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The catalytic hydroconversion of light cycle oil (LCO) from a fluid catalytic cracking (FCC) unit into petrochemical light aromatics was conducted in a fixed-bed down-flow reactor under 6 MPa. A hydrocracking (HDC) study was conducted using pre-hydrotreated LCO (HDT-LCO). Due to the wide molecular size distribution of the aromatic compounds in LCO, which range from mono- to tri+-ring aromatics, a combination of H-ZSM-5 (Z), H-Beta (B) and mesoporous H-Y(Y) zeolite was employed as zeolite supports for the HDC catalysts. The Mo-S/BYZ catalyst was found to achieve higher yield of light aromatics and higher conversion of large molecular-size C11+ heavy aromatics than those for Mo-S/BZ without mesoporous H-Y in the HDC of HDT-LCO. Although the Mo-S/ H-Y catalyst itself did not show selectivity toward light aromatics in the HDC of tetralin, the incorporation of a small fraction of mesoporous H-Y in the HDC catalyst promoted the cracking of large molecular-size C11+ heavy aromatics into light aromatics including benzene, toluene and xylene (BTX). The Mo-S/BYZ catalyst also exhibited an excellent stability over more than 100 h. Hence, the Mo-S/BYZ catalyst, which produced a high yield of BTX-rich light aromatics and demonstrated excellent catalyst stability, represents a promising HDC catalyst for LCO upgrading.

Comprehensive series tests on hydrotreating (HDT) and hydrocracking (HDC) of fluid catalytic cracking (FCC) light cycle oil (LCO) into high-value light aromatics rich in benzene, toluene, and xylenes (BTX) were conducted in a fixed-bed down-flow reactor under medium pressure (6 MPa). Two different LCOs, LCO-1 (a full-range LCO) and LCO-2 (340 °C− LCO which contained a smaller fraction of refractory alkyl(C2+)-carbazoles and heavy tri+-aromatics (three and more rings aromatics) than LCO-1), were used as feedstocks. Comparison of NiW-S, NiMo-S, and CoMo-S supported on γ-Al2O3 and a commercial catalyst (for vacuum gasoil hydrodesulfurization) as LCO HDT catalysts revealed that NiMo-S/γ-Al2O3 allowed for highly selective hydrogenation (HYD) of di+-aromatics (two and more rings aromatics) into mono-aromatics with minimal loss of aromatics at high HDN conversion rates. For HDC catalysts, NiMo-S, CoMo-S, and Mo-S were supported on a hybrid zeolite, BZ(x) (a mixture of H-Beta (B) and H-ZSM-5 (Z) (x wt%)). Since Mo-S exhibited moderate HYD power and H-ZSM-5 promoted the dealkylation of alkyl-aromatics into BTX, Mo-S/BZ(10) yielded the largest amount of BTX in the HDC model of tetralin among the three catalyst analyzed. The HDC of hydrotreated LCO-1 (HDT-LCO-1) over Mo-S/BZ(10) catalyst generated a low yield of BTX-rich light aromatics because of the limited conversion of C11+ heavy aromatics. However, during the HDC of HDT-LCO-2, the yield of BTX-rich light aromatics was close to the theoretical yield (48.4 wt%) over a wide temperature range when Mo-S/BZ(10) was used as catalyst, which indicated the highly selective HDC behavior of Mo-S/BZ(10) for this reaction. Therefore, NiMo-S/γ-Al2O3 and Mo-S/BZ(10), which exhibited well-balanced metallic and/or acidic functions, were promising HDT and HDC catalysts, respectively, for the selective conversion of LCOs into high-value BTX-rich light aromatics at high yields.

The crucial roles of ethylenediaminetetraacetic acid (EDTA) in the poly(acrylic acid) (PAA)-binder system were investigated for the high electrochemical performance silicon anode in lithium-ion batteries. The EDTA supports the construction of a mechanically robust network through the formation of sbndCOOH linkage with the SiO2 layer of the Si nanoparticles. The mixture of the PAA/EDTA binder and the conductive agent exhibited an improved elastic modulus and peeling strength. The creation of hydrogen fluoride (HF) was effectively suppressed through the elimination of the H2O. An H2O–phosphorous pentafluoride (PF5) reaction, which is known for its use in the etching of metal oxides including its creation of the solid electrolyte interphase (SEI) layer, generates the HF. A remarkably sound cyclability with a discharge capacity of 2540 mA h g−1 was achieved as a result of the synergistic effect between robust mechanical properties and suppression of the HF creation for the stability of the SEI layer.

For practical implementation of high-capacity silicon anodes, porous silicon (pSi) structures have demonstrated outstanding cycling stability against the large volume changes typical of solid silicon particles. The conventional magnesiothermic reduction (MR) of silica under static conditions limits the yield of pSi and sometimes produces low-purity of pSi owing to limited mass transfer and many side reactions. Hence, we devise a rotational MR (R-MR) system with rapid magnesium transport in which a uniform Mg/SiO2 molar ratio is readily achievable, and a short reaction time can be applied. Compared to conventional MR, the R-MR process has an extremely high yield (∼90 wt%) of pSi at almost complete conversion of precursor, whereas side reactions are substantially suppressed. Mg 2p X-ray photoelectron spectroscopy analysis of the reduction product reveals that pSi yield is well correlated with the conversion of Mg to MgO. The carbon-coated pSi/C samples and their hybrids with graphite (pSi/C@Gr) composites demonstrate stable cycling performance for 300−600 cycles at high capacity with high cycling efficiency (∼99.9%). Therefore, high-conversion R-MR can be a very efficient and scalable process for obtaining pSi for use in carbon composites (such as pSi/C and pSi/C@Gr) that offer outstanding cycling performance in high-capacity anodes for high-energy LIBs.

Various metallic components (Ni, NiSn, NiW-S, CoMo-S and NiMo-S) with different hydrogenation (HYD) activities were supported on H-Beta or hybrid zeolites (BZ( x ), where x denotes the weight percentage of H-ZSM-5 in the physical mixture of H-Beta and H-ZSM-5). These bifunctional catalysts were applied to the hydrocracking (HYC) of tetralin in a fixed-bed down-flow reactor at 4 MPa as a model reaction for polycyclic aromatic hydrocarbon (PAH) conversion to high-value benzene, toluene, and xylenes (BTX). From the HYC of tetralin over the series of metals/H-Beta catalysts, it was found that CoMo-S/H-Beta and NiMo-S/H-Beta, whose metallic components show moderate activities in the HYD of tetralin, exhibit higher BTX yields than the other catalysts whose metals have excessively high or low HYD activities. However, these catalysts show limited BTX yield (∼47.3 wt% at 425 °C) owing to the large coproduction of alkylbenzenes other than BTX. When metals with moderate HYD activities are supported on the hybrid zeolites, the BTX yield is significantly enhanced by the effect of H-ZSM-5 in the dealkylation of alkylbenzenes into BTX. NiMo-S/BZ(10) provides a BTX yield of 54.3 wt% and a total 1-ring aromatic yield as high as 63.8 wt% (corresponding to 94.4% of the theoretical maximum of 67.6 wt%) at 425 °C. Therefore, the NiMo-S/BZ(10) catalyst, where the metallic and acidic functions and structural properties of the zeolite are well balanced, show promise as an HYC catalyst for the hydroconversion of PAHs into high-value BTX mixtures.

