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CN-121974308-A - ZnSe/SnSe preparation by metal substitution method2Method and application of hollow polyhedron @ C

CN121974308ACN 121974308 ACN121974308 ACN 121974308ACN-121974308-A

Abstract

The invention discloses a method for preparing ZnSe/SnSe 2 @C hollow polyhedron by a metal replacement method and application thereof, the method comprises the following steps of (1) etching a ZIF-8 material by tannic acid to obtain a HZIF-8 material, (2) annealing the HZIF-8 material in an argon atmosphere to obtain a hollow microporous carbon material, (3) carrying out a metal replacement reaction on the hollow microporous carbon material and an anhydrous stannous chloride solution in a methanol and ethylene glycol mixed solution to obtain a Zn/Sn@C HP material, and (4) uniformly mixing the Zn/Sn@C HP material with selenium powder and annealing the mixture in a hydrogen argon mixed gas atmosphere to obtain the ZnSe/SnSe 2 @C hollow polyhedron material. The ZnSe/SnSe 2 @C HP material obtained by the metal substitution method is used for preparing a negative electrode material of a sodium ion battery, and the electrochemical performance of the battery is improved.

Inventors

  • WU YUCHENG
  • KANG XIANGLI
  • CUI JIEWU

Assignees

  • 合肥工业大学

Dates

Publication Date
20260505
Application Date
20260210

Claims (10)

  1. 1. A method for preparing ZnSe/SnSe 2 @C hollow polyhedron by a metal substitution method, which is characterized by comprising the following steps: (1) Etching the ZIF-8 material with tannic acid to obtain HZIF-8 material; (2) Annealing HZIF-8 material in argon atmosphere to obtain hollow microporous carbon material; (3) Carrying out metal replacement reaction on the hollow microporous carbon material and anhydrous stannous chloride solution by reacting in a mixed solution of methanol and ethylene glycol to obtain a Zn/Sn@C HP material; (4) Uniformly mixing the Zn/Sn@C HP material with selenium powder, and annealing in a hydrogen-argon mixed gas atmosphere to obtain the ZnSe/SnSe 2 @C hollow polyhedral material.
  2. 2. The method for preparing ZnSe/SnSe 2 @C HP material by a metal substitution method according to claim 1, wherein in the step (1), the ZIF-8 material is prepared by mixing a zinc salt solution and a 2-methylimidazole solution.
  3. 3. The method according to claim 2, wherein in the step (1), the zinc salt is zinc acetate dihydrate, the concentration of the zinc salt solution is 0.2-0.4 mmol/ml, and the concentration of the 2-methylimidazole solution is 2-4 mmol/ml.
  4. 4. The method for producing ZnSe/SnSe 2 @CHP material according to claim 1, wherein in the step (1), the concentration of tannic acid is 0.01-0.02 mmol/ml, and the etching time is 15-30 min.
  5. 5. The method for preparing ZnSe/SnSe 2 @C HP material by a metal substitution process according to claim 1, wherein in the step (2), the annealing temperature is 700-900 ℃, the heating rate is 2-4 ℃ per minute, and the heat preservation time is 2-4 h.
  6. 6. The method for preparing ZnSe/SnSe 2 @C HP material by a metal substitution method according to claim 1, wherein the step (3) is specifically characterized in that anhydrous stannous chloride is dissolved into a mixed solution of ethylene glycol and methanol to obtain solution C, a hollow microporous carbon material is added into the solution C, the solution C is placed in a water bath kettle and stirred at a constant temperature, the metal element substitution reaction is completed in the stirring process, and after the substitution is completed, the solution C is centrifugally cleaned and dried to obtain Zn/Sn@C HP material.
  7. 7. The method for preparing ZnSe/SnSe 2 @C HP material by a metal substitution method according to claim 1, wherein in the step (3), the volume ratio of methanol to glycol in the mixed solution is 1:3-1:5, the concentration of the anhydrous stannous chloride solution is 0.15-0.2 mmol/ml, the reaction temperature is 60-80 ℃, and the reaction time is 18-24 h.
  8. 8. The method for preparing ZnSe/SnSe 2 @C HP material by the metal substitution method according to claim 1, wherein in the step (4), the mass ratio of Zn/Sn@C HP material to selenium powder is 1:1, the annealing temperature is 330-370 ℃, the heating rate is 2-4 ℃ per minute, and the heat preservation time is 1-3h.
  9. 9. A ZnSe/SnSe 2 @c HP hollow polyhedral material prepared by the method of preparing ZnSe/SnSe 2 @c hollow polyhedral according to any one of claims 1 to 8.
  10. 10. The method for preparing the ZnSe/SnSe 2 @C HP material, which is characterized in that the ZnSe/SnSe 2 @C hollow polyhedral material is used for preparing a negative electrode material of a sodium ion battery.

