KR101718880B1 - Preparing method of lithum-lanthanum-zirconium-based solid electrolyte - Google Patents

Abstract

The present invention relates to a method for preparing a lithium (Li)-lanthanum (La)-zirconium (Zr)-based solid electrolyte, comprising the following steps: adding a first lithium source to a La-Zr precursor and primarily thermally treating the same, and preparing a first Li-La-Zr-based precursor; adding a second lithium source to the Li-La-Zr-based precursor, secondarily thermally treating the same, and preparing a second Li-La-Zr-based precursor; and sintering the second Li-La-Zr-based precursor and producing a solid electrolyte including a Li-La-Zr-based composite oxide. According to the present invention, physical processability and electrical properties (especially, ion conductivity) can be improved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium-lanthanum-zirconium-based solid electrolyte,

The present invention relates to a process for producing Li-La-Zr based solid electrolytes containing lithium, lanthanum, zirconium, and oxygen using lithiation.

In the case of existing lithium secondary batteries, safety problems are caused by the use of liquid electrolytes. Although inorganic and inorganic solid electrolytes for replacing liquid electrolytes have been developed, they are difficult to commercialize because they have low ion conductivity compared to liquid electrolytes. Development of a solid electrolyte is urgent to improve the safety of the liquid electrolyte. Accordingly, efforts to improve the low ion conductivity of solid electrolytes have been continued, and as a result, sulfide-based solid electrolytes showing similar ion conductivity to liquid electrolytes have been developed, followed by oxide-based solid electrolytes.

In the case of a sulfide-based solid electrolyte, although it has a high ionic conductivity, there is a problem that it is difficult to mass-produce the sulfide-based solid electrolyte due to the restriction of the manufacturing environment due to reaction with moisture in the atmosphere and odor. In addition, although the oxide-based solid electrolyte has an advantage that it can be produced in the air, it has a disadvantage in that it is difficult to apply it practically due to the low ion conductivity.

Korean Patent Laid-Open Publication No. 2015-0005136 discloses a solid electrolyte for a solid lithium secondary battery and a method for producing the same. Part of the lithium source is partially evaporated during sintering, and thus added lithium is not reacted. However, it is disadvantageous in that it is not completely reacted in the synthesis of the lithium source and the precursor by performing only the first retraction, and the retention is carried out by the hydroxide-based lithium source There is a problem in that the powder is hardened excessively due to the aggregation of the powder after sintering and is difficult to be pulverized, thereby making pelletization difficult.

The present invention relates to a process for preparing a Li-La-Zr-based precursor by adding a first lithium source to a La-Zr-based precursor and then subjecting it to a first heat treatment; Preparing a second Li-La-Zr-based precursor by adding a second lithium source to the Li-La-Zr-based precursor and then performing a second heat treatment; And a step of sintering the second Li-La-Zr-based precursor to prepare a solid electrolyte including a Li-La-Zr based composite oxide, .

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a method of manufacturing a lithium secondary battery, comprising: preparing a first Li-La-Zr based precursor by adding a first lithium source to a La-Zr based precursor; Preparing a second Li-La-Zr-based precursor by adding a second lithium source to the first Li-La-Zr-based precursor and then performing a second heat treatment; And sintering the second Li-La-Zr-based precursor to prepare a solid electrolyte including a Li-La-Zr-based composite oxide.

According to one embodiment of the present invention, the La-Zr-based precursor may be prepared by solid phase method, coprecipitation method, or sol-gel method, but is not limited thereto.

According to one embodiment of the invention, the first lithium source and the second lithium source are each independently selected from LiOH · H ₂ O, Li ₂ CO _3, LiF, Li ₂ S, LiOH, Li ₂ O, and combinations thereof But are not limited to, those selected from the group consisting of:

According to one embodiment of the present invention, the first lithium source and the second lithium source may include, but are not limited to, different materials.

According to an embodiment of the present invention, the step of preparing the first Li-La-Zr based precursor may include adding the first lithium source to the first lithium source in an amount of about 1 wt% to about 20 wt% But are not limited thereto.

According to one embodiment of the present application, the primary heat treatment may be performed at a temperature of about 800 ° C to about 900 ° C, but is not limited thereto.

