JP2003007305A - Electrode for secondary lithium battery and secondary lithium battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrode made by stacking on the current collector an active thin films which can electrochemically or chemically occulude and release lithium for a secondary lithium battery, which can restrain deformation such as wrinkles, etc., on the current collector by charging and discharging, and can increase energy density per volume of the battery. SOLUTION: It is featured in that the current collector comprises a copper alloy and has tensile strength of 400 N/mm<2> or more, proportional limit of 160 N/mm<2> or less, elastic coefficient of 1.1 N/mm<2> or more, and surface roughness Ra of 0.01-1 μm for a face of the current collector forming the active material thin film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrode for a lithium secondary battery and a lithium secondary battery using the same.

[0002]

2. Description of the Related Art In recent years, lithium secondary batteries have been actively developed. In the lithium secondary battery, battery characteristics such as charge / discharge voltage, charge / discharge cycle life characteristics, and storage characteristics greatly depend on the electrode active material used.

When lithium is used as the negative electrode active material, a battery having a high energy density per weight and volume can be constructed, but there is a problem that lithium is deposited in dendrite form during charging and causes an internal short circuit. (Solid State Ionics, 113-115, p57 (1998)).

On the other hand, a lithium secondary battery using aluminum, silicon, tin, etc., which is electrochemically alloyed with lithium during charging, as a negative electrode active material has been reported (JP-A-10-255768). .

However, these active materials that occlude lithium by alloying expand and contract in volume by occluding and releasing lithium, so that the active material is pulverized with charge and discharge, or the active material is Peel off the current collector. Therefore, there is a problem that good charge / discharge cycle characteristics cannot be obtained.

[0006]

The applicant of the present invention has found that a current collector such as a copper foil can be formed on a collector such as a copper foil by a CVD method or a sputtering method.
It has been found that an electrode for a lithium secondary battery formed by depositing an amorphous silicon thin film or a microcrystalline silicon thin film exhibits good charge / discharge cycle characteristics because the active material thin film is in close contact with the current collector. (Japanese Patent Application No. 2000-321201)
issue).

However, in such an electrode for a lithium secondary battery, since the active material thin film is in close contact with the current collector, the volume of the active material thin film expands and contracts due to the charge / discharge reaction, and A large stress acts on the current collector, which may cause deformation such as wrinkles on the current collector. When the current collector is deformed such as wrinkles, when the electrode is housed in a battery, the volume occupied by the electrode becomes large and the energy density per volume decreases.

An object of the present invention is to prevent deformation of the current collector due to charging and discharging, such as wrinkles, and increase the energy density per volume of the lithium secondary battery. An object is to provide an electrode for lithium and a lithium secondary battery using the same.

[0009]

The electrode for a lithium secondary battery according to the first aspect of the present invention has an active material thin film capable of electrochemically or chemically absorbing and releasing lithium deposited on a current collector. Is an electrode for a lithium secondary battery formed by forming a current collector made of a copper alloy and having a tensile strength of 400 N / mm
² or more, a proportional limit 160 N / mm ² or more, the elastic modulus is at 1.1 N / mm ² or more and a surface roughness Ra of the surface of the collector where the active material thin film is formed 0.01~1μm
It is characterized by being.

According to the first aspect, the tensile strength is 400 N.
/ Mm ² or more, a proportional limit 160 N / mm ² or more, since the elastic coefficient is used a current collector made of 1.1 N / mm ² or more copper alloys, the expansion of the active material thin film caused by occlusion and release of lithium -The collector will not be deformed such as wrinkles even if it receives stress due to contraction. In the first aspect,
Tensile strength of the current collector is preferably 480N / mm ² or more, preferably proportional limit is 162N / mm ² or more, it is preferred that the elastic modulus is 1.15 N / mm ² or more.

The above-mentioned tensile strength, proportional limit, and elastic coefficient are, for example, Instron type 556 manufactured by Instron Co., Ltd.
It can be measured by using a universal testing machine. The electrode for a lithium secondary battery according to the second aspect of the present invention is for a lithium secondary battery formed by depositing an active material thin film capable of electrochemically or chemically absorbing and releasing lithium on a current collector. It is an electrode and the current collector is Cu-Ni-Si alloy or C
The surface roughness Ra of the surface of the current collector, which is made of a u-Cr-Zr-based alloy and on which the active material thin film is formed, is 0.01 to 1 μm.
It is characterized by being m.