Despite its highest theoretical capacity, the practical applications of the silicon anode are still limited by severe capacity fading, which is due to pulverization of the Si particles through volume change during charge and discharge. In this study, silicon nanoparticles are embedded in micron-sized porous carbon spheres (Si-MCS) via a facile hydrothermal process in order to provide a stiff carbon framework that functions as a cage to hold the pulverized silicon pieces. The carbon framework subsequently allows these silicon pieces to rearrange themselves in restricted domains within the sphere. Unlike current carbon coating methods, the Si-MCS electrode is immune to delamination. Hence, it demonstrates unprecedented excellent cyclability (capacity retention: 93.5% after 500 cycles at 0.8 A g–1), high rate capability (with a specific capacity of 880 mAh g–1 at the high discharge current density of 40 A g–1), and high volumetric capacity (814.8 mAh cm–3) on account of increased tap density. The lithium-ion...

Cobalt promoted Mo/β (Beta zeolite) catalysts were prepared with different metallic loadings (0.5–1.5) by a co-impregnation method. The catalytic activities of the synthesized catalysts were investigated for the selective hydrocracking of tetralin and pyrolysis fuel oil (PFO) into mono-aromatic hydrocarbons (MAH) such as benzene, toluene and xylene (BTX) in a fixed-bed reactor system. Prior to using the CoMo/β catalyst for crude PFO hydrocracking, different reaction parameters (including metallic loading, temperature, H2 pressure, and LHSV) were investigated for the hydrocracking of a model feed, tetralin, to determine the best conditions for maximum BTX yield. The CoMo(0.5)/β catalyst with a Co/Mo ratio of 0.5 produced the highest MAH yield of 62.6% at 99.5% conversion of tetralin, continuously for 140 h of reaction time without any deactivation. Furthermore, the CoMo(0.5)/β catalyst was found to be superior among the tested CoMo/β catalysts for hydrocracking real feed PFO, and it produced a maximum MAH yield of 54.8% at 99.1% conversion of PFO. The synthesized catalysts were characterized using different characterization techniques, including BET, NH3-TPD, SEM-EDS and ICP, to evaluate their physiochemical properties and determine the active sites present in the catalysts.

A mesoporous MnOx network (MMN) structure and MMN/C composites were prepared and evaluated as anodes for high-energy and high-rate lithium-ion batteries (LIB) in comparison to typical manganese oxide nanoparticle (MnNP) and graphite anodes, not only in a half-cell but also in a full-cell configuration (assembled with an NCM523, LiNi0.5Co0.2Mn0.3O2, cathode). With the mesoporous features of the MMN, the MMN/C exhibited a high capacity (approximately 720 mAh g−1 at 100 mA g−1) and an excellent cycling stability at low electrode resistance compared to the MnNP/C composite. The MMN/C composite also showed much greater rate responses than the graphite anode. Owing to the inherent high discharge (de-lithiation) voltage of the MMN/C than graphite as anodes, however, the MMN║NCM523 full cell showed approximately 87.4% of the specific energy density of the Gr║NCM523 at 0.2 C. At high current density above 0.2 C, the MMN║NCM523 cell delivered much higher energy than the Gr║NCM523 mainly due to the excellent rate capability of the MMN/C anode. Therefore, we have demonstrated that the stabilized and high-capacity MMN/C composite can be successfully employed as anodes in LIB cells for high-rate applications.

The widespread use of lithium–sulfur (Li–S) batteries is still hindered by the low electrochemical activity of sulfur-species, and a short cycle life owing to anode instability coupled with polysulfide shuttle effects. As a first measure to counteract these issues, a new and simple sulfur-loading method consisting of solution impregnation and subsequent melt-diffusion (IM) is demonstrated and compared to the conventional method of physical mixing followed by melt-diffusion (PM). Using the IM method, sulfur is well encapsulated and highly dispersed in conducting mesoporous carbons (MCs) that possess an ideal pore diameter (around 10 nm) and a large pore volume (∼2.8 cm3 g−1). S/MC cathodes prepared by the IM method deliver much higher capacities, better rate responses and cycling stabilities up to 300 cycles (the fading rate was as low as −0.037% per cycle) with less concerns in lithium polysulfide (LPS) shuttling and impedance build up than S/MC cathodes prepared by the PM method. The S/MC cathodes prepared by the IM method has a pseudo-optimum sulfur content of 65 wt%, and when coupled with a new type of carbon-coated separator (CCS), a high areal capacity of >2.5 mA h cm−2 is successfully achieved, combined with excellent cycling stability and rate capability.

A series of Si/graphene sheet/carbon (Si/GS/C) composites was prepared by electrostatic self-assembly between amine-grafted silicon nanoparticles (SiNPs) and graphene oxide (GO). The Si/GS derived from carbonization of Si/GO assemblies showed limited cycling stability owing to loose cohesion between SiNPs and graphene, and increased impedances during cycling. To counteract the cycling instability of Si/GS, an additional carbon-gel coating was applied to the Si/GO assemblies in situ in solution followed by carbonization to yield dense three-dimensional particulate Si/GS/C composite with many internal voids. The obtained Si/GS/C composites showed much better electrochemical performances than the Si/GS owing to enhanced cohesion between the SiNPs and the carbon structures, which reduced the impedance buildup and protected the SiNPs from direct exposure to the electrolyte. A strategy for practical use of a high-capacity Si/GS/C composite was also demonstrated using a hybrid composite prepared by mixing it with commercial graphite. The hybrid composite electrode showed specific and volumetric capacities that were 200% and 12% larger, respectively, than those of graphite, excellent cycling stability, and CEs (>99.7%) exceeding those of graphite. Hence, electrostatic self-assembly of SiNPs and GO followed by in situ carbon coating can produce reliable, high-performance anodes for high-energy LIBs.

