A Supercapacitor with High Specific Volumetric Capacitance Produced by 12-Phosphomolybdate Anchored on Graphene Balls

Abstract

Rational design and exploitation of graphene-based supercapacitors with high specific volumetric capacitance are highly desired, yet very challenging. Herein, a series of CGB/PMo 12 (n) hybrids (n = 1, 2, 3, 4), namely, Keggin-type 12-phosphomolybdate (PMo 12 ) anchored on highly crumpled 3D graphene balls (CGB), were successfully synthesized through a water-in-oil emulsion method. As expected, the CGB/PMo 12 (n) as electrode materials for supercapacitors exhibit higher specific volumetric capacitance in 1 M H 2 SO 4 media. Specifically, CGB/PMo 12 (3) show a specific capacitance of 632 F cm −3 (340 F g −1 ) at 1 A g −1 . This is mainly attributed to more electrochemically active sites of PMo 12 and the conductive substrate of CGB, high packing density (1.86 g cm −3 ), and their synergy. Furthermore, the assembled symmetric supercapacitor cell delivers a maximum energy and power density of 18.

Assembly and pseudocapacitive electrode materials application of octamolybdates based coordination polymers

“…For IR spectrum of compound Cu‐Mo 8 (shown in Fig.S2), there are four characteristic peaks at 611, 814, 910 and 942 cm −1 , are attributed to stretching vibration of ν(Mo=Ot, terminal oxygen) and ν(Mo‐O‐Mo), and bands in the regions of 1573–1083 cm −1 are attributed to the mbix molecules [45] . For PXRD, the diffraction peaks of simulated and experimental patterns of Cu‐Mo 8 match well, conforming the structural correctness and phase purity (Fig.3a).…”

Electrochemical analysis of asymmetric supercapacitors based on BiCoO3@g-C3N4 nanocomposites

“…The calculated packing density was 0.55 g cm −3 . 52,53 The volumetric-specific capacitance values were calculated to be Dalton Transactions Paper 190, 181, 176, 172, and 170 F cm −3 for BiCoO 3 @g-C 3 N 4 nanocomposites with current densities 1, 2, 3, 4, and 5 A g −1 , respectively (Fig. S8 (A) †).…”

Ternary Fe3O4/reduced graphene oxide/phytic acid doped polyaniline hybrid based supercapacitive electrode with high capacitance retention and good cycling stability

“…5,6,[8][9][10][11][12] Among various green energy devices, SCs, also known as electrochemical capacitors, are of special attention due to their high power density, robust reversibility and rapid charging/discharging rate compared to lithium-ion batteries and fuel cells. [13][14][15][16] According to their energy storage mechanisms, SCs can be mainly divided into electric double-layer capacitors (EDLCs: energy storage based on charge separation at the electrode/electrolyte interface) and pseudocapacitors (energy storage based on the redox reaction at the electrodes). In general, pseudocapacitors display a higher C s and energy density than those of EDLCs.…”