KR102568211B1 - Anode for lithium secondary battery comprising lithiun powder and zinc powder or zinc oxide powder and method for preparing same - Google Patents

Abstract

The present invention is lithium (Li) powder; zinc (Zn) powder or zinc oxide (ZnO) powder; And a binder; it relates to a negative electrode for a lithium secondary battery comprising a. A negative electrode for a lithium secondary battery and a method for manufacturing the same of the present invention prepare a negative electrode including lithium powder and zinc (Zn) powder or zinc oxide (ZnO) powder, so that the interface resistance is small, the electrodeposition and desorption characteristics of lithium are excellent, and the cycle There is an effect of improving the characteristics.

Description

Negative electrode for lithium secondary battery comprising lithium powder, zinc powder or zinc oxide powder and method for manufacturing the same

The present invention relates to a negative electrode for a lithium secondary battery comprising lithium powder, zinc powder or zinc oxide powder and a method for manufacturing the same, and more particularly, by mixing lithium powder and zinc powder or zinc oxide powder in a certain ratio, the interface resistance is It relates to a negative electrode for a lithium secondary battery that is small, has excellent reversibility for electrodeposition and desorption of lithium, and has improved life characteristics of a cell, and a manufacturing method thereof.

Since the commercialization of lithium secondary batteries in the 1990s, demand for them has increased rapidly along with the spread of electronic devices, portable computers, mobile phones, and the like. A lithium secondary battery is composed of a positive electrode, a negative electrode, an electrolyte, and a separator, and in particular, the performance of the battery is greatly influenced by the electrochemical characteristics of the negative electrode material.

In the early days, lithium metal having a large theoretical capacity was used as an anode active material for a lithium secondary battery. However, lithium metal grows in the form of dendrites during the charge/discharge process, and an internal short circuit occurs due to contact with the positive electrode, which may cause a rapid reaction and cause the battery to explode. In addition, since the dendrite phase growth of lithium metal becomes more active as the current density increases, there is a problem that is not suitable for batteries requiring high-speed charging.

In order to compensate for the disadvantages of lithium metal, a method of using a carbon-based material such as graphite as an anode active material has been proposed. Carbon-based negative electrode active materials have been used for a long time because they satisfy low occlusion/discharge potential, high reversible capacity, small volume change during charge/discharge, stability in electrolyte, etc. required for a negative electrode material of a battery.

Recently, with the rapid development of electric and electronic and communication-related industries, precision electric and electronic products are required to be light and thin, and accordingly, lithium secondary batteries are also required to be thin, miniaturized, and high-capacity. However, the carbon-based negative active material has a theoretical capacity of 372 mAh/g (based on LiC ₆ ) and currently shows capacity behavior close to about 95%, so it is difficult to expect further capacity increase. Accordingly, research on various materials such as silicon-based materials and metal oxide-based materials as non-carbon-based materials capable of exhibiting high capacity is being conducted, but the degree of improvement in battery performance using them is still insufficient.

An object of the present invention is to solve the above problems, and by including lithium powder and zinc powder or zinc oxide powder, an anode for a lithium secondary battery having low interfacial resistance, excellent reversibility of electrodeposition and desorption of lithium, and improved cycle characteristics And to provide a manufacturing method thereof.

In addition, it is an object of the present invention to provide a negative electrode for a lithium secondary battery that can be easily and simply manufactured by mixing lithium powder and zinc powder or zinc oxide powder and coating them in a wet method, and a manufacturing method thereof.

According to one aspect of the present invention, lithium (Li) powder; zinc (Zn) powder or zinc oxide (ZnO) powder; And a binder; there is provided a negative electrode for a lithium secondary battery comprising a.

The negative electrode is 75 to 97 wt% of the lithium powder; 1 to 20 wt% of the zinc oxide powder; And 1 to 10 wt% of the binder; may include.

The negative electrode is 20 to 80 wt% of the lithium powder; 10 to 70 wt% of the zinc powder; And 1 to 10 wt% of the binder; may include.

