In Situ Pre-Metallization Cleaning of CoSi Contact-Hole Patterns with Optimized Etching Process.

We examined how controlling variables in a pre-metallization Ar sputter-etching process for in situ contact-hole cleaning affects the contact-hole profile, etching rate, and substrate damage. By adjusting process parameters, we confirmed that increasing plasma power lowered the DC bias but enhanced the etching rate of SiO, while increasing RF power raised both, with RF power having a more pronounced effect. Higher Ar flow rate reduced etching uniformity and slightly lowered the DC bias.

Electrochemical Circuit Model Based State of Health Prognostics for Evaluation of Reusability of Lithium-Ion Batteries from Electric Vehicle.

For the purpose of predicting the state of health of already used lithium-ion batteries from 85 kWh electric vehicles, a simplified equivalent circuit model is utilized to estimate the electrochemical time constant from constant current discharge profiles. The grading process among as-obtained LIB cells is classified into three level types according to the remaining capacity and direct current resistance. Theoretically, the logarithmic equation describing cycling behavior is derived and utilized in the prediction of the state of health of the used cells.

Thermal Decomposition Study on LiO for LiNiO Synthesis as a Sacrificing Positive Additive of Lithium-Ion Batteries.

Herein, thermal decomposition experiments of lithium peroxide (LiO) were performed to prepare a precursor (LiO) for sacrificing cathode material, LiNiO. The LiO was prepared by a hydrometallurgical reaction between LiOH·HO and HO. The overall reaction during annealing was found to involve the following three steps: (1) dehydration of LiOH·HO, (2) decomposition of LiO, and (3) pyrolysis of the remaining anhydrous LiOH.

Analog Memristive Characteristics of Mesoporous Silica-Titania Nanocomposite Device Concurrent with Selection Diode Property.

A threshold resistive switching (RS) device concurrently demonstrating analog memristive property with mesoporous silica-titania (m-ST) nanocomposites is introduced in this study. The nanostructured m-ST layer in an Al/m-ST/Pt device was constructed by facile soft templating of evaporation-induced self-assembly (EISA) method to demonstrate nonlinear threshold RS behaviors accompanying with discrete synaptic characteristics along with adaptive motions. The EISA layer was composed of well-ordered mesopores (∼10 nm), where paths of electrical currents could be controllably guided and sequentially activated by repeated voltage sweeps.

Investigation of the Supercapacitor Performance of NiCoAl(OH)₂ from the Co-Precipitation Method.

Herein, NiCoAl(OH)₂ materials, a by-product in the preparation of the precursor of cathode materials for lithium ion batteries, were employed as supercapacitor electrodes. The reaction time was changed from 2 to 48 h to produce hydroxide products, which were analyzed using physical and electrochemical methods. The hydroxide material reacted for 2 h exhibited a good average particle strength of 34.

Fabrication of β-CoVO nanorods embedded in graphene sheets and their application for electrochemical charge storage electrode.

The fabrication of β-CoVO nanorods embedded in graphene sheets and their application as electrochemical charge storage electrodes is reported. From the surfactant treatment of raw graphite, graphene was directly prepared and its nanocomposite with β-CoVO nanorods distributed between graphene layers (β-CoVO-G) was synthesized by a hydrothermal method. When applied as an anode in lithium-ion batteries, the β-CoVO-G anode exhibits greatly improved charge and discharge capacities of 790 and 627 mAh · g, respectively, with unexpectedly high initial efficiency of 82%.

Direct Synthesis of Carbon Sheathed Tungsten Oxide Nanoparticles via Self-Assembly Route for High Performance Electrochemical Charge Storage Electrode.

Using a stabilizing agent-assisted co-assembly method, a novel nanocomposite of mesoporous carbon embedded with uniform tungsten oxide nanorods is obtained, which is converted into carbon-sheathed tungsten oxide nanoparticles by delicate calcination and further reduction. Through optimization of tungsten content, it is found that highly crystalline tungsten oxide nanoparticles are uniformly coated with an ultra-thin carbon layer. When applied into electrochemical charge-storage electrodes for supercapacitor and lithium-ion battery, an excellent average capacitance (129 F g−1, above 400 F cm−3), higher rate performance and significantly advanced cycle stability are observed.

Facile Synthesis of Nb2O5@Carbon Core-Shell Nanocrystals with Controlled Crystalline Structure for High-Power Anodes in Hybrid Supercapacitors.