Mesoporous carbon microspheres (MCM) with a uniform size distribution (1–2 μm in diameter) were replicated from mesoporous silica microspheres (MSM) by using sucrose as a carbon source. MCM (BET surface area=1,001 m2/g, total pore volume=0.82 cc/g, average pore size=3.4 nm) was used as the support of MnO x nanocrystals (Mn3O4 with MnO as a minor phase). The MnO x /MCM composite was prepared by pore-filling wet-impregnation of Mn nitrate solution followed by a moderate annealing under Ar flow. Thus obtained MnO x /MCM composite was characterized as a high capacity anode for lithium ion battery (LIB). The electrochemical responses of MnO x /MCM were investigated in comparison with those of commercial graphite. The MnO x /MCM composite exhibited the reversible capacity of ∼720 mAh g−1 at the current density of 200 mA g−1 with an excellent cycling stability up to 100 cycles. The MnO x /MCM composite also showed much higher volumetric capacity and better rate capability than the state of the art graphite anode, suggesting its potential use as a new anode material for LIBs.

Hydrocracking (HYC) of tetralin was studied in a fixed-bed down-flow reactor under 4 MPa as a model reaction for polyaromatic hydrocarbons (PAHs) conversion to light aromatic hydrocarbons such as BTX and C9 aromatics. HYC catalysts were prepared by supporting various metals, (Ni, Ni-Sn and CoMo-S) possessing different hydrogenation (HYD) activity, on H-Beta. HYC of tetralin over Ni/H-Beta catalysts with various Ni contents (1-10 wt%) resulted in a non-selective HYC behavior to give low BTX yield but high yields of gaseous and naphtha products due to strong HYD activity of Ni. The HYD activity of Ni was suppressed by forming Ni-Sn intermetallic compounds by Sn addition. Thus, Ni-Sn/H-Beta catalysts showed BTX and BTX+C9A (C9 aromatics) yields as high as 48.1 wt% and 53.1 wt%, respectively. The BTX and BTX+C9A yields corresponded to about 75 and 83% of the theoretical yield, respectively. CoMo-S/H-Beta, whose metal showed the lowest HYD activity, also exhibited BTX (47.4 wt%) and BTX+C9A (55.5 wt%) yields comparable to those obtained over Ni-Sn/H-Beta. Besides metallic function in HYC catalysts, H2/tetralin molar ratio greater than 4 and H-Beta with a moderate acidity are desirable to achieve a highly selective HYC of tetralin into BTX with high yield at low hydrogen consumption.

The Mo/β (beta zeolite) catalyst was prepared by wet-impregnation and modified with cobalt promoter. The catalytic activity of monometallic Mo/β catalyst in selective hydrocracking of tetralin into monocyclic aromatic hydrocarbons (MAH) such as benzene, toluene and xylene (BTX) was investigated in fixed bed reactor and compared its activity with bimetallic CoMo/β catalyst. The catalytic results indicates that, incorporation of promoter (Co) not only improved their catalytic activity in hydrocracking reactions but also showed long term stability as compared with Mo/β. Effect of different SiO 2 /Al 2 O 3 ratio (25, 75, 150) in beta zeolite was investigated on catalytic activity of CoMo/β. CoMo/β with SiO 2 /Al 2 O 3 of 25, gave highest 62.6% of desired MAH yield at 99.5% conversion of tetralin for more than 140 h of reaction time. Likely, CoMo/β catalyst was also found to be effective for the conversion of pyrolysis fuel oil (PFO) into MAH. Crude PFO was distilled out at 170 °C and total amount of 55 wt.% PFO was received after distillation. In the PFO hydrocracking, it produced 43.3% of MAH product yield at 70% conversion of PFO, which is significantly higher than the conversion (48%) and MAH yield (34.2%) obtained from monometallic Mo/β catalysts. CoMo/β catalyst was found to be more stable as well as active for longer reaction time (140 h).

In order to fabricate high-energy and stable lithium-ion batteries (LIB), herein, mesoporous silicon (mpSi-Y) microparticles were prepared via a facile magnesiothermic reduction of commercial zeolite Y. The electrochemical characteristics of carbon-coated mpSi-Y (mpSi-Y/C) were evaluated in a lithium-ion battery full cell as well as a half-cell configuration and compared with those of silicon nanoparticle-carbon composite (SiNP/C) and graphite (Gr) anodes. With the mesoporous structural features of mpSi-Y, the high-capacity mpSi-Y/C (1200 mAh.g − 1 at 0.05 C) in a half-cell showed a much better cycling stability at a much less impedance build-up and electrode thickness increase than SiNP/C composite. It also presented much faster charging/discharging kinetics than does the graphite anode. A pretreated mpSi-Y/C was paired with a NCM (LiNi0.6Co0.2Mn0.2O2) cathode to fabricate a full cell, mpSi∥NCM. The mpSi∥NCM cell exhibited a comparable cycling performance to that of the Gr∥NCM cell at 0.5 C for 200 cycles. More importantly, detail analysis revealed that the size of the mpSi∥NCM cell can be smaller than that of the Gr∥NCM by more than 50%. The gain in specific energy density of the mpSi∥NCM cell over the Gr∥NCM was about 33%. Thus, the mpSi-Y/C can be promising anodes for stable and high-energy lithium-based batteries.

For the practical use of high-capacity silicon anodes in high-energy lithium-based batteries, key issues arising from the large volume change of silicon during cycling must be addressed by the facile structural design of silicon. Herein, we discuss the zeolite-templated magnesiothermic reduction synthesis of mesoporous silicon (mpSi) (mpSi-Y, -B, and -Z derived from commercial zeolite Y, Beta, and ZSM-5, respectively) microparticles having large pore volume (0.4–0.5 cm3/g), wide open pore size (19–31 nm), and small primary silicon particles (20–35 nm). With these appealing mpSi particle structural features, a series of mpSi/C composites exhibit outstanding performance including excellent cycling stabilities for 500 cycles, high specific and volumetric capacities (1100–1700 mAh g–1 and 640–1000 mAh cm–3 at 100 mA g–1), high Coulombic efficiencies (approximately 100%), and remarkable rate capabilities, whereas conventional silicon nanoparticles (SiNP)/C demonstrate limited cycle life. These enhanced electro...

Silicon-based composites are very promising anode materials for boosting the energy density of lithium-ion batteries (LIBs). These silicon-based anodes can also replace the dendrite forming lithium metal anodes in lithium metal-free Li–O2 and Li–S batteries, which can offer energy content far beyond that of current LIBs. However, it is challenging to design silicon-based materials for use as anodes in real energy storage devices. In this review, we discuss how to boost the energy content of LIBs, the pros and cons of silicon-based anodes, and challenges associated with silicon-based anodes. A major focus of this review is on the rational design of silicon-based composite anodes to address the outstanding issues. In addition, high energy LIBs and Li–S batteries that employ silicon-based anodes are introduced and discussed.

