KR20180027486A - All solid lithium secondary batteries including conducting polymer and manufacturing method for the same - Google Patents

Abstract

The present invention relates to an all-solid-state lithium secondary battery comprising: an anode including anode active materials and a first conductive polymer; a cathode including cathode active materials and a second conductive polymer; and a composite solid-state electrolytic layer including LLZO between the anode and cathode and a third conductive polymer, wherein LLZO is aluminum-doped or undoped LLZO. The anode, the composite solid-state electrolytic layer and the cathode of the all-solid-state lithium secondary battery of the present invention comprise conductive polymers at the same time to enhance discharging capacity and cycle characteristics. Moreover, the method for manufacturing the all-solid-state lithium secondary battery of the present invention reduces manufacturing costs by manufacturing the all-solid-state lithium secondary battery in a non-sintering manner by including the conductive polymers at the same time in the anode, the composite solid-state electrolytic layer and the cathode; and reduces resistance of the battery by enhancing an interfacial property between an electrolyte and an electrode.

Description

TECHNICAL FIELD [0001] The present invention relates to an all-solid-state lithium secondary battery including a conductive polymer, and a method for manufacturing the same.

The present invention relates to a pre-solid lithium secondary battery including a conductive polymer and a method for producing the same, and more particularly, to a pre-solid lithium secondary battery including a positive electrode, a complex solid electrolyte layer and a conductive polymer containing a conductive polymer at the same time, .

Lithium secondary batteries have large electrochemical capacities, high operating potentials, and excellent charge / discharge cycle characteristics, so demand for portable information terminals, portable electronic devices, small household power storage devices, motorcycles, electric vehicles and hybrid electric vehicles . With the spread of such applications, improvement of safety and high performance of lithium secondary batteries are required.

Conventional lithium secondary batteries use a liquid electrolyte and are readily ignited when exposed to water in the air, thus posing a problem of stability. These safety issues are becoming more and more common as electric vehicles become more visible.

Recently, all solid-state secondary batteries using a solid electrolyte made of an inorganic material, which is a nonflammable material, have been actively studied for the purpose of improving safety. BACKGROUND ART Solid-state secondary batteries are attracting attention as a next-generation secondary battery in terms of safety, high energy density, high output, long life, simplification of manufacturing process, enlargement / compactification of batteries, and low cost.

The core technology of all solid secondary batteries is to develop solid electrolytes that exhibit high ionic conductivity. Solid electrolytes for all solid secondary batteries known so far include sulfide solid electrolytes and oxide solid electrolytes.

Korean Patent Laid-Open Publication No. 2012-0132533 discloses a pre-solid lithium secondary battery having excellent output characteristics by using a sulfide-based solid electrolyte as an electrolyte. However, the sulfide solid electrolyte has a problem that hydrogen sulfide (H ₂ S) gas, which is a toxic gas, is generated.

Oxide solid electrolytes exhibit lower ionic conductivity than sulfide solid electrolytes, but have attracted attention recently because of their excellent stability. However, there is a problem that the resistance of the battery increases due to the interface reaction between the electrolyte and the electrode, and the discharge capacity and the cycle characteristics may be lowered, as compared with the conventional solid lithium lithium secondary battery using the conventional oxide-based solid electrolyte. Therefore, it is necessary to develop a technique which can reduce the resistance of a battery even though it contains an oxide-based solid electrolyte.

An object of the present invention is to provide a pre-solid lithium secondary battery in which a cathode, a composite solid electrolyte layer and a cathode simultaneously contain a conductive polymer, thereby improving discharge capacity and cycle characteristics.

In addition, by manufacturing the all-solid lithium secondary battery in a non-sintering manner by including the conductive polymer in the anode, the composite solid electrolyte layer, and the cathode simultaneously, it is possible to reduce the manufacturing cost and improve the interfacial characteristics between the electrolyte and the electrode, The present invention provides a method for manufacturing a pre-solid lithium secondary battery.

