Achieving superb sodium storage performance on carbon anodes through an ether-derived solid electrolyte interphase

Synergistic effect by high specific surface area carbon black as secondary filler in silica reinforced natural rubber tire tread compounds

ZnCo-ZIF derived CoSe2 on carbon nanotubes: A nanotubular catalyst for enhanced water splitting

Introduction PEFCs are attracting attention as a power source for automobiles, residential, and portable devices due to their low environmental impact and high energy efficiency 1-2). However, the cathode of PEFCs requires a large amount of platinum to accelerate the ORR reaction. The high cost of Pt has hindered the extensive development of PEFCs for large-scale commercialization. Therefore, the research that combines reduced Pt usage with the high activity of electrocatalysts is highly desirable. A commonly applied approach to develop highly efficient and low-cost electrocatalysts is to reduce the Pt loading in the catalysts supported on high specific surface area carbon and to alloy Pt with transition metals, which could lead to a significant improvement in the cell performance. In this study, the PtNi nanoparticle alloy catalysts were synthesized as the cathode catalysts using high specific surface area carbon, utilizing Ni, which is an inexpensive metal, and their catalytic activity was evaluated. Experimental A Pt/C catalyst was prepared with loadings of 35% and 50% weight by ethanol reduction method 3). Briefly, nickel nitrate precursor was precipitated into the Pt/C powder by controlling pH at 10. Drying black powder then annealed at 900 °C for 15, 30, 60, 90 min in H2/Ar flow. The resulting powder was noted as PtNi/C(BT). To obtain Pt rich surface, acid treatment was performed in 0.5 M H2SO4 at 80 °C. The resulting powder was noted as PtNi/C(AT). The physical characteristics were evaluated by using various techniques such as TEM, XRD, and XRF. CV was measured to calculate the ECSA in 0.1 M HClO4 at room temperature. LSV was performed to evaluate the ORR mass activity and initial activity of the PtNi/C catalyst. Finally, the I-V cell performance of the PtNi/C catalyst was evaluated using MEA as a cathode for ORR in PEFCs. Results and Discussion TEM images revealed that the PtNi/C catalyst particles were homogeneously dispersed. The average particle sizes increased with increasing annealing time. Fig.1 shows the XRD patterns obtained for the 39.7 ° peak on the Pt(111) plane was shifted to a wider angle, indicating the formation disordered fcc-phase of PtNi alloy. The peaks became sharper with increasing annealing time, suggesting higher crystallinity. The crystalline size was calculated by using the Scherrer equation (3.73 nm, 5.21 nm, 5.94 nm and 6.49 nm), respectively. The ECSA of all PtNi/C catalysts was higher compared to the commercial PtCo/C catalysts. Acid treatment would cause Ni leaching from the surface, leading to a Pt-enriched surface, which could result in higher ECSA. The ECSA values decreased with increasing the annealing time, possibly due to particle growth and larger particle size with longer annealing time. The ORR activity for all PtNi/C catalysts was improved and higher than commercial PtCo/C. This increase in ORR activity would be due to the internal alloying of Ni and the improved electronic structure resulting from annealing at 900 °C. Fig.2 shows similar I-V performance was observed for 60 and 90 min annealing time in PtNi/C catalysts. Instead, the PtNi/C catalyst annealed for 15 min had lower performance, which could be attributed to Ni leaching and particle agglomeration. After ADT, the cell voltage at high current density region (1.0 A cm−2) for 60 min catalysts of PtNi/C (AT) was lower degradation compared to the commercial PtCo/C catalyst, indicating improved durability. In this study, the improvement of ORR activity was investigated at different annealing times, and it was found that 60 minutes of annealing time showed better durability and activity.This study was partly supported by NEDO, Japan. References (1) S. Maiti, et al., Energy Environ. Sci., 14, 3717 (2021).(2) R. Borup, et al., Chem. Rev., 107, 3904 (2007).(3) N. Narischat, et al., J. Phys. Chem. C, 118, 23003, (2014). Figure 1

High specific surface area carbon aerogels are being studied for various electrochemical applications. Their utility in these applications is limited due to moderate electrical conductivity. The current manuscript briefs about the effect of high temperature (HT) treatment (-1400 °C) on the conductivity and surface properties of resorcinol-formaldehyde (R-F) based carbon aerogels. Aqueous medium based carbon aerogel with high specific surface area (1796 m2/g) was synthesized by R-F gelation, ambient drying followed by CO2 activation treatment. The samples of carbon aerogel with HT treatment (CA-HT) were characterized for textural properties, conductivity, X-ray diffraction and specific capacitance. The specific surface area of CA-HT (1742 m2/g) showed only marginal decrease after HT treatment mainly due to partial collapse of micropores. The bulk electrical conductivity of CA-HT showed ∼ 35% improvement over the untreated CA with respective values of 165 S/m and 115 S/m. The specific capacitance for both CA and CA-HT were evaluated nearly ∼ 112 F/g at scan rate of 10 mV/s. For higher scan rate 100 mV/s, the CA showed drastic decrease in specific capacitance to 74 F/g, however, for CA-HT the value decreased only to 92 F/g. Equivalent series resistance (ESR), a crucial electrochemical parameter, improved to 0.5 n after HT treatment. The higher specific capacitance at faster scan rates and lower ESR for CA-HT is attributed to improvement in bulk conductivity which makes it a better choice for supercapacitor application.