An in situ bimolecular reaction, in which syngas is fed with toluene as a secondary reactant (hereafter Tol in situ methylation), was studied over bifunctional catalysts comprised of methanol synthesis catalyst and H-ZSM-5 in a fixed-bed down-flow reactor at 460 psig. When physically mixed with H-ZSM-5 to form bifunctional catalysts, CrZ_HZ (Cr2O3/ZnO + HZSM-5) catalyst showed much higher activity than CZA_HZ (CuO/ZnO/Al2O3 + H-ZSM-5) in the Tol in situ methylation, while CrZ catalyst exhibited substantially lower activity than CZA in methanol synthesis. CO conversion to methanol in the Tol in situ methylation was estimated by Bz in situ methylation. The CO conversion to methanol was calculated to be in the range of 11–27 %, while that in methanol synthesis over CrZ was about 5 % at most due to chemical equilibrium limitation. By employing a silicalite-coated H-ZSM-5 (Sil/HZ) in bifunctional catalyst, xylene selectivity and para-xylene yield were much improved in the Tol in situ methylation.

FeF 3 microspheres/reduced graphene oxide (r-GO) composites were synthesized by a simple hydrothermal route with HF vapor. The size of the microspheres was controllable simply by adjusting the amount of graphene oxide in the precursor solution from about 1 to 10 wt%. The FeF 3 microspheres/r-GO composites showed improved discharge capacity and cycling stability in the voltage ranges of 1.5–4.5 V and 2.0–4.5 Vat room temperature compared to those of bulk FeF 3 . For example, the composites delivered an initial discharge capacity of about 196 mAhg −1 at a rate of 0.1C with 0.28% fading per cycle during 50 cycles in the range of 2.0–4.5 V. The composites also showed significantly enhanced rate capabilities in the range of 0.1–20C (e.g., about 170 mAhg −1 at a rate of 1C).

Iron trifluoride (FeF3 ) has been actively studied as an alternative cathode material due to its cost effectiveness, low toxicity, and high theoretical capacities of 237 and 712 mAhg −1 at 2.0−4.5 V and 1.5−4.5 V, respectively. In spite of these advantages, FeF3 has serious shortcomings of poor electronic conductivity and a slow diffusion rate of lithium ions, leading to a lower reversible specific capacity than its theoretical value. In this work, we prepared FeF3 /activated carbon foam (ACF) nanocomposites by impregnating FeF3 nanoparticles in the mesoporous ACF. The FeF3 /ACF nanocomposites showed improved electrochemical performances compared to bulk FeF3 . For example, the FeF3 /ACF nanocomposites showed an initial discharge capacity of 195 mAhg −1 at 0.1 C with a capacity retention of ~93% during 50 cycles in the voltage range 2.0−4.5 V. The cycling stability at 1.5−4.5 V was also superior to that of bulk FeF3 .

2-Ring aromatics such as naphthalene and alkyl-naphthalenes constitute a high fraction in the diesel boiling point range by-products from oil refining and petrochemical plants. A two-step catalytic process, consisting of a selective hydrogenation of naphthalenes to tetralins and a subsequent hydrocracking of tetralins into light alkyl-aromatic hydrocarbons rich in BTX (benzene, toluene, xylenes), was postulated and studied in a fixed bed down-flow reactor under a moderate pressure of 3–4 MPa. For the selective hydrogenation of naphthalenes to tetralins, it was found that the catalytic performances of Mo2C-supported catalysts were superior in terms of tetralins yield as well as selectivity to the conventional metal-supported catalysts such as Pt, Co, Ni and NiW supported catalysts. The hydrocracking of tetralin was demonstrated to produce light alkyl-aromatic hydrocarbons rich in BTX over a monofunctional H-Beta and a bifunctional Ni/H-Beta catalyst. For the high per pass yield of BTX in the hydrocracking of tetralin in which chemical equilibrium limits its conversion and product selectivity, the bifunctional Ni/H-Beta catalyst was found to be highly promising compared with the monofunctional H-Beta catalyst. The bifunctional Ni/H-Beta showed the BTX selectivity in liquid product and the total BTX yield as high as 69.5% and 40.7 wt%, respectively, at the tetralin conversion of 99.5% at 450 °C under 4 MPa. The catalytic behavior of Ni/H-Beta suggests that BTX yield can be much improved by properly controlling the hydrogenation power of metallic sites (i.e., suppressing the hydrogenation activity), the acidity of H-Beta and their balance on the bifunctional hydrocracking catalysts.

It is challenging to design silicon anodes exhibiting stable cycling behavior, high volumetric and specific capacity, and low volume expansion for Li-based batteries. Herein, we designed Si/C-IWGN composites (Si/C composites internally wired with graphene networks). For this purpose, we used simple aqueous sol–gel systems consisting of varying amounts of silicon nanoparticles, resorcinol–formaldehyde, and graphene oxide. We found that a small amount of graphene (1–10 wt%) in Si/C-IWGNs efficiently stabilized their cycling behavior. The enhanced cycling stability of Si/C-IWGNs could be ascribed to the following facts: (1) ideally dispersed graphene networks were formed in the composites, (2) these graphene networks also created enough void spaces for silicon to expand and contract with the electrode thickness increase comparable to that of graphite. Furthermore, properly designed Si/C-IWGNs exhibited a high volumetric capacity of ∼141% greater than that of commercial graphite. Finally, a hybrid sample, Si–Gr, consisting of a high capacity Si/C-IWGN and graphite was prepared to demonstrate a hybrid strategy for a reliable and cost-effective anode with a capacity level required for high-energy Li-ion cells. The Si–Gr hybrid exhibited not only high capacity (800–900 mA h g−1 at 100 mA g−1) but also a high electrode volumetric capacity of 161% greater than that of graphite.

Among various candidates to replace the low capacity graphitic carbon anode in current lithium ion batteries (LIBs), manganese oxides possess the advantages of high lithium storage capacity, low cost, high intrinsic density, environmental friendliness and low lithium storage voltage, i.e., 0.5 V Li+/Li. Manganese oxides, however, have to be incorporated with conducting and porous matrix due to poor electrical conductivity and large volume expansions associated with conversion reaction upon cycling. In this study, a facile one-pot route was attempted for the synthesis of MnO/C nanocomposite for which Mn3O4 nanoparticles were grown in aqueous medium followed by carbon gel formation in a one-pot reactor. Thus obtained Mn3O4/C carbon gel was transformed into MnO/C nanocomposite by thermal annealing in an Ar flow. The MnO nanoparticles (60wt%) of 20–50 nm in diameter were well dispersed throughout the MnO/C composite. The MnO/C composite delivered reversible capacity of 541mAh g−1 with an excellent cycling stability over 100 cycles, while parent Mn3O4 lost most of its capacity in 10 cycles. The MnO/C composite also exhibited much higher rate capability than a commercial graphite anode. Hence, the MnO/C composite based on low cost materials and facile synthetic process could be an attractive candidate for large-scale energy storage applications.

