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DE-202026101405-U1 - Positive electrode sheet, lithium-ion battery and electrical device

DE202026101405U1DE 202026101405 U1DE202026101405 U1DE 202026101405U1DE-202026101405-U1

Abstract

A positive electrode sheet characterized in that it comprises a positive current collector and a positive electrode material applied to the positive current collector, wherein the positive electrode material contains a positive active material, the positive active material comprising a lithium manganese iron phosphate agglomerate and a ternary positive electrode material, wherein the positive electrode sheet satisfies: 16.8 ≤ S·R ≤ 23.2, where S is in a range of 20 to 25, and R is in a range of 0.6 to 0.98; where S represents a ratio of a peak area of a diffraction peak of a (003)-crystal plane to a peak area of a diffraction peak of a (102)-crystal plane in an XRD spectrum of the positive electrode material for a fully charged positive electrode sheet, and where R represents a roundness of the ternary positive electrode material, where R = Ri /R c , where Ri and R c represent a maximum incircle radius and a minimum circumcircle radius of a particle of the ternary positive electrode material, respectively, where Ri and Rc are given in the same unit.

Assignees

  • CALB GROUP CO LTD

Dates

Publication Date
20260513
Application Date
20260312
Priority Date
20250529

Claims (20)

  1. Positive electrode sheet, characterized in that it comprises a positive current collector and a positive electrode material applied to the positive current collector, wherein the positive electrode material contains a positive active material, the positive active material comprising a lithium manganese iron phosphate agglomerate and a ternary positive electrode material, wherein the positive electrode sheet satisfies: 16.8 ≤ S·R ≤ 23.2, where S is in a range of 20 to 25, and R is in a range of 0.6 to 0.98; where S represents a ratio of a peak area of a diffraction peak of a (003)-crystal plane to a peak area of a diffraction peak of a (102)-crystal plane in an XRD spectrum of the positive electrode material for a fully charged positive electrode sheet, and where R represents a roundness of the ternary positive electrode material, where R = Ri /R c , where Ri and R c represent a maximum inradius and a minimum circumradius of a particle of the ternary positive electrode material, respectively, where Ri and Rc are given in the same unit.
  2. Positive electrode sheet according to Claim 1 , characterized in that a primary particle in the lithium-manganese-iron-phosphate agglomerate has a particle size of 50 to 180 nm; wherein a primary particle in the ternary positive electrode material has a particle size greater than 300 nm.
  3. Positive electrode sheet according to Claim 1 , characterized in that the positive electrode sheet further satisfies 32 ≤ S·d ≤ 320, where d represents the Dv50 particle size of the lithium manganese iron phosphate agglomerate and is given in µm.
  4. Positive electrode sheet according to Claim 3 , characterized in that the positive electrode sheet further satisfies: 108 ≤ S·d ≤ 158.
  5. Positive electrode sheet according to Claim 3 , characterized in that d lies in a range of 2.5 to 10 µm.
  6. Positive electrode sheet according to Claim 5 , characterized in that d lies in a range of 4.2 to 6.8 µm.
  7. Positive electrode sheet according to Claim 1 , characterized in that the mass ratio of the lithium manganese iron phosphate agglomerate to the ternary positive electrode material is 1: (0.05 to 20).
  8. Positive electrode sheet according to Claim 1 , characterized in that the ternary positive electrode material is selected from at least one of lithium nickel cobalt manganese oxide and lithium nickel cobalt aluminum oxide.
  9. Positive electrode sheet according to Claim 1 , characterized in that the chemical formula of the ternary positive electrode material is LiNiaCobQ(1-ab)O2, wherein the element Q is at least one of Mn and Al, where a is 0.1 to 0.92 and b is 0.05 to 0.35.
  10. Positive electrode sheet according to Claim 1 , characterized in that the ternary positive electrode material contains a doping element, wherein the doping element comprises at least one of titanium, tin, tantalum, niobium and lanthanide metal elements.
  11. Positive electrode sheet according to Claim 1 , characterized in that the Dv50 particle size of the ternary positive electrode material is 0.5 to 4.5 µm.
  12. Positive electrode sheet according to Claim 1 , characterized in that the surface of the positive active material is partially or completely covered with a coating layer formed by a coating material, wherein the coating layer contains at least one element selected from: Al, P, Si, Ti, W, B, Co or Y.
  13. Positive electrode sheet according to Claim 1 , characterized in that the chemical formula of the lithium manganese iron phosphate agglomerate is LiMncFe1-cPO4, where 0 < c < 1 applies.
  14. Positive electrode sheet according to Claim 1 , characterized in that the lithium-manganese-iron-phosphate agglomerate contains no dopant element.
  15. Positive electrode sheet according to Claim 1 , characterized in that the lithium-manganese-iron-phosphate agglomerate contains a dopant element, wherein the dopant element is at least one of Ti, Mg, V, W.
  16. Positive electrode sheet according to Claim 1 , characterized in that the surface of the lithium manganese iron phosphate agglomerate is partially or completely covered with a carbon layer.
  17. Positive electrode sheet according to Claim 1 , characterized in that the mass fraction of the positive active material in the positive electrode material is 94% to 97.5%.
  18. Positive electrode sheet according to Claim 1 , characterized in that the positive electrode material further contains a conductive agent and a binder.
  19. Positive electrode sheet according to Claim 18 , characterized in that the conductive material in the positive electrode material comprises at least one of the following materials: carbon nanotubes, carbon black, graphite, carbon fiber, activated carbon, mesoporous carbon, fullerenes.
  20. Positive electrode sheet according to Claim 18 , characterized in that the mass fraction of the conductive medium in the positive electrode material is 0.5% to 2.0%.

