title: Cobalt hexacyanoferrate nanoparticles as a high-rate and ultra-stable supercapacitor electrode material.
abstract: Although great recent efforts have been invested to improve the performance of supercapacitors, these energy storage devices still fall short of meeting our expectations because of their limited working voltage, insufficient cycle life, and high manufacturing cost. Here, we report the facile preparation of cobalt hexacyanoferrate (CoHCFe) nanoparticles, which have an analogous structure to Prussian blue but with many vacant ferricyanide sites. In 0.5 M Na2SO4, CoHCFe exhibits specific capacitance of >250 F/g, excellent rate capability, and ultrahigh cycling stability with capacitance retention of 93.5% after 5000 cycles. Furthermore, CoHCFe was paired up with a carbon black modified graphene (mRGO) negative electrode to form asymmetric supercapacitors. They deliver a wide working voltage of ∼2.4 V in Na2SO4, large energy density and power density. Given its high electrochemical performance, chemical robustness, environmental benignity, ease of preparation and low cost, CoHCFe as well as other Prussian blue analogues clearly deserve more attention for future energy storage applications.
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215123, China.
authors.forename: Feipeng
authors.initials: F
authors.lastname: Zhao
authors.forename: Yeyun
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaona
authors.initials: X
authors.lastname: Xu
authors.forename: Yiling
authors.initials: Y
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Song
authors.forename: Guang
authors.initials: G
authors.lastname: Lu
authors.forename: Yanguang
authors.initials: Y
authors.lastname: Li