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CN-122000444-A - Solid electrolyte coated with gallium-based liquid alloy, and preparation method and application thereof

CN122000444ACN 122000444 ACN122000444 ACN 122000444ACN-122000444-A

Abstract

The invention discloses a solid electrolyte coated with gallium-based liquid alloy and a preparation method and application thereof, wherein the preparation method of the solid electrolyte comprises the following steps of uniformly mixing a Na source, a Zr source, a Pr source, a Si source and a P source to obtain powder, and calcining the powder to obtain precursor powder; adding a binder into precursor powder, pressing and forming to obtain a blank, firstly preserving heat of the blank, then calcining to obtain a NZSP:Pr solid electrolyte sheet, uniformly coating gallium-based liquid alloy on the surface of the NZSP:Pr solid electrolyte sheet, heating and drying to obtain the solid electrolyte coated with the gallium-based liquid alloy.

Inventors

  • MAO ZHIYONG
  • HOU YUFAN
  • DONG CHENLONG
  • WANG XINXIN
  • CHEN JINGJING
  • LUO ZHIQIANG

Assignees

  • 天津理工大学

Dates

Publication Date
20260508
Application Date
20260212

Claims (10)

  1. 1. A method for preparing a solid electrolyte coated with a gallium-based liquid alloy, comprising the steps of: Step 1, uniformly mixing a Na source, a Zr source, a Pr source, a Si source and a P source to obtain powder, calcining the powder at 1100-1300 ℃ for 12-14 hours to obtain precursor powder, adding a binder into the precursor powder, and performing compression molding at 10-20 MPa to obtain a blank, wherein the ratio of Na in the Na source, zr in the Zr source, zr in the Pr source, si in the Si source and P in the P source is 3.795:1.7 (0.1-5): 2:1, the ratio of the mass fraction of the precursor powder to the volume fraction of the binder is (0.5-0.6): 0.05, the unit of the mass fraction is g, the unit of the volume fraction is mL, and the binder is a polyvinyl alcohol aqueous solution; step 2, the green body is firstly subjected to heat preservation for 2-3 hours at 600-650 ℃, and then calcined for 12-14 hours at 1100-1300 ℃ to obtain NZSP:Pr solid electrolyte sheets; And step 3, uniformly coating the gallium-based liquid alloy with the temperature of 60-80 ℃ on the surface of NZSP:Pr solid electrolyte sheet, heating for 0.5-1 h at the temperature of 40-100 ℃, and drying to obtain the solid electrolyte coated with the gallium-based liquid alloy, wherein the gallium-based liquid alloy comprises Ga, sn and Zn, and the ratio of Ga, sn and Zn in the gallium-based liquid alloy is (80-90): (5-15): (0.5-5) in parts by weight.
  2. 2. The method according to claim 1, wherein in the step 1, the Na source is sodium carbonate, the Zr source is zirconium oxide, the Pr source is hexapraseodymium undecanoxide, the Si source is silicon dioxide, and the P source is ammonium dihydrogen phosphate.
  3. 3. The method according to claim 1, wherein in the step 1, the aqueous polyvinyl alcohol solution comprises polyvinyl alcohol and water, and the ratio of the polyvinyl alcohol to the water in the aqueous polyvinyl alcohol solution is (10-15) (85-90) in parts by mass.
  4. 4. The preparation method according to claim 1, wherein in the step 1, the uniform mixing is achieved through ball milling, the ball milling is wet ball milling, the ball milling is performed for 0.5-1 h until the uniform mixing is achieved, the ball milling is performed, the drying is performed after the ball milling, the drying temperature is 80-100 ℃, and the drying time is 3-4 h.
  5. 5. The method according to claim 1, wherein in the step 2, NZSP:Pr solid electrolyte sheet has a diameter of 14 to 16mm.
  6. 6. The method according to claim 1, wherein in the step 3, the gallium-based liquid alloy forms an intermediate layer, and the thickness of the intermediate layer is 0.5-5 μm.
  7. 7. The method for preparing a gallium-based liquid alloy according to claim 1, wherein in the step 3, the method comprises uniformly mixing liquid metals Ga, sn and Zn, and grinding to obtain a gallium-based liquid alloy; NZSP Pr solid electrolyte sheet surface is coated with 1-4 mg of gallium-based liquid alloy per 1cm 2 .
  8. 8. A gallium-based liquid alloy coated solid electrolyte obtained by the preparation method according to any one of claims 1 to 7.
  9. 9. A solid sodium metal battery comprising a solid electrolyte coated with a gallium-based liquid alloy according to claim 8.
  10. 10. Use of the gallium-based liquid alloy coated solid electrolyte according to claim 8 in a battery.

