KR20190019026A - Electrochemical device comprising different two gel polymer electrolytes - Google Patents

Abstract

The present disclosure relates to an electrochemical device comprising heterogeneous gel polymer electrolytes. More specifically, the present invention relates to the electrochemical device comprising at least two heterogeneous gel polymer electrolytes composed of different compositions, wherein each gel polymer electrolyte is integrated with an anode and a cathode. Since the liquid electrolyte component of each gel polymer electrolyte is not mixed, a battery having a heterogeneous electrolyte layer can be manufactured.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrochemical device including a heteropoly gel polymer electrolyte,

The present invention relates to an electrochemical device comprising a heterogeneous gel polymer electrolyte. More specifically, the present invention relates to an electrochemical device comprising at least two kinds of heterogeneous gel polymer electrolytes of different compositions, wherein each of the gel polymer electrolytes is integrated into a positive electrode and a negative electrode.

Generally, a method of manufacturing an electrode includes a step of preparing a slurry by mixing an active material, coating the current collector, and then compressing and cutting. Next, a separator is inserted between the electrodes, and the battery is wound by inserting the separator into a cylindrical shape or by laminating it into a pouch, and injecting a liquid electrolyte into the pouch. A battery using such a liquid electrolyte has no mechanical flexibility and thus is not applicable to a flexible battery, and there is a risk of leakage. Accordingly, studies have been conducted to bond the solid electrolyte to the electrode using the solid electrolyte.

The electrolyte plays a role in facilitating the smooth movement of charges between the electrodes, and is generally made of a solvent and a salt. In order to satisfy basic performance such as operating voltage and energy density, theoretically, it is determined by materials constituting the anode and cathode. However, it is important to select the optimum electrolyte because high ion transfer between both electrodes is required to obtain good performance of the cell.

The electrolyte plays the role of ion conduction and serves to transport the charge from the anode to the cathode during charging and from the cathode to the anode during discharge. The electrolyte penetrates into the micropores of the electrode to supply ions and exchange ions at the interface with the active material.

Generally, a high HOMO (high occupied molecular orbital) energy level is superior to an electron donor to facilitate oxidation reaction, while a low LUMO (low unoccupied molecular orbital) energy level is excellent in electron acceptance, (See FIG. 4).

The ideal electrolyte should operate only as an ion transfer medium, but when the energy level of the anode is higher than the energy level of the HOMO of the electrolyte, or when the energy level of the cathode is lower than the energy level of the LUMO of the electrolyte, Thereby causing a side reaction, thereby causing a problem of deteriorating battery performance.

In order to suppress such side reactions of the electrolyte, an electrolyte having a wide range of potential windows should be used. However, since an electrolyte having excellent oxidation stability is easily reduced and an electrolyte having excellent reduction stability is easily oxidized, The study of the electrolytes of electrolytes is mainly focused on finding appropriate compromises of oxidation / reduction stability.

In order to overcome this problem, there is a study to apply a hetero-electrolyte to an anode and a cathode based on an inorganic solid electrolyte which can be conducted only by lithium ion. However, there is a limit of the ion conductivity due to the thickness of the inorganic solid electrolyte, There is a problem in that it can not be applied to a flexible battery because there is no mechanical flexibility.

The present invention provides an electrochemical device comprising two or more kinds of gel polymer electrolyte layers having different compositions in order to provide a wide range of potential windows. More specifically, it is composed of an electrolyte having electrochemical characteristics optimized for each electrode (cathode and anode), and each electrolyte is physically and chemically bonded by a polymer matrix, so that even when each gel polymer electrolyte layer is joined to each other, And to provide an electrochemical device in which components are not mixed with each other.

Specifically, the gel polymer electrolyte which is in contact with the cathode has a low reduction potential and the gel polymer electrolyte which is in contact with the anode side has a wide potential window by using a solid electrolyte having a high oxidation potential, and suppresses side reactions. To provide an electrochemical device in which the solubility parameters are different from each other and do not mix.

Another object of the present invention is to provide an electrochemical device capable of producing a printable electrolyte paste further comprising inorganic particles at the time of preparing a gel polymer electrolyte layer and suppressing the risk that may be caused by mechanical deformation of the battery. The present invention also provides an electrochemical device which can be continuously produced by a printing method and can easily control the thickness and the number of layers of each layer.

Further, the present invention does not require a further liquid electrolyte and a separator, and is intended to provide an electrochemical device which is superior in charge / discharge efficiency and lifetime characteristics of a battery compared to a solid electrolyte using a gel polymer electrolyte. The present invention also provides an electrochemical device including a separator as required to improve stability against internal short circuit of the battery and improve mechanical properties.

The present invention also provides an electrochemical device capable of being applied to a flexible device having flexibility and being applicable to a surface having curvature instead of a flat surface.

One embodiment includes a cathode-electrolyte combination having a cathode coated with a first gel polymer electrolyte layer, and a cathode-electrolyte combination coated with a second gel polymer electrolyte layer on the cathode, wherein the first gel polymer electrolyte layer And the second gel polymer electrolyte layer are made of different compositions and face each other.

The embodiments have a polymer matrix structure, and the liquid electrolyte is physically and chemically bonded to the polymer matrix, and when applied to a battery, the liquid electrolyte components of the respective gel polymer electrolytes are not mixed, so that battery fabrication with a hetero- It is possible. Accordingly, there is an advantageous effect in improving the performance, such as the lifetime characteristics of the electrochemical device to which it is applied. In addition, by forming a gel polymer electrolyte layer having different solubility parameters in the positive electrode and the negative electrode, the liquid electrolyte components are not mixed with each other, so that it is possible to manufacture a battery having a heterogeneous electrolyte layer.

In addition, since a gel polymer electrolyte layer having different chemical compositions and having different energy levels or solubility parameters from each other can be formed on the anode and the cathode, a wide range of potential windows can be provided.

In addition, since the gel polymer electrolyte layer in contact with the anode and the gel polymer electrolyte layer in contact with the cathode are separated from each other without mixing, functional additives of different kinds can be added. In the case of using an existing electrolyte layer The electrochemical device having excellent oxidation / reduction stability can be provided, and the performance such as lifetime characteristics of the electrochemical device can be improved.

In addition, the gel polymer electrolyte layer of the present invention can be applied to various processes such as spraying, roll-to-roll printing, ink-jet printing, and screen printing due to its inherent rheological properties, And it is possible to manufacture continuously, and the productivity can be improved. In addition, the gel polymer electrolyte layer can be uniformly and closely contacted to the positive electrode and the negative electrode.

In addition, since the gel polymer electrolyte layer can be formed by directly applying to the electrode, the electrochemical device performance is improved by stabilizing the interface between the electrode and the gel polymer electrolyte layer, and when applied to a flexible battery, It is possible to realize stable battery performance, and it is possible to suppress the danger that may be caused from the shape deformation of the battery.

1 shows an embodiment of the electrochemical device of the present invention.
2 shows another embodiment of the electrochemical device of the present invention.
3 shows an embodiment of the gel polymer electrolyte layer of the present invention.
FIG. 4 is a diagram showing HOMO and LUMO according to energy levels. FIG.
5 is a graph showing the energy level of the solvent.
6 is a graph showing charge-discharge characteristics (0.1 C / 0.1 C) of Example 1. Fig.
7 is a graph showing the life characteristics (0.2C / 0.2C) of Example 1. Fig.
8 is a graph showing charge-discharge characteristics (0.1 C / 0.1 C) of Example 2. Fig.
9 is a graph showing the life characteristics (0.2C / 0.2C) of the second embodiment.
10 is a graph showing the charge-discharge characteristics (0.1 C / 0.1 C) of Example 3. Fig.
11 is a graph showing the life characteristic (0.2C / 0.2C) of the third embodiment.
12 is a graph showing charge-discharge characteristics (0.1 C / 0.1 C) of Example 4. Fig.
13 is a graph showing life characteristics (0.2C / 0.2C) of Example 4. Fig.
14 is a graph showing the charge-discharge characteristics (0.1 C / 0.1 C) of Example 5. Fig.
15 is a graph showing the life characteristic (0.2C / 0.2C) of Example 5. Fig.
16 is a graph showing charge-discharge characteristics (0.1 C / 0.1 C) of Example 6. Fig.
17 is a graph showing life characteristics (0.2C / 0.2C) of Example 6. Fig.
18 is a graph showing charge-discharge characteristics (0.1 C / 0.1 C) of Example 7. Fig.
19 is a graph showing the life characteristics (0.2C / 0.2C) of Example 7. Fig.
20 is an electron micrograph showing the excellent interfacial stability of Example 8;
21 is a graph showing the charge-discharge characteristics (0.1 C / 0.1 C) of Example 8;
22 is a graph showing the life characteristics (0.2C / 0.2C) of the eighth embodiment.
23 is a graph showing charge-discharge characteristics (0.1 C / 0.1 C) of Example 9. Fig.
24 is a graph showing the life characteristics (0.2C / 0.2C) of Example 9. Fig.
25 is a graph showing the charge-discharge characteristics (0.1 C / 0.1 C) of Comparative Example 1. Fig.
26 is a graph showing the charge-discharge characteristics (0.1 C / 0.1 C) of Comparative Example 2. Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described more fully hereinafter with reference to the accompanying drawings, It should be understood, however, that the invention is not limited thereto and that various changes and modifications may be made without departing from the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention is merely intended to effectively describe a specific embodiment and is not intended to limit the invention.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In the present invention, " facing each other " includes those that are directly in close contact with each other or face to face with each other.

In the present invention, 'different composition' means that the kind of one or two or more components constituting the first gel polymer electrolyte layer and the second gel polymer electrolyte layer are different or have different contents. More preferably, the energy level may be different or the solubility parameter may be a different composition.

