KR20180072469A - Organic-inorganic composite solid electrolyte, lithium secondary cell comprising the same, and manufacturing method for the lithium secondary cell - Google Patents

Abstract

The present invention relates to an organic-inorganic composite solid electrolyte, a lithium secondary battery including the same, and a method for manufacturing the same. By using the organic-inorganic composite solid electrolyte, the lithium secondary battery including the same, and the method for manufacturing the same according to the present invention, an organic-inorganic composite solid electrolyte for the lithium secondary battery having enhanced ionic conductivity and a method for manufacturing the same can be provided. In addition, according to the present invention, since a solid electrolyte having a high conductivity is used, a battery having better electrical characteristics can be provided.

Description

[0001] The present invention relates to an organic-inorganic composite solid electrolyte, a lithium secondary battery including the same, and a manufacturing method thereof. [0002]

The present invention relates to an organic-inorganic composite solid electrolyte, a lithium secondary battery including the same, and a manufacturing method thereof. More particularly, the present invention relates to an organic-inorganic hybrid solid electrolyte having improved ionic conductivity and formed of solid solution formed by adding solid- , A lithium secondary battery including the same, and a method of manufacturing the same.

In recent years, large-sized batteries for use in automobile batteries and fixed batteries have attracted a great deal of attention. The background of the invention is not limited to small batteries for portable devices, which have been mainstream to date, This is because demand for batteries is rapidly increasing.

For this reason, battery characteristics different from those described above are required. Especially, in order to secure stability and increase battery life, it is demanded that the performance of lithium rechargeable battery is higher than that of current lithium rechargeable battery.

That is, a lithium secondary battery is composed of a positive electrode, a negative electrode and an electrolyte. Currently, an organic electrolyte is most widely used in a lithium secondary battery, and a lithium secondary battery operating in an organic electrolyte has a large discharge capacity and an energy density, This is because of safety issues such as fire risk and electrolyte leakage.

Therefore, a method of using a solid electrolyte as a safe and reliable electrolyte instead of an organic electrolyte has been studied. The solid electrolyte can be divided into a ceramic-based solid electrolyte and a polymer-based solid electrolyte. On the other hand, a battery using a ceramic-based solid electrolyte is known to be the safest, and a ceramic-based solid electrolyte can be further divided into a sulfide-based solid electrolyte and an oxide-based solid electrolyte.

To date, the development of ceramic-based solid electrolytes has been dominated by the development of sulfides and oxide-based solid electrolytes, and some studies have reported ionic conductance up to liquid electrolyte levels.

However, solid electrolytes still show a relatively low ionic conductivity compared to liquid electrolytes, and many studies have been conducted to overcome or compensate for the disadvantages of the increase of interfacial contact resistance and the generation of hydrogen sulfide by water and reaction (in the case of sulfides) Should proceed.

1. Polymer electrolyte, method for producing the same, and lithium secondary battery using the same 2. Description of the Related Art Solid polymer electrolyte composite materials having improved strength and lithium secondary batteries containing the same are disclosed in Japanese Patent Application Laid-Open No. 10-2010-0035221 (Apr.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide an organic-inorganic hybrid electrolyte improved in ion conductivity.

A second object of the present invention is to provide a method for producing an organic-inorganic hybrid electrolyte improved in ion conductivity.

A third object of the present invention is to provide a lithium secondary battery including an organic / inorganic composite solid electrolyte having improved ionic conductivity and improved capacity retention.

In order to achieve the above object, the organic-inorganic hybrid electrolyte according to the present invention has ion conductivity in the range of 1.00 × 10 ^-5 to 9.99 × 10 ^-3 at 25 ° C. to 32 ° C.

Here, the organic-inorganic composite solid electrolyte preferably includes a polymer electrolyte and a lithium ion conductor.

Here, it is preferable that the lithium ion conductor further includes titanium.

Here, it is preferable that the lithium ion conductor further includes silicon.

Here, the polymer electrolyte and the lithium ion conductor are preferably contained in a weight ratio of 100: 1 to 20: 1.

Here, the polymer electrolyte preferably includes a plasticizer, a crosslinking agent, and a lithium salt.