The binder may include at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyimide (PI), and ethylene-vinyl acetate (EVA).

According to another aspect of the present invention, the negative electrode for the lithium secondary battery; anode; and a separator interposed between the positive electrode and the negative electrode.

The positive electrode may include a positive electrode active material, a conductive material, and a binder.

The cathode active material may include lithium-nickel-cobalt-manganese-based oxide (NCM) represented by Chemical Formula 1.

[Formula 1]

Li _1+a Ni _x Co _y Mn _z O ₂ (0≤a≤0.2, 0<x<1, 0<y<1, 0<z<1, x+y+z=1)

The conductive material may include at least one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fiber, carbon nanotube, and graphene.

The binder is polyvinylidenefloride (PVDF), polytetrafluoroethylene (PTFE), carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), polyvinyl butyral (polyvinyl alcohol). vinyl butyral (PVB), poly-Nvinylpyrrolidone (PVP), styrene butadiene rubber (SBR), polyamide-imide, ethylene vinyl acetate and It may include one or more selected from the group consisting of polyimide.

The lithium secondary battery may further include an electrolyte.

The electrolyte may include an organic solvent and a lithium salt.

The organic solvent is ethylene carbonate (EC), ethylmethyl carbonate (ethylmethyl carbonate), dimethyl carbonate (DMC), diethyl carbonate (DEC), acetonitrile (AC), propylene carbonate (propylene carbonate, PC), polyethylene glycol (polyehthylen glycol), butylene carbonate, vinylene carbonate (VC), 1,3-propane sultone (PS), fluoroethylene carbonate ( fluoroelthylene carbonate (FEC), tetrahydrofuran, 1,2-dioxane, 2-methyltetrahydrofuran, butyrolactone, dimethylformamide, 1,2 dimethoxylethane (DME) and succinonitrile (Succinonitrile, SC) It may include one or more selected from the group consisting of.

The lithium salt is lithium perchlorate (LiClO ₄ ), lithium bis(fluorosulfonyl)imide (LiFSI), lithium triflate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LiPF ₆ ), At least one selected from the group consisting of lithium tetrafluoroborate (LiBF ₄ ), lithium trifluoromethanesulfonylimide (LiN(CF ₃ SO ₂ ) ₂ ) and lithium difluoro oxalate phosphate (LiDFOP) can do.

According to another aspect of the present invention, (a) preparing a slurry by mixing lithium (Li) powder, zinc (Zn) powder or zinc oxide (ZnO) powder, and a binder; And (b) preparing a negative electrode by coating the slurry on a substrate; a method for producing a negative electrode for a lithium secondary battery is provided.

The negative electrode is 75 to 97 wt% of the lithium powder; 1 to 20 wt% of the zinc oxide powder; And 1 to 10 wt% of the binder; may include.

The negative electrode is 20 to 80 wt% of the lithium powder; 10 to 70 wt% of the zinc powder; And 1 to 10 wt% of the binder; may include.

Step (b) may be a step of coating the slurry on a substrate and drying it to prepare a negative electrode.

After step (b), step (c) of rolling the negative electrode may be further included.

Step (c) may be a step of rolling the negative electrode at a rolling rate of 30 to 60% of the initial thickness.

According to another aspect of the present invention, (1) preparing a negative electrode according to the manufacturing method of the negative electrode for a lithium secondary battery; (2) preparing an anode; and (3) preparing a lithium secondary battery by disposing a separator between the negative electrode and the positive electrode.

A negative electrode for a lithium secondary battery and a method for manufacturing the same according to the present invention include lithium powder and zinc powder or zinc oxide powder, so that the interfacial resistance is small, the reversibility of electrodeposition and desorption of lithium is excellent, and the cycle characteristics are improved.

In addition, the present invention can be easily, cheaply and simply manufactured by mixing lithium powder and zinc powder or zinc oxide powder and coating them in a wet method.

