Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5187889 | Polymer | 2008 | 7 Pages |
Ethyl cellulose derivatives [EC-T and EC-P] and cellulose acetate derivatives [CA-T and CA-P] carrying TEMPO or PROXY radicals (TEMPOÂ =Â 2,2,6,6-tetramethyl-1-piperidinyloxy, PROXYÂ =Â 2,2,5,5-tetramethyl-1-pyrrolidinyloxy) were synthesized with moderate number-average molecular weights of 62â400-126â000 in 84-88% yield by the reaction of 4-carboxy-TEMPO or 3-carboxy-PROXY with residual hydroxyl group of ethyl cellulose or cellulose acetate. All the free radical-containing cellulose derivatives demonstrated reversible charge/discharge processes, whose discharge capacities were 42.8-61.1Â AÂ h/kg. In particular, the CA-T-based cell displayed two-stage discharge process, and the first-stage discharge capacity reached 29.5Â AÂ h/kg which corresponds to 74% of its theoretical value, and that of the total capacity was 61.1Â AÂ h/kg which approaches up to 153% of the theoretical value for one-electron redox reaction.