Heterochain polymer carbon modified transition metal composites for fabricating high energy-density supercapacitors

Abstract

Although transition metals have special electronic structures and high theoretical capacitance, their low conductivity and structural instability greatly limit their practical applications. In this work, a heterochain polymer PZS containing C, N, P, S, O was used as a carbon precursor containing heteroatoms, and Ni(HCO3)2 nanoparticles were grown in situ on its surface. After calcination, a nanocage shaped PZSC/NiO (+) was acquired with large specific capacity (188 mAh g−1). Meanwhile, utilizing the adjustable pore size, sufficient surface area, and easy ion introduction of MOFs, PZS coated on the surface of CoFe-MOF was calcined to prepare a stalactite like Co3Fe4(PO4)6/PZSC (-) with expected specific capacity (114.2 mAh g−1). The assembled PZSC/NiO (+) // Co3Fe4(PO4)6/PZSC (-) supercapacitor presents an extremely high energy-density and excellent cycling stability (54.6 Wh kg−1, 93 %, 10,000 r), as well as a high specific capacity (68.5 mAh g−1).