We developed a series of micro-sized porous coordination polymers from Mn ( III )-porphyrin biscarboxylate and In ( III ) whose morphologies were systematically modulated by the addition of adequate amount of water. Regardless of a wide range of morphology distribution, they are isostructural, confirmed by the identical PXRD patterns. Furthermore, their use as heterogeneous catalysts for the olefin oxidations has been successfully demonstrated. Specially, their catalyst stability, lifetime and re-usability were dramatically improved, suggesting that the incorporation of active catalyst into coordination polymer supports inhibited successfully the degradation of catalysts.

High capacity electrodes based on a Si composite anode and a layered composite oxide cathode, Ni-rich Li[Ni0.75Co0.1Mn0.15]O2, are evaluated and combined to fabricate a high energy lithium ion battery. The Si composite anode, Si/C-IWGS (internally wired with graphene sheets), is prepared by a scalable sol–gel process. The Si/C-IWGS anode delivers a high capacity of >800 mAh g−1 with an excellent cycling stability of up to 200 cycles, mainly due to the small amount of graphene (∼6 wt%). The cathode (Li[Ni0.75Co0.1Mn0.15]O2) is structurally optimized (Ni-rich core and a Ni-depleted shell with a continuous concentration gradient between the core and shell, i.e., a full concentration gradient, FCG, cathode) so as to deliver a high capacity (>200 mAh g−1) with excellent stability at high voltage (∼4.3 V). A novel lithium ion battery system based on the Si/C-IWGS anode and FCG cathode successfully demonstrates a high energy density (240 Wh kg−1 at least) as well as an unprecedented excellent cycling stability of up to 750 cycles between 2.7 and 4.2 V at 1C. As a result, the novel battery system is an attractive candidate for energy storage applications demanding a high energy density and long cycle life.

A high-capacity silicon-carbon core-shell (Si/C) supported by ball-milled graphite (BMG) was synthesized in situ using a hydrosilylation reaction and tested as an anode material for lithium ion batteries (LIBs) in the investigation of the effects of dual buffer layers of carbon shell and BMG. The Si/C/BMG sample effectively absorbed high volumetric expansion/contraction generated during charge/discharge process due to the assistance of dual elastic buffers of carbon shell and BMG. As a result, after 50 charge/discharge cycles, the Si/C/BMG electrodes still had a very high capacity of 1615 mAh/g, whereas raw Si, Si/C, and a mechanical mixture of Si/C and BMG were less than 500 mAh/g. The results of various electrochemical characterization techniques revealed that the dual buffer layers were favorable in decreasing electron and ion transfer resistance. It was also shown from ex situ TEM results that the carbon layers behaved as anti-amorphization layers decreasing the amorphization rate of crystalline Si during the alloying/dealloying of Li with Si.

MnO x /C nanocomposite, in which MnO x nanocrystals (64 wt%, mainly MnO with Mn 3 O 4 phase) 5–30 nm in size are formed in situ in the confined pores of a preformed mesoporous carbon, is prepared by a facile process. The morphology and structure of MnO x /C are characterized using N 2 adsorption/desorption measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). As an anode for Li-ion batteries (LIB), the MnO x /C delivers the theoretical capacity of MnO x (700–750 mAh g −1 at 100 mA g −1 ) with excellent rate capability. MnO x /C prelithiated is combined with a delithiated LiMn 2 O 4 (LMO) cathode for a complete Li-ion battery cell in a charged state with a cathode limiting capacity. The LMO-MnO x /C cell exhibits reversible capacity of the LMO cathode, with the cycling stability and rate capability dependent upon those of the MnO x /C anode. An LMO-MnO x /C cell with anode loading in slight excess delivers reversible capacity of LMO without capacity fading for up to 245 cycles, and exhibits an appreciable rate capability at 2 C. The LMO-MnO x /C configuration can be developed as a reliable LIB, potentially offering low cost, high rate capability, safety, and reliability.

Magnetite, Fe3O4, is a promising anode material for lithium ion batteries due to its high theoretical capacity (924 mA h g−1), high density, low cost and low toxicity. However, its application as high capacity anodes is still hampered by poor cycling performance. To stabilize the cycling performance of Fe3O4 nanoparticles, composites comprising Fe3O4 nanoparticles and graphene sheets (GS) were fabricated. The Fe3O4/GS composite disks of mm dimensions were prepared by electrostatic self-assembly between negatively charged graphene oxide (GO) sheets and positively charged Fe3O4-APTMS [Fe3O4 grafted with (3-aminopropyl)trimethoxysilane (APTMS)] in an acidic solution (pH = 2) followed by in situ chemical reduction. Thus prepared Fe3O4/GS composite showed an excellent rate capability as well as much enhanced cycling stability compared with Fe3O4 electrode. The superior electrochemical responses of Fe3O4/GS composite disks assure the advantages of: (1) electrostatic self-assembly between high storage-capacity materials with GO; and (2) incorporation of GS in the Fe3O4/GS composite for high capacity lithium-ion battery application.

The in situ methylation of toluene using syngas ( in situ methylation hereafter) was studied to produce xylenes over bifunctional catalysts comprising Cr 2 O 3 /ZnO (CrZ) and HZSM-5 (SiO 2 /Al 2 O 3 = 30) in a fixed-bed down-flow reactor at 460 psig. In this study, three basic aspects in the in situ methylation were investigated: (1) the catalytic activity of CrZ as the methanol synthesis catalyst with respect to the equilibrium conversion, (2) the evaluation of catalytic synergies in the in situ methylation over bifunctional catalyst, and (3) the effect of the ratio of catalytic functions regarding the ratio of methanol synthesis catalyst to HZSM-5, and their intimacy. The CrZ catalyst exhibited very low CO conversion to methanol in the methanol synthesis reaction, which is controlled by the equilibrium. However, the bifunctional mixture of CrZ and HZSM-5 catalysts exhibited significant catalytic synergies in the in situ methylation in terms of catalytic activity and product selectivities, with about a 10-times-higher CO conversion rate, and 2- to 3-times-higher toluene conversion and xylene production rates compared to the monofunctional catalysis of methanol synthesis and toluene disproportionation, respectively. The in situ methylation also gave rise to higher catalytic performance than in typical toluene methylation conducted with a molar feed ratio of methanol/toluene of 0.5. The catalytic synergy was manifested when both metallic and acidic functions were brought into close intimacy with a weight ratio of CrZ/HZSM-5 close to one in the in situ methylation.