The inventors of the present invention have studied to provide a wide range of potential windows while suppressing the side reaction of the electrolyte and have found that a gel polymer electrolyte layer is formed by using different kinds of compositions optimized for a cathode and an anode, Can be solved. That is, a gel polymer electrolyte layer is formed using a composition having an electron donor having a HOMO energy level so that an oxidation reaction can easily occur in the anode, and an electron accepting property having a LUMO energy level It is possible to suppress a side reaction by forming a gel polymer electrolyte layer using the composition and to provide a wide range of potential window, thus completing the present invention.

As a result of studies to prevent components of the gel polymer electrolyte layer integrated with the positive electrode and the negative electrode from being mixed with each other, it has been found that by forming crosslinked polymer matrices and having different solubility parameters, It is possible to provide an electrochemical device in which the liquid electrolytes are not mixed with each other and the stability and the cell efficiency are improved, thereby completing the present invention.

Further, by developing a composition which can be formed by a printing method when forming a gel polymer electrolyte layer, and by developing a composition having excellent adhesion with an electrode and a good adhesion, it is physically and chemically bonded to an anode and a cathode, And the present invention has been completed.

One aspect of the present invention is to provide a positive electrode-electrolyte composite body 100 in which a first gel polymer electrolyte layer 11 is coated on an anode 10 and a second gel polymer electrolyte membrane 11 on a cathode 20, The first gel polymer electrolyte layer 11 and the second gel polymer electrolyte layer 21 are composed of different compositions, and the first gel polymer electrolyte layer 11 and the second gel polymer electrolyte layer 21 have different compositions, Is an electrochemical device.

1, the first polymer electrolyte layer 11 may partially or wholly penetrate the positive electrode 10 and the negative electrode-electrolyte complex 200 may be formed on the first polymer electrolyte layer 11, as shown in FIG. 1 to explain one embodiment of the positive electrode- electrolyte combination 100 and the negative electrode- And the second gel polymer electrolyte layer 21 may be one which is partially or wholly permeated into the cathode 20 and integrated.

In one embodiment of the present invention, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may each independently include at least one separation membrane.

And more preferably at least one separator between the first gel polymer electrolyte layer and the second gel polymer electrolyte layer. 2, a positive electrode-electrolyte composite 100 in which a first gel polymer electrolyte layer 11 is coated on an anode 10 and a second gel electrolyte layer 11 on a negative electrode 20, Electrolyte composite layer 200 coated with a polymer electrolyte layer 21 and at least one separator 30 or a separator 30 is interposed between the first gel polymer electrolyte layer 11 and the second gel polymer electrolyte layer 21, And may further include a solid electrolyte (not shown). In one embodiment of the present invention, the separator may be impregnated with a liquid electrolyte.

As shown in FIG. 3, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may be formed by stacking two or more layers independently of each other. In this case, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have.

In one embodiment of the present invention, the anode and the cathode are

(I) an electrode made only of a current collector,

Ii) an electrode coated with an active material layer including an electrode active material and a binder on the current collector, and

Iii) a composite electrode coated with a composite active material layer containing an electrode active material, a crosslinked polymer matrix and a liquid electrolyte on a current collector

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In one embodiment of the present invention, the active material layer and the composite active material layer may further include a conductive material.

In one aspect of the present invention, the coating process may be coated by a printing method selected from inkjet printing, gravure printing, gravure offset, aerosol printing, stencil printing and screen printing.

In one embodiment of the present invention, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may have different energy levels from each other.

In one embodiment of the present invention, the difference in energy level between the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may be 0.01 eV or more.

In one embodiment of the present invention, the first gel polyelectrolyte layer and the second gel polyelectrolyte layer may have different solubility parameters.

In one aspect of the invention, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer can be greater than the solubility parameter difference 0.1 MPa ^1/2.

In one embodiment of the present invention, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may comprise a polymer matrix, an organic solvent, and a dissociable salt.

In one embodiment of the present invention, at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may further comprise any one or two or more additives selected from inorganic particles and a flame retardant.

In one embodiment of the present invention, the first gel polyelectrolyte layer further comprises a positive electrode antilatation inhibitor which is any one selected from succinonitrile and sebaconitrile or a mixture thereof,

The second gel polyelectrolyte layer may further comprise an SEI layer stabilizer which is any one selected from vinylene carbonate, ethylene carbonate carbonate and catechol carbonate or a mixture thereof.

In one embodiment of the present invention, the polymer matrix may be obtained by polymerizing a monomer having two or more functional groups or by copolymerizing a monomer having two or more functional groups and a monomer having one functional group.

In one embodiment of the present invention, the polymer matrix may be a semi-interpenetrating semi-IPN structure further comprising a linear polymer.

In one embodiment of the present invention, the solvent may be any one or a mixture of two or more solvents selected from a carbonate solvent, a nitrile solvent, an ester solvent, an ether solvent, a ketone solvent, an alcohol solvent, It can be used.

In one embodiment of the present invention, the first gel polyelectrolyte layer may include a carbonate-based solvent as a solvent, and the second gel polyelectrolyte layer may include an ether-based solvent as a solvent.

In one embodiment of the present invention, the carbonate-based solvent is any one selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, and butylene carbonate Is a mixture of two or more,

The ether solvent may be any one or a mixture of two or more selected from dimethyl ether, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran and tetrahydrofuran.

In one aspect of the invention, said dissociable salt is lithium hexafluorosilicate phosphate (LiPF _6), lithium tetrafluoroborate (LiBF _4), lithium hexafluorosilicate antimonate (LiSbF _6), lithium hexafluorosilicate acetoxy carbonate (LiAsF ₆ ), lithium difluoro methane sulfonate _{(LiC 4 F 9 SO 3)} , lithium perchlorate (LiClO _4), lithium aluminate (LiAlO _2), lithium tetrachloro- aluminate (LiAlCl _4), lithium chloride (LiCl), lithium iodide (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y + 1} SO ₂ (Li ₂ O)), lithium bisoxalatoborate (LiB (C ₂ O ₄ ) ₂ ), lithium trifluoromethanesulfonylimide ) (Where x and y are natural numbers), and derivatives thereof, or a mixture of two or more thereof.

In one embodiment of the present invention, at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may have a salt concentration of 2 moles or more.

In one embodiment of the present invention, at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may have a cross-link density gradient.

In an embodiment of the present invention, at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may have a multi-layer structure including two or more layers.

In one embodiment of the present invention, the multi-layer structure may have a different gradient of crosslink density or salt concentration of each layer.

In an embodiment of the present invention, the electrochemical device may be a primary cell or a secondary cell capable of an electrochemical reaction.

In one aspect of the present invention, the electrochemical device is a lithium secondary battery, a lithium secondary battery, a lithium-sulfur battery, a lithium-air battery, a sodium battery, an aluminum battery, a magnesium battery, a calcium battery, a zinc battery, A fuel cell, a lead-acid battery, a nickel-cadmium battery, a nickel-metal hydride battery, and an alkaline battery, which are selected from the group consisting of sodium-air batteries, aluminum-air batteries, magnesium-air batteries, calcium-air batteries, super capacitors, dye sensitized solar cells, Lt; / RTI >

Hereinafter, each configuration of the present invention will be described in more detail.

(1) anode-electrolyte combination

In one embodiment of the present invention, the anode-electrolyte assembly 100 means that the anode 10 and the first gel polymer electrolyte layer 11 are integrated as shown in Fig. 1 is a view for explaining an embodiment of each layer, in which the anode and the first gel polymer electrolyte layer may be separated as shown in Fig. 1, or a part or the whole of the first gel polymer electrolyte layer may be separated from the anode And may be integrally formed. At this time, the first gel polymer electrolyte layer may consist of one layer, or may be a layer in which two or more layers are stacked as shown in FIG. 3, and the number of layers is not limited. The first gel polymer electrolyte layer 11 may be formed by coating on the anode, and a coating solution may be applied between the anode surface and the pores by coating. More uniform, and more closely formed. The coating liquid for forming the first gel polymer electrolyte layer will be described below.

First, the anode will be described first. In one embodiment of the present invention, the anode may be made of various embodiments, and specifically, for example, an electrode made of only i) a current collector, ii) a cathode active material and a binder And iii) a composite electrode on which a composite active material layer including a positive electrode active material, a crosslinked polymer matrix and a liquid electrolyte is coated on the current collector. More preferably, a liquid electrolyte in view of improving the conductivity of the ion, and the liquid electrolyte may also be included in the ii) mode. The liquid electrolyte may have the same composition as or different from the liquid electrolyte used in the first gel polymer electrolyte layer. In the case of the crosslinked polymer matrix, as in the case of (iii), the adhesive strength to the gel polymer electrolyte layer and the interfacial adhesion can be further improved. In this case, the crosslinked polymer matrix used for the anode may be the same as or different from the polymer matrix used for the first gel polymer electrolyte layer, but from the viewpoint of further improving the adhesion and interfacial adhesion and further improving the ionic conductivity It is preferable that the same polymer and cross-linking density are achieved.

The collector may be any one selected from the group consisting of a conductive metal, a conductive metal oxide, and the like, provided that the current collector is not limited to the substrate having excellent conductivity used in the related art. The current collector may be formed of a conductive material as a whole, or may be a conductive metal, a conductive metal oxide, a conductive polymer, or the like coated on one or both surfaces of the insulating substrate. In addition, the current collector may be made of a flexible substrate, and can easily be bent, thereby providing a flexible electronic device. Further, it may be made of a material having a restoring force that is bent and then returned to its original shape. More specifically, for example, the current collector may be made of aluminum, stainless steel, copper, nickel, iron, lithium, cobalt, titanium, nickel foams, copper foams and polymer substrates coated with a conductive metal, It is not.

The anode may have a pattern formed on its surface. When the pattern is formed, the surface area is further increased, and the application and adhesion of the first gel polymer electrolyte layer can be further improved. The pattern may be adjusted according to the thickness of the current collector, and may be in the form of a dot pattern, an oblique pattern, a depressed pattern, a V-shaped pattern, a honeycomb, a zigzag, or a combination thereof. The pattern may be formed at intervals of 1 to 100 mu m, and the depth of the pattern may be 1 mu m to 100 mu m.

