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CN-117602682-B - Precursor with hollow structure, preparation method of precursor, positive electrode material, positive electrode and battery

CN117602682BCN 117602682 BCN117602682 BCN 117602682BCN-117602682-B

Abstract

The invention discloses a precursor with a hollow structure, a preparation method thereof, a positive electrode material, a positive electrode and a battery. The preparation method of the precursor comprises the steps of introducing a nickel-iron-manganese mixed salt solution, a zinc-containing solution, a complexing agent solution and a precipitant solution into a reaction kettle with a base solution under a protective atmosphere, stopping introducing the zinc-containing solution when particles D50 in the reaction kettle grow to 2-5 mu m, continuing introducing the nickel-iron-manganese mixed salt solution, the complexing agent solution and the precipitant solution, stopping introducing all the solutions after the particles D50 in the reaction kettle grow to a target size, and then introducing a sodium hydroxide solution into the reaction kettle until the pH value is 12.5-13.8, so that zinc is dissolved out, until the particles D50 in the reaction kettle reach a final target particle size. The preparation method can prepare the precursor with a hollow structure, and the prepared positive electrode material has good cycle performance.

Inventors

  • Yue Chuanfeng
  • XU BIN
  • SUN HONG
  • LEI HUAJUN
  • LIU XIAOCUI
  • TAN LEI
  • ZUO MEIHUA
  • ZHANG BIN
  • WANG ZHENGQIANG

Assignees

  • 宜宾光原锂电材料有限公司

Dates

Publication Date
20260505
Application Date
20231124

Claims (10)

  1. 1. A method for preparing a precursor of a hollow structure, comprising: Introducing a nickel-iron-manganese mixed salt solution, a zinc-containing solution, a complexing agent solution and a precipitant solution into a reaction kettle with a base solution under a protective atmosphere; Stopping the introduction of the zinc-containing solution when the particles D50 in the reaction kettle grow to 2-5 mu m, and continuing the introduction of the nickel-iron-manganese mixed salt solution, the complexing agent solution and the precipitant solution; and in the second particle growth stage, after the particles D50 in the reaction kettle grow to the target size, stopping introducing all the solutions, and then introducing sodium hydroxide solution into the reaction kettle until the pH value is 12.5-13.8 to dissolve zinc until the particles D50 in the reaction kettle reach the final target particle size.
  2. 2. The preparation method according to claim 1, wherein the temperature of the reaction kettle is 50-75 ℃.
  3. 3. The preparation method of the aqueous solution of the complexing agent, according to claim 1, is characterized in that the complexing agent solution is ammonia water, the precipitating agent solution is sodium hydroxide solution, the mass concentration of the ammonia water is 10-20%, and the mass concentration of the sodium hydroxide solution is 28-35%.
  4. 4. The method according to claim 1, wherein the ammonia value of the base solution is 2-10 g/L and the pH is 11.2-12.5; In the first particle growth stage, the ammonia value in the reaction kettle is 2-10 g/L, and the pH value is 11.2-11.7 by dynamically adjusting the introducing rates of the complexing agent solution and the precipitant solution; In the second particle growth stage, the ammonia value in the reaction kettle is 2-10 g/L, and the pH value is 10.8-11.5 by dynamically adjusting the introducing rates of the complexing agent solution and the precipitant solution.
  5. 5. The production method according to claim 1, further comprising at least one of the following technical features (1) and (2); (1) The concentration of metal ions in the ferronickel-manganese mixed salt solution is 80-130 g/L, and the introducing rate is 150-700L/h; The concentration of zinc ions in the zinc-containing solution is 30-90 g/L, and the introducing rate is 50-300L/h; (2) In the ferronickel manganese salt mixed solution, the molar ratio of nickel to iron to manganese is a:b:c, wherein a is 0.25-0.95, b is 0.25-0.95, c is 0.25-0.95, and a+b+c=1.
  6. 6. The method according to claim 5, wherein the zinc-containing solution is prepared from a zinc salt solution and a sodium hydroxide solution, and the pH of the zinc-containing solution is 12.5 to 13.5.
  7. 7. A precursor of a hollow structure, characterized in that it is produced by the production method according to any one of claims 1 to 6.
  8. 8. A sodium-electric positive electrode material, characterized by being produced from the precursor of the hollow structure according to claim 7.
  9. 9. A positive electrode prepared from the sodium-electric positive electrode material according to claim 8.
  10. 10. A sodium ion battery comprising the positive electrode of claim 9.

