Facile and One-Step in Situ Synthesis of Pure Phase Mesoporous Li₂MnSiO₄/CNTs Nanocomposite for Hybrid Supercapacitors

Abstract

In material sciences, synergistic effect and nanostructuring are the two factors which enable researchers to look beyond the conventionally defined categories of the materials. Here, we report the synthesis mechanism of pure phase mesoporous Li 2 MnSiO 4 (LMS) with a high specific surface area by varying the concentration of metal precursors and solvents in one-step hydrothermal technique. Furthermore, the effect of MWCNTs addition on the electrochemical performance of LMS is studied. The quantitative contribution of current generating from EDLC and/or the surface pseudocapacitance reactions, and the current caused by diffusion-controlled redox reactions in the total current is also evaluated. The pure phase LMS/CNTs nanocomposite with 2% MWCNTs (abbreviated as LMS2C) is found to be the best supercapacitor material among studied nanocomposites as it exhibits specific capacitance of ∼290 F g −1 @ 1 A g −1 , good rate capability, small relaxation time constant (τ = 87 ms), and higher diffusion coefficient of electrolytic cations (D k + = 9.4 × 10 −9 cm 2 s −1 ) in 2 M KOH aqueous electrolyte. A hybrid supercapacitor cell (HSC) designed using LMS2C as positive and activated carbon as negative electrodes shows the maximum energy density of 31 W h kg −1 , which is much higher than several recently reported hybrid supercapacitor systems. Two series connected HSCs can power a drone motor and light up 8 red LEDs for more than 3 min, indicating practical applicability of our designed hybrid supercapacitor system.

Pentafluoropyridine functionalized novel heteroatom-doped with hierarchical porous 3D cross-linked graphene for supercapacitor applications

“…[51][52][53] The higher specic surface area predicts the availability of more interfacial area between the electrolytic ions and the active electrode material and might provide better performance. 54 As shown in Fig. 4b, the DFT pore size distribution curves of NPFG-0.3, NFG, PG, and rGO revels that all the samples have a wide range of pore size distribution extended from microporous (0.39-1 nm) to mesoporous (2-50 nm) regions.…”

Assessment of Biochar Produced by Flame-Curtain Pyrolysis as a Precursor for the Development of an Efficient Electric Double-Layer Capacitor

“…Although the main peak appeared at 128 ppm for both samples, the peak intensity for the KOH-activated sample was weak as it In this study, the addition of KOH resulted not only in the increase in micropore volume but also in a shift of the pore size distribution. The solid 13 C-NMR data of the biochar (starting material) and the activated sample (KOH 75 wt.%) are shown in Figure 6. In the case of the biochar, the peak at 128 ppm can be assigned to aromatic C-resonance and the peak 150 ppm can be assigned to oxygen-substituted aromatic resonance (C-O, C-OH) from the carboxyl, ester or quinone moieties [43].…”

“…The authors would like to thank the Cooperative Studies Using Collaborative Research Facilities of Wood Composite of Research Institute for Sustainable Humanosphere of Kyoto University. This work was performed under the Cooperative Research Program of "Network Joint Research Center for Materials and Devices" for solid 13 C-NMR measurement.…”

“…However, such materials may originate from non-renewable sources and their preparation is often lengthy and complex. Lately, the combination of metal oxide nanoparticles with carbon materials for the production of hybrid electrodes has received attention [13][14][15][16]. However, metal oxides such as Ru 2 O are expensive, thus limiting their industrial application [17].…”

A Critical Review on Electrochemical Properties and Significance of Orthosilicate‐Based Cathode Materials for Rechargeable Li/Na/Mg Batteries and Hybrid Supercapacitors

“…The Al 2 O 3 coated Li 2 MnSiO 4 nanocomposite was employed as an electrode material for HSC which showed the specific capacitance of 141.5 F g −1 and high‐power density of 4020.8 W kg −1 [241] . Recently, a multi‐walled carbon nanotube (MWCNT) embedded mesoporous Li 2 MnSiO 4 nanocomposite was synthesised and used as an electrode material for a hybrid supercapacitor in the aqueous electrolyte solution (2 M KOH) [242] . The symmetric supercapacitors were assembled using 2 % MWCNT incorporated Li 2 MnSiO 4 (LMS2 C) as positive and negative electrodes which delivered the energy and power density of 7 Whkg −1 and 150 Wkg −1 .…”