Solid electrolyte for all-solid-state battery and all-solid-state battery comprising same

Abstract

The present invention relates to a solid electrolyte for an all-solid-state battery and an all-solid-state battery comprising same. The solid electrolyte for an all-solid-state battery, according to one embodiment of the present invention, is composed of an oxide material containing Li, B, Al, Cl, and an alkaline earth metal.

Description

Solid electrolyte for all-solid-state batteries and all-solid-state battery including the same

[0001] The present invention relates to a solid electrolyte for an all-solid-state battery and an all-solid-state battery comprising the same.

[0002] Secondary batteries are used in various fields, ranging from IT devices such as mobile phones to electric vehicles and energy storage devices.

[0003] Lithium-ion batteries using liquid electrolytes are the most widely used secondary batteries. However, liquid electrolytes pose a risk of leakage if the battery is subjected to external impact, requiring additional components and devices to ensure safety.

[0004] Recently, active development is underway for all-solid-state lithium-ion batteries that utilize solid electrolytes to improve the safety of lithium-ion batteries. Solid electrolytes for all-solid-state lithium-ion batteries include polymer-based, oxide-based, and sulfide-based electrolytes. Among these, sulfide-based solid electrolytes exhibit excellent electrochemical performance due to high ionic conductivity and particle deformation capabilities, but they present a problem in that they react with moisture in the air to generate toxic hydrogen sulfide gas. Polymer-based electrolytes have the advantage of relatively simple manufacturing processes and the ability to utilize existing lithium-ion battery manufacturing processes, but they have the disadvantage of significantly low ionic conductivity.

[0005] Oxide-based electrolytes have the advantage of excellent safety and relatively high ionic conductivity, although lower than that of sulfide-based electrolytes. Currently, LAGP, LLZO, etc. 10 -4 Oxide-based solid electrolytes with high ionic conductivity of S / cm or higher are being developed. However, these solid electrolytes have limitations in improving electrochemical performance due to a narrow electrochemical voltage range and high-temperature sintering processes of over 1,000°C, which can lead to increased production costs and limited usability.

[0006] The present invention aims to solve the problems of the aforementioned prior art by providing an oxide-based solid electrolyte for an all-solid-state battery that can be sintered at low temperatures and has excellent ion conductivity, and an all-solid-state battery containing the same.

[0007] A solid electrolyte for an all-solid-state battery according to one embodiment of the present invention is composed of an oxide containing Li, B, Al, Cl, and an alkaline earth metal.

[0008] According to one embodiment of the present invention, the alkaline earth metal may be at least one of Ba, Ca, Mg, and Sr.

[0009] According to one embodiment of the present invention, alkaline earth metal may be included in an amount of 0.4 to 11 mol%.

[0010] According to one embodiment of the present invention, alkaline earth metal may be included in an amount of 0.4 to 10 mol%.

[0011] A solid electrolyte for an all-solid-state battery according to one embodiment of the present invention may comprise 21 to 29 mol% of Li2O, 24 to 46 mol% of B2O3, 9 to 21 mol% of Al2O3, and 16 to 31 mol% of LiCl.

[0012] A solid electrolyte for an all-solid-state battery according to one embodiment of the present invention can be prepared from a precursor powder comprising Li2CO3, H3BO3, Al2O3, LiCl, and an alkaline earth metal oxide.

[0013] A solid electrolyte for an all-solid-state battery according to one embodiment of the present invention has an ionic conductivity of 1.1 × 10⁻⁶ -5 It may be greater than S / cm.

[0014] An all-solid-state battery according to one embodiment of the present invention comprises a positive electrode layer, a negative electrode layer, and a solid electrolyte layer, and the solid electrolyte layer may be made of an oxide comprising Li, B, Al, Cl, and an alkaline earth metal.

[0015] In addition to this, the solid electrolyte for an all-solid-state battery according to the present invention may further include other additional components within a scope that does not impair the technical concept of the present invention.

[0016] According to one embodiment of the present invention, a solid electrolyte for an all-solid-state battery is an oxide-based solid electrolyte and is composed of an oxide containing Li, B, Al, Cl, and an alkaline earth metal, thereby enabling low-temperature sintering while having excellent ionic conductivity.

[0017] FIG. 1 is a perspective view schematically showing an all-solid-state battery.

[0018] Figure 2 is a diagram exemplarily showing a cross-section of an all-solid-state battery.