According to an aspect of the present invention, there is provided a cathode comprising: a cathode comprising a cathode active material and a first conductive polymer; A negative electrode comprising a negative electrode active material and a second conductive polymer; And a composite solid electrolyte layer comprising LLZO and a third conductive polymer between the anode and the cathode, wherein the LLZO is an LLZO doped or undoped with aluminum, the non-doped LLZO is represented by a general formula , And the doped LLZO is represented by the following general formula (2).

[Chemical Formula 1]

Li _x La _y Zr _z O ₁₂ (6? X? 9, 2? Y? 4, 1? Z? 3)

(2)

Li _x La _y Zr _z Al _w O ₁₂ (5? X? 9, 2? Y? 4, 1? Z? 3, 0 <

The first conductive polymer, the second conductive polymer and the third conductive polymer are each independently selected from the group consisting of polyethylene oxide, polyethylene glycol, polypropylene oxide, polyphosphazene, polysiloxane Polysiloxane) and copolymers thereof.

The first conductive polymer, the second conductive polymer, and the third conductive polymer may be independently polyethylene oxide having an average molecular weight of 500 to 1,000,000.

The cathode active material may be a three-component lithium metal oxide (NMC) of Ni-Co-Mn represented by the following chemical formula (3).

(3)

LiNi _p Co _q Mn _r O ₂

here 0 <p <0.9, 0 <q <0.5, 0 <r <0.5, p + q + r = 1.

The negative electrode active material may include at least one selected from graphite, coke, soft carbon, hard carbon, LTO (lithium titanium oxide), tin and silicon.

The negative electrode active material may include graphite.

The LLZO may be an aluminum-doped LLZO.

The aluminum-doped LLZO may be a garnet crystal structure.

One or more selected from the anode and the cathode may further include LLZO.

At least one selected from the positive electrode and the negative electrode may further include a conductive material.

The conductive material may include at least one selected from carbon black, acetylene black, and ketjen black.

The positive electrode, the composite solid electrolyte layer, and the negative electrode may further include a lithium salt.

Wherein the lithium salt is selected from the group consisting of lithium perchlorate (LiClO ₄ ), lithium triflate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LipF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), and lithium trifluoromethanesulfonylimide may be at least one selected from _{(LiN (CF 3 SO 2)} 2).

Wherein the pre-solid lithium secondary battery comprises a three-component lithium metal oxide (NMC) of Ni-Co-Mn and a polyethylene oxide; An anode comprising graphite and polyethylene oxide; And a composite solid electrolyte layer containing aluminum-doped LLZO and polyethylene oxide between the anode and the cathode.

According to another aspect of the present invention, there is provided a method of manufacturing a positive electrode, comprising: (a) preparing a positive electrode by mixing a positive electrode active material and a first conductive polymer; (b) mixing the negative electrode active material and the second conductive polymer to prepare a negative electrode; (c) mixing the solid electrolyte and the third conductive polymer to prepare a composite solid electrolyte layer; And (d) disposing and laminating the composite solid electrolyte layer between the positive electrode and the negative electrode. The present invention also provides a method of manufacturing a pre-solid lithium rechargeable battery.

The step (d) may be a step of arranging the composite solid electrolyte layer between the positive electrode and the negative electrode and pressing them at a pressure of 0.1 to 1.0 MPa in the temperature range (T) of the following equation (1).

[Formula 1]

Tm? T? Tm + 50 占 폚

And in the formula 1, T _m1, T _m2 and T when _m3 of T _m1 is the greater, and Tm = T _m1, and if T _m2 is the greater Tm = T _m2, if T _m3 is greatest Tm = T _m3,

_M3 and T <T _m1 = _m2 if T and _{Tm = T m1, T m2 <} T m1 = T _m3 and if Tm = T _m1, if the _{T m1 <T m2 = T m3} Tm = T m2,

_M1 = _m2 = T and T if T _m3 Tm = T _m1,

Here, T _m1 is the melting temperature of the first conductive polymer, T _m2 is the melting temperature of the second conductive polymer, T _m3 is the melting temperature of the third conductive polymer.

Wherein the first conductive polymer, the second conductive polymer, and the third conductive polymer are polyethylene oxide,

The step (d) may be a step of disposing the composite solid electrolyte layer between the anode and the cathode and pressing the mixture at a pressure of 0.1 to 1.0 MPa at a temperature of 65 ° C (melting temperature of polyethylene oxide) to 115 ° C.

