SODIUM IRON PHOSPHATE Na_2FeP_2O_7 GLASS-CERAMICS FOR SODIUM ION BATTERY

摘要

New cathode candidate Na_2FeP_2O_7 for rechargeable sodium ion second battery was successfully prepared by glass-ceramics method. The precursor glass, which is same composition in Na_2FeP_2O_7, was prepared by melt-quenching method. Na_2FeP_2O_7 was obtained by heat treatment of precursor glass powder with glucose addition as reduction agent of iron oxide at 620°C for 3h in electric furnace. Na_2FeP_2O_7 has triclinic P1- structure. By means of electrochemical charge-discharge testing, Na_2FeP_2O_7 exhibits 2.9V, 88mAh/g, in which is 90% for the theoretical capacity during 2.0-3.8V cut-off voltages. Na_2FeP_2O_7 ceramics has the potential for the safety cathode candidate for the sodium ion battery with a low materials cost.