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CN-118724576-B - Mixed sodium ion-proton conductive ceramic material and preparation method and application thereof

CN118724576BCN 118724576 BCN118724576 BCN 118724576BCN-118724576-B

Abstract

The invention provides a mixed sodium ion-proton conductive ceramic material, a preparation method and application thereof, and belongs to the technical field of inorganic materials and solids. The mixed sodium ion-proton conductive ceramic material provided by the invention has a composition expression of Ca 1‑x Na 1+ x GaSi 2 O 7‑0.5x , wherein x is 0.1-0.4, and the preparation method comprises the steps of weighing raw materials according to stoichiometric ratio, mixing the raw materials, grinding and drying the raw materials, sequentially carrying out first tabletting and presintering on the dried raw materials to obtain a presintering material, sequentially carrying out crushing, grinding, second tabletting and sintering on the presintering material to obtain the ceramic material, wherein the ceramic material reaches 1.03X10 ‑ 2 S/cm in 900 ℃ air atmosphere, and EIS impedance tests in dry nitrogen and wet nitrogen atmosphere show that the conductivity of the ceramic material has obvious difference, so that the ceramic material also has proton conductive behavior in a wet environment.

Inventors

  • XU JUNGU
  • DENG XIA
  • TANG XIN

Assignees

  • 桂林理工大学

Dates

Publication Date
20260512
Application Date
20240703

Claims (9)

  1. 1. The mixed sodium ion-proton conductive ceramic material is characterized in that the composition expression is Ca 1-x Na 1+ x GaSi 2 O 7-0.5x , wherein x is 0.1-0.4; The raw material of the ceramic material is CaCO 3 、Na 2 CO 3 、Ga 2 O 3 、SiO 2 ; The preparation method of the mixed sodium ion-proton conductive ceramic material comprises the following steps: 1) Weighing the raw materials according to the stoichiometric ratio of Ca 1-x Na 1+x GaSi 2 O 7-0.5x ; 2) Mixing the raw materials, grinding and drying; 3) Sequentially carrying out first tabletting and presintering on the dried raw materials to obtain presintering materials; 4) And (3) sequentially crushing, grinding, performing second tabletting and sintering the presintered material to obtain the ceramic material.
  2. 2. The mixed sodium ion-proton conducting ceramic material according to claim 1, wherein the purity of each raw material is not less than 99%; The grain size of each raw material is CaCO 3 ≤30um,Na 2 CO 3 ≤10um,Ga 2 O 3 ≤20um,SiO 2 to be less than or equal to 1200nm.
  3. 3. The mixed sodium ion-proton conducting ceramic material according to claim 1, wherein the grinding in step 2) and step 4) each independently uses ethanol wet grinding for 1h.
  4. 4. The mixed sodium ion-proton conducting ceramic material according to claim 1, wherein the step 2) is dried to an ethanol-free solution.
  5. 5. The mixed sodium ion-proton conducting ceramic material according to claim 1, wherein the pressure of the first pellet in step 3) is 2MPa.
  6. 6. The mixed sodium ion-proton conducting ceramic material according to claim 1, wherein the pre-firing temperature in step 3) is 900 ℃ and the pre-firing time is 3h.
  7. 7. The mixed sodium ion-proton conducting ceramic material as claimed in claim 1, wherein the pressure of the first pressing sheet in the step 4) is 2MPa, and the pressed thickness is 0.25cm.
  8. 8. The mixed sodium ion-proton conducting ceramic material according to claim 1, wherein the sintering temperature in step 4) is 1000 ℃ to 1100 ℃ and the sintering time is 5 hours.
  9. 9. Use of a mixed sodium ion-proton conducting ceramic material according to any one of claims 1-8 in a solid oxide fuel cell or a sodium ion battery.