Hybrid supercapacitors (battery-supercapacitor hybrid devices, HSCs) deliver high energy within seconds (excellent rate capability) with stable cyclability. One of the key limitations in developing high-performance HSCs is imbalance in power capability between the sluggish Faradaic lithium-intercalation anode and rapid non-Faradaic capacitive cathode. To solve this problem, we synthesize Nb2O5@carbon core-shell nanocyrstals (Nb2O5@C NCs) as high-power anode materials with controlled crystalline phases (orthorhombic (T) and pseudohexagonal (TT)) via a facile one-pot synthesis method based on a water-in-oil microemulsion system.

Reverse micelle synthesis of colloidal nickel-manganese layered double hydroxide nanosheets and their pseudocapacitive properties.

Colloidal nanosheets of nickel-manganese layered double hydroxides (LDHs) have been synthesized in high yields through a facile reverse micelle method with xylene as an oil phase and oleylamine as a surfactant. Electron microscopy studies of the product revealed the formation of colloidal nanoplatelets with sizes of 50-150 nm, and X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy studies showed that the Ni-Mn LDH nanosheets had a hydrotalcite-like structure with a formula of [Ni3 Mn(OH)8 ](Cl(-) )⋅n H2 O. We found that the presence of both Ni and Mn precursors was required for the growth of Ni-Mn LDH nanosheets.

Advanced hybrid supercapacitor based on a mesoporous niobium pentoxide/carbon as high-performance anode.

Recently, hybrid supercapacitors (HSCs), which combine the use of battery and supercapacitor, have been extensively studied in order to satisfy increasing demands for large energy density and high power capability in energy-storage devices. For this purpose, the requirement for anode materials that provide enhanced charge storage sites (high capacity) and accommodate fast charge transport (high rate capability) has increased. Herein, therefore, a preparation of nanocomposite as anode material is presented and an advanced HSC using it is thoroughly analyzed.

Simple fabrication of flexible electrodes with high metal-oxide content: electrospun reduced tungsten oxide/carbon nanofibers for lithium ion battery applications.

A one-step and mass-production synthetic route for a flexible reduced tungsten oxide-carbon composite nanofiber (WO(x)-C-NF) film is demonstrated via an electrospinning technique. The WO(x)-C-NF film exhibits unprecedented high content of metal-oxides (∼ 80 wt%) and good flexibility (the tensile strength of the specimen was 6.13 MPa) without the use of flexible support materials like CNTs or graphene.

Crystallinity-controlled titanium oxide-carbon nanocomposites with enhanced lithium storage performance.

Nanocomposites of crystalline-controlled TiO(2) -carbon are prepared by a novel one-step approach and applied in anodes of lithium ion batteries. In our nanocomposite anodes, the Li(+) capacity contribution from the TiO(2) phase was enormous, above 400 mAh g(-1) (Li(1+x) TiO(2) , x>0.2), and the volumetric capacity was as high as 877 mAh cm(-3) with full voltage utilization to 0 V versus Li/Li(+) , which resulted in higher energy density than that of state-of-the-art titania anodes.

Nano-graphite functionalized mesocellular carbon foam with enhanced intra-penetrating electrical percolation networks for high performance electrochemical energy storage electrode materials.

Mesocellular carbon foam (MSU-F-C) is functionalized with hollow nanographite by a simple solution-phase method to enhance the intrapenetrating electrical percolation network. The electrical conductivity of the resulting material, denoted as MSU-F-C-G, is increased by a factor of 20.5 compared with the pristine MSU-F-C.

Development of a high-performance anode for lithium ion batteries using novel ordered mesoporous tungsten oxide materials with high electrical conductivity.

An ordered mesoporous WO(3-X) with high electrical conductivity (m-WO(3-X)) was prepared and evaluated as an anode material for lithium ion batteries (LIBs). Ordered mesoporous tungsten trioxide (m-WO(3)) with an identical pore structure to that of m-WO(3-X) and bulk WO(3-X) (b-WO(3-X)) was prepared for the comparison purpose. An m-WO(3-X) electrode exhibited a high reversible capacity (748 mAh g(-1), 6.

A novel mesoporous carbon-silica-titania nanocomposite as a high performance anode material in lithium ion batteries.

An ordered mesoporous carbon-silica-titania material was prepared using the tetra-constituents co-assembly method. As regards its anode performance in lithium ion batteries, the composite material anode exhibited a high capacity (875 mAh g(-1)), a higher initial efficiency (56%) and an improved rate.

Development of high-performance supercapacitor electrodes using novel ordered mesoporous tungsten oxide materials with high electrical conductivity.

An ordered mesoporous WO(3-x) material was employed for use as a supercapacitor electrode. This material exhibited a high rate capability and an excellent capacitance (366 μF cm(-2), 639 F cm(-3)), which were probably attributed to the large ordered mesopores, high electrical conductivity, and high material density.