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CN-122000328-A - Positive electrode slurry, preparation method thereof, positive electrode plate and battery

CN122000328ACN 122000328 ACN122000328 ACN 122000328ACN-122000328-A

Abstract

The application discloses positive electrode slurry and a preparation method thereof, a positive electrode plate and a battery, and belongs to the technical field of batteries. The positive electrode slurry comprises a positive electrode active component, a conductive agent, a binder and a solvent, wherein the positive electrode slurry further comprises an additive, the additive is at least one of humic acid, fulvic acid and humins, and the additive accounts for 0.01-2wt% of the total amount of the positive electrode active component, the conductive agent and the binder. The additive is added into the positive electrode slurry, so that the high residual alkali characteristic of positive electrode materials (NCM, NCA, LMR) such as nickel-rich and lithium-rich systems can be reduced, the slurry gel problem is reduced, and the positive electrode materials such as nano conductive agents, nano LFP (linear heat transfer) or LMFP (linear heat transfer) systems can be effectively dispersed.

Inventors

  • DING ZEPENG

Assignees

  • 上海轩邑新能源发展有限公司

Dates

Publication Date
20260508
Application Date
20260205

Claims (10)

  1. 1. The positive electrode slurry comprises a positive electrode active component, a conductive agent, a binder and a solvent, and is characterized by further comprising an additive, wherein the additive is at least one of humic acid, fulvic acid and humins, and the additive accounts for 0.01-2wt% of the total weight of the positive electrode active component, the conductive agent and the binder.
  2. 2. The positive electrode slurry according to claim 1, wherein the additive is 0.1 to 1wt% of the total weight of the positive electrode active component, the conductive agent, and the binder.
  3. 3. The positive electrode slurry according to claim 1, wherein the additive is 0.1 to 0.5wt% of the total weight of the positive electrode active component, the conductive agent, and the binder.
  4. 4. The positive electrode slurry according to any one of claims 1 to 3, wherein the additive is a mixture of the humic acid and the fulvic acid, preferably, the weight ratio of the humic acid to the fulvic acid is 1 (0.1 to 10000), more preferably 1 (0.1 to 100), still more preferably 1 (0.1 to 10); Or the additive is a mixture of the humic acid and the humins, preferably, the weight ratio of the humic acid to the humins is 1 (0.1-10000), more preferably 1 (0.1-100), and even more preferably 1 (1-10); Or the additive is a mixture of the humins and the fulvic acid, preferably, the weight ratio of the humins to the fulvic acid is 1 (0.1-10000), more preferably 1 (0.1-100), and even more preferably 1 (1-10).
  5. 5. The positive electrode slurry according to any one of claims 1 to 3, wherein the additive is a mixture of the humic acid, the fulvic acid and the humins; Preferably, the weight ratio of the humic acid to the fulvic acid to the humins is 1 (0.1-10000), more preferably 1 (1-100), still more preferably 1 (1-10).
  6. 6. The positive electrode slurry according to any one of claims 1 to 5, wherein the positive electrode slurry comprises, in parts by weight, 90 to 99.4 parts of the positive electrode active component, 0.1 to 4 parts of the conductive agent, 0.45 to 4 parts of the binder, 0.01 to 2 parts of the additive, preferably 95 to 98 parts of the positive electrode active component, 1 to 2 parts of the conductive agent, 0.9 to 2 parts of the binder, and 0.1 to 1 part of the additive; And/or the solid content of the positive electrode slurry is 50-80 wt%, preferably 65-80 wt%.
  7. 7. The positive electrode slurry according to any one of claims 1 to 6, wherein the positive electrode active component is selected from the group consisting of LiNi x Co y Mn z T (1-x-y-z) O 2 、LiCo x' T (1-x') O 2 、LiNi x'' T' y' Mn (2-x''-y') O 4 、Li z' MPO 4 、a LiNi x Co y Mn z T (1-x-y-z) O 2 (1-A) at least one of Li 2 MnO 3 and NaNi 1/3 Co 1/3 Mn 1/3 O 2 , wherein T is at least one of Ti, mg, al, ca, sr, zr, si and Fe, 0≤x≤1, 0≤y≤1, 0≤z≤1, 0< x+y+z≤1, 0< x '. Ltoreq.1, 0.3≤x' '. Ltoreq.0.6, 0.01≤y'. Ltoreq.0.2, T 'is at least one of Ti, mg, al, co, sr, fe, si, zn, zr and Ca, 0.5≤z'. Ltoreq.1, M is at least one of Fe, co and Mn, 0≤a≤1; and/or the conductive agent is at least one selected from acetylene black, carbon black, conductive graphite, carbon fiber, carbon nanotube and graphene; And/or the binder is selected from at least one of polyvinylidene fluoride, polytetrafluoroethylene and hydrogenated nitrile rubber; and/or the solvent is N-methyl pyrrolidone.
  8. 8. A method for producing the positive electrode slurry according to any one of claims 1 to 7, wherein the positive electrode slurry is obtained by mixing the raw materials in the ratio of the raw material components.
  9. 9. The positive electrode plate comprises a positive electrode current collector and a positive electrode active coating attached to the surface of the positive electrode current collector, and is characterized in that the positive electrode active coating is obtained by drying the positive electrode slurry obtained by the positive electrode slurry according to any one of claims 1 to 7 or the positive electrode slurry obtained by the positive electrode slurry preparation method according to claim 8.
  10. 10. A battery comprises a positive electrode plate, a negative electrode plate, a diaphragm and electrolyte, and is characterized in that the positive electrode plate is the positive electrode plate according to claim 9.