Description

Mixed sodium ion-proton conductive ceramic material and preparation method and application thereof Technical Field The invention belongs to the technical field of inorganic materials and solids, and particularly relates to a mixed sodium ion-proton conductive ceramic material, a preparation method and application thereof. Background With the development of human society, the transitional exploitation of fossil energy is about to be exhausted, and meanwhile, serious environmental pollution is caused. Therefore, there is a great need to develop new, clean, renewable energy sources. Solid Oxide Fuel Cells (SOFCs) are energy conversion devices that are capable of directly and efficiently converting chemical energy in a fuel into electrical energy, and the electrolyte thereof needs to have high ionic conductivity, as low as possible, electrical conductivity. Conventional SOFCs have an electrolyte material of yttrium-stabilized zirconia (YSZ) having oxygen ion conductivity, and their conductivity is relatively low, resulting in high operating temperatures (above 800 ℃) and impeding their wide application. Therefore, there is a need to develop electrolyte materials with high ionic (oxygen ion or proton) conductivity in the medium-low temperature region (400-800 ℃) to reduce the operating temperature of SOFCs. The electrolyte material with proton conductivity generally has lower migration activation energy and higher ion conductivity than the electrolyte material with oxygen ion conductivity, and the required working temperature is relatively low, so that the electrolyte material has more practical application prospect. Compared with a lithium battery, the sodium ion battery is a novel energy storage technology, has lower raw material cost, better safety and higher energy density, is very rich in sodium resource reserves, has crust abundance of 2.64 percent, is 440 times of lithium resources, and has wide sodium resource distribution and simple extraction. The role of sodium as a substitute for lithium has emerged and has gained increasing attention in the battery field. And compared with a liquid lithium ion battery, the solid-state battery has the advantages of high safety, high energy density, high stability and the like. Melilite generally refers to an alkali or alkaline earth silicate or aluminosilicate mineral of the general formula a 2B′(B2O7) and having a layered tetrahedral network structure and solid solutions formed therefrom, with the a-site macrophyte sandwiched between adjacent tetrahedral layers being in an octacoordinate environment of five-membered ring channels. Cations at different positions in such a particular layered structure may introduce certain amounts of defects into the structure when non-equivalent substitution or oxidation occurs, thereby causing a change in the local structure and a change in physical properties. Many of the structural electrolytes of melilite have been reported and studied, especially interstitial oxygen ion conduction, while structural materials of melilite with sodium ion and proton conduction have not been reported. Disclosure of Invention In view of the above, the invention aims to provide a mixed sodium ion-proton conductive ceramic material, the prepared Ca 1-xNa1+xGaSi2O7-0.5x ceramic material has obviously improved conductivity, and also has proton conductive behavior in a wet environment, and has application prospects in the research fields of solid oxide fuel cells and sodium ion batteries. In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a mixed sodium ion-proton conducting ceramic material having a composition formula of Ca 1-xNa1+xGaSi2O7-0.5x, wherein x is 0.1-0.4. Further preferably, x in the electroceramic material Ca 1-xNa1+xGaSi2O7-0.5x is 0.4. Preferably, the raw material of the ceramic material is CaCO 3、Na2CO3、Ga2O3、SiO2; The purity of each raw material is more than or equal to 99 percent; The grain size of each raw material is CaCO 3≤30um,Na2CO3≤10um,Ga2O3≤20um,SiO2 to be less than or equal to 1200nm. In a second aspect, the present invention provides a method for preparing a ceramic material, comprising the steps of: 1) Weighing the raw materials according to the stoichiometric ratio of Ca 1-xNa1+xGaSi2O7-0.5x; 2) Mixing the raw materials, grinding and drying; 3) Sequentially carrying out first tabletting and presintering on the dried raw materials to obtain presintering materials; 4) And (3) sequentially crushing, grinding, performing second tabletting and sintering the presintered material to obtain the ceramic material. Preferably, the grinding in step 2) and step 4) are each independently ethanol wet grinding, and the grinding time is more than 1h. Preferably, the step 2) is dried to an ethanol-free solution. Further preferably, the drying in the step 2) is performed by using an infrared lamp. Preferably, the pressure of the first pressi