Wherein the plasticizer is selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl Ether, a polypropylene glycol / polyethylene glycol copolymer at the terminal of dibutyl ether, and a polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer at the terminal of dibutyl ether.

Here, the crosslinking agent preferably includes at least one selected from the group consisting of phosphazene-based, phosphate-based, and bisphenol A ethoxylate diacrylates having a crosslinkable functional group.

Here, it is preferable that the crosslinking agent and the plasticizer are contained at a weight ratio of 1: 4 to 6: 1.

Here, the lithium salt may be at least one selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoroacetate (LiAsF6), lithium difluoromethane sulfonate LiC4F9SO3), lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI), lithium bis oxalate borate (LiB (C2O4) , And lithium trifluoromethanesulfonylimide (LiTFSI). [0035] The term " a "

Here, it is preferable that the concentration of the lithium salt in the polymer electrolyte is [EO]: [Li] = 20: 0.5 to 2 molar ratio.

In order to achieve the second object, the present invention provides a method for producing an organic-inorganic hybrid solid electrolyte,

Mixing the polymer electrolyte into an organic solvent; Introducing and mixing a lithium ion conductor into the mixed organic solvent; Applying the mixed mixture onto a glass substrate; And thermally curing the applied mixture.

Here, it is preferable that the lithium ion conductor further includes titanium.

Here, it is preferable that the lithium ion conductor further includes silicon.

Here, the polymer electrolyte and the lithium ion conductor are preferably contained in a weight ratio of 100: 1 to 20: 1.

Here, the polymer electrolyte preferably includes a plasticizer, a crosslinking agent, and a lithium salt.

Wherein the plasticizer is selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl Ether, a polypropylene glycol / polyethylene glycol copolymer at the terminal of dibutyl ether, and a polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer at the terminal of dibutyl ether.

Here, the crosslinking agent preferably includes at least one selected from the group consisting of phosphazene-based, phosphate-based, and bisphenol A ethoxylate diacrylates having a crosslinkable functional group.

Here, it is preferable that the crosslinking agent and the plasticizer are contained at a weight ratio of 1: 4 to 6: 1.

Here, the lithium salt may be at least one selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoroacetate (LiAsF6), lithium difluoromethane sulfonate LiC4F9SO3), lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI), lithium bis oxalate borate (LiB (C2O4) , And lithium trifluoromethanesulfonylimide (LiTFSI). [0035] The term " a "

Here, it is preferable that the concentration of the lithium salt in the polymer electrolyte is [EO]: [Li] = 20: 0.5 to 2 molar ratio.

In order to achieve the third object, a lithium secondary battery according to the present invention comprises:

anode; cathode; And an organic-inorganic hybrid solid electrolyte disposed between the anode and the cathode, wherein the electrolyte comprises a polymer electrolyte and a lithium ion conductor.

Here, it is preferable that the lithium ion conductor further includes titanium.

Here, it is preferable that the lithium ion conductor further includes silicon.

Here, the polymer electrolyte and the lithium ion conductor are preferably contained in a weight ratio of 100: 1 to 20: 1.

Here, the polymer electrolyte preferably includes a plasticizer, a crosslinking agent, and a lithium salt.

Wherein the plasticizer is selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl Ether, a polypropylene glycol / polyethylene glycol copolymer at the terminal of dibutyl ether, and a polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer at the terminal of dibutyl ether.

Here, the crosslinking agent preferably includes at least one selected from the group consisting of phosphazene-based, phosphate-based, and bisphenol A ethoxylated diacrylates having a crosslinkable functional group.

Here, it is preferable that the crosslinking agent and the plasticizer are contained at a weight ratio of 1: 4 to 6: 1.

Here, the lithium salt may be at least one selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoroacetate (LiAsF6), lithium difluoromethane sulfonate LiC4F9SO3), lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI), lithium bis oxalate borate (LiB (C2O4) , And lithium trifluoromethanesulfonylimide (LiTFSI). [0035] The term " a "

Here, it is preferable that the concentration of the lithium salt in the polymer electrolyte is [EO]: [Li] = 20: 0.5 to 2 molar ratio.