[0019] Figure 3 is a graph showing the XRD analysis results for the powder of the solid electrolyte before sintering according to the embodiments and comparative examples of the present invention.

[0020] Figure 4 is a graph showing the XRD analysis results after sintering of solid electrolytes according to the embodiments and comparative examples of the present invention.

[0021] Figure 5 is a graph showing the EIS analysis results of a solid electrolyte according to an embodiment of the present invention.

[0022] [Explanation of the symbol]

[0023] 10: All-solid-state battery

[0024] 11: Anode layer

[0025] 12: Cathode layer

[0026] 13: Solid electrolyte layer

[0027] 14, 15: External electrodes

[0028] 16: Case

[0029] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention.

[0030] To clearly explain the present invention, descriptions of parts unrelated to the invention have been omitted, and the same reference numerals are used for identical components throughout the specification. Specific shapes, structures, and characteristics described in the specification may be modified from one embodiment to another without departing from the spirit and scope of the present invention, and it should be understood that the location or arrangement of individual components may also be modified without departing from the spirit and scope of the present invention.

[0031] Accordingly, the detailed description below is not intended to be limiting, and the scope of the invention should be understood to encompass the scope claimed by the claims and all equivalent scopes.

[0032] FIG. 1 is a perspective view schematically showing an all-solid-state battery, and FIG. 2 is a diagram schematically showing a cross-section of an all-solid-state battery. An all-solid-state battery according to one embodiment of the present disclosure is a so-called stacked ceramic battery and can be formed in the form of a small chip and can be used in small electronic devices such as wearable electronic devices.

[0033] Referring to FIGS. 1 and 2, the all-solid-state battery (10) comprises a positive electrode layer (11), a negative electrode layer (12), and a solid electrolyte layer (13). The solid electrolyte layer (13) is disposed between the positive electrode layer (11) and the negative electrode layer (12) and can come into contact with the positive electrode layer (11) and the negative electrode layer (12), respectively. The positive electrode layer (11) and the negative electrode layer (12) can each have a current collector and an active material layer, and the active material layer of the electrode layer can be formed by coating on at least one surface of each current collector and come into contact with the solid electrolyte layer (13).

[0034] In one embodiment, the positive electrode layer (11) may be formed by applying a positive active material layer to at least one surface of a positive current collector, and the negative electrode layer (12) may be formed by applying a negative active material layer to at least one surface of a negative current collector. For example, the electrode layer located at the top with respect to the stacking direction may be formed by applying a positive active material layer to one surface of a positive current collector, and the electrode layer located at the bottom may be formed by applying a negative active material layer to one surface of a negative current collector. Additionally, the electrode layers located between the top and bottom may be formed by applying a positive active material layer to both surfaces of a positive current collector or by applying a negative active material layer to both surfaces of a negative current collector.

[0035] The positive active material layer may include a positive active material and, optionally, a solid electrolyte. Additionally, the positive active material layer may optionally further include additives such as a binder or a conductive agent.

[0036] The positive electrode active material is not particularly limited as long as it can secure sufficient capacity of the all-solid-state battery (10). For example, the positive electrode active material may include lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese oxide, or a combination thereof.

[0037] The conductive agent of the positive active material layer is not particularly limited as long as it is conductive without causing chemical changes in the all-solid-state battery (10). For example, the conductive agent may be a graphite such as natural graphite or artificial graphite, carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black, conductive fibers such as carbon fiber or metal fiber, metal powders such as fluorinated carbon, aluminum, or nickel powder, conductive whiskey such as zinc oxide or potassium titanate, conductive metal oxides such as titanium oxide, or conductive materials such as polyphenylene derivatives.

[0038] A binder may be used to improve the bonding strength between the active material and the conductive agent. As a binder, polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-dienter polymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluororubber, or various copolymers may be used.

[0039] As the anode current collector, a porous material such as a network or mesh shape may be used, and a porous metal plate made of stainless steel, nickel, aluminum, etc. may be used. In addition, the anode current collector may be coated with an oxidation-resistant metal or alloy film to prevent oxidation.

[0040] The negative electrode active material layer may include a negative electrode active material and, optionally, a solid electrolyte. Additionally, the negative electrode active material layer may optionally further include additives such as a binder or a conductive agent.

[0041] The negative electrode active material may use carbon-based materials, silicon, silicon oxide, silicon-based alloys, silicon-carbon-based material composites, tin, tin-based alloys, tin-carbon composites, metal oxides, or combinations thereof, and may include lithium metal and / or lithium metal alloys.

