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CN-122025829-A - Battery monomer, positive electrode plate, positive electrode composite material, preparation method, battery device and energy storage device

CN122025829ACN 122025829 ACN122025829 ACN 122025829ACN-122025829-A

Abstract

The application relates to the technical field of batteries, in particular to a battery monomer, a positive pole piece, a positive composite material, a preparation method, a battery device and an energy storage device. The battery monomer comprises a positive electrode plate, the positive electrode plate comprises a positive electrode active layer, the positive electrode active layer comprises a positive electrode composite material, the chemical formula of the positive electrode composite material comprises Li a M 1 b M 2 c M 3 d M 4 e O f S g ;, M 1 comprises one or more of Ti and Nb, M 2 、M 3 、M 4 comprises one or more of transition metal and Al respectively and independently, M 1 、M 2 、M 3 、M 4 comprises different metal elements respectively, a=1-2, b=0.1-1, 0< c is less than or equal to 0.5,0< d is less than or equal to 0.5,0< e is less than or equal to 0.5, f=0.1-2, and g=0.1-3. The scheme of the application can well improve the battery capacity and the battery charge and discharge voltage.

Inventors

  • WU KAI
  • ZHAO GUANGXUE
  • Zheng Chuanzuo
  • Shao Qinong
  • ZHANG HONGTU
  • MENG XINHAI
  • HU BOBING
  • NING ZIYANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260512
Application Date
20241111

Claims (20)

