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CN-122000348-A - Positive electrode active material, electrochemical device, and electric device

CN122000348ACN 122000348 ACN122000348 ACN 122000348ACN-122000348-A

Abstract

The application discloses an anode active material, an electrochemical device and electric equipment, and belongs to the technical field of electrochemical energy storage devices. The positive plate containing the positive active material and the lithium metal are assembled into the button cell, the button cell is circularly charged and discharged for 100 circles by 0.5C current multiplying power and 2.8-4.4V upper and lower limit voltage, and the peak position change value of the 003 diffraction peak of the positive active material in a 100-week cycle charging state is small, so that the positive active material has excellent particle strength and crystal structure stability, is favorable for lithium ion transmission and improves the cycle performance of the positive active material.

Inventors

  • ZHANG WEICHENG
  • ZHOU ZAOYUAN

Assignees

  • 欣旺达动力科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260212

Claims (10)

  1. 1. A positive electrode active material, characterized in that the positive electrode active material contains Ni, co, and Mn elements, and satisfies: 0°<P= P1-P2≤0.15°, wherein, P1 is XRD test of the positive electrode active material, and in XRD pattern of the positive electrode active material obtained by the test, the degree of 2 theta angle corresponding to 003 diffraction peak; P2 is a degree of 2 theta angle corresponding to 003 diffraction peak in XRD spectrum of positive electrode active material in 100 circles of charge state, wherein the XRD spectrum of positive electrode active material in 100 circles of charge state is obtained by carrying out XRD test on positive electrode active material in 100 circles of charge state.
  2. 2. The positive electrode active material according to claim 1, wherein the XRD diffraction pattern of the positive electrode active material comprises a 104 diffraction peak, the peak intensity of the 003 diffraction peak is A （003） , and the peak intensity of the 104 diffraction peak is A （104） , and the conditions that A （003） /A （104） is more than or equal to 1.2 and less than or equal to 1.85 are satisfied.
  3. 3. The positive electrode active material according to claim 1, wherein the positive electrode plate containing the positive electrode active material and a lithium metal are assembled into a button cell, the button cell is circularly charged and discharged for 100 circles at a current multiplying power of 0.5C and an upper and lower limit voltage of 2.8-4.4V, XRD test is carried out on the positive electrode active material in a state of charge of 100 circles, and in an XRD spectrum of the positive electrode active material in a state of charge of 100 circles obtained by the test, 0.987-or-less theta （110） /θ （018） -or-0.994 is satisfied; wherein θ （110） 、θ （018） represents the degree of 2θ angle corresponding to 110 diffraction peak and the degree of 2θ angle corresponding to 108 diffraction peak in the XRD pattern of the positive electrode active material in the charge state of 100 cycles in the range of 63 ° to 68 °.
  4. 4. The positive electrode active material according to claim 1, wherein the positive electrode active material comprises a layered phase structure and a rock salt phase structure, the rock salt phase structure being disposed on at least a part of a surface of the layered phase structure.
  5. 5. The positive electrode active material of claim 1, wherein the positive electrode active material has a chemical formula of Li a Ni x Co y Mn z Mg q O 2 , wherein 0.7-0 <1,0< y-0.1, 0< z-0.2, x+y+z=1, a+q=1, 0< q <0.005.
  6. 6. The positive electrode active material according to claim 5, wherein x satisfies 0.70≤x≤0.82.
  7. 7. The positive electrode active material of claim 1, wherein the positive electrode active material has a polyhedral morphology.
  8. 8. The positive electrode active material according to claim 1, wherein the positive electrode active material has a particle diameter Dv50 of 0.1 to 5 μm.
  9. 9. An electrochemical device is characterized by comprising a positive electrode plate, a negative electrode plate and electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer arranged on at least one side of the surface of the positive electrode current collector, and the positive electrode active layer comprises the positive electrode active material according to any one of claims 1-8.
  10. 10. An electrical consumer comprising the electrochemical device of claim 9.