[0042] The negative electrode active material layer may also optionally include a conductive agent and a binder as described in the positive electrode active material layer.

[0043] As the cathode current collector, a porous material such as a network or mesh shape may be used, and a porous metal plate made of stainless steel, nickel, aluminum, etc. may be used. In addition, the cathode current collector may be coated with an oxidation-resistant metal or alloy film to prevent oxidation.

[0044] In one embodiment, a margin insulating layer (not shown) may be additionally disposed along the edges of the anode layer (11) and the cathode layer (12). The margin insulating layer is located on the solid electrolyte layer (13) and may be formed laterally adjacent to the edge of the anode active material layer or the cathode active material layer. Thus, the margin insulating layer may be located in the same layer in the anode layer (11) and the cathode layer (12), respectively.

[0045] The margin insulating layer may include an insulating material having low ionic conductivity. For example, the insulating material may be a polyolefin such as polyethylene or polypropylene, a polyester such as polyethylene terephthalate (PET), a polyurethane, or a polyimide.

[0046] Additionally, the margin insulating layer may include an oxide-based solid electrolyte used in the solid electrolyte layer (13). However, the material included in the margin insulating layer is not limited thereto and may include various materials.

[0047] The positive electrode layer (11) and the negative electrode layer (12) of the all-solid-state battery (10) can each be connected to an external electrode (14, 15). The external electrode (14, 15) can be connected to the exposed terminal of each current collector of the positive electrode layer (11) and the negative electrode layer (12), thereby allowing them to have a positive electrode and a negative electrode, respectively.

[0048] According to one embodiment of the present invention, the all-solid-state battery (10) comprises a positive electrode layer (11), a negative electrode layer (12), and a solid electrolyte layer (13), each formed as a plurality of layers and alternately stacked to form a cell stack. Although FIG. 2 illustrates a configuration in which the positive electrode layer (11) and the negative electrode layer (12) are alternately arranged and the solid electrolyte layer (13) is arranged between them, the arrangement of the positive electrode layer (11), the negative electrode layer (12), and the solid electrolyte layer (13) is not limited to that illustrated. In one embodiment, a protective layer (not shown) made of an insulating material may be formed on the top and bottom of the cell stack.

[0049] According to one embodiment of the present invention, the all-solid-state battery (10) may include a case (16) configured to surround a cell stack. External electrodes (14, 15) may be disposed at both ends of the case (16).

[0050] The external electrodes (14, 15) may include a conductive metal and glass. The conductive metal may be, for example, a conductive metal including copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), or an alloy thereof.

[0051] The glass component included in the external electrode (14, 15) may have a composition in which oxides are mixed. The glass component may include, for example, silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, alkaline earth metal oxide, or a combination thereof. Here, the transition metal may be selected from one or more of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni); the alkali metal may be selected from one or more of lithium (Li), sodium (Na), and potassium (K); and the alkaline earth metal may be selected from one or more of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

[0052] The method of forming the external electrodes (14, 15) is not particularly limited. For example, they may be formed by dipping a cell stack into a conductive paste containing a conductive metal and glass, or by printing the conductive paste onto the surface of the cell stack using screen printing or gravure printing. In addition, various other methods may be used, such as applying the conductive paste to the surface of the cell stack or transferring a dried film of the conductive paste onto the cell stack.

[0053] The case (16) can perform the function of protecting the cell laminate, which includes the anode layer (11), the cathode layer (12), and the solid electrolyte layer (13), from being exposed to the outside. The case (16) is required to have moisture permeability, heat resistance, and insulation to protect the internal composition from external moisture, heat, electricity, etc., and is also required to have high resistance to chemical corrosion along with long-term stability.

[0054] According to one embodiment of the present invention, an all-solid-state battery (10) can be manufactured by stacking a positive electrode layer (11), a negative electrode layer (12), a solid electrolyte layer (13), a case (16), etc., and then sintering them as a single unit. In order to prevent the properties of the electrode layer, etc. from deteriorating during this sintering process, each component including the solid electrolyte layer (13) must be sintered at a low temperature, for example, 700°C or lower.

[0055] As such, the solid electrolyte of the all-solid-state battery (10) according to one embodiment of the present invention requires excellent low-temperature characteristics.