Unlike the prior art, the pre-solid lithium lithium secondary battery of the present invention includes the conductive polymer at the same time as the anode, the composite solid electrolyte layer, and the cathode, so that the discharge capacity and the cycle characteristics can be improved.

The method of manufacturing a pre-solid lithium rechargeable battery of the present invention reduces the manufacturing cost by manufacturing a pre-solid lithium rechargeable battery in a non-sintering manner by simultaneously including a conductive polymer in the anode, the composite solid electrolyte layer, The resistance of the battery can be reduced.

1 is a schematic diagram of a pre-solid lithium secondary battery of the present invention.
FIG. 2 is a graph showing the results of measurement of charge-discharge characteristics of a pre-solid lithium secondary battery produced according to Example 1. FIG.
3 is a graph showing the results of measuring the discharge capacity of the entire solid lithium secondary battery prepared in Example 1 and Example 2 at 70 ° C according to the cycle.

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 does not limit the present invention to specific embodiments. In the following description of the present invention, detailed description of related arts will be omitted if it is determined that the gist of the present invention may be blurred .

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises ", or" having ", and the like, specify that the presence of stated features, integers, steps, operations, elements, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, or combinations thereof.

1 is a schematic diagram of a pre-solid lithium secondary battery of the present invention. Here, the anode includes lithium metal oxide (NMC) cathode active material, LLZO and PEO conductive polymer, the composite solid electrolyte layer includes LLZO and PEO conductive polymer, and the anode includes graphite anode active material, LLZO and PEO conductive polymer , Copper (Cu), and aluminum (Al) current collector, but the scope of the present invention is not limited thereto.

Hereinafter, the entire solid lithium secondary battery of the present invention will be described in detail with reference to FIG. However, it should be understood that the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

The pre-solid lithium secondary battery of the present invention comprises a cathode comprising a cathode active material and a first conductive polymer; A negative electrode comprising a negative electrode active material and a second conductive polymer; And a composite solid electrolyte layer including LLZO and a third conductive polymer between the anode and the cathode.

The LLZO may be an aluminum doped or undoped LLZO, the undoped LLZO may be represented by the following Formula 1, and the doped LLZO may be represented by the following Formula 2.

[Chemical Formula 1]

Li _x La _y Zr _z O ₁₂ (6? X? 9, 2? Y? 4, 1? Z? 3)

(2)

Li _x La _y Zr _z Al _w O ₁₂ (5? X? 9, 2? Y? 4, 1? Z? 3, 0 <

The first conductive polymer, the second conductive polymer and the third conductive polymer may each independently be selected from the group consisting of polyethylene oxide, polyethylene glycol, polypropylene oxide, polyphosphazene, polysiloxane Polysiloxane, and copolymers thereof, but may preferably be a polyethylene oxide having an average molecular weight of 500 to 1,000,000. More preferably a polyethylene oxide having an average molecular weight of 1,000 to 400,000, and still more preferably a polyethylene oxide having an average molecular weight of 5,000 to 300,000.

The first conductive polymer, the second conductive polymer and the third conductive polymer generally denote a polymer having a conductivity of 10 ^-7 Scm ^-1 or more (a value equal to or higher than a semiconductor value). In most cases, an electron acceptor or an electron donor High conductivity can be obtained by doping the polymer. Doped polyethylene, polypyrrole, polythiophene, and the like are known as typical conductive polymers. In the present invention, it is preferable to select a conductive polymer which is complexed with a lithium salt to have optimal ion conductivity, and polyethylene oxide may be preferable.

By including the conductive polymer in the positive electrode, the negative electrode, and the composite solid electrolyte layer, the interfacial characteristics between the electrolyte and the electrode are improved, so that the discharge capacity and cycle characteristics of the all-solid lithium secondary battery can be improved.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ ; Three component system of Ni-Co-Mn lithium metal oxide (NMC) of _{Li [Ni x Co 1-2x Nn x} O] 2 (0 <x <0.5) Li [Ni 1/3 Co 1/3 , which can be expressed in Nn _1/3 O] ₂ , but the present invention is not limited to these.