INDUSTRIAL APPLICABILITY By using the organic-inorganic hybrid solid electrolyte according to the present invention, the lithium secondary battery comprising the same, and the method of manufacturing the same, it is possible to provide an inorganic hybrid inorganic solid electrolyte for a lithium secondary battery having improved ionic conductivity and a method for producing the same.

 In addition, according to the present invention, since a solid electrolyte having a high conductivity is used, there is an advantage that a battery having better electrical characteristics can be provided.

1 is a graph showing ion conductivity according to temperature according to weight fractions of lithium ion conductors of Examples 1 to 4 and Comparative Example 1 according to the present invention.
FIG. 2 is a graph showing changes in battery capacity including the organic-inorganic hybrid solid electrolyte of Example 6 according to the present invention.
FIG. 3 is a graph showing a change in capacity of a battery including an organic-inorganic hybrid solid electrolyte according to Example 6 according to the present invention.
FIG. 4 is a graph showing a change in capacity according to the number of cycles of a battery including an organic-inorganic hybrid solid electrolyte of Example 6 and Comparative Example 2 according to the present invention.
FIG. 5 is a graph showing a change in capacity of a battery including an organic-inorganic hybrid solid electrolyte of Example 6 according to the present invention, according to a discharge speed.

Unless defined otherwise, all technical terms used in the present invention have the following definitions and are consistent with the meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

In addition, preferred methods or samples are described in this specification, but similar or equivalent ones are also included in the scope of the present invention. The contents of all publications referred to herein are incorporated herein by reference.

Throughout this specification, the words " comprises " and " comprising ", unless the context requires otherwise, include the steps or components, or groups of steps or elements, Steps, or groups of elements are not excluded.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited thereto.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide an organic-inorganic hybrid electrolyte improved in ion conductivity.

A second object of the present invention is to provide a method for producing an organic-inorganic hybrid electrolyte improved in ion conductivity.

A third object of the present invention is to provide a lithium secondary battery including an organic / inorganic composite solid electrolyte having improved ionic conductivity and improved capacity retention.

The lithium ion conductor described below in the present invention means an ion conductor including lithium.

So far, the development of solid electrolytes has been mainly focused on the development of sulfide and oxide solid electrolytes, and some studies have reported that the ion conductivity of solid electrolytes is increased to the ion conductivity of liquid electrolytes.

However, solid electrolytes still exhibit relatively low ionic conductivity compared to liquid electrolytes and have problems such as increase in interfacial contact resistance and generation of hydrogen sulfide (in the case of sulfides) by water and reaction.

Disclosure of the Invention The present invention has been made in order to solve the above problems, and provides an organic-inorganic hybrid electrolyte having a simple production process and improved ionic conductivity.

The present invention provides an organic-inorganic composite solid electrolyte having an ion conductivity ranging from 1.00 x 10 ^-5 to 9.99 x 10 ^-3 at 25 캜 to 32 캜.

The organic-inorganic composite, if the ionic conductivity of the solid electrolyte is lower than 1.00 × 10 ^-5, a problem arises that do not act as an electrolyte, and organic-inorganic composite had ion conductivity of the solid electrolyte is higher than 9.99 × 10 ^-3 wherein the inorganic The mechanical properties of the composite solid electrolyte deteriorate, so that the above range is preferable.

In the present invention, the organic-inorganic composite solid electrolyte has a correlation with the content of the ion conductor and the plasticizer. The correlation will be described below.

Further, the organic-inorganic hybrid solid electrolyte of the present invention includes a polymer electrolyte and a lithium ion conductor.

The lithium ion conductor may further include titanium, and more preferably, it may further include silicon.

In one embodiment of the present invention, the silica-based lithium ion conductor, the titania-based lithium ion conductor, and the alumina-based lithium ion conductor can be used, and preferably LSTP (LiSiTi (PO ₄ ) Do not.

By using the organic-inorganic composite solid electrolyte including the lithium ion conductor according to the present invention, it can be used as an inorganic or organic composite solid electrolyte without a separation membrane.

The lithium ion conductor may be in the form of powder, liquid, or pellet, but is not limited thereto.

