Material mixing process for preparing high-nickel positive electrode material and application of material mixing process

Abstract

The invention discloses a material mixing process for preparing a high-nickel positive electrode material and application of the material mixing process, and the material mixing process comprises the following steps: adding a precursor and a lithium source into a material mixing device for mixing to obtain a mixture, after the mixture is uniformly mixed, spraying liquid into the mixture under the condition that the material mixing device continues to operate, and after the liquid spraying is completed, carrying out discharging and putting the obtained mixture into a sagger for sintering, wherein the liquid is one or more of pure water, ethanol, N-methyl pyrrolidone, an additive solution or an additive dispersion liquid. According to the spraying mixing process, the mixture can be mixed more uniformly, and due to the existence of a proper amount of vaporific liquid drops, the surface of the lithium source is slightly soluble in water and can adsorb the precursor, so that the apparent density of the mixture is improved, the bowl loading amount in the sintering process is improved by 5-40%, and the productivity is improved by 10-30%.

Description

technical field [0001] The invention belongs to a preparation process of a new energy lithium-ion battery cathode material, and in particular relates to a mixing process for preparing a high-nickel cathode material and an application thereof. Background technique [0002] High-nickel ternary materials (Ni content ≥ 50%) are one of the most popular lithium-ion cathode materials in the market today. How to stand out from the fierce market is to reduce costs and improve efficiency. At present, the conventional high-nickel ternary material process is to go through one mixing, one sintering, and then remove the residual lithium on the surface of the sintered product through the water washing process, and then perform the second mixing, the second coating and sintering to obtain the final product, and Among them, the key to limit the production capacity of the process lies in the amount of feed for one sintering. The common method is to increase the filling amount on the basis of ...

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Problems solved by technology

[0003] At present, the primary mixing process of high-nickel ternary materials mostly uses LiOH·H 2 O or Li 2 CO 3 As a lithium source, the bulk density of these two lithium sources is 0.4g / cm 3 around, and the bulk density of the precursor is generally 1.4g / cm 3 Left and right, when the two are mixed, due to the existence of the lithium source, the bulk density of the first mixture will be very small, so that the actual charging of a fixed-volume sagger (length, width and height: 330*330*100mm) in a sintering process volume will be limited

The related technology mentions a method for pretreatment of ternary material mixing. The purpose of this method is to remove crystal water from lithium hydroxide monohydrate by infrared drying before primary mixing, thereby reducing the weight of lithium source and improving The amount of bowls loaded in one sintering process is used to increase production capacity, but this method requires additional drying equipment

There is also a related art that records a method of spray coating additives on the positive electrode material substrate, and controls the coating amount by controlling the amount of the spray solution. The purpose of the spray process is to adjust the coating uniformity to improve material performance. And it is used in the secondary mixing process, which cannot effectively increase the production capacity

The related technology also records a method of spraying the single-crystal precursor to increase the capacity of high-nickel single crystal. In this method, the additive is sprayed into the precursor by spraying, and then sintered at a high temperature of 400-800°C, and then ground and pulverized. , and finally mixed with the lithium source, and then sintered at high temperature to obtain the finished product. It can be seen that this scheme is mainly to improve the material performance, and compared with the conventional process, it needs one more mixing process, one more crushing process and one more sintering process, and the cost will be higher. high

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