Description

Positive electrode active material, electrochemical device, and electric device Technical Field The application relates to the technical field of electrochemical energy storage, in particular to an anode active material, an electrochemical device and electric equipment. Background Since the modern society, the problems of resource exhaustion and environmental pollution are increasingly serious due to excessive consumption of fossil energy, and the energy and environmental crisis has profoundly affected the progress of human life and national development. Under such circumstances, development and efficient use of novel clean energy have become urgent. However, clean primary energy such as wind energy, water energy and solar energy is difficult to directly apply, and the large-scale utilization can be realized by converting the clean primary energy into secondary energy such as electric energy, so that the construction of an efficient energy storage system becomes a core subject. In various energy storage technologies, lithium ion batteries are paid attention to due to high energy density and long cycle life, and positive electrode materials are used as key components for determining battery performance, the capacity characteristics of the positive electrode materials directly restrict the energy density of the batteries, and meanwhile, the manufacturing cost of the positive electrode materials occupies the dominant position of the total cost of the lithium ion batteries. The lithium nickel cobalt manganese ternary positive electrode active material has the advantages of high specific capacity and low cost, and becomes a main stream positive electrode material system. However, as the scarcity of cobalt resources increases and the price rises, ternary active materials are continually optimized toward high nickel and low cobalt. It is worth noting that the ternary positive electrode active material comprises a polycrystalline structure and a monocrystalline structure, and the monocrystalline structure has remarkable advantages compared with the polycrystalline structure, wherein the regular crystal morphology of the monocrystalline structure can effectively inhibit the stability problems of gas production, cracks and the like caused by high nickel content, but the initial coulombic efficiency and discharge capacity of the monocrystalline structure show a decreasing trend when the nickel content is increased. The preparation of the monocrystal structure needs to adopt a higher sintering temperature, but the lithium nickel mixed discharge phenomenon is easily caused by high temperature, and excessive lithium salt needs to be additionally added, so that serious agglomeration of monocrystal particles is caused. To solve this problem, agglomerated single crystal particles need to be separated by mechanical disruption, but this process is prone to damage to the crystal structure. Disclosure of Invention The application aims to overcome the defects of the prior art and provides an anode active material, an electrochemical device and electric equipment. In order to achieve the aim, the application adopts the technical scheme that in the first aspect, the positive electrode active material is provided, and is characterized in that the positive electrode active material comprises Ni, co and Mn elements, and the positive electrode active material meets the following conditions: 0°<P= P1-P2≤0.15°, wherein, P1 is XRD test of the positive electrode active material, and in XRD pattern of the positive electrode active material obtained by the test, the degree of 2 theta angle corresponding to 003 diffraction peak; P2 is a degree of 2 theta angle corresponding to 003 diffraction peak in XRD spectrum of positive electrode active material in 100 circles of charge state, wherein the XRD spectrum of positive electrode active material in 100 circles of charge state is obtained by carrying out XRD test on positive electrode active material in 100 circles of charge state. In some embodiments, the XRD diffraction pattern of the positive electrode active material comprises a 104 diffraction peak, the peak intensity of the 003 diffraction peak is A （003）, and the peak intensity of the 104 diffraction peak is A （104）, so that 1.2-A （003）/A（104） -1.85 is satisfied. In some embodiments, the positive electrode plate containing the positive electrode active material and lithium metal are assembled into a button cell, the button cell is circularly charged and discharged for 100 circles at a current multiplying power of 0.5C and an upper limit voltage and a lower limit voltage of 2.8-4.4V, XRD test is carried out on the positive electrode active material after 100 circles, and the XRD pattern of the positive electrode active material after 100 circles obtained by the test meets the conditions that theta （110）/θ（018） is less than or equal to 0.994 and theta （110）、θ（018） represents the degrees of 2 theta angles corresponding to 110 diffraction pe