An embodiment ii) of the anode of the present invention may be one in which a cathode active material composition comprising a cathode active material and a binder is coated on the current collector and the active material layer is coated thereon.

The collector may be as described above, and the cathode active material composition may be directly coated on a current collector such as aluminum and dried to form a cathode plate having a cathode active material layer formed thereon. The coating may be coated by a printing method such as ink-jet printing, gravure printing, gravure offset, aerosol printing, stencil printing, and screen printing as well as coating methods such as bar coating, spin coating, slot die coating and dip coating.

Alternatively, the cathode active material composition may be cast on a separate support, and then a film obtained by peeling the support from the support may be laminated on the current collector to produce a cathode in which the cathode active material layer is formed. The thickness of the cathode active material layer is not limited, but may be 0.01 to 500 탆, more specifically, 1 to 200 탆, but is not limited thereto.

The cathode active material composition may include, but is not limited to, a cathode active material, a binder, and a solvent, and may further include a conductive material.

The cathode active material may be used without limitation as long as it is commonly used in the art. Specifically, a lithium primary battery or a secondary battery is exemplified, and a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used. The cathode active material of the present invention may be in powder form.

Concretely, at least one selected from the group consisting of cobalt, manganese, nickel, and the like and a composite oxide of a metal and lithium combined with each other may be used. Specific examples include, but are not limited to, compounds represented by any one of the following formulas. Li _a A _{1 - b} R _b D ₂ wherein, in the formula, 0.90? A? 1.8 and 0? B? 0.5; Li _a E _{1 - b} R _b O _{2 - c} D _c , wherein 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, and 0 ≤ c ≤ 0.05; LiE _{2 - b} R _b O _{4 - c} D _{c where} 0? B? 0.5, 0? C? 0.05; Li _a Ni _{1 -b- c} Co _b R _c D _{α where} 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 <α ≦ 2; Li _a Ni _{1 -b- c} Co _b R _c O _{2 - ?} Z _{? Where} 0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05 and 0 <? Li _a Ni _{1 -b- c} Co _b R _c O _{2 - ?} Z ₂ wherein 0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, and 0 <? Li _a Ni _1-bc Mn _b R _c D _? Wherein, in the formula, 0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05 and 0 <? Li _a Ni _{1 -b- c} Mn _b R _c O _{2 - ?} Z _{? Where} 0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05 and 0 <? Li _a Ni _{1 -b- c} Mn _b R _c O _{2 - ?} Z ₂ wherein 0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05 and 0 <? Li _a Ni _b E _c G _d O ₂ wherein 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, and 0.001 ≤ d ≤ 0.1; Li _a Ni _b Co _c Mn _d G _e O ₂ wherein 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, and 0.001 ≤ e ≤ 0.1; Li _a NiG _b O ₂ (in the above formula, 0.90? A? 1.8 and 0.001? B? 0.1); Li _a CoG _b O ₂ (in the above formula, 0.90? A? 1.8 and 0.001? B? 0.1); Li _a MnG _b O ₂ wherein, in the above formula, 0.90? A? 1.8 and 0.001? B? 0.1; Li _a Mn ₂ G _b O ₄ (in the above formula, 0.90? A? 1.8 and 0.001? B? 0.1); QO _2; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiTO ₂ ; LiNiVO _4; Li _(3-f) J ₂ (PO ₄ ) ₃ (0? F? 2); Li _(3-f) Fe ₂ (PO ₄ ) ₃ (0? F? 2); And LiFePO _4.

In the above formula, A is Ni, Co, Mn or a combination thereof; R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D is O, F, S, P or a combination thereof; E is Co, Mn or a combination thereof; Z is F, S, P or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; Q is Ti, Mo, Mn or a combination thereof; T is Cr, V, Fe, Sc, Y or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu or a combination thereof.

Of course, a compound having a coating layer on the surface of the compound may be used, or a compound having a coating layer may be mixed with the compound. The coating layer may comprise, as a coating element compound, an oxide, a hydroxide of a coating element, an oxyhydroxide of a coating element, an oxycarbonate of a coating element, or a hydroxycarbonate of a coating element. The compound constituting these coating layers may be amorphous or crystalline. The coating layer may contain Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr or a mixture thereof. Any coating method may be used as long as it can be coated by a method that does not adversely affect the physical properties of the cathode active material, such as spray coating or dipping, by using these elements in the above-mentioned compound, It is a content that can be well understood by people engaged in the field, so detailed explanation will be omitted.

The cathode active material may comprise 20 to 99 wt%, more preferably 30 to 95 wt%, of the total weight of the composition, though not limited thereto. And may have an average particle diameter of 0.001 to 50 탆, more preferably 0.01 to 20 탆, but is not limited thereto.

The binder serves to adhere the positive electrode active material particles to each other and to fix the positive electrode active material to the current collector. Typical examples thereof include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide Polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon or the like alone Or a mixture of two or more of them may be used, but the present invention is not limited thereto. The content of the binder may be 0.1 to 20 wt%, more preferably 1 to 10 wt%, based on the total weight of the binder. But the content is not limited thereto.

The solvent may be any one selected from N-methylpyrrolidone, acetone, and water, or a mixture of two or more thereof, but is not limited thereto and can be used as long as it is commonly used in the art. The content of the solvent is not limited and can be used without limitation as long as the content is such that the slurry can be coated on the positive electrode current collector.

In addition, the cathode active material composition may further include a conductive material.

The conductive material is used for imparting conductivity to the electrode. The conductive material does not cause any chemical change in the battery and can be used without limitation as long as it is an electron conductive material. Specific examples thereof include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon nanotubes, and carbon fibers; Metal powders such as copper, nickel, aluminum, and silver, or metal-based materials such as metal fibers; Conductive polymers such as polyphenylene derivatives; Or a mixture thereof, may be used alone or in admixture of two or more.

The conductive material may be included in the cathode active material composition in an amount of 0.1 to 20% by weight, more specifically 0.5 to 10% by weight, and more specifically 1 to 5% by weight. The average particle diameter of the conductive material may be 0.001 to 1000 탆, more specifically 0.01 to 100 탆, but is not limited thereto.

Next, the third aspect of the anode of the present invention may be a composite electrode coated with a composite active material layer containing a cathode active material, a crosslinked polymer matrix and a liquid electrolyte on a current collector. At this time, since the current collector and the cathode active material are as described above, further explanation will be omitted.

The crosslinked polymer matrix may be the same as or different from the polymer matrix used in the first gel polymer electrolyte layer. However, from the viewpoint of further improving the adhesion and interfacial adhesion and further improving the ionic conductivity, the same polymer and crosslinking density .

The composite active material layer may be one in which a crosslinkable monomer and a derivative thereof are photo-crosslinked or thermally crosslinked by an initiator to form a crosslinked polymer matrix.

Accordingly, the composite active material layer may be formed by coating a current collector with a composite active material composition comprising a crosslinkable monomer and a derivative thereof, an initiator, a cathode active material, and a liquid electrolyte, and crosslinking the mixture by irradiating ultraviolet rays or applying heat to form a crosslinked polymer matrix The cathode active material, the liquid electrolyte, and the like may be uniformly distributed, and the evaporation process of the solvent may be unnecessary. In this case, the coating is not limited to a coating method such as a bar coating or a spin coating, but may be continuously coated by a printing method such as roll to roll printing, ink jet printing, gravure printing, gravure offset, aerosol printing, stencil printing and screen printing Lt; / RTI &gt;

Alternatively, the composite active material composition may be cast on a separate support, and then a film obtained by peeling from the support may be laminated on the current collector to produce a positive electrode having a composite active material layer. The thickness of the composite active material layer is not limited, but may be 0.01 to 500 탆, more specifically 0.1 to 200 탆, but is not limited thereto.

One embodiment of the composite active material composition may include 1 to 50% by weight, specifically 1 to 40% by weight, more specifically 2 to 30% by weight, of a crosslinkable monomer and its derivative out of 100% But is not limited to. The initiator may be 0.01 to 50 wt%, specifically 0.01 to 20 wt%, more specifically 0.1 to 10 wt%, but is not limited thereto. The content of the cathode active material may be 1 to 95% by weight, specifically 1 to 90% by weight, more specifically 5 to 80% by weight, but is not limited thereto. The liquid electrolyte may be contained in an amount of 1 to 95% by weight, specifically 1 to 90% by weight, more specifically 2 to 80% by weight, but is not limited thereto. In addition, the conductive material may further include a conductive material, if necessary, and the conductive material may be contained in an amount of 0.1 to 20% by weight, specifically 1 to 10% by weight, and is not limited thereto.

The crosslinkable monomer may be a monomer having two or more functional groups or a mixture of a monomer having two or more functional groups and a monomer having one functional group and may be used without limitation as long as it is a photo-crosslinkable or thermally crosslinkable monomer .

Specific examples of the monomer having two or more functional groups include polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, trimethylolpropane ethoxylate And may be any one or a mixture of two or more selected from triacrylate, trimethylolpropane ethoxylate trimethacrylate, bisphenol eetoxydate diacrylate, bisphenol eetoxytate dimethacrylate, and the like.

Examples of the monomers having one functional group include methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate, ethylene glycol methyl ether acrylate, ethylene glycol methyl ether methacrylate, Nitrile, vinyl acetate, vinyl chloride, vinyl fluoride, and the like, or a mixture of two or more thereof.

The initiator can be used without limitation as long as it is a photoinitiator or a thermal initiator commonly used in the art.

The liquid electrolyte may include a dissociable salt and a solvent, and may be the same or different in composition from the liquid electrolyte used in the first gel polymer electrolyte layer.

