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CN-121983571-A - Cr/Fe co-doped K0.5Mn4O8Material and preparation method thereof

CN121983571ACN 121983571 ACN121983571 ACN 121983571ACN-121983571-A

Abstract

The invention discloses a Cr/Fe co-doped K 0.5 Mn 4 O 8 material and a preparation method thereof, belonging to the field of inorganic materials. The method comprises the steps of dissolving potassium dichromate, ferric nitrate nonahydrate, urea, a manganese nitrate aqueous solution and potassium permanganate in purified water, and placing the purified water in a hydrothermal reaction kettle for constant-temperature reaction. And (3) filtering and drying the reaction product, calcining in a muffle furnace, and cooling to obtain the Cr/Fe co-doped K 0.5 Mn 4 O 8 material. The method effectively improves the electrochemical performance of the K 0.5 Mn 4 O 8 material through co-doping of Cr and Fe elements. The obtained material presents a unique shape of close symbiosis of a micron-sized laminated massive matrix and nano particles on a microstructure, and the micron-sized and nano composite structure is beneficial to increasing the contact area of an electrode and electrolyte, providing more ion migration channels, buffering volume change in the cyclic charge and discharge process, and improving the performance of the material in the positive electrode of the zinc ion battery.

Inventors

  • LI LING
  • ZHU MENGJIAO
  • GUO ZHIYING
  • ZHANG XINLING
  • YU CHUAN
  • LIU LONG
  • ZHENG YONG
  • LIU CHAO
  • FU NING
  • DU MENGHAN

Assignees

  • 安阳工学院

Dates

Publication Date
20260505
Application Date
20260210

Claims (11)

  1. A Cr/Fe co-doped K 0.5 Mn 4 O 8 material is characterized in that XRD diffraction peaks are at 12.61 degrees, 18.13 degrees, 28.75 degrees, 37.52 degrees and 41.83 degrees, XPS peaks are at 291.15 eV, 293.97 eV, 529.12 eV, 575.69 eV, 585.27 eV, 641.78 eV, 653.36 eV, 709.75 eV and 724.28 eV, cr is +3 valence, fe is +3 valence and Mn is +3 valence and +4 valence coexist.
  2. 2. The method for preparing a Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 1, comprising the steps of: Firstly, dispersing potassium dichromate and ferric nitrate nonahydrate in purified water, sequentially adding urea, a manganese nitrate aqueous solution and potassium permanganate, and uniformly stirring; Secondly, placing the uniformly stirred solution in a hydrothermal reaction kettle, performing constant-temperature reaction in an oven, and then naturally cooling; Thirdly, taking out the product from the hydrothermal reaction kettle, cleaning, filtering, and drying in an oven; and fourthly, calcining in a muffle furnace, and cooling to obtain the Cr/Fe co-doped K 0.5 Mn 4 O 8 material.
  3. 3. The method of producing a Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 2, wherein in the first step the molar ratio of potassium dichromate to ferric nitrate nonahydrate is 5:1.
  4. 4. The method for preparing the Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 2, wherein: in the first step, the molar ratio of potassium dichromate to manganese nitrate is 2:3.
  5. 5. The method for preparing the Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 2, wherein: in the first step, the molar ratio of potassium dichromate to potassium permanganate is 10:9.
  6. 6. The method for preparing the Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 2, wherein: in the first step, the molar ratio of potassium permanganate to urea is 1:8.
  7. 7. The method of claim 2, wherein the second step is performed at a constant temperature of 160℃for a period of 6 hours.
  8. 8. The method of claim 2, wherein in the third step, the reaction product is washed with purified water, the reaction product is placed in purified water to form a suspension, the suspension is subjected to ultrasonic treatment in an ultrasonic cleaner for 5 minutes, and the suspension is subjected to suction filtration for a total of 5 times.
  9. 9. The method of claim 2, wherein in the third step, the drying temperature is 85 ℃ and the drying time is 1 hour.
  10. 10. The method for preparing a Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 2, wherein in the fourth step, the calcination temperature is 450 ℃ and the constant-temperature calcination time is 5 hours, wherein the temperature-raising program is set to 2 hours and the temperature is reduced to below 200 ℃ for 2 hours.
  11. 11. The use of the Cr/Fe co-doped K 0.5 Mn 4 O 8 material according to claim 1 in aqueous zinc ion batteries.

