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CN-117416995-B - Preparation method and application of sodium ion positive electrode material

CN117416995BCN 117416995 BCN117416995 BCN 117416995BCN-117416995-B

Abstract

The invention provides a preparation method of a sodium ion positive electrode material, which comprises the steps of uniformly mixing a positive electrode material precursor Ni 1/ 3 Fe 1/3 Mn 1/3 (OH) 2 , a sodium source compound, copper oxide and ferric oxide according to a certain proportion to obtain a mixture, and sintering, crushing and sieving the mixture under a certain condition to obtain the sodium ion positive electrode material. The sodium ion positive electrode material monocrystal prepared by the preparation method has obvious appearance, high crystallinity and higher compaction density and cycle performance. The preparation method has simple process flow and is suitable for large-scale industrial production. The invention also provides a sodium ion positive electrode material prepared by the preparation method and a sodium ion battery comprising the sodium ion positive electrode material.

Inventors

  • SUN JIE
  • WANG ZHENGJIE
  • MEI JING
  • DONG YAOGANG
  • WU DABEI
  • KE ZHEN
  • HE ZHONGLIN
  • HE JIANHAO

Assignees

  • 湖北融通高科先进材料集团股份有限公司

Dates

Publication Date
20260512
Application Date
20231016

Claims (8)

  1. 1. The preparation method of the sodium ion positive electrode material is characterized by comprising the following steps of: S10, uniformly mixing a positive electrode material precursor Ni 1/3 Fe 1/3 Mn 1/3 (OH) 2 , a sodium source compound, copper oxide and ferric oxide according to a certain proportion to obtain a mixture, wherein the sodium source compound comprises sodium chloride, the molar ratio of the copper oxide to the positive electrode material precursor in the mixture is less than 0.008:1, and the molar ratio of the ferric oxide to the positive electrode material precursor in the mixture is less than 0.008:1; And S20, sintering, crushing and sieving the mixture under a certain condition to obtain the sodium ion positive electrode material.
  2. 2. The method according to claim 1, wherein the molar ratio of the sodium source compound to the positive electrode material precursor is 1 (0.87-1.04).
  3. 3. The method according to claim 1, wherein the particle size D50 of the positive electrode material precursor is 3 μm to 7 μm, and/or the mixture is mixed in a high-speed mixer for 30min to 60min at a mixing speed of 600rpm to 900rpm.
  4. 4. The preparation method of the sodium ion positive electrode material according to claim 1 is characterized by further comprising the steps of S5, mixing a mixed salt solution of Ni, fe and Mn, a sodium hydroxide solution and an ammonia solution in parallel according to a certain proportion, performing coprecipitation reaction to obtain a precipitate intermediate, and washing, drying and screening the precipitate intermediate to obtain the precursor Ni x Fe y Mn z (OH) 2 of the sodium ion positive electrode material.
  5. 5. The method according to claim 4, wherein the molar ratio of Ni, fe and Mn in the mixed salt solution is 1:1:1, the total molar concentration of Ni, fe and Mn in the mixed salt solution is 1.8mol/L to 2.5mol/L, and/or the mass fraction of the sodium hydroxide solution is 20-40%, and/or the molar concentration of the aqueous ammonia solution is 1.5mol/L to 8mol/L, and/or the coprecipitation reaction is performed under an inert atmosphere, and/or the pH of the coprecipitation reaction mixed solution is 9-11, the reaction temperature is 40 ℃ to 60 ℃, and/or the stirring speed of the coprecipitation reaction is 200r/min to 800r/min.
  6. 6. The method for preparing the sodium ion positive electrode material according to claim 5, wherein the steps of washing, drying and screening specifically comprise the steps of washing the precipitated intermediate with sodium hydroxide of 0mol/L-1mol/L for three times, washing with pure water until the conductivity is less than or equal to 30us/cm, drying to obtain Ni x Fe y Mn z (OH) 2 , screening the dried material with a 200-350-mesh screen, and screening to obtain the precursor of the positive electrode material.
  7. 7. A sodium ion positive electrode material, characterized in that the sodium ion positive electrode material is produced according to the production method of any one of claims 1 to 6.
  8. 8. A sodium ion battery according to claim 7, wherein the sodium ion battery comprises a sodium ion positive electrode material.