According to an embodiment of the present invention, the step of preparing the first Li-La-Zr based precursor may further include a step of grinding the first Li-La-Zr based precursor, but the present invention is not limited thereto .

According to one embodiment of the present invention, the ground Li-La-Zr precursor may have a particle size of about 100 μm or less, but is not limited thereto.

According to an embodiment of the present invention, the second lithium source may be added in a range of about 1% by weight to about 20% by weight based on the weight of the first lithium source, but the present invention is not limited thereto.

According to one embodiment of the present invention, the secondary heat treatment may be performed at a temperature of about 900 ° C to about 1,000 ° C, but is not limited thereto.

According to an embodiment of the present invention, the step of obtaining the second Li-La-Zr-based precursor may further include a step of pulverizing the second Li-La-Zr-based precursor, but the present invention is not limited thereto .

According to an embodiment of the present invention, the pulverized second Li-La-Zr precursor may have a particle size of about 100 μm or less, but the present invention is not limited thereto.

According to one embodiment of the present invention, the step of pelletizing the pulverized second Li-La-Zr-based precursor may be further included, but is not limited thereto.

According to one embodiment of the disclosure, the sintering may be performed at a temperature of from about 1,000 ° C. to about 1,200 ° C., but is not limited thereto.

According to an embodiment of the present invention, the Li-La-Zr based complex oxide may have a crystal structure selected from the group consisting of an isotropic crystal structure, a tetragonal crystal structure, and combinations thereof. It is not.

According to an embodiment of the present invention, the sum of the addition amount of the first lithium source and the addition amount of the second lithium source is in the range of about 5 wt% to about 20 wt% with respect to the weight of the added first lithium source But is not limited thereto.

The method for producing a Li-La-Zr based composite oxide according to an embodiment of the present invention is characterized in that lithiation is performed in two steps and the kinds and / or addition amounts of the lithium source are added at different stages Whereby it is possible to prevent the hardening phenomenon during sintering, and to improve the physical workability (pelletization) and electrical properties (in particular, ionic conductivity) of the solid electrolyte. In addition, the process for producing a Li-La-Zr based composite oxide according to the present invention has an effect of sufficiently producing the synthesis (crystallinity) of a La-Zr-based precursor and lithium, The ionic conductivity can be improved.

FIG. 1 is a flowchart illustrating a process for producing a Li-La-Zr-based composite oxide according to an embodiment of the present invention.
FIG. 2 is a flow chart showing a manufacturing process of a Li-La-Zr based composite oxide according to a conventional method as a comparative example.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

As used herein, the terms "about," " substantially, "and the like are used herein to refer to or approximate the numerical value of manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to prevent unauthorized exploitation by unauthorized intruders of the mentioned disclosure.

The term " step " or " step of ~ " as used throughout the specification does not imply " step for.

Throughout this specification, the term "combination (s) thereof " included in the expression of the machine form means a mixture or combination of one or more elements selected from the group consisting of the constituents described in the expression of the form of a marker, Quot; means at least one selected from the group consisting of the above-mentioned elements.

Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

The term "Li-La-Zr based composite oxide" as used throughout the present specification means a material containing lithium (Li), lanthanum (La), zirconium (Zr), and oxygen (O) Quot; or "LLZO ", but is not limited thereto.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and examples and drawings.

According to an aspect of the present invention, there is provided a method of manufacturing a lithium secondary battery, comprising: preparing a first Li-La-Zr based precursor by adding a first lithium source to a La-Zr based precursor; Preparing a second Li-La-Zr-based precursor by adding a second lithium source to the first Li-La-Zr-based precursor and then performing a second heat treatment; And sintering the second Li-La-Zr-based precursor to prepare a solid electrolyte including a Li-La-Zr-based composite oxide.

In order to prepare a Li-La-Zr based solid electrolyte, first a first Li source is added to a La-Zr precursor and then subjected to a first heat treatment to prepare a first Li-La-Zr precursor. Primary lithiation is performed by adding the first lithium source and then performing a first heat treatment.

In one embodiment, the La-Zr-based precursor may be prepared by a conventionally known method. For example, the La-Zr-based precursor may be prepared by a solid phase method, coprecipitation method, sol- But is not limited thereto.