In the present invention, the polymer electrolyte and the lithium ion conductor may be contained in a weight ratio of 100: 1 to 20, preferably 100: 5 to 10: 1. That is, the present inventors have attempted to synthesize an organic-inorganic hybrid polymer electrolyte having improved ionic conductivity by mixing the polymer electrolyte and the lithium ion conductor according to the present invention. Experimental results show that when the weight ratio of the lithium ion conductor is 1 weight ratio or less, And it is economically disadvantageous because it exhibits a tendency similar to the ion conductivity of the polymer electrolyte having a lithium ion conductor of not less than 20 weight ratio and no lithium ion conductor. Also, the ionic conductivity was varied depending on the weight ratio of the lithium ion conductor, and the ionic conductivity was the highest at the ratio of 5 by weight.

The polymer electrolyte according to the present invention comprises a plasticizer, a crosslinking agent, and a lithium salt. In the polymer electrolyte synthesis reaction, the reaction proceeds at a low temperature to inhibit crystallization of the organic / inorganic composite solid electrolyte, It serves to increase the conductivity.

In addition, the plasticizer serves to improve dissociation of lithium salt and lithium ion conductivity to improve ionic conductivity.

The plasticizer may be selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl ether, di Polypropylene glycol / polyethylene glycol copolymer at the terminal of butyl ether, polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer of dibutyl ether terminal, and preferably polyethylene glycol dimethyl Ether is preferable, but not limited thereto.

In the present invention, the crosslinking agent may include at least one selected from the group consisting of phosphazene-based, phosphate-based, and bisphenol A ethoxylate diacrylates having a crosslinkable functional group, but is not limited thereto.

The C = O double bond of the cross-linking agent is used as a reagent for cross-linking molecules of a polymer material to form a polymeric polymer of a network structure.

The crosslinking agent and the plasticizer may be contained in a weight ratio of 1: 4 to 6, preferably 1: 4 to 4.5. Generally, the amount of the plasticizer contained in the crosslinking agent is directly proportional to the ion conductivity of the electrolyte. If the weight ratio is less than 4 parts by weight, the effect of improving the ion conductivity is insignificant. If the weight ratio is more than 6 parts by weight, the mechanical properties of the polymer electrolyte deteriorate The above range is preferable.

The lithium salt of the present invention is used for improving the ionic conductivity of a polymer electrolyte. The lithium salt of the present invention is a lithium salt of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoride (LiCF4SO3), lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI) (LiB (C2O4) 2), lithium trifluoromethanesulfonylimide (LiTFSI), and the like, but are not limited thereto.

The concentration of the lithium salt in the polymer electrolyte may include a molar ratio of [EO]: [Li] = 20: 0.5 to 2, preferably, a molar ratio of [EO]: [Li] = 20: 1. If the concentration of the lithium salt is less than 0.5 mol, the output improvement effect may be insufficient due to the decrease in resistance. If the concentration is more than 2 mol, the solubility in the polymer electrolyte may decrease and the chemical storage stability may be deteriorated.

In the method of producing an organic-inorganic hybrid solid electrolyte according to the present invention, the organic-inorganic hybrid solid electrolyte is provided with an inorganic hybrid solid electrolyte having an ion conductivity in the range of 1.00 × 10 ^-5 to 9.99 × 10 ^-3 at 25 ° C. to 32 ° C. do.

The method for producing the organic-inorganic hybrid solid electrolyte according to the present invention will be described in detail in each step.

Mixing the polymer electrolyte into an organic solvent; Charging and mixing a lithium ion conductor and an initiator into a polymer electrolyte mixture; Applying the mixed mixture onto a glass substrate; And thermally curing the applied mixture.

First, in the step of mixing the polymer electrolyte with the solvent, the crosslinking agent, the plasticizer and the lithium salt are mixed into the organic solvent as the components of the polymer electrolyte.

The crosslinking agent, the plasticizer and the lithium salt, which are components of the polymer electrolyte, are prepared by mixing with an organic solvent according to a conventional method.

The cross-linking agent in the step may be a cross-linking agent such as phosphazene-based, phosphate-based or bisphenol A ethoxylate diacrylate having a cross-linkable functional group, but is not limited thereto.