FeF3 is of great interest as a potential candidate cathode material because of its low cost, abundance, environmental friendliness, and high theoretical capacity of about 237 mAh·g–1 in the voltage range of 2.0–4.5 V. However, FeF3 has drawbacks of poor cycling stability and rate performance because of its low intrinsic electrical conductivity and slow diffusion of lithium ions. These issues should be improved for the practical application of FeF3 in lithium-ion battery systems. In this study, FeF3/ordered mesoporous carbon (OMC) nanocomposites were synthesized by an incipient-wetness impregnation technique in a facile and scalable method. The tubular shaped OMC was utilized as both a conductive agent and a hard template for the formation of nanosized FeF3 particles. The FeF3/OMC nanocomposites showed enhanced capacity, cycling stability, and rate performance compared to bulk FeF3 in the voltage range of 2.0–4.5 V at room temperature.

Magnetite, Fe 3 O 4 , is a promising anode material for lithium ion batteries due to its high theoretical capacity (924 mA h g −1 ), high density, low cost and low toxicity. However, its application as high capacity anodes is still hampered by poor cycling performance. To stabilize the cycling performance of Fe 3 O 4 nanoparticles, composites comprising Fe 3 O 4 nanoparticles and graphene sheets (GS) were fabricated. The Fe 3 O 4 /GS composite disks of mm dimensions were prepared by electrostatic self-assembly between negatively charged graphene oxide (GO) sheets and positively charged Fe 3 O 4 -APTMS [Fe 3 O 4 grafted with (3-aminopropyl)trimethoxysilane (APTMS)] in an acidic solution (pH = 2) followed by in situ chemical reduction. Thus prepared Fe 3 O 4 /GS composite showed an excellent rate capability as well as much enhanced cycling stability compared with Fe 3 O 4 electrode. The superior electrochemical responses of Fe 3 O 4 /GS composite disks assure the advantages of: (1) electrostatic self-assembly between high storage-capacity materials with GO; and (2) incorporation of GS in the Fe 3 O 4 /GS composite for high capacity lithium-ion battery application.

Solvothermally reduced graphene oxide (STRG) that was synthesized using N-methyl-2-pyrrolidone (NMP) solvent was first employed as an conducting additive up to 15 wt% to commercial graphite anodic material. Due to numerous functional groups on the surface of the STRG, the reversible capacity decreased as the amount of STRG in the anode increased. To overcome this disadvantage, nanosized metal oxides such as CuO and Co 3 O 4 were supported on the STRG and a small amount of the composites was added to commercial graphite in order to enhance cyclic performance of the anode. A variety of characterization techniques showed that the composite additive significantly increased the reversible cyclic capacity by reducing the irreversible capacity of STRG and by providing more space for lithium ion intercalation.

Nano-sized SnO2 particles supported on ball-milled graphite were manufactured by the in situ NaBH4 reduction method and were used as an anode active material in lithium-ion batteries. Their physical and electrochemical characteristics were investigated using various characterization techniques: Raman spectroscopy, x-ray diffraction (XRD), transmission electron microscopy (TEM), and cyclic voltammetry (CV). From coin half-cell tests, the SnO2 particles supported on graphite that was ball-milled for 24 hr showed a reversible capacity better than that of commercial graphite and other SnO2/graphite materials for which the graphite was ball-milled for longer lengths of time.

Among lithium alloy metals, silicon is an attractive candidate to replace commercial graphite anode because silicon possesses about ten times higher theoretical energy density than graphite. However, electrically nonconducting silicon undergoes a large volume changes during lithiation/delithiation reactions, which causes fast loss of storage capacity upon cycling due to electrode pulverization. To alleviate these problems, electrodes comprising Si nanoparticles (20 nm) and graphene platelets, denoted as SiGP-1 (Si = 35.5 wt%) and SiGP-2 (Si = 57.6 wt%), have been prepared with low cost materials and using easily scalable solution-dispersion methods. X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) analyses indicated that Si nanoparticles were highly dispersed and encapsulated between graphene sheets that stacked into platelets in which portions of graphite phases were reconstituted. From the galvanostatic cycling test, SiGP-1 exhibited a reversible lithiation capacity of approximately 802 mAh/g with excellent capacity retention up to 30 cycles at 100 mA/g. Further cycling with a step-increase of current density (100-1,000 mA/g) up to 120 cycles revealed that it has an appreciable power capability as well, showing 520 mAh/g at 1,000 mA/g with capacity loss of 0.2-0.3% per cycle. The improved electrochemical performance is attributed to the robust electrical integrity provided by flexible graphene sheets that encapsulated dispersed Si nanopraticles and stacked into platelets with portions of reconstituted graphite phases in their structure.

Silicon nanoparticles have attracted a great deal of scientific interests due to its intense photoluminescence in the visible spectral region and its potential applications in biological fluorescence maker, RGB (red, green, blue) display, photonics and photovoltaics etc. Practical applications making use of optical and physicochemical properties of Si nanoparticles requires an efficient synthetic method which allows easy modulation of their size, size distribution as well as surface functionalities etc. In this study, a one-pot solution reduction scheme is attempted to prepare alkyl-terminated Si nanoparticles ( or mixture of (Octyl) and , containing alkyl-groups using Na(naphthalide) as reducing agent. The surface capping of Si nanoparticles with octyl-groups as well as Si nanoparticle formation was achieved in one-pot reaction. The hexane soluble Si nanoparticles with octyl-termination were in the range of 2-10 nm by TEM and some oxide groups (Si-O-Si) was present on the surface by EDS/FTIR analyses. The optical properties of Si nanoparticles measured by UV-vis and PL evidenced that photoluminescent Si nanoparticles with alkyl-termination was successfully synthesized by solution reduction of alkyl-containing Si precursors in one-pot reaction.

Spinel lithium manganese oxide was synthesized via co-precipitation. The prepared lithium manganese oxide powder was further heated at 700 ◦ C for 15 h under pressurized (3 bar) oxygen atmosphere. The resultant exhibited a highly crystalline cubic spinel phase with space group Fd3m, as confirmed by X-ray diffraction. The spinel compound exhibited a slightly smaller lattice constant than a conventional spinel compound, even though the cationic ratio of Li/Mn is the same for both compounds. Chemical titration of the Mn component showed that heat treatment under a 3 bar oxygen atmosphere resulted in slightly higher average Mn oxidation state, indicating that the amount of Mn4+ increased after the treatment. The Li1.05Mn1.95O3.99 electrode exhibited improved cycling performance, namely, 96.3% of capacity retention during 100 cycles at elevated temperature (60 ◦ C). The details of the structure and electrochemistry of the electrode are discussed.

