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Graphite electrode surfaces are pretreated by spray-deposition method with 0.5 mol L−1 Li2SO4 aqueous solution. The physical and electrochemical properties of a solid electrolyte interphase (SEI) film formed on the surface of Li2SO4-treated graphite electrode are investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical measurements. The results show that the SEI film formed, promoted by Li2SO4, is thin, stable, effective, and elastic to accommodate volume changes of graphite electrode during electrochemical cycles. Due to the fact that the Li/mesophase carbon microbeads (MCMB) cell based on Li2SO4-treated graphite electrode exhibits excellent cycling performance and low interfacial impedance, we can deduce that such modifies have positive implications for lithium-ion batteries (LIBs), offering the possibility of faster-charging LIBs and LIBs that are suitable for rate-demanding applications, such electric vehicles and hybrid electric vehicles. [ABSTRACT FROM AUTHOR]

Adsorbed natural gas (ANG) provides a better alternative for onboard storage of methane. We have measured methane adsorption at low pressure (∼1 bar) and ultrahigh pressure (∼400 bar) for three different micro-mesoporous carbons. The highest methane uptake was below 70 % in near-ambient temperature and 400 bar, or 25 % at 35 bar. Although gravimetric uptake is lower than the Department of Energy (DoE) target, a comparative study suggests that this adsorption amount is higher than that of most of the metal-organic frameworks (MOFs) and all covalent-organic frameworks (COFs). The highest volumetric methane uptake was above 500 v/ v at ca. 400 bar or ∼200 v/ v at 35 bar (293 K), which exceeded the DoE volumetric target for methane storage and is higher than most MOFs and COFs. Heat of adsorption values are within the range of 38 to 21 kJ mol−1 in the low-adsorption regime, higher than most MOFs or COFs. The overall results suggest that carbon-based adsorbents still remain the most promising adsorbents for the ANG process. [ABSTRACT FROM AUTHOR]

Ordered mesoporous carbon/titanium carbide composites (OMC/TiC) are synthesized by using Pluronic F127 and titanium isoproxide as the structure-directing agent and titanium precursor. Characterizations confirm the formation of an ordered mesoporous textural structure and the formation of nanocrystals of TiC in the framework of carbon. By using the resultant OMC/TiC as the support material, a platinum catalyst (Pt/OMC/TiC) is then prepared. Electrochemical measurements show that a higher activity for the methanol oxidization reaction and oxygen reduction reaction can be observed for the Pt/OMC/TiC, compared to Pt/OMC and a commercial Pt/C catalyst. The results obtained in the present work suggest that the synthesized OMC/TiC is a promising support material for platinum catalysts in proton exchange membrane fuel cells and direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Yarn supercapacitors have received much attention because of their noticeable role in advanced technologies, such as microrobots, wearable electronic textiles, and implantable medical devices. They can be prepared with different carbon-based materials, but many devices suffer from low energy densities. Conformally loaded, Faradaically active CoAl-based layered double hydroxides (CoAl LDH) are loaded onto carbon fiber (CF) yarns to prepare supercapacitors with enhanced capacitance and energy density, avoiding the need for binding agents. The effect of different CoAl LDH loading amounts on morphological, structural, and electrochemical properties is studied, and a loading amount of 2.3 mg cm−2 is found to achieve the maximum specific capacitance of 634.3 F g−1 at a current density of 1 Ag−1. Flexible all-solid-state supercapacitor based on CoAl LDH@CF yarns offers excellent areal capacitance (195 mF cm−2) and volumetric energy density (1.6 mWh cm−3) with 94 % cyclic stability after 4000 galvanostatic charge-discharge (GCD) cycles. The energy density and flexibility of this CoAl LDH@CFs yarn-based all-solid-state supercapacitor offer great potential for energy management in flexible electronics. [ABSTRACT FROM AUTHOR]

Rodlike manganese oxide (α-MnO2) was prepared through a homogeneous hydrothermal reaction. Air electrodes, made with a mixture of graphite/acetylene black (G/AB) with and without the as-made α-MnO2, were prepared for lithium-air cells. Linear sweep voltammetry (LSV) results show that the as-made α-MnO2 can greatly increase the rate of the oxygen reduction reaction (ORR), and that the graphite has a very low catalytic activity towards ORR, while acetylene black has a better catalytic activity towards ORR. The batteries were tested in ambient atmosphere. The results show that graphite can improve the charge and discharge performance, and acetylene black can improve the specific capacity. When using 28 % α-MnO2+56 % graphite as catalyst, the initial discharge capacity was 200 mAh g−1, and the number of cycles reached up to 5. When using 28 % α-MnO2+56 % acetylene black as catalyst, the initial discharge capacity was 1150 mAh g−1, but did not realize the charge and discharge cycles. [ABSTRACT FROM AUTHOR]