Many intermetallic materials deliver poor capacity retention when cycled vs. Li. authors have attributed this to large volume expansions of the active material. Here we report changes continuous and patterned films crystalline Al, Sn, amorphous Si (a-Si), as they reversibly react with Li measured by in situ atomic force microscopy (AFM). Although these all undergo expansions, phases reversible shape changes. The do not. We attribute difference homogeneous expansion contraction that occurs...

Li-ion cells have been investigated by many groups and their behavior in standard electrolytes such as 1 M ethylene carbonate: diethyl carbonate (EC:DEC) is well known. Here we report on the of these with 2,5-ditertbutyl-1,4-dimethoxybenzene added to electrolyte a redox shuttle additive prevent overcharge overdischarge. We explore methods increase current-carrying capacity heating practical during extended overcharge. The solubility was determined function salt concentration lithium...

Graphite has been used as the negative electrode in lithium-ion batteries for more than a decade. To attain higher energy density batteries, silicon and tin, which can alloy reversibly with lithium, have considered replacement graphite. However, volume expansion of these metal elements upon lithiation result poor capacity retention. Alloying active element an inactive material limit overall improve cycle life. This paper presents summary tin-based materials electrodes. After reviewing...

A multitarget sputtering machine with a water-cooled rotating substrate table has been modified to produce films on 75 mm × wafers which map large portions of ternary phase diagrams. The system is unconventional because the stoichiometries elements sputtered wafer vary linearly position and in an orthogonal manner. Subsequent screening film properties therefore quite intuitive, since compositional variations are simple. Depositions made under continuous rotation, so either intimate mixing...

Thin film libraries of sputtered have been investigated for use as negative electrode materials in Li-ion rechargeable batteries. Results from over 200 compositions are reported here. The observed capacity decreases transition metal content increases, approaching zero around 50 atom % Si, and can be approximated assuming active Si an inactive SiM Fe, Mn or Ni) matrix. Plots differential vs. potential characteristic a-Si inert matrix, agreement with X-ray diffraction results. behavior Si-Mn...

We present an investigation into the influence of nanocrystal size on reactivity silicon nanocrystals (Si-NCs) in near-UV photochemical hydrosilylation. The size-dependent Si-NCs with photoluminescence (PL) visible and near-infrared regions was evaluated using PL Fourier-transform infrared (FTIR) spectroscopy, small-angle X-ray scattering (SAXS). Under excitation, spectral region react faster than near-IR PL, allowing partial separation a mixture Si-NC sizes through This is attributed to...

Abstract A cationic and water‐soluble polythiophene [poly[3‐(6‐pyridiniumylhexyl)thiophene bromide] (P3PHT + Br − )] is synthesized used in combination with anionic poly(3,4‐ethylenedioxythiophene):poly( p ‐styrenesulfonate) (PEDOT:PSS) to produce hybrid coatings on indium tin oxide (ITO). Two coating strategies are established: i) electrostatic layer‐by‐layer assembly colloidal suspensions of , ii) modification an electrochemically prepared film ITO. The found modify the work function ITO...

Design, testing, and performance of a 64-channel combinatorial electrochemical cell are described. This is used for high-throughput screening materials use as Li-ion rechargeable battery electrodes. Our sealed has 64 separate positive electrodes Li foil the reference counter was designed to complement our existing science infrastructure. Using decreases time labor associated with test assembly, improves repeatability assembly procedure, increases number compositions we can in given amount...

Amorphous alloys of Si and Sn exhibit large specific volumetric capacities when cycled electrochemically vs. lithium. To improve the electrochemical performance these materials, we explore here effect Al additions to alloys. Combinatorial films were prepared by magnetron sputtering then analyzed for structure, composition, performance. If film is amorphous, voltage-capacity behavior cell smooth differential capacity potential shows no sharp peaks, indicating homogeneous insertion contains...

Controlled-porosity Si thin films suitable for use as high-aspect-ratio microbattery electrodes were produced using the glancing angle deposition (GLAD) technique. GLAD is a high-vacuum physical vapor method that can be used to produce variety of film morphologies from most vacuum-compatible materials. No lithographic steps required create porous, columnar films. Initial electrochemical results indicate large gravimetric and areal capacities (, , respectively), good capacity retention (...

This work explores the applicability of atomic layer deposition (ALD) in producing highly oriented crystalline gallium oxide films on foreign substrates at low thermal budgets. The effects substrate, temperature, and annealing process formation are discussed. Ga2O3 exhibited a strong preferred orientation c-plane sapphire substrate. onset is determined, which only two sets planes, i.e., α-Ga2O3 (006) β-Ga2O3 (4̅02), present parallel to surface. More specifically, this reports, for first...