Description

Cr/Fe co-doped K 0.5Mn4O8 material and preparation method thereof Technical Field The invention discloses a Cr/Fe co-doped K 0.5Mn4O8 material and a preparation method thereof, belonging to the technical field of water-based zinc ion batteries in inorganic materials. Background Along with the continuous improvement of the renewable energy power generation ratio and the rapid development of the electric automobile industry, the development of a novel energy storage technology with high safety, low cost and environmental friendliness has become global consensus. Among the many energy storage systems, aqueous zinc ion batteries are of particular interest for their unique advantages. The water-based electrolyte adopted by the system has the characteristics of high ion conductivity, low cost, good safety and the like, so that the system has important application potential in the field of large-scale energy storage. However, the commercialization process of aqueous zinc ion batteries still faces a key challenge, one of which is the lack of high performance positive electrode materials to match. The ideal positive electrode material should have a stable crystal structure to support reversible intercalation and deintercalation of Zn ions, and a high electrical conductivity to enable rapid charge transfer, and be resistant to structural degradation during long-term charge-discharge cycles. Among the numerous candidate materials, the manganese-based oxide has the advantages of various ion valence states, abundant raw material reserves, low production cost, simple preparation method and the like, and is widely applied to the anode materials of batteries. The K 0.5Mn4O8 material, because of its open ion diffusion channels, is capable of providing higher theoretical capacity, is considered one of the very promising positive electrode materials. Aiming at the challenges of K 0.5Mn4O8 material in the aspects of cycle stability and structural evolution, researchers continuously improve the electrochemical performance of the K 0.5Mn4O8 material by optimizing synthesis conditions, introducing multi-element transition metal and other modes, and promote the application of the K 0.5Mn4O8 material in energy storage materials. Most of the current research focuses on the regulation of bulk crystal structure by single ion doping, while the systematic research on multi-ion co-doping is not yet in depth. The multi-ion collaborative doping is expected to realize more comprehensive performance improvement through complementary advantages. Fe 3+ is widely studied because of its close radius to Mn 3+ ion and low cost, and its doping can improve structural stability to some extent, but often has limited capacity improvement. The Cr 3+ doped has unique advantages in the aspect of enhancing structural rigidity due to strong metal oxygen bond covalent property, and the co-doping of Cr 3+ and Fe 3+ is expected to exert a synergistic stabilizing effect, so that the comprehensive performance of the K 0.5Mn4O8 material is improved. Disclosure of Invention In order to improve the electrochemical performance of the K 0.5Mn4O8 material, the invention provides a Cr/Fe co-doped K 0.5Mn4O8 material and a preparation method thereof. In the process of preparing the material, potassium dichromate, ferric nitrate nonahydrate, urea, manganese nitrate aqueous solution and potassium permanganate are sequentially added into purified water, and the mixed solution is fully stirred and then placed into a hydrothermal reaction kettle for constant-temperature reaction. And (3) filtering and drying the reaction product, calcining in a muffle furnace, and cooling to obtain the Cr/Fe co-doped K 0.5Mn4O8 material. The synthesis method is simple, low in cost and suitable for large-scale industrial production. The XRD diffraction peaks of the Cr/Fe co-doped K 0.5Mn4O8 material are 12.61 degrees, 18.13 degrees, 28.75 degrees, 37.52 degrees and 41.83 degrees, the XPS diffraction peaks are 291.15 eV, 293.97 eV, 529.12 eV, 575.69 eV, 585.27 eV, 641.78eV, 653.36 eV, 709.75 eV and 724.28 eV, cr is +3 valence, fe is +3 valence, and Mn is +3 valence and +4 valence coexist. The invention also provides a preparation method of the Cr/Fe co-doped K 0.5Mn4O8 material, which comprises the following steps: firstly, dispersing potassium dichromate and ferric nitrate nonahydrate in deionized water, sequentially adding urea, a manganese nitrate aqueous solution and potassium permanganate, and uniformly stirring; Secondly, placing the uniformly stirred solution in a hydrothermal reaction kettle, performing constant-temperature reaction in an oven, and then naturally cooling; Thirdly, taking out the product from the hydrothermal reaction kettle, cleaning, filtering, and drying in an oven; and fourthly, calcining in a muffle furnace, and cooling to obtain the Cr/Fe co-doped K 0.5Mn4O8 material. Further, in the technical scheme, in the first step, the molar ratio of potassium dichromate to f