Carbons from Pyrolyzed Hard-Carbon Precursors

5 Microporous Carbons from Pyrolyzed Hard-Carbon Precursors 

In lithium-ion battery applications, it is important to reduce the cost of electrode materials as much as possible. In this section, we will discuss hard carbons with high capacity for lithium, prepared from phenolic resins. It is also our goal, to collect further evidence supporting the model in Fig. 24. 

1 Preparation of microporous carbons and their electrochemical testing 

A hard carbon with high capacity can be made from epoxy novolac resin [12]. The epoxy resins used cost about US 2.50 per pound and give pyrolysis yields between 20 and 30%. However, it is well known that phenolic (or phenol-formaldehyde) resins can be pyrolyzed to give hard carbons with a yield of over 50% [42]. In addition, these resins cost about US 1.00 per pound. Phenolic resins therefore offer significant cost advantages over epoxy resins, so we 

Two electrochemical lithium/carbon cells were made for each of the pyrolyzed materials. We used currents of 18.5 mA/g (20-hour rate) for the first three charge-discharge cycles and 37 mA/g (10-hour rate) for the extended cycling test. 

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Microporous Carbons from Pyrolyzed Hard-Carbon Precursors. . . 375... 

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