound layer containing lithium carbonate. After depositing a large number of lithium metal particles on the current collector, the large number of lithium metal particles deposited on the current collector are compressed to form a lithium metal-lithium compound composite material as an active material. Since the lithium metal and the lithium compound layer are sufficiently bonded to each other and a boundary layer that prevents the transport of lithium ions is not formed at the interface, lithium ions are easily transported from the lithium metal through the lithium compound layer. The electrode plate for a secondary battery according to claim 1 having a lithium ion transport function can be realized.

According to the method of manufacturing an electrode plate for a secondary battery according to claim 8, the evaporated or sprayed lithium metal is reacted with a predetermined atmospheric gas to form a lithium compound layer containing lithium carbonate and lithium fluoride. After depositing a large number of lithium metal particles whose surface is covered by the current collector,
By compressing a large number of lithium metal particles deposited on the current collector to form a lithium metal-lithium compound composite material as an active material, the lithium metal and the lithium compound layer are sufficiently bonded, 3. The secondary battery according to claim 2, which has a lithium ion transport function in which a lithium ion is easily transported from lithium metal through a lithium compound layer because no boundary layer is formed to hinder the transport of lithium ions. An electrode plate for a battery can be realized.

Further, according to the method for manufacturing an electrode plate for a secondary battery according to the ninth aspect, lithium metal is evaporated or sprayed to react with plasma of a predetermined atmospheric gas, and the lithium metal layer is formed by a lithium compound layer containing lithium carbonate. By depositing the lithium metal particles coated on the surface on the current collector, the lithium metal and the lithium compound layer are sufficiently bonded and a boundary layer that prevents the transport of lithium ions is not formed at the interface. In addition, the electrode plate for a secondary battery according to claim 1 having a lithium ion transport function in which lithium ions are easily transported from lithium metal through a lithium compound layer can be realized.

Further, according to the method for manufacturing an electrode plate for a secondary battery according to the tenth aspect, lithium metal is evaporated or sprayed to react with a plasma of a predetermined atmospheric gas to contain lithium carbonate and lithium fluoride. By depositing lithium metal particles whose surface is covered with a lithium compound layer on a current collector, even when an inert gas is used as an atmosphere gas for ensuring safety, etc., the lithium metal and lithium compound layer Do not form a boundary layer at the interface that hinders the transport of lithium ions, and thus has a lithium ion transport function in which lithium ions are easily transported from lithium metal through the lithium compound layer. Further, the electrode plate for a secondary battery according to claim 2 can be realized.

According to the method for manufacturing an electrode plate for a secondary battery according to claim 11, in the method for manufacturing an electrode plate for a secondary battery according to claim 7, the lithium metal particles are reacted with lithium metal to form lithium metal particles. CO, as an atmosphere gas for forming a lithium compound layer containing lithium carbonate on the surface,
CO ₂ , CH ₃ OH, C ₂ H ₅ (OH) or (CH
₃ ) By using ₂ CO or a mixed gas of these,
Lithium metal particles with excellent uniformity are formed, and the decrease in discharge capacity when the discharge current is increased is relatively small,
A lithium secondary battery having excellent load current characteristics can be realized. The electrode plate for a secondary battery according to claim 1 can be realized.

According to the method for manufacturing an electrode plate for a secondary battery according to claim 12, in the method for manufacturing an electrode plate for a secondary battery according to claim 8, the lithium metal particles are reacted with lithium metal to form lithium metal particles. CO, CO ₂ , CH ₃ OH, C ₂ H ₅ (O ₂₎ are used as atmosphere gases for forming a lithium compound layer containing lithium carbonate and lithium fluoride on the surface.
By using H) or (CH ₃ ) ₂ CO or a gas obtained by adding F ₂ to a mixed gas thereof, lithium metal particles having excellent uniformity are formed, and a decrease in discharge capacity when the discharge current is increased is prevented. A lithium secondary battery which is relatively small and has excellent load current characteristics can be realized.