The plasticizer used in the above step may be a plasticizer generally used for improving the ionic conductivity of the polymer electrolyte. Examples of the plasticizer include polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol di Butyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl ether, dibutyl ether-terminated polypropylene glycol / polyethylene glycol copolymer, dibutyl ether-terminated polyethylene glycol / polypropylene Glycol / polyethylene glycol block copolymer, and the like, but are not limited thereto.

At this time, the crosslinking agent and the plasticizer may be contained at a weight ratio of 1: 4 to 6, preferably 1: 4 to 4.5.

 In addition, since the crosslinking agent has a high degree of crystallinity, it inhibits the movement of lithium ions and brings about a low ionic conductivity, so that the ionic conductivity can be improved by mixing at a proper mixing ratio.

In addition, the lithium salt of the above step is used for improving the ion conductivity of the polymer electrolyte, and it is preferable to use lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6) (LiCF4), lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide ), Lithium bisoxalate borate (LiB (C 2 O 4) 2), and lithium trifluoromethanesulfonylimide (LiTFSI), and the present invention is not limited thereto.

The concentration of the lithium salt in the polymer electrolyte may include a molar ratio of [EO]: [Li] = 20: 0.5 to 2, and preferably a molar ratio of [EO]: [Li] = 20: 1.

In the present invention, NMP is used as the organic solvent, but the kind thereof is not limited.

Next, when the polymer electrolyte mixture according to the present invention is prepared, a lithium ion conductor and an initiator are added and mixed.

The lithium ion conductor and the initiator are put into a polymer electrolyte mixture and stirred at 400 to 800 rpm for 1 to 3 hours to prepare a mixture.

The polymer electrolyte and the lithium ion conductor may be contained in a weight ratio of 100: 1 to 20, preferably 100: 5 to 10: 1.

In addition, the ionic conductivity values varying from 1 to 20 weight ratios depending on the weight ratio of the lithium ion conductor are exhibited, and the highest ionic conductivity values are shown when the ratio is 5 by weight.

The lithium ion conductor preferably has a particle size of 0.001 to 1 micron.

The ion conductivity of the organic / inorganic composite solid electrolyte can be improved by charging and mixing the lithium ion conductor.

Specifically, the lithium ion conductor may further include titanium, and may further include silicon, but is not limited thereto.

For example, the silica-based lithium-ion conductor, the titania-based lithium-ion conductor, and the alumina-based lithium-ion conductor can be used, and preferably LSTP (LiSiTi (PO ₄ )) can be used.

The initiator used was tertbutyl peroxypivalate as an initiator for promoting crosslinking, but the present invention is not limited thereto.

Next, the mixed mixture is applied onto a glass substrate.

The coating step can be applied according to a conventional method.

Next, the applied mixture is thermally cured to prepare an organic-inorganic hybrid solid electrolyte.

The thermally curing step may be performed at a temperature of 80 to 100 ° C. for 0.5 to 2 hours after sealing the mixture coated on the glass substrate so that oxygen does not reach the glass substrate.

The present invention relates to a positive electrode; cathode; And an organic-inorganic hybrid solid electrolyte disposed between the anode and the cathode.

In the present invention, the positive electrode and the negative electrode may be used as a positive electrode and a negative electrode used in a solid polymer electrolyte secondary battery, but the present invention is not limited thereto.

In addition, in the present invention, the organic-inorganic hybrid solid electrolyte contained in the secondary battery includes an electrolyte and a lithium ion conductor, which is the same as that described above, and the manufacturing method thereof has been fully described.

However, in the step of thermally curing the secondary battery, an organic composite solid electrolyte is cast on the anode, and an electrode is formed by a cathode. Then, the electrode is sealed so that oxygen does not touch it, and the electrode is heated at a temperature of 80 to 100 ° C for 0.5 to 2 hours It can be cured.

The secondary battery including the organic-inorganic hybrid solid electrolyte according to the present invention exhibits excellent cycle characteristics and rate characteristics due to its low interface resistance with the electrode.

Hereinafter, the present invention will be described in more detail with reference to the following Examples and Experimental Examples.

However, the following examples and experimental examples are intended to illustrate the contents of the present invention, but the scope of the invention is not limited by the examples and the experimental examples.