Description

Solid electrolyte coated with gallium-based liquid alloy, and preparation method and application thereof Technical Field The invention belongs to the technical field of solid-state batteries, and particularly relates to a solid-state electrolyte coated with gallium-based liquid alloy, and a preparation method and application thereof. Background As an emerging energy storage technology, the solid-state sodium metal battery has the advantages of abundant resources, low cost, high theoretical energy density and the like, is considered as a powerful candidate of the next-generation high-specific-energy battery, and particularly shows the potential of replacing the lithium ion battery. However, in practical applications, solid state sodium metal batteries face serious interfacial compatibility challenges, mainly arising from the solid-solid interface problem between the sodium metal anode and the solid state electrolyte. On the one hand, the physical contact between rigid solids is difficult to achieve continuous and intimate, resulting in the formation of a high impedance interfacial layer, thereby impeding the efficient migration of sodium ions. On the other hand, such non-uniform interfacial contact is prone to induce heterogeneous deposition and dendrite growth of sodium metal, thereby causing cell shorting, capacity fade, and safety concerns. The low melting point and strong reactivity of sodium metal further exacerbate interfacial instability, especially at high current densities, the interfacial resistance can increase significantly, affecting the kinetic performance and cycle life of the battery. Although the traditional NASICON type Na 3Zr2Si2PO12 (NZSP) solid electrolyte has higher ionic conductivity, the interface compatibility between the rigid surface and sodium metal is poor, so that the interface impedance is too high, and the battery performance is severely restricted. Strategies for introducing interlayers, such as polymer coatings or solid alloy layers, are often employed to alleviate interfacial problems. However, such methods often have limitations in that the polymer coating may impede rapid ion transport and reduce ion conductivity, while the solid alloy layer is difficult to accommodate sodium deposition/exfoliation at high current densities, lacking self-healing functionality at the interface. As a new type of interface modifying material, liquid metal still faces significant challenges in practical applications. The problem of weakening of battery cycle performance caused by volume expansion in the cycle process is particularly prominent in the charge and discharge processes, and the long-term cycle stability of the battery is directly affected. Secondly, the high surface tension of the liquid metal leads to insufficient wettability with the solid electrolyte, gaps or cavities are easy to appear at the interface, and further problems of interface impedance increase, dendrite generation and the like are caused, so that the battery performance is finally invalid. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a preparation method of a solid electrolyte coated with a gallium-based liquid alloy, which comprises the steps of firstly adopting a solid-phase sintering method to obtain a NZSP:Pr solid electrolyte sheet doped with praseodymium (Pr), then coating the surface of the Pr solid electrolyte sheet with the gallium-based liquid alloy to form an intermediate layer capable of stabilizing an interface, and further obtaining the solid electrolyte coated with the gallium-based liquid alloy. It is another object of the present invention to provide a solid electrolyte coated with a gallium-based liquid alloy. Another object of the present invention is to provide a solid sodium metal battery including a solid electrolyte coated with a gallium-based liquid alloy, which successfully constructs a sodium sheet/solid electrolyte interface layer having both high sodium affinity and electrochemical stability, wherein the intermediate layer in the solid electrolyte can reduce the contact angle of the sodium sheet/solid electrolyte interface layer, improve the interface wettability between the sodium sheet and the solid electrolyte, provide surface-to-surface contact, eliminate space charge layers and non-uniform sodium deposition caused by point-to-point contact, thereby enhancing interface adhesion and cycling stability, and can solve the problems of poor interface compatibility, poor stability, dendrite growth, etc. between the solid electrolyte and the sodium metal negative electrode in the existing solid sodium metal battery. The aim of the invention is achieved by the following technical scheme. A method of preparing a solid electrolyte coated with a gallium-based liquid alloy, comprising the steps of: Step 1, uniformly mixing a Na source, a Zr source, a Pr source, a Si source and a P source to obtain powder, calcining the powder at 1100-1300 ℃ for 12-1