The cathode active material may preferably be a three-component lithium metal oxide (NMC) of Ni-Co-Mn represented by the following formula (3).

(3)

LiNi _p Co _q Mn _r O ₂

here 0 <p <0.9, 0 <q <0.5, 0 <r <0.5, p + q + r = 1.

The negative electrode active material may be graphite, coke, soft carbon, hard carbon, LTO (lithium titanium oxide), tin, silicon or the like, preferably graphite.

Preferably, the LLZO may be an aluminum-doped LLZO, and the aluminum-doped LLZO may be a garnet crystal structure. The garnet crystal structure is a structure having high ionic conductivity and excellent dislocation stability.

The anode and the cathode may further include the LLZO.

The positive electrode and the negative electrode may further include a conductive material.

The conductive material may be carbon black, acetylene black, ketjen black, or the like, preferably carbon black.

The positive electrode, the composite solid electrolyte layer, and the negative electrode may further include a lithium salt.

The lithium salt is selected from the group consisting of lithium perchlorate (LiClO ₄ ), lithium triflate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LipF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium trifluoromethanesulfonylimide _{(LiN (CF 3 SO 2)} 2) , such as the one available, and may be preferably lithium perchlorate.

The pre-solid lithium secondary battery preferably comprises a three-component lithium metal oxide (NMC) of Ni-Co-Mn and a polyethylene oxide; An anode comprising graphite and polyethylene oxide; And a composite solid electrolyte layer containing aluminum-doped LLZO and polyethylene oxide between the anode and the cathode.

Hereinafter, the production method of the pre-solid lithium secondary battery of the present invention will be described in detail.

First, the positive electrode is prepared by mixing the positive electrode active material and the first conductive polymer (step a).

More specifically, the anode may be prepared by casting a slurry containing the cathode active material and the first conductive polymer, followed by drying.

Next, a negative electrode is prepared by mixing the negative electrode active material and the second conductive polymer (step b).

More specifically, a slurry obtained by mixing the negative electrode active material and the second conductive polymer may be cast and dried to produce a negative electrode.

Next, the solid electrolyte and the third conductive polymer are mixed to prepare a composite solid electrolyte layer (step c).

More specifically, a mixture of the solid electrolyte and the third conductive polymer may be coated on a substrate to produce a composite solid electrolyte layer.

The substrate may be PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), PES (polyethersulfone), PC (Polycarbonate), PP (polypropylene) or the like, preferably PET.

The coating may be any coating method that does not damage the substrate.

Finally, the composite solid electrolyte layer is disposed between the positive electrode and the negative electrode and laminated (step d).

Preferably, the composite solid electrolyte layer is disposed between the positive electrode and the negative electrode and is laminated by pressurization at a pressure of 0.1 to 1.0 MPa in the temperature range (T) shown below.

[Formula 1]

Tm? T? Tm + 50 占 폚

And in the formula 1, T _m1, T _m2 and T when _m3 of T _m1 is the greater, and Tm = T _m1, and if T _m2 is the greater Tm = T _m2, if T _m3 is greatest Tm = T _m3,

_M3 and T <T _m1 = _m2 if T and _{Tm = T m1, T m2 <} T m1 = T _m3 and if Tm = T _m1, if the _{T m1 <T m2 = T m3} Tm = T m2,

_M1 = _m2 = T and T if T _m3 Tm = T _m1,

Here, T _m1 is the melting temperature of the first conductive polymer, T _m2 is the melting temperature of the second conductive polymer, T _m3 is the melting temperature of the third conductive polymer.

The pressurization can be preferably carried out at a pressure of 0.1 to 1.0 MPa, more preferably 0.1 to 0.8 MPa, even more preferably 0.2 to 0.4 MPa.

The pressurization can be performed for 5 seconds to 5 minutes, preferably 5 seconds to 3 minutes, more preferably 5 seconds to 1 minute.