Example  1: Preparation of inorganic and organic composite solid electrolyte

First, 0.2 g of crosslinking agent bisphenol A ethoxylate diacrylate, 0.8 g of polyethylene glycol dimethyl ether as a plasticizer and 0.2698 g of lithium triflate were mixed with 2 ml of NMP solvent.

Then, 0.01 g of lithium ion conductor (LSTP) and 0.002 g of tert-butyl peroxypivalate as initiator were added to the mixed solution, followed by stirring at 600 rpm for 2 hours.

The mixture was applied on a glass substrate, sealed without oxygen, and thermally cured at 90 ° C for 1 hour to prepare an inorganic hybrid solid electrolyte.

Example  2 :  Abs  Preparation of complex solid electrolyte 2

The same procedure as in Example 1 was carried out except that 0.05 g of lithium ion conductor (LSTP) was added.

Example  3:  Abs  Preparation of Composite Solid Electrolyte 3

The same procedure as in Example 1 was carried out except that 0.1 g of lithium ion conductor (LSTP) was added.

Example  4 :  Abs  Preparation of Composite Solid Electrolyte 4

The same procedure as in Example 1 was carried out except that 0.2 g of lithium ion conductor (LSTP) was added.

Manufacturing example  1: Preparation of battery containing inorganic and organic composite solid electrolyte 1

0.5 g of lithium iron phosphate (LFP) as a positive electrode active material, 0.25 g of PVdF as a polymer binder, 0.126 g of polyethylene glycol diacrylate as an ion conductive plasticizer, and lithium trifluoromethanesulfonyl 0.042 g of imide and 0.08 g of conductive carbon were mixed with 2 ml of NMP solvent to prepare a cathode slurry.

Thereafter, the positive electrode slurry was coated on an aluminum foil as a current collector and dried at a temperature of 120 DEG C to prepare a positive electrode.

Next, the organic-inorganic hybrid solid electrolyte prepared in Example 1 was prepared.

Next, the organic / inorganic composite solid electrolyte prepared in Example 1 was applied on the anode, and a lithium metal foil and an SUS spacer were laminated on the anode as a cathode. Then, the lithium-metal foil and the SUS spacer were sealed, And cured to prepare a battery including the organic-inorganic composite solid electrolyte.

Manufacturing example  2: Manufacture of battery containing inorganic and organic composite solid electrolyte 2

A battery was produced in the same manner as in Production Example 1 except that the organic-inorganic hybrid solid electrolyte prepared in Example 2 was used.

Manufacturing example  3:  Abs  Of a battery containing a composite solid electrolyte Manufacturing 3

A battery was produced in the same manner as in Production Example 1 except that the organic-inorganic hybrid solid electrolyte prepared in Example 3 was used.

Manufacturing example  4 :  Abs  Of a battery containing a composite solid electrolyte Manufacturing 4

A battery was produced in the same manner as in Production Example 1 except that the organic-inorganic hybrid solid electrolyte prepared in Example 4 was used.

Comparative Example  One

The same procedure as in Example 1 was carried out except that the lithium ion conductor was not added.

Comparative Example  2

Was carried out in the same manner as in Example 5, but without adding a lithium ion conductor.

The amounts of lithium ion conductors used in Examples 1 to 4, Preparation Examples 1 to 4, and Comparative Examples 1 and 2 according to the present invention are shown in Table 1.

Bulb Production Example 1 Production Example 2 Production Example 3 Production Example 4 Comparative Example 2 Organic / inorganic composite polymer electrolyte Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Lithium ion conductor usage 0.01 g 0.05 g 0.1 g 0.2 g -

{Evaluation results}

Experimental Example  1: Ion conductivity analysis of inorganic and organic solid electrolyte

In order to measure the ion conductivity values of the organic-inorganic hybrid solid electrolytes according to the present invention, the inorganic hybrid solid electrolytes prepared in Examples 1 to 4 and Comparative Example 1 were analyzed using an analyzer (Impedance analyzer, Zahner Elekrik model IM6) The conductivity was analyzed and the results are shown in Fig.

As shown in Fig. 1, it was confirmed that Examples 1 to 4 including a lithium ion conductor had higher ion conductivity than Comparative Example 1, which did not include a lithium ion conductor.

