Graphitized mesocarbon

Hard Carbon Graphitized Mesocarbon Coated Natural Synthetic Graphite... 

In addition to the beneficial effect on the electrochemical performance, the graphite conductive additives influence the electrode density positively. Typically, the graphitized mesocarbon or... 

Most commercial lithium-ion cells maufactured today use graphitic carbons from region 1 of Fig. 2. These are of several forms, with mesocarbon microspheres and natural graphites being the most commonly used. The specific capacity of these carbons is near 350 mAh/g. 

Mesocarbon microbeads (MCMB) particles, obtained from Osaka Gas Co., which are round graphite particles. They are also far from having a smooth morphology and have crevices on their surface. 

Attempts were made to discover the correlation between the crystalline structure of carbonaceous materials and their capability to reversibly intercalate lithium. This correlation has not been definitely established, but still, one can assume as a certain general principle that the optimum materials would contain an amorphous matrix with inclusions of a mesophase nuclei of graphite crystallites. Such materials are various cokes, pyrographite, and products of pyrolysis (carbonization) of various polymers. For practical purposes, the industry mastered some special materials providing high characteristics of negative electrodes in lithium ion batteries. The most popular material is manufactured by the Japanese company of Osaka Gas Co. under the name of mesocarbon microbeads, MCMB it represents the carbonization product of pitchy resins under a certain temperature regime. 

Lei, Y, Z. H. Huang, Y. Yang et al. 2013. Porous mesocarbon microbeads with graphitic shells Constructing a high-rate, high-capacity cathode for hybrid supercapacitor. Scientific Reports 3 2477. 

Another high-temperature approach for generating silicon/carbon composites is to deposit silicon particles on carbon or vice versa using CVD. Xie et al. [44] reported the deposition of silicon on mesocarbon microbeads (MCMB) by CVD of silane at 450°C and 500°C, but only a very small amount of silicon actually deposited on the MCMB. The material also demonstrated a very high (55%) irreversible loss. Vacuum deposition of nanometer-sized silicon particles on graphite surfaces has also been reported [45, 46]. The as-prepared anode showed an... 

Many materials given the name graphite actually have a considerable amount of stacking disorder. For carbons in general, the situation is more complex. Most cokes, petroleum cokes, carbon blacks, carbon fibers, pyrolyzed polymers and mesocarbon microspheres have disordered structures. In such structures the size of the crystallites is small and there is a high probability of random stacking (shifts or rotations) of adjacent carbon layers. This type of disorder is called turbostratic disorder. Hundreds of carbons are commercially available however, selecting the best carbon for use in lithium-ion cells is a subject for much current research. 

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