The first conductive polymer, the second conductive polymer and the third conductive polymer may preferably be polyethylene oxide. In the case of polyethylene oxide, step (d) is preferably performed by disposing the composite solid electrolyte layer between the anode and the cathode, (Melting temperature of polyethylene oxide) to 115 캜 at a pressure of 0.1 to 1.0 MPa and laminating them.

The entire solid lithium secondary battery of the present invention is pressurized at a temperature higher than the melting temperature of the first conductive polymer, the second conductive polymer and the third conductive polymer, so that the first conductive polymer contained in the anode, the second conductive polymer contained in the composite solid electrolyte layer The second conductive polymer and the third conductive polymer included in the cathode are melted and adhered to improve the interface characteristics between the electrolyte and the electrode between the cathode and the composite solid electrolyte layer, thereby reducing the resistance of the battery.

[Example]

Hereinafter, preferred embodiments of the present invention will be described. However, this is for illustrative purposes only, and thus the scope of the present invention is not limited thereto.

Preparation Example 1: Preparation of aluminum-doped lithium lanthanum zirconium oxide (Al-LLZO)

(La (NO ₃ ) ₃ .6H ₂ O), zirconium nitrate (ZrO (NO ₃ ) ₂ .2H ₂ O) so that the molar ratio of La: Zr: Al in distilled water is 3: And aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O) were dissolved to prepare a starting material solution having a starting molar concentration of 1 mol.

A proper amount of 0.6 mol of ammonia water and an aqueous solution of sodium hydroxide as a starting material solution and a complexing agent were added through the injection part of a quattroiler vortex reactor so as to obtain a mixed solution whose pH was adjusted to 11. The reaction temperature was 25 ° C, The agitation speed of the stirrer was coprecipitated at 1,300 rpm to discharge the precursor slurry in the form of a liquid slurry to the discharge portion. The Taylor number in the coprecipitation reaction of the Kuett Taylor vortex reactor was 640 or more.

The precursor slurry was washed with purified water and dried overnight. The dried precursor was ground with a ball mill and excess LiOH.H ₂ O was added and mixed with a ball mill to prepare a mixture. The LiOH.H ₂ O content of the mixture was 3 wt% in an excess amount such that the Li content in the LiOH.H ₂ O was 103 parts by weight based on 100 parts by weight of Li in the resulting solid electrolyte. The mixture was calcined at 900 캜 for 2 hours and then pulverized to prepare Li _6.25 La ₃ Zr ₂ Al _0.25 O ₁₂ , which is an aluminum-doped LLZO (Al-LLZO).

Production Example 2: Preparation of positive electrode

A conductive polymer (PEO), average molecular weight: 200,000, melting temperature: 65 占 폚), and an Al-Cu alloy prepared according to Production Example 1 were used as a positive electrode active material (lithium nickel cobalt manganese oxide, NMC) LLZO was mixed so that the weight ratio (wt%) was 70: 10: 10: 10.

Specifically, NMC, Super-p, and Al-LLZO prepared according to Production Example 1 were weighed in the weight ratio, and then mixed using a mortar for 30 minutes to prepare a mixed powder. The mixed powder was transferred into a container dedicated to a Thinky mixer, and then PEO was mixed at the weight ratio, and the mixture was mounted in a mixer and mixed once for 3 minutes at 2,000 rpm for 5 minutes. Next, ACN (acetonitrile) was mixed with the mixture, adjusted to an appropriate viscosity, zircon balls were added, and mixed at 2,000 rpm for 5 minutes to prepare a slurry. Finally, the slurry was cast on an aluminum foil and dried in a vacuum oven at 60 DEG C for 24 hours to prepare a positive electrode. The thickness after drying was adjusted to about 35 탆.

Production Example 3: Preparation of composite solid electrolyte layer

The Al-LLZO and the PEO solid electrolyte binder were weighed so that the content of Al-LLZO was 70 wt% with respect to the total weight of Al-LLZO and PEO produced according to Production Example 1 (Al-LLZO + PEO) The mixture was stirred at 2,000 rpm for 5 minutes to prepare a mixture.