  1. 1. The battery cell is characterized by comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode active layer, the positive electrode active layer comprises a positive electrode composite material, and the chemical formula of the positive electrode composite material comprises Li a M 1 b M 2 c M 3 d M 4 e O f S g ; Wherein M 1 comprises one or more of Ti and Nb, M 2 、M 3 、M 4 comprises one or more of transition metal and Al independently, and M 1 、M 2 、M 3 、M 4 is a different metal element; a=1~2,b=0.1~1,0<c≤0.5,0<d≤0.5,0<e≤0.5,f=0.1~2,g=0.1~3。
  2. 2. the battery cell of claim 1, wherein a=1.2 to 1.7, and/or, B=0.3 to 0.7, and/or, C=0.01 to 0.5, and/or, D=0.01 to 0.5, and/or, E=0.01 to 0.5, and/or, F=0.5 to 1.5, and/or, g=1~2。
  3. 3. The battery cell of claim 1 or 2, wherein the transition metal comprises one or more of Ni, co, mn.
  4. 4. The battery cell of any one of claims 1-3, wherein M 2 comprises Ni, c = 0.05-0.5.
  5. 5. The battery cell of any one of claims 1-4, wherein M 3 comprises one or more of Mn, al, d = 0.08-0.4.
  6. 6. The battery cell of any one of claims 1-5, wherein M 4 comprises Co, e = 0.01-0.2.
  7. 7. The battery cell of any one of claims 1-6, wherein the positive electrode composite comprises one or more of Li 1.5 Ti 0.5 Ni 0.25 Mn 0.2 Co 0.05 OS 1.5 、Li 1.33 Ti 0.33 Ni 0.33 Mn 0.27 Co 0.07 O 1.33 S、Li 1.67 Ti 0.67 Ni 0.17 Mn 0.13 Co 0.03 O 0.67 S 2 、Li 1.5 Ti 0.5 Ni 0.17 Mn 0.17 Co 0.17 OS 1.5 .
  8. 8. The battery cell according to any one of claims 1 to 7, wherein the positive electrode composite material has a periodic layered structure, and/or the space group of the positive electrode composite material is R-3m.
  9. 9. The battery cell according to any one of claims 1 to 8, wherein diffraction peaks appear at positions of 21 ° to 22 °, 24 ° to 25 ° in an X-ray diffraction pattern of the positive electrode composite material.
  10. 10. The battery cell according to any one of claim 1 to 9, wherein the relationship between the c-axis unit cell parameter c and the a-axis unit cell parameter a in the X-ray diffraction pattern of the positive electrode composite material satisfies c >4.9a, and/or, The value range of the unit cell parameter a of the a-axis is 2.8-3.0, the value range of the unit cell parameter c of the c-axis is 14.2-14.3, and/or, The ratio of the diffraction peak intensity I 003 of the 003 crystal plane to the diffraction peak intensity I 101 of the 101 crystal plane satisfies 0.18< I 101 /I 003 <0.2.
  11. 11. The battery cell of any one of claims 1-10, wherein the positive electrode active layer further comprises a solid state electrolyte comprising a sulfide solid state electrolyte.
  12. 12. The positive electrode plate is characterized by comprising a positive electrode active layer, wherein the positive electrode active layer comprises a positive electrode composite material, and the chemical formula of the positive electrode composite material comprises Li a M 1 b M 2 c M 3 d M 4 e O f S g ; Wherein M 1 comprises one or more of Ti and Nb, M 2 、M 3 、M 4 comprises one or more of transition metal and Al independently, and M 1 、M 2 、M 3 、M 4 is a different metal element; a=1~2,b=0.1~1,0<c≤0.5,0<d≤0.5,0<e≤0.5,f=0.1~2,g=0.1~3。
  13. 13. the positive electrode sheet of claim 12, wherein the positive electrode active layer further comprises a solid state electrolyte comprising a sulfide solid state electrolyte.
  14. 14. A positive electrode composite material is characterized in that the chemical formula comprises Li a M 1 b M 2 c M 3 d M 4 e O f S g ; Wherein M 1 comprises one or more of Ti and Nb, M 2 、M 3 、M 4 comprises one or more of transition metal and Al independently, and M 1 、M 2 、M 3 、M 4 is a different metal element; a=1~2,b=0.1~1,0<c≤0.5,0<d≤0.5,0<e≤0.5,f=0.1~2,g=0.1~3。
  15. 15. The preparation method of the positive electrode composite material is characterized by comprising the following steps of reacting a multi-element lithium metal oxide or a modified compound thereof and a thio lithium compound or a modified compound thereof according to the element proportion of Li a M 1 b M 2 c M 3 d M 4 e O f S g under a protective atmosphere; Wherein the lithium sulfide compound comprises M 1 , the multi-lithium metal oxide comprises M 2 、M 3 、M 4 ,M 1 comprising one or more of Ti, nb, M 2 、M 3 、M 4 each independently comprising one or more of transition metal, al, and M 1 、M 2 、M 3 、M 4 each is a different metal element; a=1~2,b=0.1~1,0<c≤0.5,0<d≤0.5,0<e≤0.5,f=0.1~2,g=0.1~3。
  16. 16. the method of preparing a positive electrode composite material according to claim 15, wherein the multi-lithium metal oxide comprises a ternary material.
  17. 17. The method of preparing a positive electrode composite material according to claim 16, wherein the ternary material comprises one or more of a nickel cobalt manganese ternary material and a nickel cobalt aluminum ternary material.
  18. 18. The method for preparing a positive electrode composite material according to any one of claims 15 to 17, wherein the lithium sulfide compound includes one or more of Li 2 TiS 3 、Li 2 NbS 3 、Li 3 NbS 4 、Li 2 Ti 1-x3 Si x3 S 3 , wherein 0< x3 is equal to or less than 0.5.
  19. 19. The method for producing a positive electrode composite material according to any one of claims 15 to 18, wherein the molar ratio between the multi-element lithium metal oxide or modified compound thereof and the lithium sulfide compound or modified compound thereof is 1 (0.5 to 2).
  20. 20. The method for producing a positive electrode composite material according to claim 19, wherein a molar ratio between the multi-element lithium metal oxide or the modified compound thereof and the lithium sulfide compound or the modified compound thereof is 1 (0.8 to 1.5).