Examples of the dissociable salt include, but are not limited to, lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroantimonate (LiSbF ₆ ), lithium hexafluoroacetate (LiAsF _6), lithium difluoro methane sulfonate _{(LiC 4 F 9 SO 3)} , lithium perchlorate (LiClO _4), lithium aluminate (LiAlO _2), lithium tetrachloro- aluminate (LiAlCl _4), lithium chloride (LiCl) , lithium iodide (LiI), lithium bis oxalate reyito borate _{(LiB (C 2 O 4)} 2), lithium trifluoro methane sulfonyl imide _{(LiN (C x F 2x +} 1 SO 2) (C y F 2y + ₁ SO ₂ ) (where x and y are natural numbers), and derivatives thereof. The concentration of the dissociable salt is 0.1-10.0 M, more specifically 1-5 M , But is not limited thereto.

The solvent may be any one or a mixture of two or more solvents selected from a carbonate solvent, a nitrile solvent, an ester solvent, an ether solvent, a ketone solvent, a glidant solvent, an organic solvent such as an alcohol solvent and an aprotic solvent, . &Lt; / RTI &gt;

Examples of the carbonate solvent include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC) EC), propylene carbonate (PC), and butylene carbonate (BC).

The nitrile solvent may be acetonitrile, succinonitrile, adiponitrile, sebaconitrile, or the like.

Examples of the ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, 1,1-dimethyl acetate, Methylpropionate, ethylpropionate, γ-butylolactone, decanolide, valerolactone, mevalonolactone, caprolactone, caprolactone, ) May be used.

Examples of the ether solvent include dimethyl ether, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran and the like. As the ketone solvent, cyclohexanone Can be used.

Examples of the gelling agent solvent include ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and the like.

As the alcoholic solvent, ethyl alcohol, isopropyl alcohol and the like can be used. As the aprotic solvent, R-CN (R is a straight chain, branched or cyclic hydrocarbon group of C2 to C20, An aromatic ring or an ether bond), amides such as dimethylformamide, dioxolanes such as 1,3-dioxolane, and sulfolanes.

The solvent may be used alone or in combination of one or more. If one or more of the solvents is used in combination, the mixing ratio may be appropriately adjusted according to the performance of the desired battery, and this may be widely understood by those skilled in the art .

Next, the first gel polymer electrolyte layer coated and integrated on the above-described anode will be described in more detail.

The first gel polymer electrolyte layer is formed by coating the first gel polymer electrolyte composition on the anode by a printing method such as roll-to-roll printing, inkjet printing, gravure printing, gravure offset, aerosol printing, and screen printing to enable continuous production .

The first gel polymer electrolyte layer may be one in which a crosslinkable monomer and a derivative thereof are photo-crosslinked or thermally crosslinked by an initiator to form a crosslinked polymer matrix. By the crosslinking, the mechanical strength and structural stability of the gel polymer electrolyte layer are improved, and in particular, the structural stability of the gel polymer electrolyte layer and the anode interface can be further improved when combined with the positive electrode of i) to iii).

Accordingly, the first gel polymer electrolyte layer may be formed by coating a first gel polymer electrolyte composition comprising a crosslinkable monomer and a derivative thereof, an initiator, and a liquid electrolyte on a positive electrode, and crosslinking the polymer by applying ultraviolet light or heat, The liquid electrolyte and the like may be uniformly distributed in the liquid electrolyte, and the evaporation process of the solvent may be unnecessary. Preferably, the first gel polymer electrolyte composition has a viscosity suitable for the printing process. For example, the first gel polymer electrolyte composition may have a viscosity of 0.1 to 10,000,000 cps, more preferably 1.0 to 1,000,000 cps, measured using a Brookfield viscometer at 25 ° C, More preferably from 1.0 to 100,000 cps, and is preferably within a range suitable for the printing process in the above range, but is not limited thereto.

The first gel polymer electrolyte composition may include, but is not limited to, 1 to 50% by weight, specifically 2 to 40% by weight, of the crosslinkable monomer and the derivative thereof in 100% by weight of the total composition. The initiator may be 0.01 to 50 wt%, specifically 0.01 to 20 wt%, more specifically 0.1 to 10 wt%, but is not limited thereto. The liquid electrolyte may be contained in an amount of 1 to 95% by weight, specifically 1 to 90% by weight, more specifically 2 to 80% by weight, but is not limited thereto.

The types of the crosslinkable monomer and its derivatives, the initiator and the liquid electrolyte are the same as those described above in the complex active material composition, and therefore, the repeated explanation is omitted. In addition, the monomer used in the first gel polymer electrolyte composition may be the same or different from the monomer used in the composite active material composition. And more preferably by using the same monomers to further improve adhesion.

Also, the polymer matrix of the first gel polymer electrolyte layer may be a semi-interpenetrating semi-IPN structure including a linear polymer. In this case, the first gel polymer electrolyte layer and the anode-electrolyte combination have excellent flexibility and are resistant to stresses such as bending when used as a battery, so that the battery can be normally driven without deteriorating performance. Therefore, the present invention can be applied to a flexible battery or the like.

The linear polymer is not limited as long as it is easy to mix with the crosslinkable monomer and can impregnate the liquid electrolyte. Specific examples thereof include polyvinylidene fluoride (PVDF), polyvinylidene fluoride (PVI) -co-hexafluoropropylene (PVdF-co-HFP), polymethyl And any one selected from the group consisting of polymethyl methacrylate (PMMA), polystyrene (PS), polyvinylacetate (PVA), polyacrylonitrile (PAN), polyethylene oxide Or a combination of two or more, but is not limited thereto.

The linear polymer may be contained in an amount of 1 to 90% by weight based on the weight of the crosslinked polymer matrix. 1 to 80% by weight, 1 to 70% by weight, 1 to 60% by weight, 1 to 50% by weight, 1 to 40% by weight and 1 to 30% by weight. That is, when the polymer matrix is a semi-interpenetrating network (semi-IPN) structure, the cross-linkable polymer and the linear polymer may be contained in a weight ratio of 99: 1 to 10:90. When the linear polymer is included in the above range, the crosslinked polymer matrix can secure flexibility while maintaining proper mechanical strength. Accordingly, when applied to a flexible battery, it is possible to realize stable battery performance even when deformed by various external forces, and it is possible to suppress the risk of battery ignition and explosion which may be caused by the shape deformation of the battery.

In addition, the first gel polymer electrolyte composition may further contain inorganic particles as required. The inorganic particles can be printed by controlling the rheological properties such as viscosity of the first gel polymer electrolyte composition. The inorganic particles may be used to improve ionic conductivity of the electrolyte and improve mechanical strength, but may be porous particles, but are not limited thereto. For example, metal oxides, carbon oxides, carbon-based materials and organic-inorganic complexes may be used, and they may be used singly or in combination of two or more. More specifically, for example, SiO ₂ , Al ₂ O ₃ , TiO ₂ , BaTiO ₃ , Li ₂ O, LiF, LiOH, Li ₃ N, BaO, Na ₂ O, Li ₂ CO ₃ , CaCO ₃ , LiAlO ₂ , SrTiO ₃ , SnO ₂ , CeO ₂ , MgO, NiO, CaO, ZnO, ZrO ₂ , SiC, and the like. By using the inorganic particles, though not limited thereto, not only the affinity with the organic solvent is high but also the thermal stability is very high, so that the thermal stability of the electrochemical device can be improved.

The average diameter of the inorganic particles is not limited, but may be 0.001 탆 to 10 탆. Specifically 0.1 to 10 탆, more specifically 0.1 to 5 탆. When the average diameter of the inorganic particles satisfies the above range, excellent mechanical strength and stability of the electrochemical device can be realized.

The content of the inorganic particles in the first gel polymer electrolyte composition may be from 1 to 50% by weight, more specifically from 5 to 40% by weight, and more specifically from 10 to 30% by weight, But is not limited to, 0.1 to 10,000,000 cps, more preferably 1.0 to 1,000,000 cps, and even more preferably 1.0 to 100,000 cps.

Further, the first gel polymer electrolyte composition may further include a flame retardant agent as the case requires, or may further include a positive-electrode thermal inhibitor which is any one selected from succinonitrile and sebaconitrile or a mixture thereof. have. The content may be 0.01 to 10% by weight, more specifically 0.1 to 10% by weight, based on the weight of the first gel polymer electrolyte composition, but is not limited thereto.

The flame retardant may be used without limitation as long as it is a phosphate-based flame retardant conventionally used in the field. The content of the flame retardant is in the range of 0.01 to 10% by weight, more specifically 0.1 to 10% by weight in the first gel polymer electrolyte composition But is not limited thereto.

The thickness of the first gel polymer electrolyte layer may be 0.01 탆 to 500 탆. Specifically, it may be 5 to 100 mu m. When the thickness of the first gel polymer electrolyte layer satisfies the above range, the performance of the electrochemical device can be improved while facilitating the manufacturing process. However, the present invention is not limited thereto.

In addition, the first gel polymer electrolyte layer may have a gradient in which the cross-linking density decreases from the surface toward the anode. By forming a cross-link density gradient, there is an effect that the charge-discharge cycle is further improved. When the cross-linking density is increased, the mechanical strength and the structural stability are improved. However, ionic conductivity of the gel polymer electrolyte may be lowered due to the dense polymer structure. However, in the case of forming a cross-link density gradient, Stability and ionic conductivity can be solved.

In one embodiment of the present invention, the first gel polyelectrolyte layer may have a multi-layer structure including at least two layers. More specifically, it may be a two-layer structure including a first layer 11a and a second layer 11b as shown in FIG. 3, or a three-layer structure not shown, and the number of the layers is not limited .

At this time, the two or more layers may be the same or different from each other. More specifically, the first layer 11a directly facing the anode may have a gradient in which the crosslink density or the concentration of the salt is different from that of the second layer 11b. Specifically, the second layer 11b may have a higher crosslink density or a higher salt concentration than the first layer 11a. When such a gradient is formed, the ion conductivity can be further increased and the side reaction can be suppressed, which is more preferable.

Further, if necessary, it may further comprise a separation membrane between two or more first gel polymer electrolyte layers.