At this time, the PEO solid electrolyte binder was a mixed solution containing PEO, ACN and LiClO ₄ , and PEO was adjusted to 25 wt% based on the total weight of the PEO solid electrolyte binder. Also, the PEO solid electrolyte binder was designed to have ionic conductivity, and the content ratio of PEO and LiClO ₄ was set to [EO]: [Li] = 15: 1.

The mixture was mixed with ACN and stirred with a Sinky mixer to adjust the viscosity to an appropriate value. Next, 2 mm zircon balls were added and stirred at 2,000 rpm for 5 minutes with a Sinky mixer to prepare a slurry. The slurry was cast on a PET (polyethylene terephthalate) film, dried at room temperature, and adjusted to have a thickness of 80 탆 to prepare a composite solid electrolyte layer.

Production Example 4: Preparation of a cathode

The mixing ratio of graphite dried at 110 DEG C for 2 days before use, Al-LLZO prepared according to Preparation Example 1, Super P and PEO solid electrolyte binder was set to a weight ratio (wt%) of 57: 12: 1: 30 And the mixture was stirred at 2,000 rpm for 5 minutes using a Sinky mixer to prepare a mixture.

At this time, the PEO solid electrolyte binder was a mixed solution containing PEO, ACN and LiClO ₄ , and PEO was adjusted to 25 wt% based on the total weight of the PEO solid electrolyte binder. Also, the PEO solid electrolyte binder was designed to have ionic conductivity, and the content ratio of PEO and LiClO ₄ was set to [EO]: [Li] = 15: 1.

The mixture was mixed with ACN and stirred with a Sinky mixer to adjust the viscosity to an appropriate value. Next, 2 mm zircon balls were added and stirred at 2,000 rpm for 5 minutes with a Sinky mixer to prepare a slurry. The slurry was cast on a copper foil, vacuum-dried at 60 DEG C for 24 hours, and adjusted to have a thickness of 60 to 65 mu m to form a negative electrode including a copper foil (current collector).

Example 1: Preparation of a pre-solid lithium secondary battery

The composite solid electrolyte layer prepared according to Preparation Example 3 and the negative electrode prepared according to Preparation Example 4 were each punched into 14 sizes and then laminated in the order of the positive electrode, the composite solid electrolyte layer and the negative electrode. Next, a pressure of 0.3 MPa was applied for about 10 seconds while heating to about 70 to 80 to prepare a laminate. A total solid lithium secondary battery was prepared from the above-mentioned laminate using a 2032 coin cell.

Example 2: Preparation of a pre-solid lithium secondary battery

A pre-solid lithium secondary battery was prepared in the same manner as in Example 1, except that it was made into a pouch cell instead of a coin cell.

[Test Example]

Test Example 1: Measurement of charge / discharge characteristics

2 is a graph showing the charging / discharging characteristics of a pre-solid lithium secondary battery manufactured in a coin cell type according to Example 1 at a current of 0.1 C at 70 ° C.

Referring to FIG. 2, the entire solid lithium battery produced according to Example 1 was found to maintain a discharge capacity of about 100 mAh / g at 70 ° C.

Accordingly, it was confirmed that the capacity of the pre-solid lithium lithium secondary battery produced according to Example 1 including the conductive polymer PEO in the anode, the composite solid electrolyte layer, and the cathode decreased according to the cycle.

Test Example 2: Measurement of Discharge Capacity According to Cycle

FIG. 3 shows the results of measuring the discharge capacity of the secondary battery prepared in Example 1 and Example 2 at 70 ° C according to the cycle.

Referring to FIG. 3, the pre-solid lithium lithium secondary battery produced according to Example 1 showed a discharge capacity of about 76% compared to the initial capacity in 20 cycles, and all of the solid lithium lithium produced according to Example 2 The discharge capacity of the battery was maintained at about 65% of the initial capacity.