In one embodiment of the present application, a material that is the first lithium source is selected from the group consisting of LiOH · H ₂ O, Li ₂ CO _3, LiF, Li ₂ S, LiOH, Li ₂ O, and combinations thereof But are not limited thereto.

In one embodiment of the present invention, the step of preparing the first Li-La-Zr-based precursor comprises adding the first lithium source in an amount of about 1 wt% to about 20 wt% based on the weight of the added first lithium source, But are not limited thereto. For example, the additional amount of the first lithium source may be from about 1 wt% to about 20 wt%, from about 1 wt% to about 15 wt%, from about 1 wt% to about 10 wt%, from about 1 wt% to about 8 wt% From about 1% to about 6%, from about 1% to about 4%, from about 1% to about 2%, from about 3% to about 20%, from about 5% to about 15% By weight, or from about 7% by weight to about 10% by weight.

In one embodiment of the present invention, the primary heat treatment may be performed at a temperature of about 800 ° C to about 900 ° C, but is not limited thereto. For example, the primary heat treatment temperature may be from about 800 ° C to about 900 ° C, from about 800 ° C to about 870 ° C, from about 800 ° C to about 850 ° C, from about 800 ° C to about 830 ° C, from about 830 ° C to about 900 ° C, About 850 ° C to about 900 ° C, or about 870 ° C to about 900 ° C, but is not limited thereto. For example, the primary heat treatment may be performed for about 2 hours or more, or about 2 hours to about 3 hours, but is not limited thereto.

In one embodiment of the present invention, the step of preparing the first Li-La-Zr-based precursor may further include a step of pulverizing the first Li-La-Zr-based precursor, but the present invention is not limited thereto . For example, the pulverization can be carried out by a method such as induction, ball mill, etc., but is not limited thereto.

In one embodiment of the invention, the ground first Li-La-Zr precursor may have a particle size of less than about 100 μm, but is not limited thereto. For example, the particle size of the pulverized first Li-La-Zr precursor may be less than about 100 μm, less than about 80 μm, less than about 60 μm, less than about 40 μm, less than about 20 μm, less than about 10 μm, Less than about 5 占 퐉, or less than about 1 占 퐉, but is not limited thereto.

Next, a second lithium source is added to the first Li-La-Zr-based precursor and then subjected to a second heat treatment to produce a second Li-La-Zr-based precursor. Secondary lithiation is performed by adding the second lithium source and then performing a secondary heat treatment.

In one embodiment of the present application, a material that is the second lithium source is selected from the group consisting of LiOH · H ₂ O, Li ₂ CO _3, LiF, Li ₂ S, LiOH, Li ₂ O, and combinations thereof But are not limited thereto.

In one embodiment of the present invention, the first lithium source and the second lithium source may include, but are not limited to, different materials.

In one embodiment of the present invention, the second lithium source may be added in an amount ranging from 1% by weight to 20% by weight based on the weight of the first lithium source, but the present invention is not limited thereto. For example, the amount of the second lithium source may be about 1 wt% to about 20 wt%, about 1 wt% to about 15 wt%, about 1 wt% to about 10 wt% based on the weight of the first lithium source, About 1 wt% to about 2 wt%, about 3 wt% to about 20 wt%, about 1 wt% to about 8 wt%, about 1 wt% to about 6 wt%, about 1 wt% , From about 5 wt% to about 15 wt%, or from about 7 wt% to about 10 wt%, by weight of the composition.

In one embodiment of the present invention, the secondary heat treatment may be performed at a temperature of from about 900 [deg.] C to about 1,000 [deg.] C, but is not limited thereto. For example, the second heat treatment temperature may be from about 900 캜 to about 1,000 캜, from about 900 캜 to about 970 캜, from about 900 캜 to about 950 캜, from about 900 캜 to about 930 캜, , About 950 ° C to about 1,000 ° C, or about 970 ° C to about 1,000 ° C, but is not limited thereto. For example, the secondary heat treatment may be performed for about 2 hours or more, or about 2 hours to about 3 hours, but is not limited thereto.

In one embodiment of the present invention, the step of obtaining the second Li-La-Zr-based precursor may further include a step of pulverizing the second Li-La-Zr-based precursor, but the present invention is not limited thereto .

