Graphite synthetic

Property Modifiers. Property modifiers can, in general, be divided into two classes nonabrasive and abrasive, and the nonabrasive modifiers can be further classified as high friction or low friction. The most frequently used nonabrasive modifier is a cured resinous friction dust derived from cashew nutshell Hquid (see Nuts). Ground mbber is used in particle sizes similar to or slightly coarser than those of the cashew friction dusts for noise, wear, and abrasion control. Carbon black (qv), petroleum coke flour, natural and synthetic graphite, or other carbonaceous materials (see Carbon) are used to control the friction and improve wear, when abrasives are used, or to reduce noise. The above mentioned modifiers are primarily used in organic and semimetallic materials, except for graphite which is used in all friction materials. 

Fig. 3. Second cycle voltage profiles of carbons representative of regions (I), (2), and (3). a) JMI synthetic graphite, b) Crowley petroleum pitch heated to 550°C, and c) a resole resin heated to 1000°C.

Since these materials have significant microporosity, we expect their bulk densities to be low. For example, the tap density (100 taps) of BrlOOO was measured to be 0.81 g/cc, compared to 1.34 g/cc for the synthetic graphitic carbon powder, MCMB2700, measui ed by the same method. 

Carbon source Needle Calcined Electrodes Synthetic graphite... 

The majority of carbons produced for commercial use, that is as electrodes and nuclear graphite, are produced from cokes, coals or existing natural or synthetic graphite as follows ... 

The carbon raw material in the form of coke, coal or natural or synthetic graphite is ground and sieved (following calcination at 700-1300°C to control volatiles, if necessary) to give a desired particle size distribution. The distribution depends upon the size of the artifact to be formed and the method of forming. 

Natural graphite and synthetic graphite were used as fillers for the manufacture of conducting composite materials by the polymerization filling technique [24, 53-56], The manufacture of conducting polymer composite materials by this technique on the basis of some kinds of carbon black is also known [51, 52],... 

Practically every battery system uses carbon in one form or another. The purity, morphology and physical form are very important factors in its effective use in all these applications. Its use in lithium-ion batteries (Li-Ion), fuel cells and other battery systems has been reviewed previously [1 -8]. Two recent applications in alkaline cells and Li-Ion cells will be discussed in more detail. Table 1 contains a partial listing of the use of carbon materials in batteries that stretch across a wide spectrum of battery technologies and materials. Materials stretch from bituminous materials used to seal carbon-zinc and lead acid batteries to synthetic graphites used as active materials in lithium ion cells. 

Figure 8. Constant current charge/discharge cycling (1.-3. cycles) of graphite (Lonza KS44 synthetic graphite) in 1 MLiCl04 in y-hutyrolactone as electrolyte without and with C02 (saturated in electrolyte) as electrolyte additive, i lOpA mg 1, cut-off 0-1.5V vs. Li/Li+...

Figure 10. Integrated irreversible capacities of LiC in y-butyrolactone based electrolytes without (full symbols) and with (open symbols) C02 as electrolyte additive using various electrolyte salts LiCl04 (top, left), LiBF4 (top, right), LiPF6 (bottom, left), LiN(S02CF3)2 (bottom, right). Carbon Lonza KS44 synthetic graphite, i = 10 pA mg 1, cut-off 0-1.5 V vs. Li/Li+ [12],...

Figure 11. First cycle constant current charge/discharge curves of synthetic graphite TIMREX SFG 44 using 1 MLiCl04 in PC PS (propylene sulfite) (95 5 by volume) as electrolyte, i = +20 mA g1, cut-off = 1.8/0.025 Vvs. Li/Li+.

Figure 12. F cycle constant current charge curves of synthetic graphite LONZA KS 44 (i) using 1 MLiN(S02CF3)2 in EC.DME (dimethoxy ethane, CH3OCH2CH2OCH3) (3 2) as electrolyte. The measurement was stopped when the graphite was exfoliated, (ii) using 1 M LiN(S02CF3)2 in EC F-DME (partially fluorinated dimethoxy ethane, CH3OCF2CF2OCH3) (3 2) as electrolyte, i = 20 mA g1, cut-off = 0.0 V vs. Li/Li+ (adaptedfrom [12]).

Figure 13. Cyclic voltammogram of graphite (Lonza KS6, synthetic graphite) in 1 MLiCl04 in PC/novel fluorinated additive (90 10, v v) scan rate 30 pV s 1, Potentials vs. Li/Li+.

Two different natural graphites manufactured by Superior Graphite Co. (SL-20 and LBG-73) were tested as received on the possibility of using as anode of a cylindrical Li-ion battery. For comparison, typical synthetic graphite KS-15 from Lonza was examined. 

Synthetic graphite flakes, obtained from Timrex Inc., whose morphology has been characterized by a high level of crevices in the facets perpendicular to the basal planes, through which lithium ions are inserted into the graphite lattice (edge planes). 

Figure 3. An illustration of morphology, surface processes and changes during a Li insertion-deinsertion cycle of an electrode comprising synthetic graphite flakes in EC-DMC solutions, in which the electrodes behave reversibly.

Figure 6. Potential vs. capacity curves obtainedfrom cycling tests of synthetic graphite flakes in EC-PC/LiCIO4 solutions in different discharge rates. Notice that as the discharge rate decreases - the irreversible capacity decreases accordingly.

Figure 7. In-situ AFM imaging of synthetic graphite flakes (a, b), MCMB particles (c, d) and natural graphite particles (e,f during the first cathodic polarization of the electrodes in the probe solution (LiClO/EC-PC), measured at the indicated potentials vs. Li/Li. The arrows and circles point to the relevant morphological processes, as detailed in the text (see ref 26).

High-power Li-ion cells with a LiNio.8Coo.15Alo.05O2 cathode, a synthetic graphite anode, 1.2 M LiPF6 + ethylene carbonate + ethyl-methyl carbonate (EC/EMC) electrolyte, and a Celgard 2300 separator, were... 

One of the more important considerations in determining the end use of synthetic graphite is its contamination with metallic components Metals such as iron, vanadium, and especially in nuclear applications, boron are deleterious to the performance of graphite Table 3 presented the extraction yields of NMP-soluble material for three bituminous coals. For these coals, mineral matter and insoluble coal residue were separated from the extract by simple filtration through 1-2 pm filter paper fable 13 lists the high-temperature ash content in the dry coal, and in their corresponding NMP-insoluble and NMP-soluble products. The reduced ash content of the extract is typically between 0.1 to 0.3 wt% using traditional filtration techniques for the small-scaled extraction experiments... 

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