Lithographic techniques were used to develop patterned silicone rubber membranes that provide 15 microm high microchannels for artificial lungs. Two types of devices were fabricated as a proof-of-concept: one has a series of parallel, straight, open rectangular channels that are each 300 microm wide, separated by 200-microm walls, and 3-mm long and the other is a wide rectangular channel with support posts, also 3- mm long. Experiments with 30% hematocrit, venous, bovine blood showed average oxygen fluxes ranging from 11 x 10(-7) moles/(min x cm(2)) at a residence time of 0.04 sec to 6.5 x 10(-7) moles/(min x cm(2)) at a residence time of 0.20 sec. The average oxygen flux vs. residence time, which is due to transverse molecular diffusion, follows the same relation for all membranes tested. The corresponding increase in hemoglobin saturation ranged from 9% at the residence time of 0.04 sec to 24% at the residence time of 0.20 sec. The support-post channel membranes are attractive for designers because they can be arbitrarily wide and would be less prone to blockage.

Recently Li-ion battery has been used extensively as a portable power source for small electronic devices, a power source for electric vehicles and an attractive option for energy storage. Artificial graphite, natural graphite, hard carbon, such as carbon-based materials as anode active material have been applied, According to the requirements of high capacity, high theoretical capacity such Si (ca. 4200mAh/g) which is 5 times higher than carbon-based mateirlas has been actively studied in recent years. There are several problems to overcome despite the advantages of the theoretical capacity values of the Si. First low electrical conductivity, second due to the significant change in volume of the active material of the Si particle during Li insertion/extraction, it causes pulverization of the active material particels. In order to overcome these problems, the mixture of high carbon Si/carbon composite was synthesized, but showed a limitation in the number of times the cycle test because of the lack of sufficient change in volume of the internal volume of Si. Our study was performed to study the synthesis of a nanoparticle dual carbon-coated Si porous-C composite using glucose and PVDF to form an inner space. Also, GO was added to improve the cyclability. Characterization of Si porous-C was explored by Scaning transmission electron microscopy (STEM), X-ray photoelectron scpectroscopy (XPS) and the electrochemical performace was carried out as shown in figure. Two different current density (100, 500mA/g) was applied. 100mA/g was applied upto 5th cycles and the rest of cycels was obtained at 500mA/g. Figure 1

With an ever-expanding application of energy storage systems, lithium-ion batteries (LIBs) have attracted a significant scientific and industrial attention during last decades. However, the current LIBs based on lithium metal oxides or phosphate cathodes and graphitic carbon anodes have intrinsic limitation in energy density. To further improve the specific and volumetric energy densities of current LIBs, graphite anode has to be replaced with a high capacity alternative. Thus, silicon has received a great attention due to its high theoretical capacity (3572 mAh/g at RT as a form of Li15Si4) [1] and relatively low working potential. However, the huge volume expansion (~300%) of silicon associated with lithiation and delithiation during cycling leads to electrode pulverization causing the common rapid capacity fading. Another issue associated with silicon is its low electrical conductivity. Therefore, composites of silicon with conducting carbons could be a practical solution. Among many classes of carbon, graphene has been identified as an attractive supporting material that may address the critical issues associated with Si anodes [2, 3]. For practical application of silicon-graphene assemblies in LIB anodes, it is desirable to form a dense particulate assembly which can give high volumetric capacity and be readily adaptable in industrial coating process [4, 5]. In this study, we employed an electrostatic self-assembly process between amine-functionalized SiNPs (Si-APTMS) and graphene oxide (GO) in an acidic aqueous solution (pH=2) followed by carbon coating process to form dense particulate Si/GS/C assemblies. For carbon coating, two different carbon sources such as poly-vinylidenefluoride (PVdF) or sucrose were employed to prepare the Si/GS/C-P and Si/GS/C-S samples, respectively. For comparison, a Si/GS was prepared by a direct carbonization of Si/GO assembly. The characteristic features of the Si/GS and Si/GS/C samples were assessed with elemental analysis (EA), FT-IR, TGA, SEM, TEM, XRD and XPS etc. The electrochemical responses of samples were obtained with galvanostatic cycling test, and cyclic voltammetry and impedance tests using CR-2032 coin-type cells with a Li-foil as the reference electrode. The TEM image in Fig. 1a shows that SiNPs are all attached on GO surface in the Si/GO assembly. Different from the Si/GS, the Si/GS/C-S formed dense particulate composites (Fig. 1b and c), in which SiNPs are well distributed between graphene sheets and the whole structure become dense with additional carbon coating. As compared in Fig. 1d, the Si/GS (80% Si) showed very poor cycling stability at 500 mA g-1. On the other hand, the Si/GS/C-P (60% Si) and Si/GS/C-S (50% Si) showed much enhanced cycling stability at 500 mA g-1. In particular, the Si/GS/C-S prepared by an in-situ carbon-gel coating in solution of Si/GO assembly delivered reversible capacities over 1300 mAh g-1 at 100 mA g-1 and over 900 mAh g-1 at 500 mA g-1 without capacity fading. The excellent cycling performance of the Si/GS/C-S can be attributed to its structural features. First, the volume variations of SiNPs are effectively damped by flexible and highly conducting graphene sheets encapsulating them. Second, additional carbon coating surrounding the Si/GS assemblies enhances the coherence between SiNPs and graphene in comparison to the Si/GS obtained by direct carbonization of Si/GO assembly without carbon coating. [1] M. N. Obrovac, L. Christensen, Electrochem Solid State Lett. 7, A93 (2004). [2] J. K. Lee, K. B. Smith, C. M. Hayner, and H. H. Kung, Chem. Commu., 46 ,2025-2027 (2010). [3] R. Raccichini, A. Varzi, S. Passerini, and B. Scrosati, Nat. Mater., 14, 271-279 (2015). [4] C. Chae, H.-J. Noh, J. K. Lee, B. Scrosati, and Y.-K. Sun, Adv. Funct. Mater,, 24, 3036-3042 (2014). [5] J. Kim, C. Oh, C. Chae, D.-H. Yeom, J. Choi, N. Kim, E.-S. Oh, and J. K. Lee, J. Mater. Chem. A., 3,18684-18695 (2015). Fig.1. TEM image of (a) Si/GO assembly and (b) Si/GS/C-S, (c) SEM image of dense particulate form of Si/GS/C-S, and d) cycling performances of Si/GS, Si/GS/C-P and Si/GS/C-S (Inset shows TGA profiles of samples). Figure 1