In particular, it was confirmed that Example 2 according to the present invention exhibits a high ionic conductivity value of 6.79 x 10 ^-4 S / cm at room temperature.

The results of Example 2 (lithium ion conductor content: 0.01 g), which is higher than that of Examples 3 to 4 in which the content of lithium ion conductor (LSTP) is higher in Experimental Example 1, is higher than that of Lithium Ion Conductor As the dispersity of the ion conductor decreased, the ionic conductivity was lowered by interfering with the progress of Li ⁺ .

Experimental Example  2: Capacity evaluation of batteries containing inorganic and organic composite solid electrolyte

In order to evaluate the capacity of the battery containing the organic-inorganic hybrid solid electrolyte according to the present invention, the battery containing the organic-inorganic composite solid electrolyte of Production Example 2, which exhibited the highest ionic conductivity value among the production examples, was charged and discharged at a rate of 0.5 C And the charge / discharge test was carried out. The results are shown in FIG. 2 and FIG.

The graphs shown in FIGS. 4 and 5 are graphs showing the results of performance evaluation according to discharge rates of the organic-inorganic hybrid solid electrolytes prepared in Production Example 2 and Comparative Example 2. FIG.

The charging rate was 0.1 C and the discharging rate was varied 0.1, 0.2, 0.5, 1.0 and 2.0 C, respectively.

As a result, even after 100 cycles of the battery including the organic-inorganic composite solid electrolyte of Production Example 2 (containing 0.01 g of the lithium ion conductor), the capacity retention ratio was higher than the initial capacity, and the battery exhibited deterioration It is shown that the phenomenon does not occur.

In the case of Comparative Example 2 (containing 0 g of lithium ion conductor), Comparative Example 2 and Preparation Example 2 at 0.2 C based on the capacity shown at 0.1 C showed rate characteristics maintaining 98% and 99% 1C, the capacity retention ratios of 82%, 87% and 2C were 55% and 65%, respectively, and it was confirmed that the capacity retention ratio according to the discharge rate of Production Example 2 was remarkably high.

As a result, it was confirmed that the lithium secondary battery according to the present invention exhibits excellent conductivity characteristics without causing deterioration.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. It will also be appreciated that many modifications and variations will be apparent to those skilled in the art without departing from the scope of the present invention.

Claims (31)