[0056] A solid electrolyte layer (13) according to one embodiment of the present invention includes an oxide-based electrolyte as a solid electrolyte.

[0057] Among oxide-based solid electrolytes, Nasicon-type solid electrolytes such as LAGP and Garnet-type solid electrolytes such as LLZO are known, and through continuous research and development, the ionic conductivity of these oxide-based solid electrolytes is 10 -4 It is known to have improved to the S / cm level.

[0058] However, there are limitations to further improving ion conductivity with the above-mentioned Nasicon and Garnet type oxide-based solid electrolytes. Furthermore, since these oxide-based solid electrolytes are sintered at high temperatures of 1,000°C or higher, as described above, even if a certain degree of excellent ion conductivity can be obtained, an increase in manufacturing costs due to high-temperature sintering cannot be avoided. In particular, when high-temperature sintering is performed, it becomes practically impossible to sinter the solid electrolyte as a single unit with the anode and cathode layers.

[0059] In one embodiment of the present invention, excellent ion conductivity is secured while lowering the sintering temperature through a new oxide-based solid electrolyte that overcomes the limitations of such conventional oxide-based solid electrolytes.

[0060] A solid electrolyte for an all-solid-state battery according to one embodiment of the present invention may be composed of an oxide comprising Li, B, Al, Cl, and an alkaline earth metal. Specifically, a solid electrolyte according to one embodiment of the present invention may comprise Li2O, B2O3, Al2O3, LiCl, and an alkaline earth metal oxide. Here, the alkaline earth metal may be at least one of Ba, Ca, Mg, and Sr.

[0061] In solid electrolytes, Li2O can function as a network modifier and plays a role in improving ionic conductivity by providing Li ions.

[0062] In solid electrolytes, B2O3 has strong inherent bonding and a small cation size, allowing it to function as a main network-forming agent.

[0063] In solid electrolytes, Al2O3 can function as an intermediate. That is, Al2O3 can function as a network-forming agent or a network-modifying agent depending on its concentration in the composition. This is attributed to the high vacancy concentration of Al ions.

[0064] In solid electrolytes, alkaline earth metal oxides can function as intermediates or network modifiers.

[0065] In solid electrolytes, LiCl plays a role in enhancing ionic conductivity by increasing the concentration of Li and Cl ions. In this process, the increased Cl ions can migrate into the network structure as free ions, thereby increasing the lattice constant of the oxide crystal structure. Consequently, a wider migration path for Li ions is secured within the crystal structure, which can further enhance ionic conductivity.

[0066] In solid electrolytes, oxides of B form trigonal and tetrahedral structures centered around B ions, whereas oxides of Al form tetrahedral structures centered around Al ions. Alkaline earth metal ions (X 2+ Since the ionic radius of ) is similar to the ionic radius of the Li ion, alkaline earth metal ions (X 2+ ) can replace Li ions at Al ion sites. However, alkaline earth metal ions (X 2+ The difference in the state of Li ions and atoms causes a charge imbalance in the lattice. This charge imbalance distorts the positions of surrounding atoms, thereby affecting Li vacancies. The presence of Li vacancies lowers the energy barrier for movement, making it easier for Li ions to move from one position to another. Consequently, the mobility of Li ions within the lattice increases, which can lead to an increase in ionic conductivity.

[0067] In one embodiment, preferably, the solid electrolyte may contain 0.4 to 11 mol% of an alkaline earth metal. More preferably, the solid electrolyte may contain 0.4 to 10 mol% of an alkaline earth metal.

[0068] A solid electrolyte for an all-solid-state battery according to one embodiment of the present invention may comprise 21 to 29 mol% of Li2O, 24 to 46 mol% of B2O3, 9 to 21 mol% of Al2O3, and 16 to 31 mol% of LiCl.

[0069] A solid electrolyte according to one embodiment of the present invention can be prepared from a precursor powder comprising Li2CO3, H3BO3, Al2O3, LiCl, and an alkaline earth metal oxide. Specifically, a solid electrolyte according to one embodiment of the present invention can be prepared through the following process.

[0070] (1) Prepare a precursor powder containing Li2CO3, H3BO3, Al2O3, LiCl, and an alkaline earth metal oxide (the alkaline earth metal is at least one of Ba, Ca, Mg, and Sr).

[0071] (2) The precursor powder is uniformly mixed through dry or wet mixing.

[0072] (3) The mixture of precursor powders is melted in an aluminum crucible at a temperature of about 900°C or higher.