(2) cathode-electrolyte combination

In one embodiment of the present invention, the cathode-electrolyte assembly 200 means that the cathode 20 and the second gel polymer electrolyte layer 21 are integrated as shown in FIG. 1 is a view for explaining an embodiment of each layer, in which the cathode and the second gel polymer electrolyte layer may be separated as shown in Fig. 1, or a part or the whole of the second gel polymer electrolyte layer may be separated from the anode And may be integrally formed. At this time, the second gel polymer electrolyte layer may be a single layer or a layer in which two or more layers are stacked, and the number of layers is not limited. The second gel polymer electrolyte layer 21 may be formed by coating on the negative electrode. The coating solution may be applied to the surface of the negative electrode and the pores by coating, More uniform, and more closely formed. The coating liquid for forming the second gel polymer electrolyte layer will be described below.

First, the negative electrode will be described. In an embodiment of the present invention, the negative electrode may be formed in various forms. Specifically, for example, the negative electrode may be formed of i) an electrode made only of a collector, ii) an anode active material and a binder And iii) a composite electrode coated with a composite active material layer containing a negative electrode active material, a crosslinked polymer matrix, and a liquid electrolyte on the current collector. More preferably, a liquid electrolyte in view of improving the conductivity of the ion, and the liquid electrolyte may also be included in the ii) mode. The liquid electrolyte may have the same composition as or different from the liquid electrolyte used in the second gel polymer electrolyte layer. In the case of the crosslinked polymer matrix, as in the case of (iii), the adhesive strength to the gel polymer electrolyte layer and the interfacial adhesion can be further improved. In this case, the crosslinked polymer matrix used for the cathode may be the same as or different from the polymer matrix used for the second gel polymer electrolyte layer. However, from the viewpoint of further improving the adhesion and interfacial adhesion and further improving the ionic conductivity It is preferable that the same polymer and cross-linking density are achieved.

In the cathode of the present invention, the current collector may be a thin film or a mesh, and the material thereof may be a metal such as lithium metal, lithium aluminum alloy, lithium metal alloy, or a polymer.

The negative electrode of the present invention may be one in which the current collector of the thin film or mesh shape is used as it is, or the collector in the form of a thin film or a mesh is stacked on the conductive substrate and integrated.

In addition, the current collector can be used without limitation as long as it is a conductive substrate used in the art. Specifically, it may be made of, for example, any one selected from a conductive metal, a conductive metal oxide, and the like. The current collector may be formed of a conductive material as a whole, or may be a conductive metal, a conductive metal oxide, a conductive polymer, or the like coated on one or both surfaces of the insulating substrate. In addition, the current collector may be made of a flexible substrate, and can easily be bent, thereby providing a flexible electronic device. Further, it may be made of a material having a restoring force that is bent and then returned to its original shape. More specifically, for example, the current collector may be made of aluminum, stainless steel, copper, nickel, iron, lithium, cobalt, titanium, nickel foams, copper foams and polymer substrates coated with a conductive metal, It is not.

The negative electrode may have a pattern formed on its surface. When the pattern is formed, the surface area is further increased, and the application and adhesion of the second gel polymer electrolyte layer can be further improved. The pattern may be adjusted according to the thickness of the current collector, and may be in the form of a dot pattern, an oblique pattern, a depressed pattern, a V-shaped pattern, a honeycomb, a zigzag, or a combination thereof. The pattern may be formed at intervals of 1 to 100 mu m, and the depth of the pattern may be 1 mu m to 100 mu m.

The second aspect of the negative electrode of the present invention may be one in which the active material layer is coated by applying the negative electrode active material composition containing the negative electrode active material and the binder on the current collector.

The current collector may be as described above, and the negative electrode active material composition may be directly coated on a current collector such as a metal thin film and dried to form a positive electrode plate having a positive electrode active material layer. The coating may be coated by a printing method such as ink-jet printing, gravure printing, gravure offset, aerosol printing, stencil printing, and screen printing as well as coating methods such as bar coating, spin coating, slot die coating and dip coating.

Alternatively, the negative electrode active material composition may be cast on a separate support, and then a film obtained by peeling the support from the support may be laminated on the current collector to produce a negative electrode having a negative electrode active material layer. The thickness of the negative electrode active material layer is not limited, but may be 0.01 to 500 탆, more specifically 0.1 to 200 탆, but is not limited thereto.

The negative electrode active material composition may include, but is not limited to, an anode active material, a binder, and a solvent, and may further include a conductive material.

The negative electrode active material can be used without limitation as long as it is commonly used in the art. Specifically, a lithium primary battery or a secondary battery is exemplified, and a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used. The negative electrode active material of the present invention may be in powder form.

More specifically, it may be, for example, any one or a mixture of two or more selected from lithium-alloyable metals, transition metal oxides, non-transition metal oxides, and carbon-based materials.

The lithium-alloyable metal may be Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, But is not limited thereto.

The transition metal oxide may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, or the like, or may be a single or a mixture of two or more thereof.

Wherein the non-transition metal oxide is at least one selected from the group consisting of Si, SiOx (0 <x <2), Si-C composite, Si-Q alloy (Q is an alkali metal, an alkaline earth metal, a Group 13 to Group 16 element, (Wherein R is an alkali metal, an alkaline earth metal, a Group 13 to Group 16 element, a transition metal, a rare earth element or a combination thereof, and Sn (a combination of Sn and Sn) And the like). The specific elements of Q and R include Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Sb, Bi, S, Se, Te and Po, or a mixture of two or more thereof.

As the carbon-based material, any one or a mixture of two or more selected from crystalline carbon, amorphous carbon, and combinations thereof may be used. Examples of the crystalline carbon include graphite such as amorphous, plate-like, flake, spherical or fibrous natural graphite, artificial graphite, etc. Examples of the amorphous carbon include soft carbon, hard carbon, mesophase pitch carbide, And the like, but the present invention is not limited thereto.

The negative electrode active material may include 1 to 90% by weight, more preferably 5 to 80% by weight, of the total weight of the composition. And may have an average particle diameter of 0.001 to 20 탆, more preferably 0.01 to 15 탆, but is not limited thereto.

The binder serves to adhere the positive electrode active material particles to each other and to fix the positive electrode active material to the current collector. Typical examples thereof include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide Polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon or the like may be used But is not limited thereto.

The solvent may be any one selected from N-methylpyrrolidone, acetone, and water, or a mixture of two or more thereof, but is not limited thereto and can be used as long as it is commonly used in the art.

In addition, the negative electrode active material composition may further include a conductive material.

The conductive material is used for imparting conductivity to the electrode. Any material can be used as long as it does not cause any chemical change in the battery. Examples of the conductive material include natural graphite, artificial graphite, carbon black, acetylene black, , Carbon-based materials such as carbon fibers; Metal powders such as copper, nickel, aluminum, and silver, or metal-based materials such as metal fibers; Conductive polymers such as polyphenylene derivatives; Or a mixture thereof may be used.

The content of the conductive material may be 1 to 90% by weight, more specifically 5 to 80% by weight, of the negative electrode active material composition, but is not limited thereto.

The average particle diameter of the conductive material may be 0.001 to 100 탆, more specifically 0.01 to 80 탆, but is not limited thereto.

Next, the embodiment (iii) of the cathode of the present invention may be a composite electrode coated with a composite active material layer containing a negative electrode active material, a crosslinked polymer matrix and a liquid electrolyte on a current collector. At this time, since the current collector and the negative electrode active material are as described above, further explanation is omitted.

The cross-linked polymer matrix may be the same as or different from the polymer matrix used in the second gel polymer electrolyte layer. However, from the viewpoint of further improving the adhesion and interfacial adhesion and further improving the ionic conductivity, the same polymer and cross- .

The composite active material layer may be one in which a crosslinkable monomer and a derivative thereof are photo-crosslinked or thermally crosslinked by an initiator to form a crosslinked polymer matrix.

Accordingly, the composite active material layer may be formed by coating a current collector with a composite active material composition comprising a crosslinkable monomer and a derivative thereof, an initiator, a negative electrode active material, and a liquid electrolyte, and irradiating ultraviolet rays or applying heat thereto to crosslink the crosslinked polymer matrix The anode active material, the liquid electrolyte, and the like may be uniformly distributed, and the evaporation process of the solvent may be unnecessary. In this case, the coating may be a coating method such as bar coating or spin coating, but also a coating method such as roll-to-roll printing, ink-jet printing, gravure printing, gravure offset, aerosol printing and screen printing to enable continuous production .

Alternatively, the composite active material composition may be cast on a separate support, and then a film obtained by peeling the support from the support may be laminated on the current collector to produce a negative electrode having a composite active material layer. The thickness of the composite active material layer is not limited, but may be 0.01 to 500 탆, more specifically 0.1 to 200 탆, but is not limited thereto.

The composite active material composition is the same as that used for the positive electrode, and a further explanation will be omitted.

Next, the second gel polymer electrolyte layer coated and integrated on the above-described negative electrode will be described in more detail.

The second gel polymer electrolyte layer is formed by coating a second gel polymer electrolyte composition on a cathode by a printing method such as roll-to-roll printing, inkjet printing, gravure printing, gravure offset, aerosol printing, and screen printing to enable continuous production .

The second gel polymer electrolyte layer may be one in which a crosslinkable monomer and its derivative are photo-crosslinked or thermally crosslinked by an initiator to form a crosslinked polymer matrix. By the crosslinking, the mechanical strength and the structural stability of the gel polymer electrolyte layer are improved, and the structural stability of the gel polymer electrolyte layer and the anode interface is further improved, particularly when combined with the positive electrode of i) to iii).

Therefore, the second gel polymer electrolyte layer may be formed by coating a second gel polymer electrolyte composition comprising a crosslinkable monomer and its derivative, an initiator, and a liquid electrolyte on a negative electrode, and crosslinking the polymer by applying ultraviolet light or heat, The liquid electrolyte and the like may be uniformly distributed in the liquid electrolyte, and the evaporation process of the solvent may be unnecessary. The second gel polymer electrolyte composition preferably has a viscosity suitable for the printing process. Specifically, the viscosity of the second gel polymer electrolyte composition measured using a Brookfield viscometer at 25 ° C is 0.1 to 10,000,000 cps, more preferably 1.0 to 1,000,000 cps, More preferably 1.0 to 100,000, and a viscosity suitable for the printing process in the above range is preferable, but not limited thereto.

