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Nanostructured integrated electrodes with binder-free design show great potential to solve the ever-growing problems faced by currently commercial lithium-ion batteries such as insufficient power and energy densities. However, there are still many challenging problems that limit the practical application of this emerging technology, in particular complex manufacturing process, high fabrication cost, and low loading mass of active material. Different from those existing fabrication strategies, here using a Co-P alloy foil as precursor we demonstrate a simple neutral salt solution-mediated electrochemical dealloying method to well address the above issues. The resultant freestanding mesoporous np-Co(OH)

Nowadays, when fabricating electric double-layer capacitor (EDLC) electrode, 10-20% conductive carbon black (CB) is indispensable to guarantee a satisfactory power output of whole EDLCs. Herein, we constructed a series of porous frame-filling C/C composites with ample specific surface area (SSA) and adequate electrical conductivity (e-conductivity), aiming at CB-free EDLC electrode. The content of frame part and KOH dosage were well-optimized to balance the SSA and e-conductivity. An optimized sample named F310 owns, at the same time, abundant SSA of 2562 m2 g-1, high sp2-bonding carbon content of 88.2% and sufficient e-conductivity of 120 S m-1. Even totally free of any CB, the resultant EDLC electrode achieved high gravimetric capacitance of 130.4 F g-1 at 50 mA g-1 with rate capacity C10/0.05 of 56.8% in TEABF4/PC electrolyte. Significantly, it could also run independently up to 10,000 cycles at 1 A g-1 with capacitance retention of 78.3% in TEABF4/PC electrolyte. More importantly, when CB-free electrode is in use, the lifespan at stable high-rate output is obviously decided by e-conductivity rather than the mesoporous channels.

Air oxidation is introduced as a simple and feasible method of modification for mesocarbon microbeads (MCMBs), which improves the electrochemical performance of MCMBs as anodes for sodium-ion batteries (SIBs). Optimal oxidation conditions are explored. Green MCMBs, initially oxidized at 360 °C then carbonized (OC-MCMB360), exhibit a high reversible capacity up to 286 mAh g−1 at a current density of 25 mA g−1. In addition, the OC-MCMB360 sample also presents an excellent rate performance with 79 mAh g−1 at a current density of 3.2 A g−1 and a considerable reversible capacity of 166 mAh g−1 after 100 cycles at 100 mA g−1. The larger interlayer spacing and increased defect sites caused by oxidation contribute to the enhanced electrochemical performance of oxidized MCMBs in SIBs.

The SiO2/carbon composite material used as a lithium-ion battery (LIB) anode was synthesized by aerosol spraying a mixture of polyvinyl alcohol (PVA) solution and SiO2 nanoparticles, followed by coating polyacrylonitrile (PAN) on the SiO2/PVA surface and an annealing treatment at 800 °C. The as-prepared SiO2/po-C@C has a hollow core–shell structure. The hollow section contributes to accommodate the volume expansion of SiO2 nanoparticles; the skeleton of porous carbon in the core not only enhances the electronic conductivity, but also provides the lithium-ion diffusion path; the PAN-based carbon shell benefits for forming a stable solid electrolyte interphase (SEI) film. This core–shell structure could partly alleviate the pulverization of the SiO2/po-C@C particles and also perform excellent electrochemical performances. Compared with the SiO2@C composite, the SiO2/po-C@C composite possesses a high specific charge capacity of 669.8 mA h g−1 at a current density of 100 mA g−1 after 100 charge and discharge cycles with a high capacity retention of 98.6 %. Therefore, the SiO2/po-C@C composite with a hollow core-shell structure shows great potential as an anode material for future LIBs.

Alumina supported ruthenium particles with an average diameter of 2 nm were prepared by a modified ethylene glycol reduction method. Catalytic methanation of CO2 over this catalyst was studied by in situ FTIR spectroscopy. After pretreatment in H2, different types of adsorbed species were detected on the catalyst surface at 200 °C. Based on a series of targeted experiments under variation of gas composition, order of addition, reaction time and temperature, a reaction scheme and the rate-determining steps of CO2 methanation are proposed. Two potential reaction paths for the hydrogenation of CO2 to form CH4 were identified: (I) CO adsorbed on the Ru metal surface acted as active intermediate and the CO methanation followed. The dissociation of CO to form surface carbon represents the rate-determining step. (II) Formyl species formed by hydrogenation of adsorbed CO2 are the active intermediate and the formation of formyl was the rate-determining step.

Advances in micro-electro-mechanical systems (MEMS) have led to an increased fabrication of micro-channels. Microfabrication techniques are utilized to develop microfluidic channels for continuous nutrition supply to cells inside a micro-environment. The ability of cells to build tissues and maintain tissue-specific functions depends on the interaction between cells and the extracellular matrix (ECM). SU-8 is a popular photosensitive epoxy-based polymer in MEMS. The patterning of bare SU-8 alone does not provide the appropriate ECM necessary to develop microsystems for biological applications. Manipulating the chemical composition of SU-8 will enhance the biological compatibility, giving the fabricated constructs the appropriate ECM needed to promote a functional tissue array. This article investigates three frequently used surface treatment techniques: (1) plasma treatment, (2) chemical reaction, and (3) deposition treatment to determine which surface treatment is the most beneficial for enhancing the biological properties of SU-8. The investigations presented in this article demonstrated that the plasma, gelatin, and sulfuric acid treatments have a potential to enhance SU-8's surface for biological application. Of course each treatment has their advantages and disadvantages (application dependent). Cell proliferation was studied with the use of the dye Almar Blue, and a micro-plate reader. After 14 days, cell proliferation to plasma treated surfaces was statistically significantly enhanced (p

The carbon materials prepared from polyimide (PI) resin film were investigated by TG-DTG, X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analysis. TG-DTG study revealed that the weight loss of PI resin film during carbonization occurred in three stages, and the most serious changes occurred at 605.5°C. XRD results indicated that a disorder structure occurred after the carbonization at 600°C and graphite crystallite appeared gradually with increasing the temperature. And PI resin film still presented some characteristics of nongraphitizing carbon, after graphitizing at 2600°C. XPS analysis identified that pyrrole type nitrogen was a main component of surface nitrogen atoms after carbonization. When the temperature reached 2600°C, nitrogen atoms disappeared totally; the reason why oxygen atoms still existed in the material at so high temperature was our subject of interesting matter in the later study. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Li4Ti5O12 nanorods coated by anatase-TiO2 is prepared via a microemulsion consisting of cetyltrimethylammonium bromide, cyclohexane, BuOH, and LiOH to which Ti(OBu)4 is added followed by hydrothermal treatment (autoclave, 180 °C) and calcination at 550 °C in air.