Silicon is very promising anode materials not only for boosting the energy density of lithium-ion batteries (LIBs) but for replacing the dendrite forming lithium metal anodes in lithium metal free Li-O2and Li-S batteries [1-3]. However, it is challenging to design silicon-based anodes exhibiting stable cycling behavior, high volumetric and specific capacity, and low volume expansion. In this study, we proposed that a sol–gel process can serve as a facile platform for composite materials of high lithium storage capacity. These composite materials consist of silicon nanoparticles (SiNPs) coated with carbon, a small graphene network interconnecting these nanoparticles to form condensed micro-sized particles, and a large fraction of void spaces between nanoparticles and graphene networks in these composites. Since, Si/C composites are internally wired with graphene networks, they are denoted as Si/C-IWGNs hereafter. The Si/C-IWGN samples were simply prepared by carbonizing the composite gels formed in aqueous mixtures consisting of SiNPs and resorcinol (R)–formaldehyde (F) as the carbon precursor and a small amount of graphene oxide (GO) in one-pot reactions. Various Si/C-IWGN samples were prepared with different contents of SiNPs (40 or 50 wt%) and graphene (1, 5 and 10 wt%). Two types of gelation catalysts (C), Na2CO3 or NH4OH, with different concentrations (R/C ratio = 100–500 in molar) were used for forming composite gels. Various electrochemical responses of Si/C-IWGNs, such as cycling stability, volumetric as well as specific capacity, coulombic efficiency, and electrode thickness increase, are thoroughly compared with those of the following reference samples: (1) control composites, Si/C composites, which were prepared without GO addition in the gel formation process and (2) commercial graphite. Finally, we have demonstrated a hybrid strategy to develop a reliable and low cost anode material consisting of mixtures of high capacity Si/CIWGNs and commercial graphite. The characterization and electrochemical responses of this novel composite suggest that graphene networks in Si/C-IWGNs not only provide electrical networks but also generate void spaces (Fig. 1a~c), which are very effective in absorbing large volume expansions of Si to the level comparable to that of commercial graphite (Fig. 1d, inset). Thereby, graphene networks effectively tackled the issue of common electrode pulverization and ensured the cycling stability of Si-based anodes (Fig. 1d) [4]. Compared to commercial graphite, a properly designed Si/C-IWGN composite material exhibited about 420% increase in specific capacity and about 141% increase in volumetric capacity, which was determined on the basis of electrode weight or volume. We devised a reliable and cost-effective hybrid anode using a mixture of Si/C-IWGN and commercial graphite. Si–Gr is a hybrid that offers the capacity level (800–1000 mAh g-1) required to improve the energy density of current LIB cells. Moreover, the volumetric capacity of the Si–Gr electrode is 161% higher than that obtained from commercial graphite [4]. The Si–Gr hybrid also has excellent cycling stability. We conclude that the preparation of Si/C-IWGNs is a scalable process. Moreover, owing to the remarkable electrochemical responses of Si/C-IWGNs, it could be used in manufacturing energy storage devices of high energy density and long cycle life. [1] N.Liu, Z. Lu, J. Zhao, M.T. McDowell, H.-W. Lee, W. Zhao, and Yi Cui, Nat. Nanotechnol., 9, 187-192 (2014). [2] C. Chae, H.-J. Noh, J. K. Lee, B. Scrosati, and Y.-K. Sun, Adv. Funct. Mater,, 24, 3036-3042 (2014). [3] S.-K. Lee, S.-M. Oh, E. Park, B. Scrosati, J. Hassoun, M.-S. Park, Y.- J. Kim, H. Kim, I. Belharouak, and Y.-K. Sun, Nano Lett., 15, 2863-2868 (2015). [4] J. Kim, C. Oh, C. Chae, D.-H. Yeom, J. Choi, N. Kim, E.-S. Oh, and J. K. Lee, J. Mater. Chem. A., 3,18684-18695 (2015). Figure 1. (a) SEM image, (b) TEM image, (c) SEM image of particle cross-section and (d) cycling stability of Si/C and Si/C-IWGNs (Inset shows electrode thickness changes). Figure 1

A Silicon/Porous-Carbon (Si/Porous-C) composite with Ag nanoparticles was prepared by the co-assembly of polyvinylidene fluoride (PVdF), nano-SiO2 (~20 nm), AgNO3 and Si nanoparticles (~ 50 nm) followed by a carbonizing process and subsequent removal of SiO2 template. The Si/Porous-C and Ag/Si/Porous-C composite were characterized by scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD). Ag nanoparticles remained even after heat treatment at high temperature and hydrofluoric acid etching. The Ag/Si/Porous-C composite electrode exhibited good electrochemical performances with a reversible capacity of 1,470 mAh/g as an anode material in lithium-ion cells, showing a stable capacity of 1,150 mAh/g after 100 cycles at a rate of 500 mA/g per hour. Cycling performances of the Si/Porous-C and Ag/Si/Porous-C composite electrodes were determined at various rates as shown in figure. The Ag/Si/Porous-C composite electrode showed better rate capability and recovery as the rates decreased, while the capacity of the Si/Porous-C composite electrode faded drastically as the rates increased. Figure 1

Energy storage devices with high energy density and low cost are highly demanding since the existing state-of-the-art Li-ion battery systems have intrinsic limitations in energy and price. Thus, lithium-sulfur (Li-S) batteries have attracted a great attention because sulfur is abundant and it has high theoretical capacity (1672 mAh g-1) and energy density (2600 Wh kg-1) when coupled with metallic lithium anode [1]. However, it is still challenging to device Li-S batteries offering a long-term cycling stability at a high level of sulfur loading due to the dissolution of polysulfides (Li2Sx, 4

Nano-sized Cu-Sn and Cu oxide particles supported on ball-milled graphite were synthesized, and their electrochemical characteristics for use as anode active materials in lithium-ion batteries were investigated. The samples were also characterized via FE-SEM, XRD, and TGA. Most of the Cu oxides on BMG were monoclinic CuO crystals, whereas the Cu-Sn particles were composed of hexagonal Cu3Sn and tetragonal SnO2 crystals. These particles may contribute to an increase in the reversible capacity of lithium ion batteries.

The feasibility of developing micro channel artificial lungs is calculated for eight possible strategies: 12 and 25 microm circular channels imbedded in gas-permeable sheets, 12 and 25 microm high open rectangular channels with gas-permeable walls, 12 and 25 microm high broad open channels with support posts and gas-permeable walls, and two 40 microm high screen-filled rectangular channels with gas-permeable walls. Each strategy is considered by imposing a pressure drop maximum of 10 mm Hg and limiting the possibility of shear-induced blood trauma. The pressure drop limit determines the acceptable channel length and required size to oxygenate 4 L/min of venous blood. Circular channels imbedded in open-pore, gas-permeable materials are especially attractive. With 12 microm channels, such a device would require 140 million, 0.8 mm long channels, but the total size of the gas-exchange section would be only 57 ml and a blood prime of only 13 ml. Also attractive are 12 mum high broad open channels with support posts and 40 mum screen-filled rectangular channels. The total size of the former would be 250 ml with a blood prime of 13 ml, and the total size of the latter would be 270 ml with a blood prime of 27 ml.