We describe a simple multichannel pseudopotentiostat based on appropriately chosen resistors, programmable voltage source, and scanning multimeter. Our first can perform cyclic voltammetry 64 channels of combinatorial electrochemical cell that has working electrodes common counter reference electrodes. The performance the 100 channel Scribner model 900B microelectrode analyzer (MMA) are compared same cell. find for experiments arrays lithium-insertion electrodes, provides equivalent...

Combinatorial sputtering methods were used to produce thin films of amorphous Si-Al-Mn whose composition varied in a linear and orthogonal manner. Electrochemical investigations performed on over 200 compositions with either standard coin-type test cell hardware or 64-channel combinatorial electrochemical described previously. was determined be the optimum within range that can melt-spun amorphously. Li-ion rechargeable battery negative electrodes based this could lead commercial cells 40%...

Thin-film libraries were characterized for structure, composition, and electrochemical performance using combinatorial high-throughput techniques. The of a given composition cannot be treated as simple combination separate reactions Li with Al Si because ternary Al–Li–Si phases are present some compositions have significant influence on observed capacities capacity retention. or appear to very promising Li-ion negative electrode applications.

Electrostatic layer-by-layer assembly was the basis for synthesis of multilayer nanorod/polymer composite films. Cationic and water-soluble CdSe nanorods (NRs) were synthesized partnered with anionic polymers including poly(sodium 4-styrenesulfonate) (PSS) two polythiophene-based photoactive polymers, sodium poly[2-(3-thienyl)-ethoxy-4-butylsulfonate (PTEBS) poly[3-(potassium-6-hexanoate)thiophene-2,5-diyl] (P3KHT). Controlled growth is shown through UV−vis spectroscopy, cross-sectional SEM...

Sulfide- and halide-based ceramic ionic conductors exhibit comparable conductivity with liquid electrolytes are candidates for high-energy- high-power-density all-solid-state batteries. These materials, however, inherently brittle, making them unfavorable applications. Here, we report a mechanically enhanced composite Na+ conductor that contains 92.5 wt % of sodium thioantimonate (Na3SbS4, NSS) 7.5 carboxymethyl cellulose (CMC); the latter serves as binder an electrochemically inert...

We report on the optimization of nanostructured copper phthalocyanine (CuPc) thin films for idealized organic photovoltaic (OPV) architectures using advanced substrate motion and periodic seeding. Oblique angle deposition (OAD), a subset glancing (GLAD), has recently been used to enhance small molecule OPV device photoconversion efficiency by increasing surface area metal (MPc) films. Here we detailed study how direct MPc film growth towards ideal donor morphology techniques available GLAD....

Aluminum electrodes have been considered for use in lithium and ion batteries nearly four decades. Although the Al-Li equilibrium phase diagram contains multiple phases, only β-AlLi forms during room temperature cycling. Al2Li3 can be formed when electrochemically inserting Li at temperatures above 400°C, Al4Li9 is occasionally detected after extended Here, phases of (β-AlLi, Al2Li3, AlLi2−x, Al4Li9) were produced by electrochemical lithiation delithiation 1100-series aluminum foil moderate...

Future advances in Li-ion rechargeable battery performance are strongly linked to improved electrode materials. Candidate materials for the negative of future generally contain multiple elements and broad composition ranges. There surprisingly few published accounts combinatorial investigations This paper describes infrastructure Dahn group at Dalhousie University as it relates other search advanced Sample data sets provided various material systems. Special attention is paid start-up...

Comprehensive investigations of thin-film Al-M negative electrode material libraries were performed using combinatorial and high-throughput techniques. Mössbauer effect spectroscopy X-ray diffraction used to characterize library structure. The electrochemical performance over 200 compositions was determined at both room elevated temperature. All alloys are completely inactive above 15 atom % M. Thermodynamic calculations based on the macroscopic model de Boer et al. predict with least 33–65...

Thin-film libraries of (M=Cr, Fe, Mn, Ni) negative electrode materials were characterized using combinatorial and high-throughput techniques. Transition metal content had a large effect on capacity, such that alloys with more than ca. did not alloy Li during room temperature or charge-discharge cycling. The contour line was used to separate those compositions readily alloyed from not. This also approximately connects the lowest equilibrium crystalline phases. We propose all phases are...

The generation and characterization of a robust thienylsilane molecular layer on indium tin oxide substrates was investigated. found to reduce the oxidation potential required for electrochemical polymerization 3,4-ethylenedioxythiophene. resulting electrochemically prepared poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate) (ePEDOT:PSS) films were be more uniform in coverage with lower roughness higher conductivity than analogous fabricated bare ITO. A relative improvement efficiency...