According to the method for manufacturing an electrode plate for a secondary battery according to the thirteenth aspect, in the method for manufacturing an electrode plate for a secondary battery according to the ninth aspect, the lithium metal is reacted with lithium metal in a plasma. CO, CO ₂ , CH ₃ OH, C ₂ H ₅ (O ₂₎ are used as atmosphere gases for forming a lithium compound layer containing lithium carbonate on the surface of the particles.
H) or (CH ₃ ) ₂ CO or a mixed gas thereof, or a gas obtained by diluting this gas with He, H ₂ , Ar, N ₂ or O ₂ or a mixed gas thereof;
Alternatively, by using CH ₄ or C ₂ H ₄ or a gas obtained by diluting a mixed gas thereof with O ₂ , lithium metal particles having excellent uniformity are formed, and a decrease in discharge capacity when the discharge current is increased is relatively reduced. Thus, it is possible to realize a lithium secondary battery that is small in size and has excellent load current characteristics.

According to the method for manufacturing an electrode plate for a secondary battery according to the fourteenth aspect, in the method for manufacturing an electrode plate for a secondary battery according to the tenth aspect, the lithium metal is reacted with lithium metal in the plasma. CO, CO ₂ , CH ₃ OH, C ₂ H are used as atmosphere gases for forming a lithium compound layer containing lithium carbonate on the surface of the metal particles.
₅ (OH) or (CH ₃ ) ₂ CO, or a mixed gas thereof, to which CF ₄ , CHF _3, C ₂ F _6, or a mixed gas thereof is added, or a gas containing He, H ₂ , Ar, N ₂ or O ₂ or a gas diluted with a mixed gas thereof, or CH ₄ or C ₂
By using H ₄ or a gas obtained by adding CF ₄ , CHF ₃ or C ₂ F ₆ or a mixed gas thereof to a mixed gas thereof with O ₂ , lithium metal particles having excellent uniformity can be formed. In addition, a decrease in discharge capacity when the discharge current is increased is relatively small, and a lithium secondary battery having excellent load current characteristics can be realized.

According to the method for manufacturing an electrode plate for a secondary battery according to claim 15, in the method for manufacturing an electrode plate for a secondary battery according to claim 7 or 8, the atmosphere gas to be reacted with the lithium metal may be used. Pressure is 1.33mPa ~ 0.133P
By being within the range of a, lithium metal particles having excellent uniformity are formed, and the decrease in discharge capacity when the discharge current is increased is relatively small, so that a lithium secondary battery having excellent load current characteristics can be obtained. Can be realized.

According to the method of manufacturing an electrode plate for a secondary battery according to claim 16, in the method of manufacturing an electrode plate for a secondary battery according to claim 9 or 10, the atmosphere gas to be reacted with lithium metal may be used. Pressure is 13.3mPa ~ 13.3P
By being within the range of a, lithium metal particles having excellent uniformity are formed, and the decrease in discharge capacity when the discharge current is increased is relatively small, so that a lithium secondary battery having excellent load current characteristics can be obtained. Can be realized.

According to the method for manufacturing an electrode plate for a secondary battery according to claim 17, in the method for manufacturing an electrode plate for a secondary battery according to any one of claims 7 to 10, the lithium compound layer is used to cover the surface. The temperature of the current collector when depositing the lithium metal particles coated with on the current collector is −50 ° C. to −10 ° C.
, Lithium metal particles with excellent uniformity are formed, the decrease in discharge capacity when the discharge current is increased is relatively small, and lithium secondary particles with excellent load current characteristics are obtained. A battery can be realized.

According to the method for producing an electrode plate for a secondary battery according to claim 18, in the method for producing an electrode plate for a secondary battery according to any one of claims 7 to 10, the lithium compound layer is used to cover the surface. The deposition rate when depositing the lithium metal particles coated on the current collector is 0.1 μm / min to 10 μm.
Within the range of m / min, lithium metal particles having excellent uniformity are formed, the decrease in discharge capacity when the discharge current is increased is relatively small, and the lithium secondary particles having excellent load current characteristics are obtained. A battery can be realized.

According to the method of manufacturing an electrode plate for a secondary battery according to claim 18, in the method of manufacturing an electrode plate for a secondary battery according to claim 9 or 10, the discharge chamber is excited by discharge in the processing chamber. lithium metal power density supplied to the plasma generation in providing the plasma region by in the range of 0.1W / cm ² ~2W / cm ² of the area of the deposition region, with excellent uniformity was Particles are formed,
The decrease in the discharge capacity when the discharge current is increased is relatively small, and a lithium secondary battery having excellent load current characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electrode plate for a lithium secondary battery according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a processing apparatus for forming an active material layer made of a lithium metal-lithium compound composite material on a current collector in the method of manufacturing the electrode plate for a lithium secondary battery shown in FIG. is there.