The kind and content of the crosslinkable monomer and the derivative thereof, the initiator, the liquid electrolyte and the inorganic particles in the second gel polymer electrolyte composition are the same as those described above in the first gel polymer electrolyte composition, and further explanation is omitted.

However, unlike the positive electrode, the second gel polymer electrolyte composition may contain a functional additive necessary for the negative electrode. The second gel polymer electrolyte composition may further contain a flame retardant if necessary, or may be any one selected from vinylene carbonate, ethylene carbonate carbonate and catechol carbonate Or a mixture thereof. &Lt; Desc / Clms Page number 7 &gt; Vinylene carbonate (VC) can be used to improve the charge / discharge life of a battery by forming a stable SEI layer in the initial charging process and suppressing the peeling of the carbon layer structure or direct reaction with the electrolyte. The content of the functional additive may be 0.01 to 30% by weight, more specifically 0.1 to 10% by weight, based on the weight of the first gel polymer electrolyte composition, but is not limited thereto.

The thickness of the second gel polymer electrolyte layer may be 0.01 탆 to 500 탆. Specifically 1 to 100 mu m, and more preferably 5 to 50 mu m. When the thickness of the second gel polyelectrolyte layer satisfies the above range, the performance of the electrochemical device can be improved while facilitating the manufacturing process. However, the present invention is not limited thereto.

In addition, the second gel polymer electrolyte layer may have a gradient in which the cross-linking density decreases from the surface toward the anode.

In one embodiment of the present invention, the second gel polyelectrolyte layer may have a multi-layered structure including at least two layers. More specifically, it may be a two-layer structure or three-layer structure, and the number of the layers is not limited.

At this time, the two or more layers may be the same or different from each other. More specifically, the first layer facing directly to the negative electrode may be formed with a gradient in which the crosslinking density or the concentration of the salt is different from that of the second layer facing the first layer. Specifically, the second layer may have a higher crosslink density or a higher salt concentration than the first layer. When such a gradient is formed, the ion conductivity can be further increased and the side reaction can be suppressed, which is more preferable.

In the present invention, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have different compositions.

More specifically, different kinds of crosslinking polymers may be used, different types of organic solvents may be used, different kinds of dissociable salts may be used, functional additives may be added, or different compositions may be used so as to have different energy levels have. Thereby providing a wide range of potential windows. More specifically, the first gel polymer electrolyte layer coupled to the anode is configured to have a high HOMO (high occupied molecular orbital) energy level and the second gel polymer electrolyte layer coupled to the cathode has a low LUMO (Lowest unoccupied molecular orbital) energy It is possible to provide a wide range of potential windows without side reactions.

More specifically, it may satisfy the following formulas (1) and (2).

| C _e | <| CE _H | [Formula 1]

| A _e | <| AE _L | [Formula 2]

And C _e is the energy level of the positive electrode active material in the above formula 1 and 2, A _e is the energy level of the negative electrode active material, CE _H is a first of a HOMO energy level of the gel polymer electrolyte layer, AE _L is the second gel polymer electrolyte The energy level of the LUMO of the layer.

The first gel polymer electrolyte layer and the second gel polymer electrolyte layer may have an energy level difference of 0.01 eV or more. More specifically, it may be 0.01 to 7 eV.

The energy level of the HOMO is the molecular orbitals with the highest energy at which electrons can participate in binding, and the energy level of LUMO represents the molecular orbital at the lowest energy in the unconjugated region of electrons. HOMO and LUMO energy levels can be calculated using all the methods based on quantum mechanics. Typical methods are density functional theory (DFT) and ab initio molecular orbital method.

The energy level can be changed depending on the type of salt, the concentration of the salt and the type of the solvent, and the energy level of a commonly known solvent is shown in FIG.

In order to prevent the liquid electrolyte used in the first gel polymer electrolyte layer and the second gel polymer electrolyte layer from intermixing, the solubility parameters of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer are different from each other .

More specifically, the first gel polymer electrolyte layer and the second gel polymer electrolyte layer has a solubility parameter difference between 0.1 MPa ^1/2, more specifically, 0.1 ~ 20 MPa ^1/2, more preferably from ¹ ~ 20 MPa 1 ^{/ 2,} even better, it is preferable that the I ² ~ 20 MPa ^1/2 differences.

The solubility parameter may vary depending on the organic solvent used in the liquid electrolyte.

The above solubility parameters are used as selection criteria to indicate that the solubility parameters are mutually non-useful, as described in Charles M. Hansen's book (Hansen Solubility Parameters: A User's Handbook, 2nd Edition, 2nd Ed, CRC Press, 2007) Can be calculated according to the method.

In this regard, the first gel polymer electrolyte layer may include a carbonate-based organic solvent as a solvent, and the second gel polymer electrolyte layer may include an ether organic solvent as an organic solvent. More specifically, the carbonate-based solvent may be at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate And may be any one or a mixture of two or more selected from carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC). More specifically, it may be any one or a mixture of two or more selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

The ether solvent may be any one or a mixture of two or more selected from dimethyl ether, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran and tetrahydrofuran.

The concentration of the salt of the first gel polymer electrolyte layer and that of the second gel polymer electrolyte layer may be different from each other, and at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may have a salt concentration of 2 moles or more Lt; / RTI &gt; More preferably, the salt concentration of the second gel polymer electrolyte layer deposited on the cathode is higher than the salt concentration of the first gel polymer electrolyte layer. More specifically, the salt concentration of the first gel polymer electrolyte layer is 0.1 to 2.5 moles , And the concentration of the salt of the second gel polymer electrolyte layer may be 2 moles or more, more specifically 3 to 10 moles. When the salt concentration of the second gel polymer electrolyte layer is high, the reduction potential becomes lower, and the difference in energy level between the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may be widened. Also, as the concentration of the salt increases, the cohesive energy increases, and the solubility parameter difference between the first gel polymer electrolyte layer and the second gel polymer electrolyte layer may increase.

In this case, the energy level or the solubility parameter may be changed even when the first gel polymer electrolyte and the second gel polymer electrolyte use the same solvent and the same salt and only the concentration of the salt is different.

A liquid electrolyte containing one mole of a salt generally used has a large number of free solvent molecules which do not participate in solvation and solvent molecules not participating in the solvation are easily decomposed electrochemically, Resulting in property degradation. On the other hand, since the present invention uses two or more moles of high-concentration liquid electrolyte, most of the solvent participates in the solvation due to the high concentration of the salt, and there is almost no free solvent molecule not participating in solvation Thereby improving the lifetime characteristics of the battery.

(3) The membrane

As shown in FIG. 2, the electrochemical device of the present invention may further include a separation membrane 30 between the first gel polymer electrolyte layer 11 and the second gel polymer electrolyte layer 21. In addition, at least one or more separation membranes may be laminated, and a separation membrane made of the same or different materials may be used. Although not shown in the figure, when the first gel polymer electrolyte layer 11 and the second gel polymer electrolyte layer 21 are independently formed of two or more layers, the separator may further include a separator between the layers .

The separation membrane may be used from the viewpoint of improving the mechanical strength, or may be impregnated with a liquid electrolyte to further improve the ion conductivity. At this time, it is preferable that the liquid electrolyte used in the separation membrane is not mixed with the liquid electrolyte used in the first gel polymer electrolyte layer or the second gel polymer electrolyte layer. Therefore, the liquid electrolyte used in the separation membrane may be the same liquid electrolyte as the liquid electrolyte used in the first gel polymer electrolyte layer, or the same liquid electrolyte as the liquid electrolyte used in the second gel polymer electrolyte layer. Or a liquid electrolyte which is different from the liquid electrolyte used in the first gel polymer electrolyte layer and the second gel polymer electrolyte layer and is not mixed with the liquid electrolyte used in the first gel polymer electrolyte layer and the second gel polymer electrolyte layer .

And the solubility parameter of the liquid electrolyte used for the membrane To this end, the first gel solubility parameter of the liquid electrolyte used for the solubility parameter or a second gel polymer electrolyte layer of a liquid electrolyte used for the polymer electrolyte layers are each 0.1 MPa ^1/2 or more preferably, more specifically I is 0.1 ~ 20 MPa ^1/2 differences.

The separation membrane can be used without limitation as long as it is conventionally used in the field. For example, it may be a woven fabric, a nonwoven fabric, a porous film, or the like. They may be multilayer films formed by laminating one layer or two or more layers. The material of the separator is not particularly limited, but specific examples thereof include polyethylene, polypropylene, polybutylene, polypentene, polymethylpentene, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyamide, polycarbonate, , Polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalene, and copolymers thereof, and the like, or a mixture of two or more thereof. Further, the thickness is not limited, and may be 1 to 1000 mu m, more specifically, 10 to 800 mu m, which is generally used in the art, but is not limited thereto.

(4) electrochemical devices

In one embodiment of the present invention, when the electrochemical device is a set of a positive electrode-electrolyte complex and a negative electrode-electrolyte complex, two or more sets may be connected in series or in parallel.

In an embodiment of the present invention, the electrochemical device may be a primary cell or a secondary cell capable of electrochemical reaction.

More particularly, the present invention relates to a lithium secondary battery, a lithium secondary battery, a lithium-sulfur battery, a lithium-air battery, a sodium battery, an aluminum battery, a magnesium battery, a calcium battery, a sodium- But are not limited to, air cells, super capacitors, dye-sensitized solar cells, fuel cells, lead acid batteries, nickel cadmium batteries, nickel metal hydride batteries, and alkaline batteries.

In the present invention, the electrochemical device may be a flexible electrochemical device. The electrochemical device may not require a separate separator.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are merely examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

The physical properties were measured as follows.

1) Viscosity

(Dv2TRV-cone & plate, CPA-52Z) at 25 deg. C in a Brookfield viscometer.

