Graphite as anode

Cells operating at low (2,80,81) and high (79,82) temperatures were developed first, but discontinued because of corrosion and other problems. The first medium temperature cell had an electrolyte composition corresponding to KF 3HF, and operated at 65—75°C using a copper cathode and nickel anodes. A later cell operated at 75°C and used KF 2.2HF or KF 2HF as electrolyte (83,84), and nickel and graphite as anode materials. 

Non-Kolbe electrolysis of alicyclic p-hydroxy carboxylic acids offers interesting applications for the one-carbon ring extension of cyclic ketones (Eq. 35) [242c]. The starting compounds are easily available by Reformatsky reaction with cyclic ketones. Some examples are summarized in Table 13. Dimethylformamide as solvent and graphite as anode material appear to be optimal for this reaction. 

The model cylindrical Li-ion battery (AA-size) was manufactured using SL-20 graphite as anode active material. The general appearance of the cells is shown by Figure 2 for more detailed description of the cells see the experimental part of the paper. 

SURFACE TREATED NATURAL GRAPHITE AS ANODE MATERIAL FOR HIGH-POWER LI-ION BATTERY APPLICATIONS... 

Guo, K., Pan, Q., Wang, L. and Fang, S., Nano-scale copper coated graphite as anode material for lithium-ion batteries, J. Applied Electrochemistry (2002) 32 679-685. 

Veeraraghavan, B., Durairajan, A., Haran, B., Popov, B., and Guidotti, R., Study of Sn-coated graphite as anode material for secondary lithium-ion batteries, J. Electrochem. Society, (2002) 149, (6), A675-A681. 

Figure 72. Capacity and capacity retention of the fuii lithium ion cells based on graphite as anode, LiNiOj as cathode, and LiPFe or LiBOB in EC/EMC as electrolytes (a) room temperature (b) elevated temperatures. (Reproduced with permission from ref 155 (Figure 5). Copyright 2002 The Electrochemical Society.)...

The electrochemical oxidation of furans has been exploited since 1952 [170]. The usual electrolyte is ammonium bromide in methanol, at - 5 °C, using an undivided cell with either platinum or graphite as anode and a nickel or stainless steel... 

Yoon SH, Park CW, Yang HJ, Korai Y, Mochida I, Baker RTK, Rodriguez NM. Novel carbon nanofibers of high graphitization as anodic materials for lithium ion secondary batteries. Carbon 2004 42 21-32. 

By anodic decarboxylation carboxylic acids can be converted simply and in large variety into radicals. The combination of these radicals to form symmetrical dimers or unsymmetrical coupling products is termed Kolbe electrolysis (Scheme 1, path a). The radicals can also be added to double bonds to afford additive monomers or dimers, and in an intramolecular version can lead to five-membered heterocycles and carbocycles (Scheme 1, path b). The intermediate radical can be further oxidized to a carbenium ion (Scheme 1, path c). This oxidation is favored by electron-donating substituents at the a-carbon of the carboxylic acid, a basic electrolyte, graphite as anode material and salt additives, e.g. sodium perchlorate. The carbocations lead to products that are formed by solvolysis, elimination, fragmentation or rearrangement. This pathway of anodic decarboxylation is frequently called nonKolbe electrolysis. 

The formation of alcohols or ethers is favored by low current densities, porous graphite as anode material, a solvent such as water/pyridine instead of methanol, a pH of the electrolyte above 7 and anions, such as bicarbonate, sulfate or perchlorate, as additives. Electron-donating substituents at C-2 of the carboxylic acid favor the oxidation of the intermediate radical. Thus a-alkyl, a-cycloal-kyl207,208 a-chloro, a-bromo, a-amino, a-alkoxy, a-hydroxy, a-acyloxy and a,a-diphenyl substituents more or less promote the formation of nonKolbe products. 

Liu J., Vissers D.R., Amine K., Barsukov I.V., Doninger J.E. Surface Treated Natural Graphite as Anode Material for High-Power Li-Ion Battery Applications. In New Carbon-Based Materials for Electrochemical Energy Storage Systems Batteries, Fuel Cells and Supercapacitors. Barsukov I., Johnson C., Doninger J., Barsukov V. eds. NATO ARW series Volume. Springer (2005) - in this book. 

Zhou, Y. R Xie, S. Chen, C. H. Pyrolytic polyurea encapsulated natural graphite as anode material for lithium ion batteries. Electrochimica Acta (2005), 50(24), 4728—4735. 

Fig. 5.1 Illustration of the charge/discharge process involved in a lithium-ion cell consisting of graphite as anode and layered LiCo02 as the cathode (reproduced with permission by the American Chemical Society from [4])...

Fig. 2-2. Normalized current density i as a function of the applied voltage U for silver bromide with Ag as cathode and graphite as anode [14]. The ionic current is blocked, and the electronic current is measured. L is the sample length.

Behm M, Simonsson D (1999) Graphite as anode material for the electrochemical production of polysulfide ions in white liquor. J Appl Electrochem 29 521-524... 

Molten carbonate electrolyzer cell (MCEC) has molten Li2C03 electrolyte, Ti-Al metal alloy as cathode (CO evolution), and graphite as anode (O2 evolution) [3]. 

Galvanostatic lithium intercalation/de-mtercalation profiles, cycle life data and rate capability for PVC coated natural graphite and MCMB samples. (Reprinted with permission from H.L. Zhang et al., Poly(vinyl chloride) (PVC) coated idea revisited Influence of carbonization procedures on PVC-coated natural graphite as anode materials for lithium ion batteries. /. Phys. Chem. C, 122,2008, 7767-7772, Copyright 2008, American Chemical Society.)... 

In the arc discharge synthesis of CNTs, Bethune and co-workers used thin electrodes with hored holes filled with a mixture of pure powdered metals (Fe, Ni, or Co) and graphite as anodes. The electrodes were vaporized with a current of 95-105 A in 100-500 Ton of helium gas. TEM analysis of the obtained samples revealed that only cocatalyzed CNTs had single-atomic-layer walls with uniform diameters of 1.2 0.1 nm (Figure 7). 

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