High‐Performance Supercapacitor Afforded by a High‐Connected Keggin‐Based 3D Coordination Polymer

Abstract

A new coordination polymer, [Ag5(brtmb)4][VW10V2O40] [1, brtmb = 1‐bromo‐4‐(1,2,4‐triazol‐1‐ylmethyl)benzene], has been synthesized by a hydrothermal method. Its structure was determined by single‐crystal X‐ray diffraction analysis and further characterized by scanning electron microscopy, energy dispersive spectroscopy, bond valence sum (BVS) analysis, FTIR spectroscopy, and powder X‐ray diffraction. Each of the [VW10V2O40]5– clusters in polymer 1 acts as an octadentate connector, connecting with eight silver–brtmb subunits to generate a three‐dimensional structure. When employed as as the electrode material in supercapacitors, compound 1 showed remarkable electrochemical performances with a high capacitance of 13.3 mF cm–2 at 0.5 mA (206 F g–1 at 110 A g–1) and good cycling ability at various currents up to 2.0 mA (440 A g–1) with 81.7 % of the initial capacitance remaining after 1000 cycles. The above results reveal that polyoxometalate‐based hybrid coordination polymers may be a new‐generation alternative electrode material for high‐performance electrochemical capacitors.

Electrochemistry of Polyoxometalates: From Fundamental Aspects to Applications

“…At the moment, the combination of Keggin‐type [PW 12 O 40 ] 3− and activated carbon or reduced graphene oxide exhibit the best performance of supercapacitor in terms of maximum capacitance and stability for charge‐discharge cycles ,. Wells‐Dawson type [P 2 Mo 18 O 62 ] 6− and vanadium‐substituted POMs, [VV 2 W 10 O 40 ] 5− and [PV x Mo 12‐x O 40 ] (3+x)− (x=1–3), performed the similar level of capacitance to the other POMs, but exhibit poorer stability than [PMo 12 O 40 ] 3− and [PW 12 O 40 ] 3− –. However, the stability of [PV 2 Mo 10 O 40 ] 5− was improved by using SWCNT as a deposit material .…”

“…A variety of cationic substances, conducting polymers and polymeric ionic liquids, have been investigated with anionic POMs to fabricate POMs-modified electrodes because POMs are needed to immobilize on the surface of electrode to check their capacitance ( Table 7). [26] At the moment, the combination of Keggin-type [PW 12 O 40 ] 3À and activated carbon or reduced graphene oxide exhibit the best performance of supercapacitor in terms of maximum capacitance and stability for chargedischarge cycles. [26n,o] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 other POMs, but exhibit poorer stability than [PMo 12…”

Enhancing Energy Storage via TEA‐Dependent Controlled Syntheses: Two Series of Polyoxometalate‐Based Inorganic‐Organic Hybrids and their Supercapacitor Properties

“…(c) Relationship between crystal structure on the molecular level and their capacitance performance of the POM hybrids : POM is a class of nano‐scaled molecules with poor conductivity due to their isolated cluster structures. Herein, combining POM with metal cations or metal‐organic segments is an effective way to improve their capacitor performance,, yet the mechanism has been not clear. In order to initially explore that mechanism, two systems of POM hybrids have been prepared (Scheme ) and the capacitor performance have been compared.…”

A High‐Capacity Negative Electrode for Asymmetric Supercapacitors Based on a PMo12 Coordination Polymer with Novel Water‐Assisted Proton Channels

“…[27,28] However, to the best of our knowledge, supercapacitor electrodes fabricated by POM-based coordination polymers have only been reported in a few cases. [15,[29][30][31][32] In view of these scarce previous studies, we have decided to study POM-based coordination polymers as material for the preparation of an ASC device to study its actual application performance for the first time. similar to those found in other POMs.…”