Description

Preparation method and application of sodium ion positive electrode material Technical Field The invention relates to the technical field of batteries, in particular to a preparation method of a sodium ion positive electrode material, the sodium ion positive electrode material and a sodium ion battery. Background As a representative secondary battery with the highest comprehensive performance, commercialization of a lithium ion battery can be traced back to the 90 th century, and research on the lithium ion battery has been conducted for many years to have a mature battery technology route. However, lithium ion batteries are difficult to support in the current growing energy storage market, limited by the abundance of lithium element crust. The working principle of the sodium ion battery is similar to that of a lithium ion battery, the sodium salt reserves are rich, the exploitation is simple, and the method has more advantages in the large-scale application direction in the subsequent energy storage field. Sodium-electricity positive electrode material is the energy density source of sodium ion battery, and research scholars find in the preparation process that the sodium positive electrode material that uses the precursor sintering to obtain is in the process, and sintering temperature only needs to be less than 1000 ℃ in order to fully react, obtains sodium positive electrode material on the one hand, and secondly because sintering temperature is too high, finally sinters into the sodium positive electrode material that single crystal appearance is mostly sheet structure. On the one hand, the high temperature causes the waste of energy and also causes the increase of production cost, and on the other hand, the obtained sodium positive electrode material with the sheet structure causes the attenuation of the battery cycle performance due to the structural change or the phase transformation. In the prior art, researchers also add CuO as a sintering aid to a precursor of the sodium-electricity positive electrode material to perform sintering, and the sintering aid effect can be achieved only by adding copper oxide in an amount which is more than 2% of the molar amount of the precursor of the sodium-electricity positive electrode material, and the sintering temperature can be successfully reduced to be not higher than 1000 ℃. However, such excessive addition of copper oxide can enhance the firing assisting effect, but also results in generation of a hetero-phase, thereby causing a decrease in the electrical properties of the obtained sodium-electric positive electrode material. Disclosure of Invention In view of the above, the present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides a preparation method and application of a sodium ion positive electrode material. The preparation method provided by the invention can be used for preparing the sodium ion positive electrode material with low sulfur and low impurities, and further can be used for preparing the ferric hydrogen phosphate and the sodium ion positive electrode material with low impurities, and can be used for improving the utilization rate of the battery material. Meanwhile, the preparation method has simple process flow and is suitable for large-scale industrial production. To this end, in a first aspect, an embodiment of the present invention provides a method for preparing a sodium ion positive electrode material, where the method includes: s10, uniformly mixing a positive electrode material precursor Ni 1/3Fe1/3Mn1/3(OH)2, a sodium source compound, copper oxide and ferric oxide according to a certain proportion to obtain a mixture; And S20, sintering, crushing and sieving the mixture under a certain condition to obtain the sodium ion positive electrode material. Preferably, the sodium source compound comprises at least one of sodium carbonate, sodium hydroxide, sodium phosphate, sodium chloride. Preferably, the molar ratio of the copper oxide to the addition of the positive electrode material precursor in the mixture is less than 0.02:1. Preferably, the molar ratio of the copper oxide to the addition of the positive electrode material precursor in the mixture is less than 0.008:1, and/or the molar ratio of the iron oxide to the addition of the positive electrode material precursor in the mixture is less than 0.008:1, and/or the molar ratio of the sodium source compound to the addition of the positive electrode material precursor is (0.87-1.04): 1. Preferably, the particle size D50 of the positive electrode material precursor is 3 μm to 7 μm, and/or, The mixing time of the mixture in a high-speed mixer is 30-60 min, and the mixing rotating speed is 600-900 rpm. Preferably, the preparation method further comprises: S5, mixing the mixed salt solution of Ni, fe and Mn, the sodium hydroxide solution and the ammonia water solution in parallel according to a certain proportion, a