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CN-122006555-A - Homogenization mixing method of electrolytic manganese dioxide and graphite

CN122006555ACN 122006555 ACN122006555 ACN 122006555ACN-122006555-A

Abstract

The invention is suitable for the technical field of alkaline manganese battery electrode material preparation, and provides a homogenization mixing method of electrolytic manganese dioxide and graphite, which eliminates material physical property differences through a liquid phase environment and adopts two liquid phase pretreatment modes to realize high-efficiency dispersion of graphite; the invention can protect the graphite flake/lamellar conductive structure, obviously improve the compaction density of the electrode flake, reduce the internal resistance, optimize the discharge capacity and the repeatability of test data, and adapt to large-scale production.

Inventors

  • LIANG YUHUI
  • GU JUNXIN
  • NONG HU

Assignees

  • 万博禄矿业(中国)有限公司

Dates

Publication Date
20260512
Application Date
20260113

Claims (10)

  1. 1. The homogenizing mixing method of electrolytic manganese dioxide and graphite is characterized by comprising the following steps: S1, carrying out dispersion treatment on graphite in a liquid phase pretreatment mode, wherein the liquid phase pretreatment is one of the following two modes, and the damage of mechanical force to a graphite structure is avoided through a liquid phase environment: adding graphite powder into a liquid medium, performing ultrasonic treatment, and scattering graphite agglomerated particles by utilizing an ultrasonic cavitation effect, wherein the technological parameters of the ultrasonic treatment are limited by the fact that graphite can form uniform suspension, so as to prepare graphite suspension; Adding partial Electrolytic Manganese Dioxide (EMD) powder and graphite powder into a liquid medium, premixing by using dispersing equipment, and inhibiting the floating or segregation trend of graphite by utilizing the buffer action of partial EMD, wherein the mass of the partial EMD powder accounts for the mass of the total EMD powder to limit the uniform dispersion so as to form homogeneous slurry; s2, mixing the graphite suspension or the homogeneous slurry processed in the step S1 with the rest of EMD powder to obtain an electrode material mixture, wherein the mass ratio of the EMD to the graphite is suitable for the preparation requirement of the alkaline manganese cell electrode material.
  2. 2. The method of homogenizing a mixture of electrolytic manganese dioxide and graphite of claim 1 wherein the liquid medium is deionized water.
  3. 3. The homogenizing mixing method of electrolytic manganese dioxide and graphite according to claim 1, wherein in the mode A, the power of the ultrasonic treatment is 20-100W, the ultrasonic time is 3-10 min, wherein the ultrasonic time is 10min when the ultrasonic power is 20W, and the ultrasonic time is 5min when the ultrasonic power is 50W or 80W.
  4. 4. A method of homogenising a mixture of electrolytic manganese dioxide and graphite according to claim 1, characterised in that in mode B the mass of the partial EMD powder is between 10% and 50%, preferably 20%, 30% or 50% of the total EMD powder mass.
  5. 5. The method of claim 2, wherein the deionized water is used in an amount sufficient to disperse the graphite without excessive liquid accumulation, preferably 30mL.
  6. 6. The method of homogenizing and mixing electrolytic manganese dioxide and graphite of claim 1, further comprising the steps of: S3, screening, wherein the number of the adopted screening meshes is limited by removing impurities and not dispersing agglomeration, and is preferably 60-mesh.
  7. 7. The method of homogenizing and mixing electrolytic manganese dioxide and graphite according to claim 6, further comprising the steps of S4 granulating the sieved mixture by a granulating device; S5, tabletting, namely preparing the granulated material into electrode slices through tabletting equipment.
  8. 8. The method for homogenizing and mixing electrolytic manganese dioxide and graphite according to claim 1, wherein the mass ratio of EMD to graphite is 94:6, specifically 47:3 as verified by experiment.
  9. 9. The method of claim 1, wherein in the mode B, the dispersing device is a high-speed dispersing machine, the premixing is high-speed shearing mixing, and the mixing uniformity is enhanced by three-dimensional movement.
  10. 10. The method according to claim 1, wherein in the liquid phase pretreatment and the subsequent mixing, capillary action or buffer action of the liquid medium causes graphite particles to be uniformly attached or inserted among the EMD particles, thereby constructing a continuous conductive network.

