Mesophase carbon microsphere is a micron level spherical carbon material formed by separating the small spheres in mesophase pitch from the asphalt matrix, which is called MCMB for short. Mesophase carbon microsphere is a new kind of carbon material. It is developed in the process of studying mesophase, and its theoretical basis is mesophase theory.
The preparation of mesophase carbon microspheres can be divided into direct polycondensation method and indirect method, and the indirect method can be divided into suspension method and emulsification method. The commonly used production methods in China are direct polycondensation and emulsification. The direct polycondensation method is that raw materials are thermally polycondensated in an inert atmosphere, and pitch containing Mesophase Spheres is prepared at a certain temperature and residence time. The indirect rule is that 100% mesophase pitch is prepared from raw materials under strict conditions, and then mesophase pellets are prepared by grinding or dispersing.
Preparation of mesophase carbon microspheres by direct polycondensation:
Advantages: simple process, easy to control conditions and easy to realize continuous production.
Disadvantages: the small balls are easy to melt, with wide size distribution, uneven shape and size, and low yield. If the yield is improved by retaining the primary Qi in the system or adding additives, these substances will affect the final performance of MCMB.
Preparation of mesophase carbon microspheres by indirect method:
Advantages: MCMB has narrow size distribution, low content of internal light components and few impurities.
Disadvantages: the process is complex and cumbersome, MCMB must be treated without melting, and there are difficulties in the preparation process, and the industrialization prospect is dim.
Mesophase carbon microsphere is a new type of functional material. It has the advantages of good chemical stability, high bulk density, easy graphitization, good thermal stability, excellent conductivity and thermal conductivity. It is a high-quality precursor for preparing high-performance carbon materials. It has broad application and development prospects in lithium-ion batteries, composite materials, active carbon microsphere, liquid chromatography column packing, catalyst carrier, etc.
1. Negative electrode material of lithium-ion battery: MCMB has a low surface area, which reduces the skin reaction during charging and discharging. In addition, the crystal structure of MCMB is arranged radially, which means that there are many exposed graphite crystal edges, so it can be charged and discharged at high current density.
2. Composite material: MCMB is a micron spherical particle, and by adjusting the composition β The resin content can have appropriate self-adhesive property, so it is a high-quality raw material for preparing composite materials.
3. Catalyst support: mesophase carbon microspheres can absorb some catalysts to become catalysts. If they are pretreated by plasma, the adsorption capacity of catalysts can be increased. MCMB can also be used as a catalyst support for electrodes due to its relatively high conductivity.
4. Activated carbon microspheres: with high content of mesoporous pore volume, it is an ideal double-layer capacitor material.
5. In addition, mesophase carbon microspheres can also be used as filling materials, conductive materials, cation exchangers, functional composites and surface modified carbon materials.