2) Evaluation of battery performance

The initial charge / discharge capacity was observed at a current of 0.1 C (= 0.3 mA / cm 2) in a voltage range of 3.0 to 4.2 V at room temperature (25 캜) The lifetime characteristics of the lithium battery according to the number of charge / discharge cycles were observed.

The initial discharge capacity is the discharge capacity (mAh / cm ² ) in the first cycle. The initial charge-discharge efficiency is the ratio of the charge capacity to the discharge capacity in the first cycle. The capacity retention rate for the life characteristics was calculated by the following equation.

Capacity retention rate (%) = [200th cycle discharge capacity / first cycle discharge capacity] × 100

3) Flexibility evaluation

The manufactured battery was bent so as to be folded using tweezers, and it was confirmed whether it was peeled off when the battery was wound.

[ Example  One]

1) Preparation of anode-electrolyte combination

A lithium cobalt composite oxide (LiCoO ₂ ) having an average particle diameter of 5 탆 was used as a cathode active material, 5% by weight of Super-P having an average particle size of 40 nm as a conductive material and 5% by weight of polyvinylidene fluoride as a binder in an organic solvent N-methyl-2-pyrrolidone to have a solid content of 50% by weight To prepare a positive electrode active material composition (positive electrode mixture slurry). The cathode active material composition was applied to an aluminum foil having a thickness of 20 탆 by using a doctor blade, dried at 120 캜 and rolled by a roll press to prepare a cathode coated with an active material layer.

The first gel polymer electrolyte composition was coated on the prepared active material layer of the anode using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm &lt; ² & gt ^; for 20 seconds to form a first gel polymer electrolyte layer having a thickness of 40 [ Thereby preparing a positive electrode-electrolyte combination.

The first gel polymer electrolyte composition was prepared by mixing trimethylolpropane ethoxylate triacrylate in an amount of 9.9 wt%, hydroxymethylphenylpropanone in an amount of 0.1 wt% as a photoinitiator, and 90 wt% of a liquid electrolyte. As the liquid electrolyte, A liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in propylene carbonate, which is a cyclic carbonate-based organic solvent excellent in oxidation stability, was used. The viscosity of the first gel polymer electrolyte composition was 5 cps at 25 DEG C and the solubility parameter was about 27 MPa & ^{lt ; 1/2 &} gt ;.

2) Preparation of cathode-electrolyte combination

A negative electrode active material composition was prepared by adding 95 wt% of natural graphite powder, 2 wt% of carbon black having an average particle size of 40 nm as a conductive material, 1.5 wt% of styrene-butadiene rubber as a binder and 1.5 wt% of carboxymethyl cellulose as a negative electrode active material, Mixture slurry). The negative electrode active material composition was applied to a copper foil having a thickness of 20 탆 using a doctor blade, dried at 120 캜, and rolled by a roll press to prepare a negative electrode coated with an active material layer.

The second gel polymer electrolyte composition was coated on the prepared anode active material layer using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm &lt; ² & gt ^; for 20 seconds to form a second gel polymer electrolyte layer having a thickness of 40 [ To prepare a negative electrode-electrolyte combination.

The second gel polymer electrolyte composition was prepared by mixing trimethylolpropane ethoxylate triacrylate in an amount of 9.9% by weight, hydroxymethylphenylpropanone in an amount of 0.1% by weight as a photoinitiator, and liquid electrolyte in an amount of 90% by weight. A liquid electrolyte in which 5 moles of LiTFSI (lithium bis (trifluoromethanesulfonyl) imide) was dissolved in dimethyl ether as a linear ether organic solvent excellent in reduction stability was used. The viscosity of the second gel polymer electrolyte composition was 50 cps at 25 DEG C and the solubility parameter was about 17.7 MPa & ^{lt ; 1/2 &} gt ;.

3) Manufacture of lithium ion secondary battery

The cell (coin cell) was prepared by laminating the anode-electrolyte combination and the cathode-electrolyte combination as shown in FIG. 1 without using a conventional porous separator and a liquid electrolyte.

As a result of evaluating the flexibility, it was confirmed that the peeling did not occur and the flexibility was excellent, and the charge-discharge characteristics were evaluated and shown in FIG. 6 and the life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  2]

1) Preparation of anode-electrolyte combination

The first gel polymer electrolyte composition was coated on the active material layer of the anode of Example 1 using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm &lt; ² & gt ^; for 20 seconds to crosslink the first gel polymer electrolyte layer To prepare a positive electrode-electrolyte combination.

The first gel polymer electrolyte composition was prepared by mixing 9.9% by weight of trimethylolpropane ethoxylate triacrylate, 0.1% by weight of hydroxymethylphenylpropanone as photoinitiator, 70% by weight of a liquid electrolyte, alumina having an average particle size of 300 nm as inorganic particles And a liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in propylene carbonate solvent was used as the liquid electrolyte. The viscosity of the first gel polymer electrolyte composition is ranged from 25 ℃ 200 cps, the solubility parameter was about 27 MPa ^1/2.

2) Preparation of cathode-electrolyte combination

The second gel polymer electrolyte composition was coated on the negative electrode active material layer of Example 1 using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm &lt; ² & gt ^; for 20 seconds to form a second gel polymer electrolyte layer having a thickness of 40 [ To prepare a negative electrode-electrolyte combination.

The second gel polymer electrolyte composition contained 9.9 wt% trimethylolpropane ethoxylate triacrylate, 0.1 wt% hydroxymethylphenylpropanone as a photoinitiator, 70 wt% liquid electrolyte, alumina having an average particle size of 300 nm as inorganic particles , And a liquid electrolyte in which 5 mol of LiTFSI was dissolved in dimethyl ether was used as the liquid electrolyte. The viscosity of the second gel polymer electrolyte composition was 300 cps at 25 DEG C and the solubility parameter was about 17.7 MPa & ^{lt ; 1/2 &} gt ;.

3) Manufacture of lithium ion secondary battery

A battery was prepared in the same manner as in Example 1.

As a result of evaluating the flexibility, it was confirmed that the peeling did not occur and the flexibility was excellent, and the charging and discharging characteristics were evaluated, and it was shown in FIG. 8 and the life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  3]

2, except that a positive electrode-electrolyte composite, a separation membrane, and a negative electrode-electrolyte combination were sequentially laminated using a celgard 3501, a polyolefin-based microporous membrane having a thickness of 25 탆, as a separator in Example 1 Were prepared in the same manner as in Example 1. The separator was formed by impregnating propylene carbonate with a liquid electrolyte in which 1 mol of LiPF ₆ was dissolved. The result of evaluating the flexibility was found to be excellent in flexibility without peeling, 10, and the life characteristics were evaluated and shown in Fig.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  4]

In Example 1, the first gel polymer electrolyte composition having different salt concentrations was applied and cured to prepare a first gel polymer electrolyte layer having a concentration gradient of salt and having a thickness of 40 탆 laminated in two layers in the preparation of the anode- Was prepared in the same manner as in Example 1.

The first layer applied to the anode was the same composition as in Example 1 and the second layer applied on the first layer was the same as Example 1 except that a liquid electrolyte in which 2 moles of LiPF ₆ was dissolved was used .

As a result of evaluating the flexibility, it was confirmed that the peeling did not occur and the flexibility was excellent, and the charging and discharging characteristics were evaluated, and it was shown in FIG. 12 and the life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  5]

In Example 1, a second gel polymer electrolyte composition having different salt concentrations was applied and cured to prepare a second gel polymer electrolyte layer having a concentration gradient of salt and having a thickness of 40 탆 laminated in two layers in the preparation of the negative electrode- Was prepared in the same manner as in Example 1.

The same procedure was followed as in Example 1 except that the first layer applied to the cathode was the same composition as in Example 1 and the second layer applied on the first layer was a liquid electrolyte in which 2 moles of LiTFSI was dissolved .

As a result of evaluating the flexibility, it was confirmed that the peeling did not occur and the flexibility was excellent, and the charging and discharging characteristics were evaluated and shown in FIG. 14 and the life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  6]

In the same manner as in Example 1 except that an aluminum thin film having a thickness of 20 탆 was used as a negative electrode in Example 1 and a second gel polymer electrolyte composition was applied on the aluminum thin film to prepare a negative electrode- .

As a result of evaluation of flexibility, it was confirmed that peeling did not occur and flexibility was excellent. Charging and discharging characteristics were evaluated and shown in FIG. 16, and life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  7]

In the same manner as in Example 1 except that a lithium thin film having a thickness of 20 탆 was used as a negative electrode in Example 1 and a second gel polymer electrolyte composition was applied on the lithium thin film to prepare a negative electrode- .

As a result of evaluating the flexibility, it was confirmed that no peeling occurred and the flexibility was excellent, and the charging and discharging characteristics were evaluated and shown in FIG. 18, and the life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  8]

1) Preparation of anode-electrolyte combination

A lithium cobalt composite oxide (LiCoO ₂ ) having an average particle diameter of 5 탆 was used as a cathode active material, 12% by weight of Super-P having an average particle diameter of 40 nm as a conductive material, 3.9% by weight of trimethylolpropane ethoxylate triacrylate, 0.1% by weight of hydroxymethylphenylpropanone as a photoinitiator, 36% by weight of a liquid electrolyte, To prepare a composite active material composition. As the liquid electrolyte, a liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in propylene carbonate solvent was used. The composite active material composition was coated on an aluminum thin film having a thickness of 20 탆 using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm ^-2 for 20 seconds to prepare a positive electrode coated with a composite active material layer having a thickness of 60 탆.

The first gel polymer electrolyte composition was coated on the prepared composite active material layer using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm & lt ^; &quot; ² & gt ^; for 20 seconds to obtain a positive electrode having a first gel polymer electrolyte layer -Electrolyte conjugate.