Wherein the ionic conductivity is in the range of 1.00 x 10 ^-5 to 9.99 x 10 ^-3 at 25 ° C to 32 ° C.
The method according to claim 1,
Wherein the organic / inorganic composite solid electrolyte comprises a polymer electrolyte and a lithium ion conductor.
3. The method of claim 2,
Wherein the lithium ion conductor further comprises titanium. ≪ RTI ID = 0.0 > 11. < / RTI >
The method of claim 3,
Wherein the lithium ion conductor further comprises silicon.
3. The method of claim 2,
Wherein the polymer electrolyte and the lithium ion conductor are contained in a weight ratio of 100: 1 to 20: 1.
6. The method according to any one of claims 1 to 5,
Wherein the polymer electrolyte comprises a plasticizer, a crosslinking agent, and a lithium salt.
The method according to claim 6,
The plasticizer may be selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl ether, di A polypropylene glycol / polyethylene glycol copolymer having a terminal end of butyl ether, and a polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer having a terminal end of dibutyl ether. .
The method according to claim 6,
Wherein the cross-linking agent comprises at least one selected from the group consisting of phosphazene-based, phosphate-based, and bisphenol-A ethoxylate diacrylates having cross-linkable functional groups.
The method according to claim 6,
Characterized in that the cross-linking agent and the plasticizer are contained in a weight ratio of 1: 4 to 6: 1.
The method according to claim 6,
The lithium salt is selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoroacetate (LiAsF6), lithium difluoromethane sulfonate (LiC4F9SO3) Lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI), lithium bis oxalate borate (LiB (C2O4) Fluoromethanesulfonylimide (LiTFSI). ≪ RTI ID = 0.0 > 11. < / RTI >
The method according to claim 6,
Wherein the concentration of the lithium salt in the polymer electrolyte is [EO]: [Li] = 20: 0.5 to 2 molar ratio.
Mixing the polymer electrolyte into an organic solvent;
Introducing and mixing a lithium ion conductor into the mixed organic solvent;
Applying the mixed mixture onto a glass substrate;
And thermally curing the applied mixture. ≪ RTI ID = 0.0 > 11. < / RTI >
13. The method of claim 12,
Wherein the lithium ion conductor further comprises titanium. ≪ RTI ID = 0.0 > 11. < / RTI >
14. The method of claim 13,
Wherein the lithium ion conductor further comprises silicon. ≪ RTI ID = 0.0 > 11. < / RTI >
13. The method of claim 12,
Wherein the polymer electrolyte and the lithium ion conductor are contained in a weight ratio of 100: 1 to 20: 1.
16. The method according to any one of claims 12 to 15,
Wherein the polymer electrolyte comprises a plasticizer, a crosslinking agent, and a lithium salt.
17. The method of claim 16,
The plasticizer may be selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl ether, di A polypropylene glycol / polyethylene glycol copolymer having a terminal end of butyl ether, and a polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer having a terminal end of dibutyl ether. ≪ / RTI >
17. The method of claim 16,
Wherein the cross-linking agent comprises at least one selected from the group consisting of phosphazene-based, phosphate-based and bisphenol A ethoxylate diacrylates having cross-linkable functional groups.
17. The method of claim 16,
Wherein the cross-linking agent and the plasticizer are contained at a weight ratio of 1: 4 to 6: 1.
17. The method of claim 16,
The lithium salt is selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoroacetate (LiAsF6), lithium difluoromethane sulfonate (LiC4F9SO3) Lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI), lithium bis oxalate borate (LiB (C2O4) Fluoromethanesulfonylimide (LiTFSI). 2. The method according to claim 1, wherein the fluorine-containing compound is at least one selected from the group consisting of fluoromethanesulfonylimide (LiTFSI) and fluoromethanesulfonylimide (LiTFSI).
17. The method of claim 16,
Wherein the concentration of the lithium salt in the polymer electrolyte is [EO]: [Li] = 20: 0.5 to 2 molar ratio.
anode;
cathode; And
And an organic-inorganic hybrid solid electrolyte disposed between the anode and the cathode,
Wherein the electrolyte comprises a polymer electrolyte and a lithium ion conductor.
23. The method of claim 22,
Wherein the lithium ion conductor further comprises titanium.
24. The method of claim 23,
Wherein the lithium ion conductor further comprises silicon.
23. The method of claim 22,
Wherein the polymer electrolyte and the lithium ion conductor are contained in a weight ratio of 100: 1 to 20: 1.
26. The method according to any one of claims 22 to 25,
Wherein the polymer electrolyte comprises a plasticizer, a crosslinking agent, and a lithium salt.
27. The method of claim 26,
The plasticizer may be selected from the group consisting of polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol dipropyl ether, polyethylene glycol dibutyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diglycidyl ether, di Polypropylene glycol / polyethylene glycol copolymer at the terminal of butyl ether, polyethylene glycol / polypropylene glycol / polyethylene glycol block copolymer of dibutyl ether terminal.
27. The method of claim 26,
Wherein the crosslinking agent comprises at least one selected from the group consisting of phosphazene-based, phosphate-based, and bisphenol-A ethoxylate diacrylates having a crosslinkable functional group.
27. The method of claim 26,
Wherein the cross-linking agent and the plasticizer are contained in a weight ratio of 1: 4 to 6: 1.
27. The method of claim 26,
The lithium salt is selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroantimonate (LiSbF6), lithium hexafluoroacetate (LiAsF6), lithium difluoromethane sulfonate (LiC4F9SO3) Lithium perchlorate (LiClO4), lithium aluminate (LiAlO2), lithium tetrachloroaluminate (LiAlCl4), lithium chloride (LiCl), lithium iodide (LiI), lithium bis oxalate borate (LiB (C2O4) Fluoromethanesulfonylimide (LiTFSI). ≪ Desc / Clms Page number 24 >
27. The method of claim 26,
Wherein the concentration of the lithium salt in the polymer electrolyte is [EO]: [Li] = 20: 0.5 to 2 molar ratio.

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