Description

The present application is a partial application of the application with the application number CN 202510703234.0 , which was submitted on May 29, 2025 and whose title is “Positive Electrode Sheet, Lithium-Ion Battery and Electrical Device”. Technical field The present invention relates to the field of battery technology, in particular to a positive electrode sheet, a lithium-ion battery and an electrical device. Technical background Lithium manganese iron phosphate (LMFP) is widely used due to its advantages, such as a high voltage plateau, large theoretical specific capacity, and low price. LMFP aggregates are secondary particles formed by the aggregation of two or more primary particles and exhibit an aggregated state. Compared to non-agglomerated LMFP primary particles, the use of LMFP agglomerates can improve the solid-phase transfer capability of the positive electrode system and reduce the battery impedance. However, LMFP agglomerates have a relatively large particle size and are difficult to compact, which limits the increase in the packing density of the positive electrode sheet and results in a lower battery energy density. Content of the invention The object of the present invention is to overcome the aforementioned shortcomings of the prior art and to provide a positive electrode sheet, a lithium-ion battery, and an electrical device. By controlling and regulating the ratio of a peak area of a diffraction peak of a (003) crystal plane to a peak area of a diffraction peak of a (102) crystal plane in an XRD spectrum of the positive electrode material when the positive electrode sheet is fully charged, and the roundness of the ternary positive electrode material, such that they satisfy a specific relationship, it is possible for the battery to simultaneously exhibit excellent energy density and cycle performance. To solve the above-mentioned problem, the present invention provides, in a first aspect, a positive electrode sheet comprising a positive current collector and a positive electrode material applied to the positive current collector, wherein the positive electrode material contains a positive active material, the positive active material comprising a lithium-manganese-iron-phosphate agglomerate and a ternary positive electrode material, wherein the positive electrode sheet fulfills: 16.8 ≤ S·R ≤ 23.2, where S is in a range of 20 to 25, and R is in a range of 0.6 to 0.98; where S represents a ratio of a peak area of a diffraction peak of a (003)-crystal plane to a peak area of a diffraction peak of a (102)-crystal plane in an XRD spectrum of the positive electrode material for a fully charged positive electrode sheet, and where R represents the roundness of the ternary positive electrode material. In a second aspect, the present invention provides a battery comprising the positive electrode sheet. In a third aspect, the present invention provides an electrical device comprising the battery. In comparison to the prior art, the advantageous effects of the present invention are as follows: By mixing or combining the LMFP agglomerate with the ternary positive electrode material, and by regulating the ratio of the peak areas of the diffraction peaks of the (003) crystal plane and the (102) crystal plane in the XRD spectrum of the positive electrode material with a fully charged positive electrode sheet and the roundness of the ternary positive electrode material such that they satisfy the aforementioned specific relationship, the present invention achieves that the posi The positive electrode sheet has a suitable compression density, which means that a battery containing this positive electrode sheet can have both good energy density and good cycle performance. Images 1 shows a schematic representation of the measurement method for the maximum incircle radius Ri and the minimum circumcircle radius Rc of a particle of a ternary positive electrode material. Description of embodiments To clarify the tasks, technical solutions, and advantages of the embodiments of the present invention, the technical solutions in these embodiments are described clearly and completely below. Obviously, the described embodiments represent only a subset of the embodiments of the present invention and do not encompass all possible embodiments. All other embodiments that could be obtained by a person skilled in the art, without inventive effort, based on the embodiments in the present invention, fall within the scope of protection of the present invention. In the present invention, technical features that are openly described include both closed technical solutions consisting of the listed features and open technical solutions that contain the listed features. In the present invention, unless otherwise specified, a numerical range is considered continuous and includes the minimum and maximum values of that range, as well as every value between these minimum and maximum values. Furthermore, if a range refers to integers, i