Examples of Cu-Ni-Si alloys include Corson alloys. Corson alloy is Ni ₂
Cu-Ni ₂ is an age hardening alloy that uses Si phase as the precipitation phase.
It is an alloy regarded as a Si pseudo binary system. Since such a Corson alloy has high tensile strength, proportional limit, and elastic modulus, it can be used also as a material for the current collector used in the first aspect. Examples of Corson alloys include N
i content 1.0 to 4.0% by weight, Si content 0.1 to
A Cu-Ni-Si based alloy of 1.0% by weight may be mentioned.
In addition, if necessary, this alloy contains Mg 0.05 to
0.3 wt%, Zn 0.05-5.0 wt%, Sn5.
0 wt% or less and P less than 0.1 wt% may be contained.

The Cu-Cr-Zr alloy has a Cr content of 0.05 to 0.5% by weight and a Zr content of 0.01 to.
0.3% by weight may be mentioned. In addition, if necessary, the alloy contains 0.01 to 0.3% by weight of Mg, Zn0.
05 to 5.0% by weight, Sn 5% by weight or less, and P less than 0.1% by weight may be contained.

According to the second aspect, by using a current collector made of a Cu-Ni-Si alloy or a Cu-Cr-Zr alloy, it is possible to prevent the current collector from being deformed such as wrinkles. Therefore, the energy density per volume of the lithium secondary battery can be increased.

In the first aspect and the second aspect of the present invention, a current collector is used in which the surface roughness Ra of the surface on which the active material thin film is formed is 0.01 to 1 μm. By using the current collector having such a surface roughness Ra, the adhesion between the current collector and the active material thin film can be enhanced. The surface roughness Ra is based on Japanese Industrial Standards (JIS B 0601-
1994) and can be measured by, for example, a surface roughness meter.

By forming an active material thin film on the current collector having the above surface roughness Ra, irregularities corresponding to the irregularities formed on the surface of the current collector are also formed on the surface of the active material thin film. be able to. By forming the unevenness on the surface of the active material thin film, it becomes easy to form a cut in a region in the thickness direction connecting the valley of the unevenness of the surface of the active material thin film and the valley of the unevenness on the surface of the current collector. Such a break can be formed by expansion and contraction of the active material thin film, and is usually formed by charge and discharge after the first time. By forming such a cut in the thickness direction, the active material thin film is separated into columns by the cut. By separating the active material thin film into columns, voids are formed around the columnar portions, and the voids can absorb changes in expansion and contraction of the active material thin film due to charge / discharge cycles. Therefore, the stress due to the expansion and contraction of the thin film due to the charge / discharge cycle can be relaxed, the active material thin film can be prevented from being pulverized, and the active material thin film can be prevented from peeling from the current collector. The cycle characteristics can be obtained.

Further, in the first aspect and the second aspect of the present invention, it is preferable that the components of the current collector are diffused in the active material thin film. By diffusing the components of the current collector in the active material thin film, the adhesion between the current collector and the active material thin film can be enhanced. When an element such as copper that does not alloy with lithium is diffused as a component of the current collector, alloying with lithium is suppressed in the diffusion region, so that expansion and contraction of the thin film due to charge / discharge reaction is suppressed. Therefore, it is possible to suppress the generation of stress that causes peeling of the active material thin film from the current collector.

The surface roughness Ra of the current collector surface is 0.01 to 1
Roughening treatment may be performed to obtain a thickness of μm. Examples of such roughening treatment include a plating method, a vapor phase growth method, an etching method, and a polishing method. The plating method and the vapor-phase growth method are methods for roughening the surface by forming a thin film layer having irregularities on the surface of a substrate made of a copper alloy or a Cu—Ni—Si alloy. Examples of the plating method include an electrolytic plating method and an electroless plating method.
Further, as the vapor phase growth method, sputtering method, CVD
Methods, vapor deposition methods and the like.