1 is a flowchart sequentially showing a method for manufacturing a negative electrode for a lithium secondary battery according to the present invention.
2 is a graph of impedance change of a symmetric lithium cell according to Device Example 1 and Device Comparative Example 1;
3 is a graph showing electrodeposition and desorption characteristics of lithium in a lithium symmetric cell according to Device Example 1 and Device Comparative Example 1;
4A and 4B are graphs showing charge and discharge characteristics of batteries according to Device Example 1 and Device Comparative Example 1 at 0.1 C and 0.5 C.
FIG. 5A is a graph showing discharge capacity over cycles of batteries according to Device Example 1 and Device Comparative Example 1, and FIG. 5B is a graph showing coulombic efficiency over cycles of batteries according to Device Example 1 and Device Comparative Example 1. 5C is a graph showing the discharge capacity and coulombic efficiency according to cycles of the battery according to Device Example 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

However, the following description is not intended to limit the present invention to specific embodiments, and in describing the present invention, if it is determined that the detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted. .

Terms used herein are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, or combination thereof described in the specification, but one or more other features or It should be understood that the presence or addition of numbers, steps, operations, elements, or combinations thereof is not precluded.

Hereinafter, a negative electrode for a lithium secondary battery and a lithium secondary battery including the negative electrode of the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

The present invention is lithium (Li) powder; zinc (Zn) powder or zinc oxide (ZnO) powder; And a binder; it provides a negative electrode for a lithium secondary battery comprising a.

The negative electrode is 75 to 97 wt% of the lithium powder; 1 to 20 wt% of the zinc oxide powder; and 1 to 10 wt% of the binder; preferably, 80 to 93 wt% of the lithium powder; 5 to 15 wt% of the zinc oxide powder; and 1 to 7 wt% of the binder; more preferably, 85 to 90 wt% of the lithium powder; 6 to 12 wt% of the zinc oxide powder; And 1 to 5 wt% of the binder; may include. Also, in the negative electrode, the content of the lithium powder and the binder may vary according to the content of the zinc oxide powder. In the negative electrode, if the content of the zinc oxide powder is less than 1 wt%, the interfacial resistance is large and the performance of the cell is degraded, which is undesirable. not.

The negative electrode is 20 to 80 wt% of the lithium powder; 10 to 70 wt% of the zinc powder; and 1 to 10 wt% of the binder; preferably, 35 to 60 wt% of the lithium powder; 35 to 60 wt% of the zinc powder; And 1 to 7 wt% of the binder; may include, more preferably 45 to 50 wt% of the lithium powder; 45 to 50 wt% of the zinc powder; And 1 to 5 wt% of the binder; may include. Also, in the negative electrode, the content of the lithium powder and the binder may vary according to the content of the zinc powder. In the negative electrode, if the content of the zinc powder is less than 10 wt%, the overvoltage of the cell is large and performance of the cell is degraded, which is not preferable, and if the content is more than 70 wt%, the specific capacity of the cell is low, which is not preferable.

The binder may include at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyimide (PI), and ethylene-vinyl acetate (EVA).

In addition, the present invention is the negative electrode for the lithium secondary battery; anode; and a separator interposed between the positive electrode and the negative electrode.

The positive electrode may include a positive electrode active material, a conductive material, and a binder.

The cathode active material may include lithium-nickel-cobalt-manganese-based oxide (NCM) represented by Chemical Formula 1.

[Formula 1]

Li _1+a Ni _x Co _y Mn _z O ₂ (0≤a≤0.2, 0<x<1, 0<y<1, 0<z<1, x+y+z=1)

The lithium-nickel-cobalt-manganese oxide (NCM) is LiNi _0.4 Co _0.2 Mn _0.4 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O ₂ and LiNi _0.8 Co _0.1 Mn _0.1 O ₂ It may include one or more selected from the group consisting of.

The conductive material may include at least one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fiber, carbon nanotube, and graphene.