The first gel polymer electrolyte composition was prepared by mixing 9.9% by weight of trimethylolpropane ethoxylate triacrylate, 0.1% by weight of hydroxymethylphenylpropanone as photoinitiator, 70% by weight of a liquid electrolyte, alumina having an average particle size of 300 nm as inorganic particles And a liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in propylene carbonate solvent was used as the liquid electrolyte.

2) Preparation of cathode-electrolyte combination

48 wt% of lithium titanate powder as an anode active material, 12 wt% of carbon black having an average particle diameter of 40 nm as a conductive material, 3.9 wt% of trimethylolpropane ethoxylate triacrylate, 0.1 wt% of hydroxymethylphenylpropanone as a photoinitiator, , And 36 wt% of a liquid electrolyte were added to prepare a composite active material composition. As the liquid electrolyte, a liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in a mixed solvent of propylene carbonate was used. The composite active material composition was coated on an aluminum thin film having a thickness of 20 탆 using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm ^-2 for 20 seconds to prepare a negative electrode coated with a composite active material layer having a thickness of 60 탆.

The second gel polymer electrolyte composition was coated on the prepared composite active material layer of the anode using a doctor blade and irradiated with ultraviolet rays at 2000 mW / cm & lt ^; & quot ^; & gt ^; for 20 seconds to form a cathode having a second gel polymer electrolyte layer -Electrolyte conjugate.

The second gel polymer electrolyte composition contained 9.9 wt% trimethylolpropane ethoxylate triacrylate, 0.1 wt% hydroxymethylphenylpropanone as a photoinitiator, 70 wt% liquid electrolyte, alumina having an average particle size of 300 nm as inorganic particles And a liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in propylene carbonate solvent was used as the liquid electrolyte.

As a result of evaluating the flexibility, it was confirmed that no peeling occurred and the flexibility was excellent. As a result of observation with an electron microscope, it was found that the interface stability was excellent as shown in FIG. The charge-discharge characteristics were evaluated and shown in Fig. 21, and the life characteristics were evaluated and shown in Fig.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Example  9]

In Example 1, 9.9% by weight of trimethylolpropane ethoxylate triacrylate, 0.1% by weight of hydroxymethylphenylpropanone as a photoinitiator, and 90% by weight of a liquid electrolyte were mixed with the first gel polymer electrolyte composition, As the electrolyte, a liquid electrolyte in which 1 mole of LiPF ₆ was dissolved in a mixed solvent of propylene carbonate: vinylene carbonate in a weight ratio of 95: 5 was prepared in the same manner as in Example 1.

In Example 1, 9.9% by weight of trimethylolpropane ethoxylate triacrylate, 0.1% by weight of hydroxymethylphenylpropanone as a photoinitiator, and 90% by weight of a liquid electrolyte were mixed with the second gel polymer electrolyte composition, As the electrolyte, a liquid electrolyte in which 5 mol of LiTFSI (lithium bis (trifluoromethanesulfonyl) imide) was dissolved in a mixed solvent in which dimethyl ether: vinylene carbonate was mixed at a weight ratio of 95: 5 was used, .

As a result of evaluating the flexibility, it was confirmed that the peeling did not occur and the flexibility was excellent, and the charging and discharging characteristics were evaluated and shown in FIG. 23, and the life characteristics were evaluated and shown in FIG.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Comparative Example  One]

After the positive electrode, negative electrode and separator of Example 1 were laminated, a liquid electrolyte was injected to prepare a battery (coin cell). At this time, 1 mole of LiPF ₆ was used as propylene carbonate for the liquid electrolyte.

Charge-discharge characteristics were evaluated and shown in Fig.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

[ Comparative Example  2]

In the same manner as in Comparative Example 1, 5 moles of LiTFSI was used as the liquid electrolyte for the dimethylether.

The charge-discharge characteristics were evaluated and shown in Fig.

In addition, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed.

division Charging / discharging efficiency (%) Capacity retention rate (%) Example 1 99.8 97.4 Example 2 97.7 97.6 Example 3 97.5 98.7 Example 4 93.8 98.9 Example 5 94.1 99.6 Example 6 90.9 86.1 Example 7 85.4 93.7 Example 8 99.8 99.7 Example 9 93.9 99.7 Comparative Example 1 0.07 × Comparative Example 2 × ×

As described above, the charging / discharging efficiency under a charging / discharging current rate of 0.1 C with a coin cell and the lifetime characteristics under a charge / discharge current rate of 0.2 C were observed. It was found that the batteries of Examples 1 to 9 exhibited high charging / discharging efficiency and lifetime characteristics. This shows that it is possible to apply a heterogeneous electrolyte component optimized for each of the positive electrode and the negative electrode in the present invention, thereby remarkably improving the charging / discharging efficiency and lifetime characteristics of the battery.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10: anode
11: First gel polymer electrolyte layer
20: cathode
21: Second gel polymer electrolyte layer
30: Membrane
100: anode-electrolyte combination
200: cathode-electrolyte combination

Claims (26)

A positive electrode-electrolyte combination in which a first gel polymer electrolyte layer is coated on an anode, and
And a negative electrode-electrolyte complex on which a second gel polymer electrolyte layer is coated on a negative electrode,
Wherein the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have different compositions and face each other. The method according to claim 1,
And at least one separation membrane between the first gel polymer electrolyte layer and the second gel polymer electrolyte layer. 3. The method of claim 2,
Wherein the separation membrane is at least one selected from a woven fabric, a nonwoven fabric, and a porous membrane. The method according to claim 1,
The positive electrode and the negative electrode are
(I) an electrode made only of a current collector,
Ii) an electrode coated with an active material layer including an electrode active material and a binder on the current collector, and
Iii) a composite electrode coated with a composite active material layer containing an electrode active material, a crosslinked polymer matrix and a liquid electrolyte on a current collector
&Lt; / RTI &gt; 5. The method of claim 4,
Wherein the active material layer and the composite active material layer further comprise a conductive material. The method according to claim 1 or 4,
Wherein the coating is coated by a printing method selected from inkjet printing, gravure printing, gravure offset, aerosol printing, stencil printing and screen printing. The method according to claim 1,
Wherein the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have different energy levels from each other. 8. The method of claim 7,
Wherein the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have an energy level difference of 0.01 eV or more. The method according to claim 1,
Wherein the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have different solubility parameters. 10. The method of claim 9,
Wherein the first gel polymer electrolyte layer and the second gel polymer electrolyte layer have a solubility parameter difference of 0.1 MPa &lt; 1/2 or more. The method according to claim 1,
Wherein the first gel polymer electrolyte layer and the second gel polymer electrolyte layer comprise a polymer matrix, a solvent, and a dissociable salt. 12. The method of claim 11,
Wherein at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer further comprises any one or two or more additives selected from inorganic particles and a flame retardant. 13. The method according to claim 11 or 12,
Wherein the first gel polymer electrolyte layer further comprises a positive electrode heat inhibitor which is any one selected from succinonitrile and sebaconitrile or a mixture thereof,
Wherein the second gel polymer electrolyte layer further comprises a SEI layer stabilizer which is any one selected from vinylene carbonate, ethylene carbonate carbonate and catechol carbonate or a mixture thereof. 12. The method of claim 11,
Wherein the polymer matrix comprises:
A monomer having two or more functional groups is polymerized or
Wherein the monomer having two or more functional groups and the monomer having one functional group are copolymerized. 15. The method of claim 14,
Wherein the polymer matrix further comprises a linear polymer and is a semi-interpenetrating network (semi-IPN) structure. 12. The method of claim 11,
Wherein the solvent is at least one selected from a carbonate solvent, a nitrile solvent, an ester solvent, an ether solvent, a ketone solvent, an alcohol solvent, an aprotic solvent and water. 17. The method of claim 16,
Wherein the first gel polymer electrolyte layer contains a carbonate-based solvent as a solvent,
Wherein the second gel polymer electrolyte layer comprises an ether-based solvent as a solvent. 18. The method of claim 17,
The carbonate-based solvent is any one or a mixture of two or more selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, and butylene carbonate,
Wherein the ether solvent is any one or a mixture of two or more selected from dimethyl ether, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran and tetrahydrofuran. 12. The method of claim 11,
The dissociable salt is at least one compound selected from the group consisting of lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroantimonate (LiSbF ₆ ), lithium hexafluoroacetate (LiAsF ₆ ), lithium difluoromethane sulfoxide (LiC ₄ F ₉ SO ₃ ), lithium perchlorate (LiClO ₄ ), lithium aluminate (LiAlO ₂ ), lithium tetrachloroaluminate (LiAlCl ₄ ), lithium chloride (LiCl), lithium iodide reyito borate _{(LiB (C 2 O 4)} 2), lithium trifluoro methane sulfonyl imide _{(LiN (C x F 2x +} 1 SO 2) (C y F 2y + 1 SO 2) ( where, x and y Is a natural number), and derivatives thereof. 12. The method of claim 11,
Wherein at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer has a salt concentration of 2 moles or more. The method according to claim 1,
Wherein at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer has a cross-link density gradient. The method according to claim 1,
Wherein at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer has a multilayer structure including two or more layers. 23. The method of claim 22,
Wherein the multi-layer structure has a gradient of different crosslink density or salt concentration of each layer. 23. The method of claim 22,
Wherein at least one of the first gel polymer electrolyte layer and the second gel polymer electrolyte layer has a multilayer structure, the separator further comprises a separator between the first gel polymer electrolyte layer and the second gel polymer electrolyte layer. The method according to claim 1,
The electrochemical device is a primary cell or a secondary cell capable of electrochemical reaction. 26. The method of claim 25,
The electrochemical device may be a lithium primary battery, a lithium secondary battery, a lithium-sulfur battery, a lithium-air battery, a sodium battery, an aluminum battery, a magnesium battery, a calcium battery, a zinc battery, Wherein the electrochemical device is one selected from the group consisting of an air cell, a magnesium-air cell, a calcium-air cell, a supercapacitor, a dye-sensitized solar cell, a fuel cell, a lead acid battery, a nickel cadmium battery, a nickel metal hydride battery and an alkaline battery.

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