Description

Homogenization mixing method of electrolytic manganese dioxide and graphite Technical Field The invention belongs to the technical field of preparation of alkaline manganese battery electrode materials, and particularly relates to a homogenization mixing method of electrolytic manganese dioxide and graphite. Background In the process of preparing the alkaline manganese cell, uniform mixing of Electrolytic Manganese Dioxide (EMD) and graphite is a key link for guaranteeing the performance of an electrode plate. At present, a mechanical dry mixing scheme is generally adopted in the industry, and the scheme has the following prominent problems in practical application, so that the EMD powder discharge performance test result has obvious deviation and reduced reliability: in the existing mechanical dry mixing, the mixing mass ratio of EMD and graphite is 94:6, and the weight ratio is seriously unbalanced. The graphite is fluffy, the tap density is obviously different from that of the EMD powder, so that the graphite with smaller density is extremely easy to segregate in the mechanical dry mixing process, uniform distribution in the EMD cannot be realized, and an ideal homogenization mixing effect is difficult to achieve; Mechanical dry mixing realizes material mixing by mechanical stirring, and stronger shearing force and mechanical force can be generated in the stirring process. The flake or lamellar structure of graphite which maintains the conductivity of the graphite can be damaged by the acting force, and the graphite breaks or curls, so that the conductivity of the graphite is reduced, and the capability of constructing a continuous and efficient conductive network among EMD particles is affected; The uneven mixing and the damage of the graphite structure directly cause the insufficient compaction density of the final electrode plate, and the mixture is difficult to form a compact and stable structure when being pressed into tablets, so that the internal resistance of the electrode is increased, the EMD utilization rate is reduced, and the battery discharge capacity is low, the fluctuation of test data is large and the reproducibility is poor; therefore, a method for homogenizing and mixing electrolytic manganese dioxide and graphite is needed to solve the above problems. Disclosure of Invention The embodiment of the invention aims to provide a homogenizing mixing method of electrolytic manganese dioxide and graphite to solve the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: a homogenizing mixing method of electrolytic manganese dioxide and graphite comprises the following steps: S1, carrying out dispersion treatment on graphite in a liquid phase pretreatment mode, wherein the liquid phase pretreatment is one of the following two modes, and the damage of mechanical force to a graphite structure is avoided through a liquid phase environment: adding graphite powder into a liquid medium, performing ultrasonic treatment, and scattering graphite agglomerated particles by utilizing an ultrasonic cavitation effect, wherein the technological parameters of the ultrasonic treatment are limited by the fact that graphite can form uniform suspension, so as to prepare graphite suspension; Adding partial Electrolytic Manganese Dioxide (EMD) powder and graphite powder into a liquid medium, premixing by using dispersing equipment, and inhibiting the floating or segregation trend of graphite by utilizing the buffer action of partial EMD, wherein the mass of the partial EMD powder accounts for the mass of the total EMD powder to limit the uniform dispersion so as to form homogeneous slurry; s2, mixing the graphite suspension or the homogeneous slurry treated in the step S1 with the rest of EMD powder to obtain an electrode material mixture, wherein the mass ratio of the EMD to the graphite is adapted to the preparation requirement of the alkaline manganese cell electrode material; Through the logic of liquid phase pretreatment and mixing, the dispersion mechanism of two pretreatment modes is defined, so that not only all feasible implementation modes are covered, but also the principle level is distinguished from the prior art, and a foundation is laid for the protection scope. According to a further technical scheme, the liquid medium is deionized water; the liquid medium is defined to be deionized water, so that impurities are prevented from being introduced into other mediums, the purity of the electrode material is guaranteed, and the liquid medium is a basic adaptive medium for liquid phase pretreatment. In a further technical scheme, in the mode A, the power of ultrasonic treatment is 20-100W, and the ultrasonic time is 3-10 min, wherein the ultrasonic time is 10min when the ultrasonic power is 20W, and the ultrasonic time is 5min when the ultrasonic power is 50W or 80W; Defining the parameter interval and specific combin