Discharge artificial graphite

The most important parameter of a lithium ion accumulator, its specific energy, of course depends on how much - reversibly dischargeable - hthium is stored in the carbon host lattice. The ideal maximum charge of the sum formula LiCe corresponds to the specific capacity of 372 mAh g. In practice natural graphite shows 330 to 350mAh g, artificial graphite a bit less. 

FIGURE 34.4 Representation of irreversible capacity asso-ciaed with the first charge/discharge process, (a) Coke, (b) Artificial graphite. 

Fig. 5 Charge-discharge profiles of graphitized mesophase pitch-based caibon fibers at 3000 °C and artificial graphite, a, c were obtained at the first eycle. b, d were obtained at the second cycle. Reproduced from Ref. [26]...

However, the discharge capacity of artificial graphite is smaller than that of natural graphite, and depends on the heat-treatment temperature. Artificial graphite made by heat-treatment at a higher temperature showed a higher discharge capacity as... 

Initial charge and discharge curves of (a) artificial graphite KS-44 (Lonza) and (b) the artificial graphite coated with coke obtained by heat treatment at 1000°C, in a 1.0 M LiC104 electrolyte in EC/DEC (v/v 1 1). (Adapted from Yoon, S. et al., /. Power Sources 94 68-73,2001.)... 

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