A kind of preparation method of positive electrode slurry

Abstract

The invention discloses a preparation method of graphene dry powder for LFP (lithium ferric phosphate) anode paste. The preparation method of graphene dry powder for LFP anode paste comprises the following steps: (1) putting a baked graphene layer into a stirrer, diluting by using NMP (N-methyl pyrrolidinone), and stirring at a low speed till the material is at a wet powder state; (2) adding the baked anode active substances of LFP, SP and PVDF (polyvinylidene fluoride) into the graphene wet powder, and stirring continuously at a low speed for 1-2 hours, thereby preparing anode premix; (3) diluting by using NMP, and stirring the anode premix at a low speed till the anode premix is at a wet powder state and the solid content of the premix is 80%-90%; (4) diluting the premix at the wet powder state by using NMP until the solid content is around 65%, and stirring the premix at a high speed until each component is uniform and dispersive, thereby preparing a mixed material; and (5) beginning to dilute the mixed material when the mixed material generates a pole climbing phenomenon, controlling the solid content of the mixed material to be around 49%, and stirring at a high speed so as to prepare the required paste. The preparation method provided by the invention can effectively disperse graphene and each component of other anode materials without adopting any additive for helping the graphene to disperse, and reduces the influence on the battery performance of substances of the type of additives.

Description

technical field [0001] The invention relates to a preparation method of positive electrode slurry. Background technique [0002] Since its discovery in 2004, graphene has been favored by researchers in the fields of physics and materials. Graphene is a two-dimensional honeycomb lattice structure carbonaceous material composed of a single layer of carbon atoms tightly packed. Although graphene is only one carbon atomic layer thick and is the thinnest known material, it is very strong and hard and is currently the most conductive material known to conduct electricity. Due to its excellent electrical and thermal conductivity, lithium-ion battery processing applications are also starting to look at the use of graphene. However, due to the super large specific surface area and strong water absorption performance of graphene itself, when graphene is used in LFP system, it is difficult to disperse and easy to agglomerate, which leads to great obstacles in the application of graph...

AI Technical Summary

Problems solved by technology

However, due to the large specific surface area and strong water absorption performance of graphene itself, when graphene is used in LFP system, it is difficult to disperse and easy to agglomerate, which leads to great obstacles in the application of graphene in lithium-ion batteries.

In the method of dispersing graphene in the traditional lithium-ion battery manufacturing process, dispersants such as PVP are added to help graphene disperse, but the introduction of such dispersants may bring unpredictable performance to the battery. negative impact

Images