The binder is polyvinylidenefloride (PVDF), polytetrafluoroethylene (PTFE), carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), polyvinyl butyral (polyvinyl alcohol). vinyl butyral (PVB), poly-Nvinylpyrrolidone (PVP), styrene butadiene rubber (SBR), polyamide-imide, ethylene vinyl acetate (Ethylene Vinyl Acetate) and It may include one or more selected from the group consisting of polyimide.

The separator may include a porous substrate, and the porous substrate may include at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polyolefin, and mixtures thereof. there is.

The lithium secondary battery may further include an electrolyte.

The electrolyte may include an organic solvent and a lithium salt.

The organic solvent is ethylene carbonate (EC), ethylmethyl carbonate (ethylmethyl carbonate), dimethyl carbonate (DMC), diethyl carbonate (DEC), acetonitrile (AC), propylene carbonate (propylene carbonate, PC), polyethylene glycol (polyehthylen glycol), butylene carbonate, vinylene carbonate (VC), 1,3-propane sultone (PS), fluoroethylene carbonate ( fluoroelthylene carbonate (FEC), tetrahydrofuran, 1,2-dioxane, 2-methyltetrahydrofuran, butyrolactone, dimethylformamide, 1,2 dimethoxylethane (DME) and succinonitrile (Succinonitrile, SC) It may include one or more materials selected from the group consisting of.

The lithium salt is lithium perchlorate (LiClO ₄ ), lithium bis(fluorosulfonyl)imide (LiFSI), lithium triflate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LiPF ₆ ), At least one selected from the group consisting of lithium tetrafluoroborate (LiBF ₄ ), lithium trifluoromethanesulfonylimide (LiN(CF ₃ SO ₂ ) ₂ ) and lithium difluoro oxalate phosphate (LiDFOP) can do.

The electrolyte may further include an inorganic compound, and the inorganic compound may include lithium nitrate (LiNO ₃ ).

1 is a flowchart sequentially showing a method for manufacturing a negative electrode for a lithium secondary battery according to the present invention. Hereinafter, a method for manufacturing a negative electrode for a lithium secondary battery and a method for manufacturing a lithium secondary battery including the negative electrode of the present invention will be described in detail with reference to FIG. 1 .

First, a slurry is prepared by mixing lithium (Li) powder, zinc (Zn) powder or zinc oxide (ZnO) powder, and a binder (step a).

Step (a) may include preparing a mixture by mixing lithium (Li) powder, zinc (Zn) powder, or zinc oxide (ZnO) powder, and preparing a slurry by dissolving the mixture in a binder.

The weight ratio of the lithium powder and the zinc powder or zinc oxide powder may be 5:5 to 10:0, preferably 7:3 to 9.5:0.5, and more preferably 9:1.

Next, the slurry is coated on a substrate to prepare a negative electrode (step b).

The negative electrode is 75 to 97 wt% of the lithium powder; 1 to 20 wt% of the zinc oxide powder; And 1 to 10 wt% of the binder; may include.

The negative electrode is 20 to 80 wt% of the lithium powder; 10 to 70 wt% of the zinc powder; And 1 to 10 wt% of the binder; may include.

Step (b) may be a step of coating the slurry on a substrate and drying it to prepare a negative electrode.

The substrate may include at least one selected from the group consisting of Cu foil, carbon-coated Cu foil, Ni foil, and SUS foil.

Any coating method that does not damage the substrate may be used for the coating.

After step (b), step (c) of rolling the negative electrode may be further included.

Step (c) may be a step of rolling the negative electrode at a rolling rate of 30 to 60% of the initial thickness.

In addition, the present invention comprises (1) preparing a negative electrode according to the manufacturing method of the negative electrode for a lithium secondary battery; (2) preparing an anode; and (3) preparing a lithium secondary battery by disposing a separator between the negative electrode and the positive electrode.

[Example]

Hereinafter, a preferred embodiment of the present invention will be described. However, this is for illustrative purposes and the scope of the present invention is not limited thereby.

