一锅法合成高性能N掺杂的Co(PO_(3))_(2)@C负极材料及其在超级电容器中的应用

One-pot synthesis of high-performance N-doped Co(PO_(3))_(2)@C negative electrode materials for supercapacitors

以植酸(PA)、三聚氰胺(MA)、四水合乙酸钴(Co(OAc)_(2)·4H_(2)O)和聚偏氟乙烯(PVDF)中空纤维膜为原料,采用一锅法合成了偏磷酸钴和氮(N)掺杂碳(C)的复合材料(Co(PO_(3))2@C).其中,PA属于六齿配体,拥有6个磷酸基,每个磷酸基中的氧原子(O)都可作为配位原子和钴离子发生络合反应,形成化学性质稳定的络合物,可以作为绿色磷(P)源.MA含有丰富的N元素,PVDF中空纤维膜中含有氟(F)元素,同时还可以提供框架结构,N和F元素的掺杂可以使多孔碳材料具有更好的润湿性,有利于电解液中电子的传输,从而极大提高了材料的电化学电容性能.所制备的最佳活性负极材料在1 A·g^(-1)时的比电容为1 067.42 F·g^(-1).即使在10 A·g^(-1)的电流密度下,20 000次循环后,仍可以达到85.79%的保留率.

We synthesized a cobalt metaphosphate and nitrogen(N) doped carbon(C) composite(Co(PO_(3))_(2)@C) by an one-pot method using green phytate(PA),melamine(MA),cobalt acetate tetrahydrate(Co(OAc)_(2)·4H_(2)O),and polyvinylidene fluoride(PVDF) hollow fiber membrane as raw materials.Among them,PA can be used as a green phosphorus(P) source since PA is a hexadentate ligand with six phosphate groups and the oxygen atom(O) in each phosphate group can be used as a coordination atom to react with cobalt ions to form a complex with stable chemical properties.MA is rich in N elements,and PVDF hollow fiber membrane contains fluorine(F) element,which can also provide a framework structure.The doping of N and F elements can make the porous carbon material have better wettability,which facilitates the electron transfer in the electrolyte,thus greatly improving the electrochemical performance of the material.The prepared active negative electrode material has a specific capacitance of 1 067.42 F·g^(-1)at the current density of 1 A·g^(-1).Even at the current density of 10 A·g^(-1),the capacitance retention rate of 85.79%can be achieved after 20 000 cycles.