As the surface roughening by the plating method, copper or copper-
The plating film mainly composed of copper such as zinc alloy is
A method of forming on a substrate made of a Cu—Ni—Si alloy or a Cu—Cr—Zr alloy can be mentioned.

As the method of roughening by electrolytic plating, for example, the method of roughening by plating which is generally used for copper foils for printed circuits disclosed in Japanese Patent Publication No. 53-39376 is preferable. Used. That is, after forming granular powder copper by so-called "burn plating", "overcoating" is performed on this granular powder copper plating layer so as not to impair the uneven shape, and a substantially smooth plating is performed. A roughening method may be mentioned in which a layer is deposited to convert the copper powder into so-called copper bumps.

As a roughening method by the vapor phase growth method,
Examples thereof include a method of forming a thin film containing copper or a copper-zinc alloy as a main component on the substrate by a sputtering method or a CVD method.

Examples of the roughening by the etching method include physical etching and chemical etching. Further, examples of the roughening by the polishing method include polishing with sandpaper and polishing by the blast method.

Items common to the first aspect and the second aspect of the present invention will be described below as the "present invention".
The active material thin film according to the present invention is a thin film that absorbs and releases lithium, and is preferably an active material that absorbs lithium by alloying. Examples of such an active material include silicon, germanium, tin, lead, zinc, magnesium, sodium, aluminum, potassium, indium and the like. Among these, silicon, germanium, and tin are preferably used because of their high theoretical capacity. Therefore, the active material thin film used in the present invention is preferably a thin film containing silicon, germanium, or tin as a main component, and particularly preferably a silicon thin film.

In the present invention, the active material thin film is
It is preferably an amorphous thin film or a microcrystalline thin film. Therefore, an amorphous silicon thin film or a microcrystalline silicon thin film is particularly preferable.

In the present invention, the active material thin film is formed by CVD.
Method, sputtering method, vapor deposition method, thermal spraying method, or plating method. Among these methods, the CVD method and the sputtering method are preferable.

In the present invention, the current collector is preferably thin, and is therefore preferably a metal foil. The active material thin film can be formed by depositing on one surface or both surfaces of the current collector. When the active material thin films are formed on both sides of the current collector, the surface roughness Ra on both sides of the current collector is preferably 0.01 to 1 μm.

Lithium may be occluded or added in advance to the active material thin film in the present invention. Lithium
You may add when forming an active material thin film. That is,
By forming an active material thin film containing lithium,
Lithium may be added to the active material thin film. Further, after forming the active material thin film, lithium may be occluded or added to the active material thin film. Examples of a method of occluding or adding lithium to the active material thin film include a method of electrochemically occluding or adding lithium.

The lithium secondary battery of the present invention comprises a negative electrode composed of the electrode for a lithium secondary battery of the present invention, a positive electrode using a material that absorbs and releases lithium as an active material, and a non-aqueous electrolyte. Is characterized by.

The non-aqueous electrolyte used in the lithium secondary battery of the present invention is an electrolyte in which a solute is dissolved in a solvent. The solvent of the non-aqueous electrolyte is not particularly limited as long as it is a solvent used in a lithium secondary battery, for example, ethylene carbonate, propylene carbonate, butylene carbonate, cyclic carbonate such as vinylene carbonate, dimethyl carbonate, diethyl carbonate,
Examples include chain carbonates such as methyl ethyl carbonate. Preferably, a mixed solvent of cyclic carbonate and chain carbonate is used. Further, a mixed solvent of the above cyclic carbonate and an ether solvent such as 1,2-dimethoxyethane or 1,2-diethoxyethane or a chain ester such as γ-butyrolactone, sulfolane or methyl acetate may be used. Good.

