Fe_(3)Se_(8)/Co_(3)Se_(4)/NiSe_(2)/NC复合材料的制备及性能

Preparation of Fe_(3)Se_(8)/Co_(3)Se_(4)/NiSe_(2)/NC composite and its performance

由于锂资源的价格逐渐攀升,亟需开发价格低廉的电池系统。通过共沉淀法合成FeCoNiCP片状前驱体,再经过包覆多巴胺、退火和在氮气下硒化,制备钠离子电池负极材料Fe_(3)Se_(8)/Co_(3)Se_(4)/NiSe_(2)/NC。在0.01~3.00 V充放电,以0.1 A/g的电流循环70次,电极仍有468.38 mAh/g的可逆比容量;在0.1 A/g、0.2 A/g、0.5 A/g、1.0 A/g、2.0 A/g和5.0 A/g的电流下,分别具有363.85 mAh/g、345.88 mAh/g、320.73 mAh/g、308.31 mAh/g、290.33 mAh/g和249.29 mAh/g的可逆比容量。Fe_(3)Se_(8)/Co_(3)Se_(4)/NiSe_(2)/NC复合材料较好的电化学性能,可归因于碳导电网络、多金属硒化物和独特的纳米结构的协同作用,缓解了充放电过程中的体积膨胀。

Due to the rising price of lithium resources,it was urgent to develop a battery system with low price.The precursor of FeCoNiCP sheets was synthesized by co-precipitation method,then the Fe_(3)Se_(8)/Co_(3)Se_(4)/NiSe_(2)/NC composites were prepared by coating dopamine,annealing and selenization under nitrogen.When used as the anode material of sodium-ion battery,Fe_(3)Se_(8)/Co_(3)Se_(4)/NiSe_(2)/NC composite had fine electrochemical performance.The reversible specific capacity of electrode still maintained 463.38 mAh/g after 70 cycles charged-discharged in 0.01-3.00 V at 0.1 A/g,it had a reversible specific capacity of 363.85 mAh/g,345.88 mAh/g,320.73 mAh/g,308.31 mAh/g,290.33 mAh/g and 249.29 mAh/g at the current of 0.1 A/g,0.2 A/g,0.5 A/g,1.0 A/g,2.0 A/g and 5.0 A/g,respectively.It could be attributed to the synergistic effect of carbon conducting networks,polymetallic selenides and unique nanostructures that alleviate volume expansion during charging-discharging process.