DENG Lingfeng, LI Xinhai, XIAO Lixin, ZHANG Yunhe. SYNTHESIS AND ELECTROCHEMICAL PROPERTIES OF POLYRADICAL CATHODE MATERIALS FOR LITHIUM SECONDARY BATTERIES[J]. Acta Polymerica Sinica, 2004,(1):8-12.
DENG Lingfeng, LI Xinhai, XIAO Lixin, ZHANG Yunhe. SYNTHESIS AND ELECTROCHEMICAL PROPERTIES OF POLYRADICAL CATHODE MATERIALS FOR LITHIUM SECONDARY BATTERIES[J]. Acta Polymerica Sinica, 2004,(1):8-12.DOI:
6-tetramethylpiperidinyloxymethaerylate)(PTMA) was synthesized from 4-hydroxy-2
2
6
6-tetramethylpiporidine and methyl methacrylate by the reaction of esterifieation
polymerization and oxidation
and its structure was determined by infrared
ultraviolet-visible
and ESR spectroscopy.Cyclic vohammograms (scan rate:5 mV·s-1) of PTMA showed that the oxidation peak current was equal to the corresponding reduction peak current and the oxidation charge passed during the anodic cycle was almost equal to the reduction charge released during the following cathodic cycle.These results suggest that PTMA possesses exceHent reversibility
and the difference of the anodic(Ea.p=3.66 V versus Li/Li*) and athodic(Ec.p=3.58 V) peak potentials is estimated as 80 mV
whichis extremely smaller than that of the other electroactive organic materials in lithium secondary batteries such as disulfide compounds
which leads to the fast electrode reaction rate of PTMA in the charging and discharging processes of the battery.The maximum discharge specific capacity of PTMA is 78.4 mAh·g-1 at a constant discharge current of 0.3 mA(0.2C)
the coulombie efficiency is about 95%.In the charging/discharging curves
there are obvious voltage plateaus at 3.65 V and 3.56 V
respectively.The charging/discharging specific capacity of the batteries was almost unchanged after 100 cycles.the decay ratio is about 2% of the maximum specific capacity of PTMA.PTMA/Li button batteries exhibited an excellent stability in the charging-discharging processes.These results show that PTMA is a promising polyradical cathode materials for lithium secondary batteries.