Activated high specific surface area carbon aerogels for EDLCs

High specific surface area carbon aerogel derived from starch for methylene blue adsorption and supercapacitors

The widespread challenges facing lithium-sulfur batteries, including the low electrical conductivity of sulfur and its species, electrode volume fluctuations during cycling, and the lithium polysulfides shuttle effect, have hindered their commercialization and practical utility [1,2].Our study addresses these issues by incorporating titanium nitride (TiN) nanoparticles onto high specific surface area porous carbon, exploring this composite's potential as both a sulfur cathode host and separator modifier. The synthesis of the carbon/TiN composite involved two key stages: firstly, the in-situ growth of titanium dioxide (TiO2) nanoparticles on the carbon surface utilizing titanium tetrachloride as a precursor; secondly, the conversion of the TiO2 nanoparticles to TiN nanoparticles through carbothermal nitridization (thermal treatment at 1400 ℃ for 4 hours in a nitrogen medium) [3,4].The lithium-sulfur cell employing the prepared C/TiN-25%@S cathode exhibited an initial discharge capacity of 1155 mAh g-1 at 0.2 C, maintaining a capacity exceeding 700 mAh g-1 after 100 cycles. Notably, the lithium-sulfur cell utilizing the C/TiN-25%@S cathode and a C/TiN-modified separator demonstrated enhanced cycling performance, delivering an initial discharge capacity of 1623 mAh g-1 with retention of over 1126 mAh g-1 after 100 charge/discharge cycles at 0.2 C. Acknowledgments This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP19677708).

Uneven lithium deposition, which leads to the growth of lithium dendrites, presents a significant challenge in the practical application of high-energy lithium metal batteries. Herein, we report a high specific surface area carbon cloth (CC@ZnO) with uniform dispersion of nano zinc oxide as a collector for lithium metal battery (LMB). The uniformly dispersed zinc oxide in the CC@ZnO helps to achieve consistent lithium nucleation and growth with its lithophility. The high specific surface area of the CC@ZnO can promote the nucleation and growth of metallic lithium inside the current collector, greatly alleviating the adverse effects of the hostless nature of the metallic lithium anode. By utilizing this three-dimensional composite carbon cloth as a collector in lithium metal batteries, the Coulombic efficiency of lithium deposition and stripping is improved. The Li-Cu asymmetrical battery achieved a Coulombic efficiency of 97.6% after 120 cycles at 3 mA cm-2, with a deposition capacity of 3 mAh cm-2 in an ether electrolyte without the addition of lithium nitrate.

Effects of flotation and acid treatment on unburned carbon recovery from atmospheric circulating fluidized bed coal gasification fine ash and application evaluation of residual carbon.

This work deals with a new route to modify polymer blend morphology in order to improve the porosity of gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). First, electrically conductive polymer‐based blends were carefully formulated using a twin‐screw extrusion process. Blend electrical conductivity was ensured by the addition of high specific surface area carbon black and synthetic graphite flakes. Final GDL porosity, in particular its macroporosity, was generated by melt blending polyamide 11 (PA11) matrix with polystyrene (PS) followed by PS extraction with tetrahydrofuran (THF) solvent at room temperature. In order to improve GDL porosity by the optimisation of PS dispersion in the PA11 matrix, PA11/PS blends were compatibilised by the addition of 2 wt.‐% of clay. It was observed that both macroporosity and pore size distribution were beneficially modified after blend compatibilisation. Final GDL conductivity of about 1.25 S cm–1, a porosity of 53% and a specific pore surface area of 75 m2 g–1 were achieved.

New Synthesis of Mo2C 14 nm in Average Size Supported on a High Specific Surface Area Carbon Material

High specific surface area carbon nanotubes from catalytic chemical vapor deposition process

Pd(1 1 1)/SnO2(1 0 1) heterostructure on porous N-carbon material as enhanced catalyst for formic acid electrooxidation

Micro-scale “top-down” construction of N/O Co-doped carbon aerogel particles for efficient hydrogen storage at ambient pressure

Electrochemical capacitors, based on the double-layer capacitance of high specific surface area carbon materials, are attracting major fundamental and technological interest as highly reversible, electrical-charge storage and delivery devices, capable of being operated at high power densities. In the present paper, studies have been carried out on nanocomposite gel polymer electrolyte comprising poly(vinylidene fluoride-co-hexafluoropropylene)-propylene carbonate-magnesium perchlorate-nanofumed silica with a view to use them as electrolyte in electrochemical double-layer capacitors (EDLCs) based on chemically treated activated charcoal as electrodes. The optimized composition of nanogel polymer electrolyte exhibits high room-temperature ionic conductivity of 5.4 × 10−3 S cm−1 with good mechanical and dimensional stability which is suitable for their application as electrolyte in EDLCs. Detailed chemical and microstructural characterization of chemically treated and untreated activated charcoal was conducted using scanning electron microscopy and Brunauer–Emmett–Teller (BET). BET studies reveal that the effective surface area of treated activated charcoal powder (1,515 m2 g−1) increases by more than double-fold compared with untreated one (721 m2 g−1). Performance characteristics of EDLCs have been tested using cyclic voltammetry, impedance spectroscopy, prolonged cyclic test, and charge–discharge techniques. Analysis shows that the treated activated charcoal electrodes have almost five times more capacitance values as compared with the untreated one. The maximum capacitance of 324 mF cm−2, equivalent to single electrode specific capacitance of 216 F g−1 was achieved. It corresponds to an energy density of 20 Wh kg−1 and a power density of 2.2 kW kg−1.