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CN-121983569-A - P2-O3 composite phase-based high-capacity sodium ion battery anode material and preparation method and application thereof

CN121983569ACN 121983569 ACN121983569 ACN 121983569ACN-121983569-A

Abstract

The invention belongs to the technical field of electrochemical energy storage materials, and discloses a high-capacity sodium ion battery anode material based on a P2-O3 composite phase, and a preparation method and application thereof. The chemical general formula of the positive electrode material is Na μ Li ν Mg γ Ni x Mn z TM y O 2 , wherein mu is more than or equal to 0.75 and less than or equal to 0.85,0.05, v is more than or equal to 0.15, gamma is more than or equal to 0.01 and less than or equal to 0.10,0.20, x is more than or equal to 0.30,0.55, z is more than or equal to 0.70,0.005 and y is more than or equal to 0.05, v+gamma+x+z+y is more than or equal to 0.95 and less than or equal to 1.05, and TM is a combination of at least two elements selected from 3d, 4d and 5d transition metal elements and/or lanthanide metal elements. The material has a composite crystal structure in which a P2 phase and an O3 phase coexist. The high-capacity sodium ion battery anode material based on the P2-O3 composite phase has higher specific capacity and good cycling stability, and can be used for sodium ion batteries.

Inventors

  • CHEN MIN
  • ZENG ZIYI
  • LI YAN
  • LI WEISHAN

Assignees

  • 华南师范大学

Dates

Publication Date
20260505
Application Date
20251231

Claims (10)

  1. 1. A positive electrode material of a sodium ion battery based on a P2-O3 composite phase is characterized in that the chemical general formula of the positive electrode material is Na μ Li ν Mg γ Ni x Mn z TM y O 2 , wherein mu is more than or equal to 0.75 and less than or equal to 0.85,0.05 and less than or equal to v is more than or equal to 0.15, gamma is more than or equal to 0.01 and less than or equal to 0.10,0.20 and less than or equal to x is more than or equal to 0.30,0.55 and less than or equal to z and less than or equal to 0.70,0.005 and less than or equal to 0.05, v+gamma+x+z+y is more than or equal to 0.95 and less than or equal to 1.05, and TM is a combination of at least two elements selected from 3d transition metal elements, 4d transition metal elements, 5d transition metal elements and lanthanide metal elements.
  2. 2. The positive electrode material for a sodium ion battery based on a P2-O3 composite phase according to claim 1, wherein μ is 0.75-0.85, ν is 0.08-0.12, and γ is 0.02-0.08.
  3. 3. The P2-O3 composite phase-based sodium ion battery cathode material according to claim 1, wherein the doping element TM element comprises at least one of TM1 and TM2, wherein TM1 is a first transition metal element, TM2 is a second transition metal element and/or a lanthanoid actinoid, wherein TM1 is selected from at least one of Ti, fe, co, cu, zn, and TM2 is selected from at least one of Zr, nb, mo, ru, rh, pd, W, la, ce.
  4. 4. The P2-O3 composite phase-based sodium ion battery cathode material according to claim 3, wherein when the doping element TM element comprises TM1 and TM2, the molar ratio of TM1 to TM2 is 10:1 to 1:2.
  5. 5. A method for preparing a positive electrode material of a sodium ion battery based on a P2-O3 composite phase according to any one of claims 1 to 4, characterized by comprising the steps of: (1) Raw material pretreatment, namely respectively performing ball milling treatment on a sodium source, a lithium source, a magnesium source, a nickel source, a manganese source and a TM source to control the average grain diameter of each raw material to be within the range of 0.5-5 mu m; (2) Mixing and ball milling, namely weighing the raw materials according to the metering ratio of the chemical general formula, and ball milling and mixing under protective atmosphere; (3) And calcining, namely heating and calcining the mixed precursor in pure oxygen atmosphere, and then cooling to room temperature to obtain the positive electrode material.
  6. 6. The preparation method of the positive electrode material of the sodium ion battery based on the P2-O3 composite phase, which is disclosed in claim 5, is characterized in that: the sodium source in the step (1) is at least one of Na 2 CO 3 、NaOH、NaNO 3 ; the lithium source in the step (1) is at least one of LiOH H 2 O、Li 2 CO 3 、Li 2 C 4 O 4 ·2H 2 O; the magnesium source in the step (1) is at least one of MgO and Mg (OH) 2 、MgCO 3 ; The nickel source in the step (1) is at least one of NiO and Ni (OH) 2 ; the manganese source in the step (1) is at least one of MnO 2 、Mn 2 O 3 、Mn 3 O 4 ; the TM source in the step (1) is an oxide of TM; Ball milling and mixing in the step (2) are carried out at a rotating speed of 300-3000 rpm for 5-15 hours, and the ball-material ratio is 10:1-30:1; the protective atmosphere in the step (2) is performed under Ar and/or N 2 atmosphere.
  7. 7. The preparation method of the positive electrode material of the sodium ion battery based on the P2-O3 composite phase, which is disclosed in claim 5, is characterized in that: The heating and calcining in the step (3) means that the temperature is raised to 880-1000 ℃ at the temperature rising rate of 1-5 ℃ per minute, the temperature is kept for 8-24 hours, the air pressure of the atmosphere is kept to be 0.95-1.2 standard atmospheric pressures in the calcining process, and a continuous oxygen introducing mode is adopted, wherein the oxygen flow is 100-200 mL per minute; the cooling to room temperature in the step (3) means cooling to room temperature at a cooling rate of 0.5-7 ℃ per minute.
  8. 8. The preparation method of the positive electrode material of the sodium ion battery based on the P2-O3 composite phase, which is disclosed in claim 5, is characterized in that: in the heating and calcining step (3), the temperature is raised to be 500-600 ℃ at 1-5 ℃ per min for 2-5 h ℃ to remove volatile components, then the temperature is raised to be 880-1000 ℃ at 1-5 ℃ per min for 8-24 hours.
  9. 9. Use of the positive electrode material of the sodium ion battery based on the P2-O3 composite phase according to any one of claims 1 to 4 in a sodium ion battery.
  10. 10. A sodium ion battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, characterized in that the positive electrode comprises the high-capacity sodium ion battery positive electrode material based on the P2-O3 composite phase as claimed in any one of claims 1 to 4, a conductive agent and a binder, wherein the mass ratio of the positive electrode material, the conductive agent and the binder is 80-90:5-15:3-10.