In one embodiment herein, the pulverized second Li-La-Zr precursor may have a particle size of about 100 μm or less, but is not limited thereto. For example, the particle size of the pulverized second Li-La-Zr electrolyte may be less than about 100 m, less than about 80 m, less than about 60 m, less than about 40 m, less than about 20 m, less than about 10 m, Less than about 5 占 퐉, or less than about 1 占 퐉, but is not limited thereto.

Next, the second Li-La-Zr-based precursor is sintered to prepare a solid electrolyte including a Li-La-Zr-based composite oxide.

In one embodiment of the present invention, the step of pelletizing the pulverized second Li-La-Zr-based precursor may be further included, but is not limited thereto. Throughout this specification, the term "pelletizing " means pressing a powdered material into a material having a size of about 1 mm to about 17 mm in diameter and a mass of about 0.3 g to about 1 g. For example, the process conditions for the pelletization may include, but are not limited to, holding for about 30 seconds at a press pressure of about 7 ton to about 10 ton.

In one embodiment of the invention, the sintering may be performed at a temperature of from about 1,000 ° C to about 1,200 ° C, but is not limited thereto. For example, the sintering temperature may range from about 1,000 ° C to about 1,200 ° C, from about 1,000 ° C to about 1,150 ° C, from about 1,000 ° C to about 1,100 ° C, from about 1,000 ° C to about 1,050 ° C, from about 1,050 ° C to about 1,200 ° C, Deg.] C to about 1,200 [deg.] C, or from about 1,150 [deg.] C to about 1,200 [deg.] C. For example, the sintering may be performed for about 2 hours to about 5 hours, but is not limited thereto.

In one embodiment of the present invention, the Li-La-Zr based composite oxide may have a crystal structure selected from the group consisting of an isotropic crystal structure, a tetragonal crystal structure, and combinations thereof. It is not.

In one embodiment of the present invention, the amount of addition of the first lithium source and the amount of addition of the second lithium source, relative to the weight of the first lithium source added in the step of producing the first Li-La-Zr based precursor, Can range from about 5 wt% to about 20 wt%, but is not limited thereto. For example, the sum of the additional amount of the first lithium source and the amount of the second lithium source may be about 5 wt% to about 20 wt%, about 5 wt% to about 15 wt%, about 5 wt% to about 10 wt% By weight, about 10% by weight to about 20% by weight, or about 15% by weight to about 20% by weight.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

[ Example ]

Comparative Example  One: Li -La- Zr series  Complex oxide 1 (additional charge: LiOH · H ₂ O 5 weight% )

Comparative Example 1 was produced by the manufacturing process shown in Fig.

Specifically, 7 M LiOH.H ₂ O was added as a lithium source to a La ₃ Zr ₂ (OH) _x type precursor prepared by a conventionally known method, and LiOH · H ₂ O 5 After addition of the weight%, the mixture was ball-milled or induction-mixed, and the mixture was reacted by heat treatment at 850 ° C for 2 hours. The reaction product was pulverized to a size of not more than 100 μm and maintained at a pressing pressure of 7 ton to 10 ton for 30 seconds for pelletization to prepare a pelletized reaction product having a mass of 1 mm to 17 mm and a mass of 0.3 g to 1 g Respectively. Subsequently, the pelletized reaction product was sintered at 1,000 ° C for 5 hours to prepare a pellet-shaped solid electrolyte having the form of Li-La-Zr composite oxide (LLZO).

Example  One: Li -La- Zr series  Complex oxide 2 (additional charge: LiOH · H ₂ O 3 weight% , Li ₂ CO ₃  2 weight% )

Example 1 was prepared by the manufacturing process shown in Fig.

Specifically, 7 M LiOH.H ₂ O was added as a first lithium source to a La ₃ Zr ₂ (OH) _x -form precursor prepared by a conventionally known method, and then to the first lithium source , LiOH.H ₂ O was further added in an amount of 3% by weight and then subjected to a primary heat treatment at 850 ° C for 2 hours to obtain a first Li-La-Zr-based precursor. The precursor of the first Li-La-Zr precursor is pulverized to a size of not more than 100 μm, and Li ₂ CO _{3 is added} to the first Li-La-Zr precursor as the second lithium source % By weight, and subjected to a second heat treatment at 950 ° C for 2 hours to obtain a second Li-La-Zr-based precursor. The Li-La-Zr precursor was pulverized to a size of 100 μm or less and then pelletized to prepare a pelletized reaction product in the same manner as in Comparative Example 1. The pelletized reaction product was sintered at 1,000 ° C. for 5 hours Thereby preparing a pellet type solid electrolyte having the form of LLZO.

