Research On Electrochemical Performance Of High Temperature Pyrolysis Phthalocyanine Polymer

Carbon-based materials,due to the high porosity,high chemical and physical stability,low cost,and reproducibility,are one of the best choices for anode materials in supercapacitors.Therefore,the search for carbon-based materials with high specific surface area,suitable pore size,and heteroatom doping is a current research hotspot.Phthalocyanine(Phthalocyanine,Pc)polymer is an engineered thermosetting resin with abundant nitrogen content and a unique 18-electron conjugated macrocyclic system.In this paper,phthalocyanine polymer was selected as carbon source,mixed with different nanomaterials and metal-free phthalocyanine,and then pyrolyzed to prepare negative carbon materials for supercapacitors,and then their electrical properties were tested.In addition,the effects of different nanomaterials on the morphology and properties of pyrolyzed phthalocyanine polymers were studied,and the mixing ratio of nanomaterials and phthalocyanine polymers was determined.The main research contents are as follows:(1)Metal-free phthalocyanine was selected as the carbon source,nano-SiO₂as a hard template,after high-temperature pyrolysis,nano-SiO₂was etched with HF to prepare nitrogen self-doped porous carbon material(NPCM).When 50%mass fraction of nano-SiO2 was added,it was found that the as-prepared NPCM had a suitable specific surface area(550.5 m~2/g)and a nitrogen content of 2.1 at%.Meanwhile,the as-prepared NPCM electrode material exhibits a high specific capacity of 248 F/g at a current density of 1A/g.(2)Metal-free phthalocyanine was selected as the carbon source,adding single-walled carbon nanotubes(SWCNTs),compounding by simple solution mixing and mechanical stirring,nitrogen self-doped sheet porous carbon materials(SPCM)were prepared after pyrolysis.Due to the?-?interaction between metal-free phthalocyanine and SWCNTs at the interface when the solution is mixed,the phthalocyanine is pyrolyzed to form a graphene-like layered structure.It was found that when adding 10%mass fraction of SWCNTs,SPCM as a supercapacitor anode material showed a high specific capacity of 228 F/g and excellent stability at 1 A/g(maintaining 93%ratio capacity after2000).(3)Metal-free phthalocyanine was selected as the carbon source,adding nano-SiO₂and SWCNTs as templates at the same time to achive the synergistic effect,after pyrolysis,nano-SiO₂ was etched with HF.Due to the synergistic effect of nano-SiO₂ and SWCNTs,lamellar porous nitrogen self-doping carbon materials were prepared.It was found that when the mass ratio of the three was Pc/SWCNTs/SiO₂=1:0.05:0.5,the specific capacity of the composite material as a supercapacitor anode material at 1 A/g was 278.3 F/g,and after 5000 cycles,the composite material still maintained a specific capacity of 88.7%,demonstrating excellent stability.