Example 1: Preparation of a negative electrode of lithium powder (Li powder) + zinc oxide powder (ZnO powder)

A slurry was prepared so that the weight ratio of lithium powder (Li powder), zinc oxide powder (ZnO powder), and binder was 87.3 : 9.7 : 3

Specifically, after dissolving PVDF binder in NMP solvent to prepare a 3% PVDF binder solution, zinc oxide powder (ZnO powder) is added to lithium powder (Li powder) at a ratio of 9:1 (weight ratio) in a high-speed mixer (Thinky Mixer) ) at 1000 rpm for 3 minutes to prepare a slurry. The slurry was cast on a 15 μm Cu foil with an applicator to coat the mixture to a thickness of 60 μm, and then dried at 70° C. for 5 hours. Thereafter, a negative electrode was prepared by rolling to have a rolling ratio of 50% of the initial thickness using a room temperature roll press (thickness of 45 μm).

Example 2: Preparation of a negative electrode of lithium powder (Li powder) + zinc powder (Zn powder)

In Example 1, instead of preparing and using a slurry so that the ratio of lithium powder, zinc oxide powder, and binder is 87.3: 9.7: 3, the weight ratio of lithium powder, zinc powder (Zn powder), and binder is 48.5: 48.5: 3. A negative electrode was prepared in the same manner as in Example 1, except that a was prepared and used.

Example 3: Preparation of positive electrode

A mixture was prepared so that the weight ratio of the cathode active material, the conductive material, and the binder was 80:10:10. That is, a mixture was prepared by mixing 12.5 parts by weight of the conductive material Super-P and 12.5 parts by weight of the PVDF binder based on 100 parts by weight of the positive electrode active material NCM. At this time, the PVDF binder includes polyvinylidene fluoride (PvdF) and 1-methyl-2-pyrrolidone (NMP) from KUREHA CORPORATION, and the PVDF is 3 A wt% dissolved binder was used.

Specifically, first, NCM and Super-p were weighed in the above weight ratio, and then mixed for 20 minutes using a mortar and pestle to prepare a mixed powder. The mixed powder was transferred to a container dedicated to a high-speed mixer (Thinky mixer) and then mixed with the PVDF binder at the weight ratio, mounted in a mixer, and mixed once at 1,500 rpm for 5 minutes to prepare a mixture. Next, 1-Methyl-2-pyrrolidone (NMP) was mixed with the mixture to adjust the viscosity to an appropriate level, and after inserting a 5 mm zircon ball, the mixture was mixed for 5 minutes at 1,500 rpm for 3 times. Thus, a slurry was prepared. The slurry was cast on aluminum foil, dried at 110° C., and then rolled to prepare a positive electrode.

Comparative Example 1: Preparation of lithium powder (Li powder) negative electrode

In Example 1, instead of preparing and using a slurry so that the weight ratio of lithium powder, zinc oxide powder, and binder is 87.3: 9.7: 3, a slurry is prepared and used so that the weight ratio of lithium powder and binder is 97: 3. Then, a negative electrode was prepared in the same manner as in Example 1.

Device Example 1: Manufacturing of Lithium Secondary Battery

A lithium secondary battery was manufactured using a negative electrode prepared according to Example 1, a positive electrode prepared according to Example 3, and a Separator Celgard 2400 PP separator.

Specifically, the positive electrode and the PP separator prepared according to Example 3 were punched into Ø14 and Ø19 sizes, respectively. On the positive electrode, an electrolyte solution in which a solvent mixed with DME + 5% LiNO ₃ was dissolved in 2M LIFSI lithium salt was applied, the PP separator was laminated, and the negative electrode prepared according to Example 1 was placed on the separator, A lithium secondary battery was manufactured using a 2032 standard coin cell.

Device Example 2: Manufacturing of Lithium Secondary Battery

A lithium secondary battery was manufactured in the same manner as in Device Example 1, except that the negative electrode prepared according to Example 2 was used instead of the negative electrode prepared according to Example 1 in Device Example 1.

