吸附聚硫化物的高性能g-C3N4/大孔碳复合材料及其在锂硫电池中的应用

摘要

为提高碳材料对聚硫化物的吸附能力,将三聚氰胺-二甲亚砜(DMSO)混合溶液真空灌注至大孔碳(MPC)孔道,并通过干燥和煅烧,在MPC孔道内壁均匀担载氮化碳(g-C3N4),得到复合材料g-C3N4/MPC.研究表明,g-C3N4/MPC中由于g-C3N4和MPC的协同作用,强化了聚硫化物的吸附,有效抑制了聚硫化物穿梭,改善了以其为载硫材料的锂硫电池循环性能.另外,MPC和三聚氰胺的较佳质量比为1:1,所得g-C3N4/MPC具有良好的聚硫化物穿梭抑制效果,而且硫电极的导电性也得到有效改善,所制备的电池表现出优异的循环性能和倍率放电性能.%In order to improve the ability of carbon material to adsorb polysulfide, melamine-dimethyl sulfoxide(DMSO) mixed solution was vacuum filled into macroporous carbon (MPC) channels followed by uniformly carrying the carbon nitride (g-C3N4) on the inner wall of MPC through the drying and calcination process and obtained the g-C3N4/Macroporous carbon(g-C3N4/MPC) composite. The results showed that g-C3N4/MPC enhanced the adsorption of polysulfide due to the synergistic effect of g-C3N4 and MPC, effectively suppressed the polysulfide shuttle and improved the cycling performance of lithium-sulfur battery with g-C3N4/MPC as sulfur-containing material.In addition, the proper mass ratio of MPC to melamine was 1:1, and the obtained g-C3N4/MPC had a good polysulfide shuttle inhibition effect, and the conductivity of the sulfur electrode was also improved. The prepared cell exhibited excellent cycling and high magnification discharge performance.