Description

Positive electrode slurry, preparation method thereof, positive electrode plate and battery Technical Field The application relates to the technical field of batteries, in particular to positive electrode slurry, a preparation method thereof, a positive electrode plate and a battery. Background The maturity of the lithium ion battery is continuously increased, various performance requirements on the battery core are gradually improved, but the actual situation still has more unresolved problems, wherein the most important slurry mixing section in the manufacturing process has the problems of difficult slurry mixing dispersion, difficult slurry stability and the like for materials such as lithium iron phosphate (LFP) or lithium iron manganese phosphate (LMFP) with olivine structures, and the problems of residual alkali on the surface of the layered nickel-rich positive electrode materials such as nickel cobalt manganese ternary materials (NCM) and nickel cobalt aluminum materials (NCA), the layered lithium-rich positive electrode materials such as LMR and spinel positive electrode materials such as Lithium Manganese Oxide (LMO) are particularly prominent in spite of the above materials having good thermal stability and superior discharge platforms. The existence of residual alkali, especially in the slurry mixing process, can lead to the pH value of the slurry to rise, thereby triggering a gel effect, leading the viscosity of the slurry to be increased sharply, leading the fluidity to be poor, and greatly influencing the subsequent coating and battery assembly processes. This phenomenon not only increases the difficulty of production, but may also lead to instability in the performance of the battery, particularly affecting the cycle life and energy density aspects of the battery. Disclosure of Invention The application mainly aims to provide positive electrode slurry, a preparation method thereof, a positive electrode plate and a battery, so as to solve the problem that slurry gel is easy to occur when the positive electrode slurry is mixed in the prior art. In order to achieve the above object, according to one aspect of the present application, there is provided a positive electrode slurry comprising a positive electrode active component, a conductive agent, a binder and a solvent, wherein the positive electrode slurry further contains an additive, the additive is at least one of humic acid, fulvic acid and humins, and the additive is 0.01 to 2wt% of the total weight of the positive electrode active component, the conductive agent and the binder. Further, the additive accounts for 0.1-1wt% of the total weight of the positive electrode active component, the conductive agent and the binder. Further, the additive accounts for 0.1-0.5wt% of the total weight of the positive electrode active component, the conductive agent and the binder. Further, the additive is a mixture of humic acid and fulvic acid. Further, the weight ratio of the humic acid to the fulvic acid is 1 (0.1-10000), preferably 1 (0.1-100), and more preferably 1 (0.1-10). Further, the additive is a mixture of humic acid and humins. Further, the weight ratio of the humic acid to the humins is 1 (0.1 to 10000), preferably 1 (0.1 to 100), and more preferably 1 (1 to 10). Further, the additive is a mixture of humins and fulvic acid. Further, the weight ratio of the humins to the fulvic acid is 1 (0.1 to 10000), preferably 1 (0.1 to 100), and more preferably 1 (1 to 10). Further, the additive is a mixture of humic acid, fulvic acid and humins. Further, the weight ratio of the humic acid to the fulvic acid to the humins is 1 (0.1-10000), preferably 1 (1-100), and more preferably 1 (1-10). Further, the positive electrode slurry comprises, by weight, 90-99.4 parts of positive electrode active components, 0.1-4 parts of conductive agents, 0.45-4 parts of binders and 0.01-2 parts of additives. Further, the positive electrode active component comprises 95-98 parts of conductive agent 1-2 parts, binder 0.9-2 parts and additive 0.1-1 part. Further, the solid content of the positive electrode slurry is 50 to 80wt%, preferably 65 to 80wt%. Further, the positive electrode active component is selected from LiNixCoyMnzT(1-x-y-z)O2、LiCox'T(1-x')O2、LiNix''T'y'Mn(2-x''-y')O4、Liz'MPO4、aLiNixCoyMnzT(1-x-y-z)O2(1-A) at least one of Li 2MnO3 and NaNi 1/3Co1/3Mn1/3O2, wherein T is at least one of Ti, mg, al, ca, sr, zr, si and Fe, 0≤x≤1, 0≤y≤1, 0≤z≤1, 0< x+y+z≤1, 0< x '. Ltoreq.1, 0.3≤x' '. Ltoreq.0.6, 0.01≤y'. Ltoreq.0.2, T 'is at least one of Ti, mg, al, co, sr, fe, si, zn, zr and Ca, 0.5≤z'. Ltoreq.1, M is at least one of Fe, co and Mn, 0≤a≤1. Further, the conductive agent is at least one selected from acetylene black, carbon black, conductive graphite, carbon fiber, carbon nanotube and graphene. Further, the binder is at least one selected from polyvinylidene fluoride, polytetrafluoroethylene and hydrogenated nitrile rubber. Further, the solvent is N-methylpyrrolidon