Description

Battery monomer, positive electrode plate, positive electrode composite material, preparation method, battery device and energy storage device Technical Field The application relates to the technical field of batteries, in particular to a battery monomer, a positive pole piece, a positive composite material, a preparation method, a battery device and an energy storage device. Background In an all-solid-state battery system using sulfide as a solid electrolyte, the lithium-rich sulfur-based material becomes one of the research hot spots of the anode material under the all-solid-state battery system due to the advantages of good adaptability to the electrolyte, less side reaction and the like. However, the lithium-rich sulfur-based material has the defects of low self capacity, low charge-discharge voltage and the like, and cannot meet the demands of people on the positive electrode material of the all-solid-state battery with high specific energy density. Disclosure of Invention The present application has been made in view of the above-described problems, and an object of the present application is to solve the problems of low capacity of a lithium-rich sulfur-based material and low charge-discharge voltage. In order to achieve the above purpose, the application provides a battery monomer, a positive electrode plate, a positive electrode composite material, a preparation method, a battery device and an energy storage device. The first aspect of the application provides a battery cell comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode active layer, the positive electrode active layer comprises a positive electrode composite material, and the chemical formula of the positive electrode composite material comprises LiaM1bM2cM3dM4eOfSg; Wherein M 1 comprises one or more of Ti and Nb, M 2、M3、M4 comprises one or more of transition metal and Al independently, and M 1、M2、M3、M4 is a different metal element; a=1~2,b=0.1~1,0<c≤0.5,0<d≤0.5,0<e≤0.5,f=0.1~2,g=0.1~3。 the battery monomer of the embodiment of the application has the characteristics of high capacity and high charging voltage, can be charged under high voltage and provides high capacity, and the principle is that in the battery cycle process, sulfur anions in the positive electrode composite material firstly participate in electrochemical reaction (a voltage platform, namely a sulfur anion voltage platform, appears in a capacity curve) due to low reaction voltage, and metals such as M 2、M3、M4 and the like have higher reaction voltage and can participate in electrochemical reaction after the sulfur anions react, so that the effective reversible capacity after the sulfur anion voltage platform can be provided, and the specific capacity of the material is improved. Meanwhile, after the sulfur anions react, the positive electrode composite material can further utilize metals such as M 2、M3、M4 to continue electrochemical reaction, namely after reaching a sulfur anion voltage platform, charge can be continued, and electrochemical reaction can be continued under higher voltage, so that the charge and discharge voltage can be well improved. Under the action of the positive electrode composite material, the battery unit can show high capacity and high charge-discharge voltage. In some embodiments, a=1.2 to 1.7, b=0.3 to 0.7, c=0.01 to 0.5, d=0.01 to 0.5, e=0.01 to 0.5, f=0.5 to 1.5, g=1 to 2. In some embodiments, the transition metal comprises one or more of Ni, co, mn. M 2、M3、M4 comprises one or more of transition metals and Al independently, and the positive electrode composite material shows good rate performance under the combination of transition metals such as Ni, co, mn and the like. And wherein Ni and Co can participate in compensation after lithium removal caused by reaction with a sulfur anion, provide effective reversible capacity after a sulfur anion voltage plateau, and improve specific capacity of the material. In some embodiments, M 2 comprises Ni, c=0.05 to 0.5, optionally c=0.1 to 0.4. In some embodiments, M 3 comprises one or more of Mn, al, d=0.08-0.4, optionally d=0.13-0.27. In some embodiments, M 4 comprises Co, e=0.01 to 0.2, optionally e=0.03 to 0.17. By optimizing the element composition of the positive electrode composite material, the positive electrode composite material can show better specific capacity, charge-discharge voltage and rate capability. In some embodiments, the positive electrode composite includes one or more of Li1.5Ti0.5Ni0.25Mn0.2Co0.05OS1.5、Li1.33Ti0.33Ni0.33Mn0.27Co0.07O1.33S、Li1.67Ti0.67Ni0.17Mn0.13Co0.03O0.67S2、Li1.5Ti0.5Ni0.17Mn0.17Co0.17OS1.5. These materials all have high specific capacity, high charge-discharge voltage and good rate capability. In some embodiments, the positive electrode composite material has a periodic layered structure, and the spatial group of the positive electrode composite material is R-3m. Through detection, the positive electrode compos