[0073] (4) Rapidly cool the molten material to room temperature on a quenching roller.

[0074] (5) Grind the cooled molten material into fine particles.

[0075] (6) The crushed material is pelletized and sintered at a temperature of around 600°C.

[0076] The solid electrolyte obtained through the above process is approximately 1.1 × 10⁻⁶ at room temperature. -5 It exhibits an ionic conductivity of S / cm or greater. Preferably, the solid electrolyte is 1.2 × 10⁻⁶ -4 It exhibits ionic conductivity greater than S / cm.

[0077] As such, the solid electrolyte for an all-solid-state battery according to one embodiment of the present invention is composed of an oxide containing Li, B, Al, Cl, and an alkaline earth metal, thereby enabling sintering at a temperature of around 700°C while having excellent ionic conductivity. Furthermore, as low-temperature sintering becomes possible, the solid electrolyte layer can be sintered simultaneously with the electrode, thereby simplifying the process and improving quality.

[0078] In addition, since the solid electrolyte for an all-solid-state battery according to one embodiment of the present invention is manufactured using a melt quenching method, a uniform distribution of dopants and additives can be achieved, which can improve the quality of the all-solid-state battery and facilitate mass production on an industrial scale.

[0079] Meanwhile, the solid electrolyte according to one embodiment of the present invention has excellent ionic conductivity and non-hygroscopicity. Accordingly, even if moisture is introduced into the all-solid-state battery, the performance of the battery is not degraded, and stable and excellent performance can be maintained.

[0080]

[0081] Experimental Example

[0082] Precursor powders containing Li2CO3, H3BO3, Al2O3, LiCl, and alkaline earth metal oxides were prepared. At this time, a total of 10 types of precursor powders were prepared by varying the amounts of Li2CO3, H3BO3, Al2O3, LiCl, and XO (where X is at least one of Ba, Ca, Mg, and Sr).

[0083] To ensure the homogeneity of the solid electrolyte, the precursor powder was thoroughly mixed through ball milling or mechanical mixing. Then, the precursor powder was placed in a crucible and melted at a temperature of 900°C or higher, and the molten material was rapidly cooled on a quenching roller. After grinding the molten material using a planetary ball mill, it was sieved to obtain micro-sized fine powder.

[0084] The composition of the fine powder prepared as above is as described in Table 1. In Table 1, the composition of XO (mol%) refers to the sum of the compositions (mol%) of BaO, CaO, MgO, and SrO.

[0085]

[0086] Classification Solid Electrolyte Composition (mol%) Li2 OB2O3 Al2O3 LiCl XO Example 1 23.6 45 9.6 16.15.7 Example 2 21.4 42.7 9.6 18.28.1 Example 3 21.9 37.9 1218.9 9.3 Example 4 26.9 34.7 14.4 20.23.8 Example 5 22.1 31.4 16.6 19.4 10.5 Example 6 28.4 30.2 16.1 22.7 2.6 Example 7 26.7 24.9 16.7 21.7 10 Example 8 24.5 25.5 20.0 30.0 0.5 Comparative Example 1 31.5 41.6 6.5 20.4 - Comparative Example 235.044.05.715.00.3

[0087]

[0088] FIG. 3 is a graph showing the XRD analysis results for the pre-sintering powder of the solid electrolyte according to the embodiment and comparative example of the present invention. Referring to FIG. 3, the XRD graph for the pre-sintering powder of the solid electrolyte according to the embodiment of the present invention does not show crystal peaks. This indicates that the pre-sintering powder is in an amorphous state, and in such an amorphous state, it is difficult to form lithium ion pathways that enable ion diffusion.

[0089] The temperature characteristics measured by DTA and HTM analysis for each example and comparative example are as described in Table 2.

[0090]

[0091] Transition temperature (Tg, ℃) Crystallization temperature (Tc, ℃) Sintering temperature (T sint , ℃) Softening point (T soft , ℃)Half Ball(T half-ball , °C) Example 1 397473426730733 Example 2 398472436730736 Example 3 390476451757766 Example 4 396472456777780 Example 5 398483468782786 Example 6 395470480785789 Example 7 390457426789791 Example 8 389464441800802 Comparative Example 1 390470478805808 Comparative Example 2 389475444767790

[0092]

[0093] Referring to Table 2, all of the examples and comparative examples analyzed show transition temperatures of 389°C to 398°C and crystallization temperatures of 457°C to 483°C.