Description

Method for preparing ZnSe/SnSe 2 @C hollow polyhedron by metal substitution method and application Technical Field The invention relates to the technical field of micro-nano composite material synthesis, in particular to a method for preparing ZnSe/SnSe 2 @C hollow polyhedron by a metal substitution method and application thereof. Background With the rapid development of renewable energy sources worldwide and the rapid growth of electric automobile demands, lithium ion batteries are the main stream technology of the current energy storage market, and face great challenges of lithium resource supply shortage and cost rise. In contrast, sodium ion batteries have received extensive attention and research due to their remarkable advantages of abundant resources, low cost, and the like. However, its energy density is relatively low, resulting in inferior cruising ability as compared to lithium ion batteries, which limits the commercialization process to some extent. Therefore, the development of electrode materials with excellent rate capability and excellent cycling stability is a key to the promotion of sodium ion battery technology. Transition metal selenides are considered as potential candidates for negative electrode materials for sodium ion batteries due to their higher theoretical capacity. However, such materials have a problem of insufficient conductivity in practical applications. More seriously, in the process of sodium intercalation/deintercalation, the transition metal selenide can undergo significant volume expansion (for example, the volume expansion of SnSe 2 can reach 440%), so that the electrode material structure collapses, the capacity is rapidly attenuated, and the cycling stability of the battery is affected. Therefore, the bimetal selenide material with the stable structure is designed to improve the multiplying power performance and the cycling stability of the sodium ion battery, and has important research significance. Disclosure of Invention The invention aims to provide a method for preparing ZnSe/SnSe 2 @C HP material by a metal substitution method and application thereof, which can improve the electrochemical performance of a negative electrode material of a sodium ion battery. In one aspect of the invention, the invention provides a method for preparing a ZnSe/SnSe 2 @C hollow polyhedron by a metal substitution method. According to an embodiment of the invention, the method comprises the following steps: (1) Etching the ZIF-8 material with tannic acid to obtain HZIF-8 material; (2) Annealing HZIF-8 material in argon atmosphere to obtain hollow microporous carbon material; (3) Carrying out metal replacement reaction on the hollow microporous carbon material and anhydrous stannous chloride solution by reacting in a mixed solution of methanol and ethylene glycol to obtain a Zn/Sn@C HP material; (4) Uniformly mixing the Zn/Sn@C HP material with selenium powder, and annealing in a hydrogen-argon mixed gas atmosphere to obtain the ZnSe/SnSe 2 @C hollow polyhedral material. In addition, the method for preparing ZnSe/SnSe 2 @C HP material by the metal substitution method according to the embodiment of the invention can also have the following additional technical characteristics: In some embodiments of the present invention, in step (1), the ZIF-8 material is prepared by mixing a zinc salt solution and a 2-methylimidazole solution. Specifically, zinc acetate dihydrate is added into deionized water to obtain a metal salt solution A, 2-methylimidazole is added into deionized water to form a solution B, the metal salt solution A is added into the solution B, the solution B is stirred at room temperature to obtain a uniform suspension, the suspension is aged 24h, and the solution is centrifugally cleaned and dried to obtain a ZIF-8 precursor. The zinc salt solution is dissolved in deionized water to release Zn 2+ ions, and the 2-methylimidazole is coordinated with Zn 2+ ions to form polyhedral ZIF-8 particles. In some embodiments of the invention, in step (1), the zinc salt is zinc acetate dihydrate, the concentration of the zinc salt solution is 0.2-0.4 mmol/ml, and the concentration of the 2-methylimidazole solution is 2-4 mmol/ml. In some embodiments of the invention, in step (1), the concentration of tannic acid is 0.01-0.02 mmol/ml and the etching time is 15-30 min. The tannic acid molecule contains a plurality of phenolic hydroxyl groups, the tannic acid molecule is weakly acidic in aqueous solution, protons can be released from the tannic acid solution, the ZIF-8 is reduced in stability under acidic conditions, protons attack Zn-N coordination bonds, the coordination bonds are broken, and Zn 2+ and imidazole ligands are released. Only internal etching can be controlled by controlling the etching time, and ZIF-8 material collapses due to overlong etching time. The HZIF-8 material obtained after etching still has a polyhedral structure, but the material is changed from a solid structure