Example  2: Li -La- Zr series  Complex oxide 3 (additional charge: LiOH · H ₂ O 1 weight% , Li ₂ CO ₃  4 weight% )

Example 2 was produced by the manufacturing process shown in FIG. 1, which is the same method as in Example 1 above.

Specifically, except that 1 wt% of LiOH 占₂ 2O was further added to the first lithium source and 4 wt% of Li ₂ CO ₃ was added as a second lithium source, the same conditions and methods as those of Example 1 were used To prepare a pellet type solid electrolyte having the shape of LLZO.

Comparative Example  2: Li -La- Zr series  Complex oxide 4 (additional charge: LiOH · H ₂ O 10 weight% )

Comparative Example 2 was produced by the manufacturing process shown in FIG. 2, which is the same method as Comparative Example 1.

Specifically, a pellet-type solid electrolyte having the form of LLZO was prepared by using the same conditions and methods as in Comparative Example 1, except that LiOH 占_{2 2} O was further added in an amount of 10 wt% to the lithium source.

Example  3: Li -La- Zr series  Composite Oxide 5 (Additional charge: LiOH · H ₂ O 6 weight% , Li ₂ CO ₃  4 weight% )

Example 3 was produced by the manufacturing process shown in FIG. 1, which is the same method as in Example 1 above.

Specifically, except that 6 wt% of LiOH · H ₂ O was further added to the first lithium source and 4 wt% of Li ₂ CO ₃ was added as a second lithium source, the same conditions and methods as those of Example 1 were used To prepare a pellet type solid electrolyte having the shape of LLZO.

Example  4: Li -La- Zr series  Complex oxide 6 (additional charge: LiOH · H ₂ O 2 weight% , Li ₂ CO ₃  8 weight% )

Example 4 was produced by the manufacturing process shown in FIG. 1, which is the same method as in Example 1 above.

Specifically, except that 2 wt% of LiOH · H ₂ O was further added to the first lithium source and 8 wt% of Li ₂ CO ₃ was added as a second lithium source, the same conditions and methods as those of Example 1 To prepare a pellet type solid electrolyte having the shape of LLZO.

Comparative Example  3: Li -La- Zr series  Complex oxide 7 (additional charge: LiOH · H ₂ O 20 weight% )

Comparative Example 3 was produced by the manufacturing process shown in FIG. 2, which is the same method as the Comparative Example 1.

Specifically, pellet type solid electrolytes having the form of LLZO were prepared using the same conditions and method as those of Comparative Example 1, except that LiOH 占_{2 2} O was further added to the lithium source in an amount of 20 wt%.

Example  5: Li -La- Zr series  Composite Oxide 8 (Additional charge: LiOH · H ₂ O 15 weight% , Li ₂ CO ₃  5 weight% )

Example 5 was produced by the manufacturing process shown in FIG. 1, which is the same method as in Example 1 above.

Specifically, except that 15 wt% of LiOH 占_{2 2} O was further added to the first lithium source and 5 wt% of Li ₂ CO ₃ was added as a second lithium source, the same conditions and methods as those of Example 1 To prepare a pellet type solid electrolyte having the shape of LLZO.

Example  6: Li -La- Zr series  Composite Oxide 9 (Additional charge: LiOH · H ₂ O 10 weight% , Li ₂ CO ₃  10 weight% )

Example 6 was produced by the manufacturing process shown in Fig. 1, which is the same method as in Example 1 above.

Specifically, except that 10 wt% of LiOH 占₂ 2O was further added to the first lithium source and 10 wt% of Li ₂ CO ₃ was added as a second lithium source, the same conditions and methods as those of Example 1 were used To prepare a pellet type solid electrolyte having the shape of LLZO.