Description

Precursor with hollow structure, preparation method of precursor, positive electrode material, positive electrode and battery Technical Field The invention relates to the technical field of battery materials, in particular to a precursor with a hollow structure, a preparation method of the precursor, a positive electrode material, a positive electrode and a battery. Background Sodium ion batteries are a novel secondary battery technology, and have high energy density, low cost and good environmental friendliness. Sodium ion batteries are more difficult to study than lithium ion batteries because of the larger radius of sodium ions, resulting in different kinetics of reaction of their ions in the battery electrolyte and electrodes than lithium ions, which is also a major challenge faced by sodium ion batteries. However, with increasing demand for renewable energy and clean energy, and attention to shortage of lithium resources, sodium ion batteries are becoming a new secondary battery technology of great interest. How to ensure the specific capacity of the ternary positive electrode material and simultaneously have excellent multiplying power performance and cycle stability is a research hot spot of the ternary positive electrode material. In particular, along with the rapid development of the rapid charging technology, higher requirements are put on the structural stability of the ternary positive electrode material, and the volume change of the ternary positive electrode material produced under long-time large-current cyclic charge and discharge and side reaction generated between the ternary positive electrode material and electrolyte can cause the damage of the material structure, so that the cyclic capacity of the ternary positive electrode material is rapidly attenuated. If a loose porous hollow structure is formed in the ternary positive electrode material, the structural damage caused by the volume change and side reaction of the material can be effectively relieved, meanwhile, the hollow internal structure can shorten the lithium ion transmission path of the ternary positive electrode material in the process of charging and discharging, accelerate the ion migration rate and simultaneously effectively reduce the electrochemical polarization. Thus, it is highly desirable to prepare a ternary precursor having a porous hollow structure. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a precursor with a hollow structure, a preparation method of the precursor, a positive electrode material, a positive electrode and a battery. The invention is realized in the following way: In a first aspect, the present invention provides a method for preparing a precursor of a hollow structure, comprising: Introducing a nickel-iron-manganese mixed salt solution, a zinc-containing solution, a complexing agent solution and a precipitant solution into a reaction kettle with a base solution under a protective atmosphere; Stopping the introduction of the zinc-containing solution when the particles D50 in the reaction kettle grow to 2-5 mu m, and continuing the introduction of the nickel-iron-manganese mixed salt solution, the complexing agent solution and the precipitant solution; and in the second particle growth stage, after the particles D50 in the reaction kettle grow to the target size, stopping introducing all the solutions, and then introducing sodium hydroxide solution into the reaction kettle until the pH value is 12.5-13.8 to dissolve zinc until the particles D50 in the reaction kettle reach the final target particle size. In an alternative embodiment, the temperature of the reaction vessel is 50-75 ℃. In an alternative embodiment, the complexing agent solution is ammonia water, the precipitant solution is sodium hydroxide solution, the mass concentration of the ammonia water is 10-20%, and the mass concentration of the sodium hydroxide solution is 28-35%. In an alternative embodiment, the base solution consists of ammonia water and sodium hydroxide solution which are introduced into the reaction kettle, wherein the ammonia value of the base solution is 2-10 g/L, and the pH value of the base solution is 11.2-12.5; In the first particle growth stage, the ammonia value in the reaction kettle is 2-10 g/L, and the pH value is 11.2-11.7 by dynamically adjusting the introducing rates of the complexing agent solution and the precipitant solution; In the second particle growth stage, the ammonia value in the reaction kettle is 2-10 g/L, and the pH value is 10.8-11.5 by dynamically adjusting the introducing rates of the complexing agent solution and the precipitant solution. In an alternative implementation mode, the concentration of metal ions in the nickel-iron-manganese mixed salt solution is 80-120 g/L, and the introducing rate is 150-700L/h; The concentration of zinc ions in the zinc-containing solution is 30-90 g/L, and the introducing rate is 50-300L/h. In an