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KR-102962196-B1 - Solid electrolyte manufacturing method and solid electrolyte manufactured thereby

KR102962196B1KR 102962196 B1KR102962196 B1KR 102962196B1KR-102962196-B1

Abstract

The present invention relates to a method for manufacturing a solid electrolyte and a solid electrolyte manufactured according to the same. Since the method for manufacturing a solid electrolyte according to the present invention is a liquid-phase-based surface modification technology for a mixture, it can be simply applied to a slurry process. Through the method, the solid electrolyte has a surface modification layer containing a surface modification material coated on the surface of a sulfide-based compound, so it has the advantage of ensuring potential stability while ensuring atmospheric stability and stability against polar solvents.

Inventors

  • 오대양

Assignees

  • 현대자동차주식회사
  • 기아 주식회사

Dates

Publication Date
20260507
Application Date
20210218

Claims (11)

  1. A step of preparing a mixture comprising a sulfide-based compound represented by the following chemical formula 1, a surface modification additive, and a solvent; and The method includes the step of evaporating the above mixture to obtain a dried mixture; A method for manufacturing a solid electrolyte characterized by the formation of a surface modification material on the surface of a sulfide compound by reacting the eluent of the sulfide compound with a surface modification additive to form a surface modification layer. [Chemical Formula 1] L a M b S c X d (In the above chemical formula 1, L is an alkali metal, and M is a type 1 element selected from the group consisting of P, Ge, Si, As, Sb, Sn, Mg, Ba, B, Al, Ga, In, Pb, N, Bi, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Hf, Ta, W, and La, and X is a first type of element selected from the group consisting of F, Cl, Br, I, Se, Te, and O, and 0<a≤10, 0<b≤10, 0<c≤10, and 0≤d≤10.
  2. In paragraph 1, A method for manufacturing a solid electrolyte, wherein the solvent comprises one or more selected from the group consisting of ethyl acetate, hexyl butyrate, water ( H₂O ), alcohol ( C₆H₂₆n +1 OH, 1≤n≤20), formic acid, and acetic acid.
  3. In paragraph 1, A method for manufacturing a solid electrolyte in which the surface modification additive comprises a compound represented by the following chemical formula 2. [Chemical Formula 2] (In the above chemical formula 2, The above n 1 to n 3 are each independently 0 to 5, and The above R1 to R3 are each independently one or more selected from the group consisting of a halogen group, a nitrile group, a nitro group, an amine group, a substituted or unsubstituted C1 - C10 alkyl group, a substituted or unsubstituted C1 - C10 alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted C5 - C14 heteroaryl group, and combinations thereof, and The substituents of R1 to R3 are each independently selected from the group consisting of halogen groups, cyano groups, nitro groups, C1 - C8 alkyl groups, and combinations thereof.
  4. In paragraph 3, A method for manufacturing a solid electrolyte, wherein the above-mentioned surface modification additive comprises one or more selected from the group consisting of Triphenyl phosphine, Tris(4-trifluoromethylphenyl)phosphine, Tris(4-fluorophenyl)phosphine, Tris[3,5-bis(trifluoromethyl)phenyl]phosphine, Tris(4-chlorophenyl)phosphine, Tris(2,4,6-trimethylphenyl)phosphine, Tris(4-methoxyphenyl)phosphine, Tris(pentafluorophenyl)phosphine, Tris(4-methoxy-3,5-dimethylphenyl)phosphine, Tris(3,5-dimethylphenyl)phosphine, Tri(o-tolyl)phosphine, and Diphenyl(p-tolyl)phosphine.
  5. In paragraph 1, A method for manufacturing a solid electrolyte in which the weight ratio of the surface modification additive/sulfide-based compound is 0.2 to 3.3.
  6. In paragraph 1, A method for manufacturing a solid electrolyte in which the evaporation of the above mixture is performed under temperature conditions of 120 to 150°C.
  7. In paragraph 1, A method for manufacturing a solid electrolyte in which the above-mentioned surface modification material is a sulfide-based material formed by the reaction of a sulfide-based eluent and a surface modification additive.
  8. A sulfide compound represented by the following chemical formula 1; and The above-mentioned sulfide-based compound surface is coated and includes a surface modification layer comprising a surface modification material, and The above surface modification material is a solid electrolyte that is a sulfide-based material. [Chemical Formula 1] L a M b S c X d (In the above chemical formula 1, L is an alkali metal, and M is a type 1 element selected from the group consisting of P, Ge, Si, As, Sb, Sn, Mg, Ba, B, Al, Ga, In, Pb, N, Bi, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Hf, Ta, W, and La, and X is a first type of element selected from the group consisting of F, Cl, Br, I, Se, Te, and O, and 0<a≤10, 0<b≤10, 0<c≤10, and 0≤d≤10.
  9. delete
  10. In paragraph 8, The above surface modification material is a solid electrolyte comprising Triphenylphosphine sulfide ( C18H15PS ).
  11. In paragraph 8, A solid electrolyte having an ionic conductivity of 0.03 to 0.04 mS/cm after exposure to air.