Therefore, it was found that the all-solid lithium secondary battery produced according to Example 2 had an initial discharge capacity and the all-solid lithium secondary battery produced according to Example 1 had a cycle characteristic.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (14)

(a) preparing a positive electrode by mixing the positive electrode active material and the first conductive polymer;
(b) mixing the negative electrode active material and the second conductive polymer to prepare a negative electrode;
(c) mixing the solid electrolyte and the third conductive polymer to prepare a composite solid electrolyte layer; And
(d) arranging and laminating the composite solid electrolyte layer between the positive electrode and the negative electrode,
Wherein the first conductive polymer, the second conductive polymer and the third conductive polymer each independently comprise at least one selected from the group consisting of polyethylene oxide, polyethylene glycol, and polypropylene oxide,
Wherein the step (d) is a step of arranging the composite solid electrolyte layer between the anode and the cathode, and laminating by pressing at a pressure of 0.1 to 0.3 MPa in the temperature range (T) of the following equation (1) Gt;
[Formula 1]
T _m T _m + 50 ℃ ≤T≤
And in the formula 1, T _m1, T _m2 and T _m3 case of T _m1 is the large T _m = T _m1,
If T _m2 is the large and T _m = T _m2,
And T is the case _m3 greater T _m = T _m3,
If T _m3 <T _m1 = T _{m 2} , T _m = T _m1 ,
If the T _m2 <T _m1 = T _m3 and T _m = T _m1,
If the T _m1 <T _m2 = T _m3 and T _m = T _m2,
If the T _m1 = T _m2 = T _m3 and T _m = T _m1,
Here, T _m1 is the melting temperature of the first conductive polymer, T _m2 is the melting temperature of the second conductive polymer, T _m3 is the melting temperature of the third conductive polymer. The method according to claim 1,
Wherein the first conductive polymer, the second conductive polymer, and the third conductive polymer are independently polyethylene oxide having an average molecular weight of 500 to 1,000,000. The method according to claim 1,
Wherein the positive electrode active material is a three-component lithium metal oxide (NMC) of Ni-Co-Mn represented by the following chemical formula (3).
(3)
LiNi _p Co _q Mn _r O ₂
here 0 <p <0.9, 0 <q <0.5, 0 <r <0.5, p + q + r = 1. The method according to claim 1,
Wherein the negative electrode active material comprises at least one selected from graphite, coke, soft carbon, hard carbon, LTO (lithium titanium oxide), tin and silicon. 5. The method of claim 4,
Wherein the negative active material comprises graphite. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; The method according to claim 1,
Wherein the solid electrolyte is an aluminum-doped LLZO. The method according to claim 6,
Wherein the aluminum-doped LLZO is a garnet crystal structure. The method according to claim 6,
Wherein at least one selected from the positive electrode and the negative electrode further comprises the aluminum-doped LLZO. The method according to claim 1,
Wherein at least one selected from the positive electrode and the negative electrode further comprises a conductive material. 10. The method of claim 9,
Wherein the conductive material comprises at least one selected from the group consisting of carbon black, acetylene black, and ketjen black. The method according to claim 1,
Wherein at least one selected from the anode, the composite solid electrolyte layer, and the cathode further comprises a lithium salt. 12. The method of claim 11,
Wherein the lithium salt is selected from the group consisting of lithium perchlorate (LiClO ₄ ), lithium triflate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LipF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), and lithium trifluoromethanesulfonylimide _{(LiN (CF 3 SO 2)} 2) 1 the method of the all-solid lithium secondary battery, characterized in that at least one selected from the. The battery according to claim 1, wherein the pre-solid lithium secondary battery
A positive electrode comprising a three-component lithium metal oxide (NMC) of Ni-Co-Mn and polyethylene oxide;
An anode comprising graphite and polyethylene oxide; And
A composite solid electrolyte layer containing aluminum-doped LLZO and polyethylene oxide between the anode and the cathode;
The method of manufacturing a pre-solid lithium secondary battery according to claim 1, The method according to claim 1,
Wherein the first conductive polymer, the second conductive polymer, and the third conductive polymer are polyethylene oxide,
Step (d) is a step of arranging the composite solid electrolyte layer between the anode and the cathode and pressing the mixture at a pressure of 0.1 to 1.0 MPa at a temperature of 65 占 폚 (melting temperature of polyethylene oxide) to 115 占 폚 Gt; &lt; RTI ID = 0.0 &gt; 1, &lt; / RTI &gt;

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