Device Comparative Example 1: Manufacturing of Lithium Secondary Battery

A lithium secondary battery was manufactured in the same manner as in Device Example 1, except for using the negative electrode prepared according to Comparative Example 1 instead of using the negative electrode prepared according to Example 1 in Device Example 1.

[Test Example]

Test Example 1: Impedance change of lithium symmetric cell

2 is a graph of impedance change of a symmetric lithium cell according to Device Example 1 and Device Comparative Example 1;

According to FIG. 2, it was found that the interface resistance value was significantly reduced in the case of Device Example 1 including a metal composite anode using a mixture of lithium powder and zinc oxide powder than in the case of Device Comparative Example 1 (Li powder anode).

Test Example 2: Electrodeposition and desorption characteristics of lithium in a lithium symmetric cell

3 is a graph showing electrodeposition and desorption characteristics of lithium in a lithium symmetric cell according to Device Example 1 and Device Comparative Example 1; A lithium symmetric cell was prepared, and charging and discharging were repeated using 2M LiFSI in DME + 5% LiNO ₃ + 1% LIDFBP) electrolyte so that the capacity per area was 2.8 mAh/cm ² and the electrodeposition and desorption current was 2.5 mA/cm ² .

According to FIG. 3, the number of lifetimes due to electrodeposition and desorption of lithium in Device Comparative Example 1 (Li powder negative electrode) was 67, but in Device Example 1 (Li powder + ZnO powder negative electrode), life due to electrodeposition and desorption of lithium The characteristics were maintained over 100 times. It can be seen that mixing the zinc oxide powder with the lithium powder improves the lifespan characteristics according to the electrodeposition and desorption of lithium, so that the reversibility of lithium is further increased.

Test Example 3: Battery charge/discharge characteristics

4A and 4B are graphs showing charge and discharge characteristics of batteries according to Device Example 1 and Device Comparative Example 1 at 0.1 C and 0.5 C. Charging and discharging were performed with a potential of 2.5V_4.2V by applying a high anode capacity of 3.8mAh/cm ² per area.

According to FIGS. 4A to 4B , the design capacity value was implemented even at a high positive electrode capacity per area at 0.1C, and a capacity of 92% or more of the designed capacity of the positive electrode was implemented even at a high current density of 0.5C. It was found that both Comparative Example 1 (Li powder negative electrode) and Example 1 (Li powder + ZnO powder negative electrode) could realize satisfactory capacity even with a high capacity per anode area, with the corresponding negative electrode capacity.

Test Example 4: Analysis of cycle characteristics and coulombic efficiency of battery

FIG. 5A is a graph showing discharge capacity over cycles of batteries according to Device Example 1 and Device Comparative Example 1, and FIG. 5B is a graph showing coulombic efficiency over cycles of batteries according to Device Example 1 and Device Comparative Example 1. am. 5C is a graph showing the discharge capacity and coulombic efficiency according to cycles of the battery according to Device Example 2. The measurement conditions were cycled by repeating charging and discharging at a voltage range of 2.5V-4.2V, a temperature of 30°C, and a current density of 0.5C.

5A and 5B, in the case of Device Comparative Example 1, when the number of repetitions of charging and discharging is 70 or more, it can be seen that the discharge capacity and coulombic efficiency decrease. However, in the case of Device Example 1, even after repeating charging and discharging 100 times or more, it can be seen that the decrease in capacity does not occur significantly and the coulombic efficiency is maintained.

In addition, according to FIG. 5C, in the case of Device Example 2 (Li powder + Zn powder cathode), it can be seen that the capacity does not significantly decrease even after 100 or more cycles, and the Coulombic efficiency is also maintained.

The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention. do.