Example  7: Li -La- Zr series  Composite Oxide 10 (Additional charge: LiOH · H ₂ O 5 weight% , Li ₂ CO ₃  15 weight% )

Example 7 was produced by the manufacturing process shown in Fig. 1, which is the same method as in Example 1 above.

Specifically, except that 5 wt% of LiOH 占₂ 2O was further added to the first lithium source and 15 wt% of Li ₂ CO ₃ was added as a second lithium source, the same conditions and methods as those of Example 1 were used To prepare a pellet type solid electrolyte having the shape of LLZO.

Experimental Example : Measurement of ionic conductivity

In order to measure the ion conductivity of the solid electrolyte, Au pelletized solid electrolytes having the LLZO form prepared in the above Examples and Comparative Examples were sputtered at the upper and lower ends thereof and then Ag paste was applied. A sample was prepared by connecting electrodes at both ends. The prepared samples were mounted on an impedance analyzer and measured from 7 MHz to 5 mHz. The results are shown in Table 1 below.

[Table 1]

As shown in Table 1, when compared by the same addition amount of the total lithium source, the lithium source was excessively added twice over the solid electrolyte of Comparative Examples 1 to 3 prepared by adding the lithium source by one excess It was confirmed by the present experiment that the ionic conductivity of the prepared Examples 1 to 7 was further improved.

As the total amount of added lithium source is increased, the overall ionic conductivity also tends to increase. However, when the additional amount of lithium source is 10 wt%, ion conductivity is maximized, so that the input amount of lithium source and ion conductivity It was not always proportional.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (16)

Preparing a first Li-La-Zr-based precursor by adding a first lithium source to a La-Zr-based precursor and then subjecting it to a first heat treatment;
Crushing the first Li-La-Zr-based precursor;
Preparing a second Li-La-Zr-based precursor by adding a second lithium source to the pulverized first Li-La-Zr-based precursor and then subjecting the resultant to a second heat treatment;
Crushing the second Li-La-Zr-based precursor;
Pelletizing the pulverized second Li-La-Zr-based precursor by pressurization; And
And sintering the pelletized second Li-La-Zr-based precursor to prepare a solid electrolyte including a Li-La-Zr-based composite oxide
Wherein the Li-La-Zr-based solid electrolyte is a solid electrolyte,
Wherein the first lithium source and the second lithium source are each independently selected from the group consisting of LiOH.H ₂ O, Li ₂ CO ₃ , LiF, Li ₂ S, LiOH, Li ₂ O, , ≪ / RTI >
Wherein the first lithium source and the second lithium source use different materials, respectively. 2. The Li-La-Zr based solid electrolyte according to claim 1, wherein the first lithium source and the second lithium source are made of different materials.
The method according to claim 1,
Wherein the La-Zr-based precursor is produced by a solid-phase method, a coprecipitation method, or a sol-gel method.
delete delete The method according to claim 1,
Wherein the step of preparing the first Li-La-Zr based precursor comprises adding 1 wt% to 20 wt% of the first lithium source to the weight of the added first lithium source, A method for producing a La-Zr based solid electrolyte.
The method according to claim 1,
Wherein the primary heat treatment is performed at a temperature of 800 to 900 占 폚.
delete The method according to claim 1,
Wherein the pulverized first Li-La-Zr-based precursor has a particle size of 100 μm or less.
The method according to claim 1,
Wherein the second lithium source is added in an amount of 1 wt% to 20 wt% with respect to the weight of the first lithium source.
The method according to claim 1,
Wherein the secondary heat treatment is performed at a temperature of 900 ° C to 1,000 ° C.
delete The method according to claim 1,
Wherein the pulverized second Li-La-Zr-based precursor has a particle size of 100 m or less.
delete The method according to claim 1,
Wherein the sintering is performed at a temperature of 1,000 ° C to 1,200 ° C.
The method according to claim 1,
The method for producing a Li-La-Zr based solid electrolyte, wherein the Li-La-Zr based complex oxide has a crystal structure selected from the group consisting of an isometric structure, a tetragonal structure, and combinations thereof .
6. The method of claim 5,
Wherein the sum of the addition amount of the first lithium source and the addition amount of the second lithium source is in the range of 5 wt% to 20 wt% with respect to the weight of the added first lithium source, Gt;

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