The solute of the non-aqueous electrolyte is not particularly limited as long as it is a solute used in a lithium secondary battery. For example, LiPF ₆ , LiBF ₄ , LiCF ₃ S.
O ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ S
O ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiC
_{(CF 3 SO 2) 3,} LiC (C 2 F 5 SO 2) 3, LiAs
F ₆ , LiClO ₄ , Li ₂ B ₁₀ Cl ₁₀ , Li ₂ B ₁₂ Cl ₁₂
And so on. In particular, LiXFy (where X is P,
As, Sb, B, Bi, Al, Ga, or In, y is 6 when X is P, As or Sb, and y is 4 when X is B, Bi, Al, Ga, or In. is there. ) And, in the lithium perfluoroalkyl sulfonic acid imide _{LiN (C m F 2m + 1} SO 2) (C n F 2n + 1 SO 2) ( wherein, m and n are each independently an integer of 1 to 4. ) Or lithium perfluoroalkyl sulfonate methide LiC (C _p F _{2p + 1} SO ₂ ) (C _q F _{2q + 1} SO ₂ ) (C _r
F _{2r + 1} SO ₂ ) (in the formula, p, q and r are each independently an integer of 1 to 4) and a mixed solute is preferably used. Among these, LiPF ₆ and LiN (C ₂ F ₅
A mixed solute with SO ₂ ) ₂ is particularly preferably used.

Further, as the non-aqueous electrolyte, a gel polymer electrolyte obtained by impregnating a polymer electrolyte such as polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride with an electrolytic solution, or an inorganic solid electrolyte such as LiI or Li ₃ N may be used. .

The electrolyte of the lithium secondary battery of the present invention is a lithium compound as a solute that exhibits ionic conductivity and a solvent that dissolves and holds the Li compound, as long as it does not decompose at the voltage during charging, discharging or storage of the battery. , Can be used without restriction.

As the positive electrode active material used for the positive electrode,
LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiMnO
₂ , LiCo _0.5 Ni _0.5 O ₂ , LiNi _0.7 Co _0.2 Mn
Lithium-containing transition metal oxides such as _0.1 O ₂ and MnO ₂
Examples thereof include metal oxides not containing lithium. In addition to this, lithium is electrochemically inserted.
Any substance that can be desorbed can be used without limitation.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to the following examples, and may be appropriately modified within the scope of the invention. It is possible to carry out.

(Examples 1 and 2) [Preparation of working electrode] Corson alloy foil was subjected to copper burn plating by electrolytic plating to form granular powder copper. Further, a dense copper plating (cover plating) is performed on the granular powder copper plating layer so as not to impair the uneven shape, and a rough surface with improved adhesion between the granular powder copper and Corson alloy foil. A copper alloy foil was produced and used as a current collector a1.

Next, the metal foil made of the Cu-Cr-Zr-Mg alloy was subjected to burn plating and cover plating in the same manner as the current collector a1 to produce a current collector a2. Table 1 shows the thickness, tensile strength, proportional limit, elastic modulus, and surface roughness Ra of the current collectors a1 and a2.

The thickness is a value measured with a micrometer, and the tensile strength, the proportional limit and the elastic modulus are values measured with an Instron type 5566 universal testing machine manufactured by Instron. The surface roughness Ra is a value measured by a surface roughness meter.

[0038]

[Table 1]

Next, a silicon thin film as a negative electrode active material was formed on the current collectors a1 and a2 by the RF sputtering method. The sputtering conditions are as follows: sputter gas: argon (Ar), sputter gas flow rate: 100 sccm,
Substrate temperature: room temperature (no heating), reaction pressure: 0.133P
a (1.0 × 10 ^-3 Torr), high frequency power: 200W
And The silicon thin film was deposited until its thickness was 5.5 μm.

Raman content of the obtained silicon thin film
When optical analysis was performed, it was 480 cm. ^-1Peaks in the vicinity are not detected
It was put out, but 520 cm^-1Is a nearby peak not detected?
It was. From this, the obtained silicon thin film is amorphous
It can be seen that it is a recon thin film.

Silicon thin film together with current collector 2 cm × 2
After cutting into a size of cm and attaching a nickel lead wire, it was dried under vacuum at 100 ° C. for 2 hours to give Example 1.
A working electrode of (current collector a1) and a working electrode of Example 2 (current collector a2) were obtained.