Claims (20)

lithium (Li) powder;
zinc (Zn) powder; and
A negative electrode for a lithium secondary battery comprising a binder;
The negative electrode for the lithium secondary battery,
20 to 80 wt% of the lithium powder;
10 to 70 wt% of the zinc powder; and
1 to 10 wt% of the binder; which would include a negative electrode for a lithium secondary battery. delete delete According to claim 1,
Lithium characterized in that the binder comprises at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyimide (PI) and ethylene-vinyl acetate (EVA) Cathode for secondary battery. a negative electrode according to claim 1;
anode;
A separator interposed between the anode and cathode;
Lithium secondary battery containing. According to claim 5,
The lithium secondary battery, characterized in that the positive electrode comprises a positive electrode active material, a conductive material and a binder. According to claim 6,
The lithium secondary battery, characterized in that the cathode active material comprises a lithium-nickel-cobalt-manganese-based oxide (NCM) represented by Formula 1.
[Formula 1]
Li _1+a Ni _x Co _y Mn _z O ₂ (0≤a≤0.2, 0<x<1, 0<y<1, 0<z<1, x+y+z=1) According to claim 6,
The lithium secondary battery, characterized in that the conductive material comprises at least one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fibers, carbon nanotubes, and graphene. According to claim 6,
The binder is polyvinylidenefloride (PVDF), polytetrafluoroethylene (PTFE), carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), polyvinylbuty polyvinyl butyral (PVB), poly-Nvinylpyrrolidone (PVP), styrene butadiene rubber (SBR), polyamide-imide, ethylene vinyl acetate A lithium secondary battery comprising at least one selected from the group consisting of acetate) and polyimide. According to claim 6,
The lithium secondary battery, characterized in that the lithium secondary battery further comprises an electrolyte. According to claim 10,
A lithium secondary battery, characterized in that the electrolyte comprises an organic solvent and a lithium salt. According to claim 11,
The organic solvent is ethylene carbonate (EC), ethylmethyl carbonate (ethylmethyl carbonate), dimethyl carbonate (DMC), diethyl carbonate (DEC), acetonitrile (AC), propylene carbonate (propylene carbonate, PC), polyethylene glycol (polyehthylen glycol), butylene carbonate, vinylene carbonate (VC), 1,3-propane sultone (PS), fluoroethylene carbonate ( fluoroelthylene carbonate (FEC), tetrahydrofuran, 1,2-dioxane, 2-methyltetrahydrofuran, butyrolactone, dimethylformamide, 1,2 dimethoxylethane (DME) and succinonitrile (SC) A lithium secondary battery comprising at least one selected from the group consisting of. According to claim 11,
The lithium salt is lithium perchlorate (LiClO ₄ ), lithium bis(fluorosulfonyl)imide (LiFSI), lithium triflate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LiPF ₆ ), At least one selected from the group consisting of lithium tetrafluoroborate (LiBF ₄ ), lithium trifluoromethanesulfonylimide (LiN(CF ₃ SO ₂ ) ₂ ) and lithium difluoro oxalate phosphate (LiDFOP) Lithium secondary battery, characterized in that to do. (a) preparing a slurry by mixing lithium (Li) powder, zinc (Zn) powder, and a binder; and
(b) preparing a negative electrode by coating the slurry on a substrate;
The cathode is
20 to 80 wt% of the lithium powder;
10 to 70 wt% of the zinc powder; and
1 to 10 wt% of the binder; a method for producing a negative electrode for a lithium secondary battery comprising a. delete delete According to claim 14,
step (b)
Method for producing a negative electrode for a lithium secondary battery, characterized in that the step of coating the slurry on a substrate and drying to prepare a negative electrode. According to claim 14,
After step (b),
Method for producing a negative electrode for a lithium secondary battery, characterized in that it further comprises the step (c) of rolling the negative electrode. According to claim 18,
step (c)
Method for producing a negative electrode for a lithium secondary battery, characterized in that; rolling the negative electrode at a rolling rate of 30 to 60% of the initial thickness. (1) preparing a negative electrode according to claim 14;
(2) preparing an anode; and
(3) preparing a lithium secondary battery by disposing a separator between the negative electrode and the positive electrode;
Method for manufacturing a lithium secondary battery comprising