[0094] In addition, the examples and comparative examples analyzed all show a low sintering temperature of 480°C or lower. This means that it can be sintered at a significantly lower temperature compared to conventional oxide-based solid electrolytes, which are sintered at high temperatures of 1,000°C or higher.

[0095] A solid electrolyte was prepared by pelletizing the powder of the composition of Table 1 above and then sintering it at a temperature of 400°C or higher.

[0096] Table 3 shows the results of measuring the ionic conductivity of solid electrolytes according to the embodiments and comparative examples of the present invention.

[0097]

[0098] Classification Ionic Conductivity (S / cm) Example 11.12×10 -5 Example 21.27×10 -4 Example 31.34×10 -4 Example 4 2.27×10 -4 Example 52.37×10 -5 Example 63.75×10 -5 Example 71.37×10 -5 Example 81.66×10 -4 Comparative Example 11.00×10 -5 Comparative Example 26.12×10 -6

[0099]

[0100] Referring to Table 3, the solid electrolytes according to Examples 1 to 8 are 1.12 × 10⁻⁶ -5 Exhibiting ionic conductivity of S / cm or higher, the comparative examples were 1.0×10 -5 It can be confirmed that it has a high ionic conductivity compared to having an ionic conductivity of S / cm or less. In particular, the solid electrolytes of Examples 2 to 4 and 8 are 10 -4It can be confirmed that it has very high ionic conductivity at the S / cm level.

[0101] Figure 4 is a graph showing the XRD analysis results after sintering of solid electrolytes according to the embodiments and comparative examples of the present invention. Referring to Figure 4, the XRD graph of the solid electrolyte after sintering shows multiple crystal peaks. In such a crystallization structure, ion flow is smooth, resulting in excellent ionic conductivity.

[0102] FIG. 5 is a graph showing the EIS analysis results of a solid electrolyte powder according to an embodiment of the present invention. As shown in FIG. 5, the solid electrolyte powder according to an embodiment of the present invention meets the real impedance axis (x-axis) at an impedance of about 3,700 ohms.

[0103] In this experimental example, the case where the alkaline earth metal is Mg was used as an example, but the same effect can be obtained for oxides of other alkaline earth metals (e.g., Ba, Ca, and Sr).

[0104] As can be confirmed through the above experimental examples, the ionic conductivity can be improved while exhibiting low-temperature characteristics as the solid electrolyte contains Li2O, B2O3, Al2O3, LiCl, and alkaline earth metal oxides. In particular, it can be confirmed that the ionic conductivity is significantly improved when the total composition contains 0.4 to 11 mol%, and especially 0.4 to 10 mol%, of alkaline earth metal oxides.

[0105] Although the present invention has been described above with specific details such as specific components and limited embodiments, the above embodiments are provided only to aid in a more comprehensive understanding of the present invention and the present invention is not limited thereto, and a person skilled in the art to which the present invention belongs can make various modifications and variations from this description.

[0106] Accordingly, the scope of the present invention should not be limited to the embodiments described above, and all variations equivalent to or equivalent to the claims set forth below, as well as the claims described below, shall be considered to fall within the scope of the concept of the present invention.

Claims

1. As a solid electrolyte for all-solid-state batteries, Composed of oxides containing Li, B, Al, Cl, and alkaline earth metals Solid electrolyte.

2. In Paragraph 1, The above alkaline earth metal is at least one of Ba, Ca, Mg and Sr, in a solid electrolyte.

3. In Paragraph 1, A solid electrolyte containing 0.4 to 11 mol% of the above alkaline earth metal.

4. In Paragraph 1, A solid electrolyte containing 0.4 to 10 mol% of the above alkaline earth metal.

5. In Paragraph 1, A solid electrolyte comprising 21 to 29 mol% Li2O, 24 to 46 mol% B2O3, 9 to 21 mol% Al2O3 and 16 to 31 mol% LiCl.

6. In Paragraph 1, Prepared from precursor powders containing Li2CO3, H3BO3, Al2O3, LiCl, and alkaline earth metal oxides, Solid electrolyte.

7. In Paragraph 1, Ionic conductivity is 1.1×10 -5 S / cm or more, Solid electrolyte.

8. Bipolar layer, cathode layer and It includes a solid electrolyte layer, The above solid electrolyte layer is composed of oxides containing Li, B, Al, Cl, and alkaline earth metals, All-solid-state battery.

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