FIG. 3 is a sectional view showing an electrode plate for a lithium secondary battery according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a processing apparatus for forming an active material layer made of a lithium metal-lithium compound composite material on a current collector in the first method for manufacturing the electrode plate for a lithium secondary battery shown in FIG. It is sectional drawing.

FIG. 4 shows a plasma processing apparatus for forming an active material layer made of a lithium metal-lithium compound composite material on a current collector in the second method of manufacturing the electrode plate for a lithium secondary battery shown in FIG. It is an outline sectional view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Current collector 11 Active material layer 12 Lithium compound layer containing lithium carbonate 13 Lithium metal particle 14 Active material layer 15 Lithium compound layer containing lithium carbonate and lithium fluoride 16 Lithium metal particle 20 Processing chamber 21 CO ₂ gas filled cylinder 22 MFC 23 evacuator 24 the variable orifice 25 lithium metal 26 deposited boat 27 deposition source 28 as the vapor material current collector holding mechanism 29 shutter mechanism 31 F ₂ cylinder 32 MFC 33 CF ₄ gas-filled Gas filled cylinder 34 MFC 35 Induction coil 36 RF power supply

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[Procedure amendment]

[Submission date] December 2, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electrode plate for a lithium secondary battery according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a processing apparatus for forming an active material layer made of a lithium metal-lithium compound composite material on a current collector in the method of manufacturing the electrode plate for a lithium secondary battery shown in FIG. is there.

FIG. 3 is a sectional view showing an electrode plate for a lithium secondary battery according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a processing apparatus for forming an active material layer made of a lithium metal-lithium compound composite material on a current collector in the first method for manufacturing the electrode plate for a lithium secondary battery shown in FIG. It is sectional drawing.

5 shows a plasma processing apparatus for forming an active material layer made of a lithium metal-lithium compound composite material on a current collector in the second method for manufacturing the electrode plate for a lithium secondary battery shown in FIG . It is an outline sectional view.

DESCRIPTION OF SYMBOLS 10 Current collector 11 Active material layer 12 Lithium compound layer containing lithium carbonate 13 Lithium metal particle 14 Active material layer 15 Lithium compound layer containing lithium carbonate and lithium fluoride 16 Lithium metal particle 20 Processing chamber Reference Signs List 21 Cylinder filled with CO ₂ gas 22 MFC 23 Vacuum exhaust device 24 Variable orifice 25 Lithium metal as evaporating substance 26 Deposition boat 27 Power supply for vapor deposition 28 Current collector holding mechanism 29 Shutter mechanism 31 Cylinder filled with F ₂ gas 32 MFC 33 Cylinder filled with CF ₄ gas 34 MFC 35 Induction coil 36 RF power supply

Claims (19)

