General formation of Prussian blue analogue microtubes for high-performance Na-ion hybrid supercapacitors

Abstract

One-dimensional (1D) hollow-structured nanomaterials with desirable compositions have aroused huge attention in the field of electrochemical energy storage. In the present study, 1D hierarchical cobalt hexacyanoferrate (CoHCF) microtubes were initially fabricated using a facile self-templated method with the electrospun polyacrylonitrile (PAN)-cobalt acetate (Co(Ac) 2 ) as templates. After the chemical reaction was performed between the templates and a potassium ferricyanide solution, the core-shell PAN-Co(Ac) 2 @CoHCF nanofibers were successfully fabricated. Subsequently, the CoHCF microtubes were finally obtained via the selective dissolution of the PAN-Co(Ac) 2 cores. Benefiting from the unique structural characteristic, the CoHCF microtubes electrode exhibited prominent electrochemical characteristics in Na 2 SO 4 aqueous electrolyte, including a high specific capacitance of 281.8 F g −1 (at 1 A g −1 ), and good rate capability as well as long cycling stability (93% capacitance retention after 5000 cycles). The hybrid supercapacitor assembled with CoHCF microtubes and activated carbon (AC) as the positive and negative electrodes, respectively, exhibited a high energy density of 43.89 W h kg −1 , a power density of 27.78 kW kg −1 , as well as a long cycle life. Note that this versatile self-templated synthetic strategy could be extended to fabricate other 1D hollow Prussian blue (PB) or its analogues (PBA) with controllable composition, which have a potential application in a range of fields.

All Si3N4 Nanowires Membrane Based High‐Performance Flexible Solid‐State Asymmetric Supercapacitor

“…[1,2] Owing to ultrahigh power density, outstanding cycling stability, fast charging/discharging process, and high reliability, supercapacitor has been considered as one of the promising energy storage systems, which has aroused the concern of scientists worldwide. [3][4][5] Especially, the rapid development of flexible and wearable electronic devices has put forward high demands for high-efficiency supercapacitors with low weight, excellent mechanical flexibility, and large power/ energy density. [6] However, the large-scale applications of flexible supercapacitors were restricted due to the relatively low energy density.…”

Toward the Design of High‐performance Supercapacitors by Prussian Blue, its Analogues and their Derivatives

“…Later, the same group also fabricated 1D hierarchical CoHCF microtubes with the electrospun polyacrylonitrile (PAN)-cobalt acetate (Co(Ac) 2 ) as templates. [74] The CoHCF microtubes electrode exhibited almost the same electrochemical characteristics (281.8 F g −1 at 1 A g −1 , 93% capacitance retention after 5000 cycles) as those of CoHCF hollow prisms. Besides hollow structures, introducing porosity into the framework of PBAs can not only increase the specific surface area but also provide large channels for facile ion mass transportation in the electrode.…”

Prussian Blue Analogs and Their Derived Nanomaterials for Electrochemical Energy Storage and Electrocatalysis

“…utilized the self‐templated method and cation exchange strategy to fabricate a series of PBAs with hollow structures, including CoHCF microtubes (CoHCF = CoFe PBA), hollow CoHCF prisms and CoHCF submicroboxes, as positive electrode in Na‐ion hybrid supercapacitors. [ 108–110 ] Their electrochemical properties were evaluated in the Na 2 SO 4 aqueous electrolyte. Specifically, the CoHCF microtubes exhibited a specific capacitance of 281.8 F g −1 (at 1 A g −1 ) and long cycling stability (93% capacitance retention after 5000 cycles).…”