[Production of Beaker Cell] Using the working electrode described above, a three-electrode beaker cell as shown in FIG. 4 was produced in a glove box under an argon gas atmosphere. Figure 4
As shown in, the beaker cell is configured by immersing the counter electrode 3, the working electrode 4, and the reference electrode 5 in the electrolytic solution placed in the container 1. As the electrolyte solution 2, ethylene carbonate and diethyl carbonate are used in a volume ratio of 3:
LiPF _{6 in an amount} of 1 mol / mol with respect to the solvent mixed in the ratio
1 liter of the dissolved electrolyte was used. Counter electrode 3 and reference electrode 5
Lithium metal was used as.

[Evaluation of Charge / Discharge Cycle Characteristics] The beaker cell manufactured as described above was charged at 25 ° C. with a constant current of 4 mA until the potential of the working electrode reached 0 V (vs. Li ^/ Li ⁺ ). After that, it was discharged with a constant current of 4 mA until the potential of the working electrode reached 2 V (vs. Li ^/ Li ⁺ ),
The discharge capacity per unit area and the charge / discharge efficiency in the initial cycle were evaluated. The charge / discharge efficiency of the initial cycle (initial charge / discharge efficiency) is calculated by the following formula. Initial charge / discharge efficiency (%) = initial discharge capacity / initial charge capacity × 100 Table 3 shows the evaluation results.

[Evaluation of Electrode Thickness] The thickness of the working electrode before and after the charge / discharge test was measured with a micrometer,
The change in thickness before and after the charge / discharge test was determined. The thickness of the electrode was measured at a total of 5 points in the center and four corners, and the average value was used as the thickness of the electrode. The evaluation results are shown in Table 4.

(Comparative Examples 1 and 2) As the current collector b1, an electrolytic copper foil having physical properties shown in Table 2 was used. Current collector b2
The rolled copper foil (surface roughness Ra = 0.1 μm) was subjected to surface roughening treatment by electrolytic plating as in Example 1. Table 2 shows the thickness, the tensile strength, the proportional limit, the elastic modulus, and the surface roughness Ra of the current collectors b1 and b2.

[0046]

[Table 2]

An amorphous silicon thin film was formed on the current collectors b1 and b2 in the same manner as in Examples 1 and 2, and Comparative Example 1 (current collector b1) was performed in the same manner as in Examples 1 and 2. A working electrode of Comparative Example 2 (current collector b2) was prepared.

Using these working electrodes, beaker cells were prepared in the same manner as in Examples 1 and 2, and the initial discharge capacity and the initial charge / discharge efficiency of each beaker cell were measured. The results are shown in Table 3. .

[0049]

[Table 3]

As is clear from the results shown in Table 3, in all the electrodes of Examples 1 and 2 and Comparative Examples 1 and 2, a discharge capacity of about 3.5 mAh / cm ² was obtained, which was 94%. The above initial charge / discharge efficiency is obtained. This is because the surface of any current collector is roughened, and since the active material thin film is separated into columns by the cuts formed in the thickness direction, the active material thin film does not peel or collapse. It is thought that this is because it is in close contact with the current collector.

Regarding the working electrodes of Comparative Examples 1 and 2, the thickness before and after the charge / discharge test was measured in the same manner as the working electrode of Examples 1 and 2, and the change in the thickness before and after the charge / discharge test was obtained. The results are shown in Table 4.

[0052]

[Table 4]

As is clear from Table 4, Examples 1 and 2
The working electrode of No. 2 has a significantly smaller change in thickness before and after the charge / discharge test than the working electrodes of Comparative Examples 1 and 2. This is because, in the working electrodes of Examples 1 and 2, the current collector was not deformed such as wrinkles even by the charge / discharge test.

FIG. 1 is a photograph showing the state of the working electrode of Example 1 after the charge / discharge test, and FIGS. 2 and 3 show the state of the working electrode of Comparative Examples 1 and 2 after the charge / discharge test, respectively. It is a photograph shown. As is clear from FIGS. 1 to 3, in the working electrodes of Comparative Examples 1 and 2, deformation of the current collector due to a large number of wrinkles was observed, whereas in the working electrode of Example 1, deformation of wrinkles and the like was observed. Almost unrecognized.

Therefore, it can be seen that by using the electrode of Example 1, a lithium secondary battery having a high energy density per volume can be obtained.