Description

P2-O3 composite phase-based high-capacity sodium ion battery anode material and preparation method and application thereof Technical Field The invention belongs to the technical field of electrochemical energy storage materials, and particularly relates to a high-capacity sodium ion battery anode material based on a P2-O3 composite phase with a multi-element synergistic effect of sodium-lithium-magnesium-nickel-manganese-transition metal, and a preparation method and application thereof. Background With global energy structure transformation, efficient, safe and low-cost energy storage technology has become a key bottleneck for restricting the large-scale utilization of renewable energy. Although lithium ion batteries have been greatly successful in the fields of portable electronic devices and electric automobiles, the application prospect of lithium resources in the field of large-scale energy storage is severely limited by uneven geographical distribution of lithium resources and continuously rising cost. Sodium ion batteries are considered as one of the most potential large-scale energy storage substitution technologies because of the abundant sodium resource reserves, wide distribution and low cost, and the electrochemical mechanism of the sodium ion batteries is highly similar to that of lithium ion batteries. In each component of a sodium ion battery, the positive electrode material is a central factor in determining the battery energy density, cycle life and cost. The positive electrode material of the sodium ion battery which is researched more at present mainly comprises three systems of Prussian blue analogues, polyanion compounds and layered transition metal oxides. Among them, the layered oxide Na xTMO2 (TM is a transition metal) has been attracting attention because of its advantages of high specific capacity, good ionic conductivity, simple preparation process, etc. Layered oxides can be largely classified into P2, P3, O2, O3, etc. according to the site occupied by Na + and the manner of oxygen stacking. Na + in the P2 type material is positioned at a triangular prism site, has a continuous two-dimensional ion diffusion channel and a lower ion diffusion energy barrier, shows excellent multiplying power performance and better air stability, and becomes an important research direction of the positive electrode material of the sodium ion battery. However, P2-type cathode materials still face significant challenges in practical applications. First, when the charge voltage exceeds 4.0V, the material undergoes complex phase transformation processes including P2-O2 phase transformation, interlayer slip and transition metal migration, resulting in collapse of the crystal structure and rapid decay of capacity. Second, the material is prone to Jahn-Teller distortion in the deep sodium removal state, particularly in the presence of Mn 3+, causing structural distortion and performance degradation. In addition, side reactions between the electrolyte and the electrode material are aggravated at high voltages, and the interface impedance is significantly increased, further limiting the high voltage application potential thereof. In order to improve the structural stability of P2-type materials, researchers have adopted various strategies. Transition metal layer doping is one of the effective means, where Li + doping has been demonstrated to be able to form a "Li-O-TM" local coordination environment, not only helping to stabilize the crystal structure, but also activating the redox reaction of lattice oxygen, providing additional capacity. However, li doping alone is often insufficient to completely suppress structural evolution at high voltages, and excessive Li doping may lead to a first reduction in coulombic efficiency. Mg 2+ as an inactive "pillar" element, doped to effectively expand interlayer spacing and suppress interlayer slip during charge and discharge, but has limited capacity improvement when used alone. Doping of transition metal elements such as Ti, cu, zn, ru and the like can stabilize the crystal framework by adjusting the electronic structure, enhancing metal-oxygen bonding, but the synergistic mechanism of the different transition metal elements is not clear. In recent years, anionic redox reactions (particularly lattice oxygen redox) have provided a new approach to breaking the capacity limit of positive electrode materials. In the lithium-rich manganese-based positive electrode material of the lithium ion battery, the specific capacity far exceeding the traditional theoretical limit can be obtained by activating the oxidation-reduction reaction of oxygen. This concept also shows great potential in the field of sodium ion batteries. However, the anionic redox reaction often accompanies irreversible oxygen precipitation, voltage hysteresis, structural degradation and other problems, which severely restrict the practical application thereof. How to achieve stable, reversible anionic redox