Description

Solid electrolyte manufacturing method and solid electrolyte manufactured thereby The present invention relates to a method for manufacturing a solid electrolyte and a solid electrolyte manufactured according to the same. Lithium-ion batteries have mainly been applied in small-scale fields such as mobile devices and laptop computers, but recently, the direction of research is expanding to medium and large-scale fields such as energy storage systems (ESS) and electric vehicles (EV). In the case of these medium-to-large lithium-ion batteries, unlike small ones, not only are the operating environments (e.g., temperature, shock) harsh, but a larger number of batteries must also be used; therefore, safety must be ensured along with excellent performance or a reasonable price. Since most currently commercialized lithium-ion batteries use organic liquid electrolytes in which lithium salts are dissolved in flammable organic solvents, they carry potential risks of leakage, ignition, and explosion. Accordingly, using a solid electrolyte to replace the aforementioned organic liquid electrolyte is gaining attention as an alternative to overcome the aforementioned safety issues. Specifically, batteries using solid electrolytes, or all-solid-state batteries, can be classified into thin-film and thick-film types. Among these, the thick-film all-solid-state battery is a so-called composite-type all-solid-state battery, which is a form in which the organic liquid electrolyte in currently commercialized lithium-ion batteries is simply replaced with a solid electrolyte. The solid electrolytes substituted above can be classified into oxide-based and sulfide-based types. In particular, since sulfide-based solid electrolytes have higher lithium ion conductivity and are stable over a wide voltage range compared to oxide-based solid electrolytes, sulfide-based solid electrolytes are currently mainly used as solid electrolytes. At this time, the sulfide-based solid electrolytes used are centered around P-S bonds. Since P-S bonds are vulnerable to atmospheric and polar environments, it was urgent to ensure the atmospheric stability and stability of the solid electrolyte against polar solvents. Most technological developments for solid electrolytes aimed at solving the aforementioned problems have been achieved through the control of solid electrolyte composition; however, issues such as reduced intrinsic ionic conductivity or decreased potential stability still persisted. FIG. 1a is an FT-IR spectrum graph of Triphenyl phospine ( PPh₃ ), a surface modification additive according to the present invention, and FIG. 1b is an FT-IR spectrum graph of a surface modification material precipitated by reacting PPh₃ , a surface modification additive according to the present invention, with the supernatant. Figure 2 is a graph showing the voltage versus capacity of all-solid-state batteries according to Example 4, Example 5, and Comparative Example 6. Figure 3 is a graph showing the capacity according to the number of cycles of all-solid-state batteries according to Example 4, Example 5, and Comparative Example 6. Figure 4 is a graph showing the Coulombic efficiency according to the number of cycles of all-solid-state batteries according to Example 4, Example 5, and Comparative Example 6. FIG. 5 is a graph showing the voltage versus capacity of an all-solid-state battery according to Example 5 and Comparative Example 6, which includes an electrode containing a solid electrolyte exposed to the atmosphere for a certain period of time. The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the invention is sufficiently conveyed to a person skilled in the art. In describing each drawing, similar reference numerals have been used for similar components. In the attached drawings, the dimensions of the structures are depicted enlarged compared to their actual size for the clarity of the invention. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should not be understood as precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Unless otherwise specified, all numbers, values, and/or expressions used herein to represent amounts of ingredients, reaction conditions, polymer compositions, and formulations should be understood to be modified by the term “approximately” in all cases, as these numbers are e