[0056]

According to the present invention, it is possible to prevent the current collector from being deformed such as wrinkles due to charge and discharge, and it is possible to increase the energy density per volume of the lithium secondary battery.

[Brief description of drawings]

FIG. 1 is a diagram showing a state of an electrode of an example according to the present invention after a charge / discharge test.

FIG. 2 is a view showing a state of a comparative example electrode after a charge / discharge test.

FIG. 3 is a view showing a state of a comparative example electrode after a charge / discharge test.

FIG. 4 is a schematic configuration diagram showing a three-electrode beaker cell.

[Explanation of symbols]

1 ... Container 2 ... Electrolyte 3 ... Counter electrode 4 ... Working pole 5 ... Reference pole

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) H01M 4/02 H01M 4/02 D 4/38 4/38 Z 10/40 10/40 Z (72) Invention Person Takashi Okamoto 2-5-5 Keihanmoto-dori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Toyoki Fujiwara 2-5-5 Keihan-hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72 ) Inventor Shigeki Matsuda 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Denki Co., Ltd. (72) Maruo Jinno 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Denki Co., Ltd. F-term (reference) 5H017 AA03 AS02 BB00 BB06 BB14 BB16 CC01 DD01 EE01 HH01 HH04 5H029 AJ03 AJ11 AK02 AK03 AL11 AL12 AM03 AM04 AM05 AM07 BJ13 CJ24 CJ25 DJ07 DJ14 DJ17 EJ01 5H050 AA08 AA14 BA17 CA02 CA07 CB11 CB12 DA07 FA04 FA10 FA15 FA18 GA22 GA24 GA25

Claims (11)

[Claims] 1. A lithium secondary battery electrode formed by depositing an active material thin film capable of electrochemically or chemically absorbing and releasing lithium on a current collector, wherein the current collector is copper. Made of an alloy, its tensile strength is 400N
/ Mm ² or more, a proportional limit 160 N / mm ² or more, an elastic modulus 1.1 N / mm ² or more and a surface roughness Ra of the surface of the current collector where the active material thin film is formed is 0 ．
An electrode for a lithium secondary battery, which has a thickness of 0 to 1 μm. 2. A lithium secondary battery electrode formed by depositing an active material thin film capable of electrochemically or chemically absorbing and releasing lithium on a current collector, wherein the current collector is Cu. An electrode for a lithium secondary battery, which is made of a —Ni—Si alloy and has a surface roughness Ra of 0.01 to 1 μm on the surface of the current collector on which the active material thin film is formed. 3. An electrode for a lithium secondary battery, which is formed by depositing an active material thin film capable of electrochemically or chemically absorbing and releasing lithium on a current collector, wherein the current collector is Cu. An electrode for a lithium secondary battery, which is made of a —Cr—Zr alloy and has a surface roughness Ra of 0.01 to 1 μm on the surface of the current collector on which the active material thin film is formed. 4. The surface of the current collector on which the active material thin film is formed is roughened by a plating method, a vapor phase growth method, an etching method, or a polishing method. The electrode for a lithium secondary battery according to any one of 1 to 3. 5. The electrode for a lithium secondary battery according to claim 4, wherein the roughening is performed by forming a plating film containing copper as a main component by a plating method. 6. The component of the current collector is diffused in the active material thin film, according to any one of claims 1 to 5.
An electrode for a lithium secondary battery according to item. 7. The active material thin film is separated into columns by a cut formed in the thickness direction thereof, and the bottom of the columnar portion is in close contact with the current collector. 7. The electrode for a lithium secondary battery according to any one of items 1 to 6. 8. The active material thin film is formed by a CVD method, a sputtering method, an evaporation method, a thermal spraying method, or a plating method.
An electrode for a lithium secondary battery according to item. 9. The electrode for a lithium secondary battery according to claim 1, wherein the active material thin film is a thin film containing silicon, germanium, or tin as a main component. 10. The electrode for a lithium secondary battery according to claim 1, wherein the active material thin film is a microcrystalline silicon thin film or an amorphous silicon thin film. 11. A negative electrode comprising the electrode according to any one of claims 1 to 10, a positive electrode using a material that absorbs and releases lithium as an active material, and a non-aqueous electrolyte. Rechargeable lithium battery.