[Claims] An active material comprising a lithium metal-lithium compound composite material obtained by compressing a large number of lithium metal particles whose surface is covered with a lithium compound layer containing lithium carbonate. Electrode plate. 2. The electrode plate for a secondary battery according to claim 1, wherein the lithium compound layer contains lithium fluoride in addition to the lithium carbonate. 3. The electrode plate for a secondary battery according to claim 1, wherein the content of the lithium carbonate in the lithium compound layer is 10% by weight or more and 90% by weight or less of the lithium compound layer. Electrode plate for secondary batteries. 4. The electrode plate for a secondary battery according to claim 2, wherein the content of the lithium carbonate in the lithium compound layer is 10% by weight or more and 90% by weight or less of the lithium compound layer. The electrode plate for a secondary battery, wherein a content of the lithium fluoride in the layer is 10% by weight or more and 100% by weight or less of a portion of the lithium compound layer excluding the lithium carbonate. 5. The electrode plate for a secondary battery according to claim 1, wherein the lithium metal particles have a particle size of 0.1 μm to 10 μm.
m, the electrode plate for a secondary battery. 6. The electrode plate for a secondary battery according to claim 1, wherein the thickness of the lithium compound layer is 10 nm to 100 n.
m, and not more than 1/10 of the particle size of the lithium metal particles. 7. In a processing chamber, lithium metal is evaporated or sprayed to react with a predetermined atmospheric gas, and a large number of lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate are formed on a current collector. A first step of depositing, and a second step of compressing the large number of lithium metal particles deposited on the current collector to form a lithium metal-lithium compound composite material as an active material on the current collector And a method for producing an electrode plate for a secondary battery. 8. The method for manufacturing an electrode plate for a secondary battery according to claim 7, wherein in the first step, lithium metal is evaporated or sprayed in the processing chamber to react with a predetermined atmospheric gas.
A method for producing an electrode plate for a secondary battery, comprising a step of depositing, on a current collector, lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate and lithium fluoride. 9. The method for manufacturing an electrode plate for a secondary battery according to claim 7, wherein in the first step, a plasma region excited by discharge is provided in the processing chamber to vaporize or spray lithium metal. To react with the plasma of the specified atmosphere gas,
A method for producing an electrode plate for a secondary battery, comprising a step of depositing, on a current collector, lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate. 10. The method for manufacturing an electrode plate for a secondary battery according to claim 7, wherein in the first step, a plasma region excited by discharge is provided in the processing chamber to vaporize or spray lithium metal. To react with the plasma of the specified atmosphere gas,
A method for producing an electrode plate for a secondary battery, comprising a step of depositing, on a current collector, lithium metal particles whose surfaces are covered with a lithium compound layer containing lithium carbonate and lithium fluoride. 11. The method for manufacturing an electrode plate for a secondary battery according to claim 7, wherein the atmosphere gas is CO, CO ₂ , CH ₃ OH, C ₂ H.
_{5 A} method for producing an electrode plate for a secondary battery, comprising (OH), (CH ₃ ) ₂ CO, or a mixed gas thereof. 12. The method for manufacturing an electrode plate for a secondary battery according to claim 8, wherein the atmosphere gas is CO, CO ₂ , CH ₃ OH, C ₂ H.
_{5 A} method for producing an electrode plate for a secondary battery, characterized in that the gas is (OH), (CH ₃ ) ₂ CO, or a mixed gas thereof with F ₂ added thereto. 13. The method for producing an electrode plate for a secondary battery according to claim 9, wherein the atmosphere gas is CO, CO ₂ , CH ₃ OH, C ₂ H.
₅ (OH), or (CH ₃ ) ₂ CO, or a mixed gas thereof, or this gas as He, H ₂ , Ar,
An electrode for a secondary battery, wherein the electrode is a gas diluted with N ₂ , O ₂ , or a mixed gas thereof, or a gas obtained by diluting CH _4, C ₂ H ₄ , or a mixed gas thereof with O _2. Plate manufacturing method. 14. The method for manufacturing an electrode plate for a secondary battery according to claim 10, wherein the atmosphere gas is CO, CO ₂ , CH ₃ OH, C ₂ H.
₅ (OH), or (CH ₃ ) ₂ CO, or a mixed gas of them with CF ₄ , CHF ₃ , or C
₂ F ₆ , a gas to which a mixed gas thereof is added, or a gas obtained by diluting this gas with He, H ₂ , Ar, N ₂ , or O ₂ , or a mixed gas thereof;
Or a gas obtained by diluting CF ₄ , CHF ₃ , C ₂ F ₆ , or a mixed gas thereof to CH ₄ or C ₂ H ₄ , or a mixed gas thereof, with O _2. Of producing an electrode plate for a secondary battery. 15. The method for producing an electrode plate for a secondary battery according to claim 7, wherein the pressure of the atmosphere gas is 1.33 mPa to 0.13 m.
A method for producing an electrode plate for a secondary battery, which is in a range of 3 Pa. 16. The method for manufacturing an electrode plate for a secondary battery according to claim 9, wherein the pressure of the atmosphere gas is from 13.3 mPa to 13.3.
A method for producing an electrode plate for a secondary battery, wherein the electrode plate is within a range of Pa. 17. The method for manufacturing an electrode plate for a secondary battery according to claim 7, wherein the lithium metal particles whose surfaces are covered with the lithium compound layer are deposited on the current collector. Wherein the temperature of the current collector is maintained in a range of -50 ° C to -10 ° C. 18. The method for manufacturing an electrode plate for a secondary battery according to claim 7, wherein the lithium metal particles whose surfaces are covered with the lithium compound layer are deposited on the current collector. Wherein the deposition rate is in the range of 0.1 μm / min to 10 μm / min. 19. The method for manufacturing an electrode plate for a secondary battery according to claim 9, wherein a power density supplied when providing a plasma region excited by discharge in the processing chamber is equal to an area of a deposition region. method of manufacturing a secondary battery electrode plate, characterized in that in the range of 0.1 W / cm ² to 2W / cm ² relative.