Strong interest in energy generation and storage has yielded excellent progress on organic based solar cells, and there is also a strong desire for equivalent advancement in polymer-based charge storage devices such as batteries and super-capacitors. Despite extensive research on electronically conducting polymers including polypyrrole, polythiophene, and polyaniline, limitations to the maximum doping density and chemical stability had been considered a significant restriction on the development of polymer batteries. Recent work appears to show a meaningful increase in the upper bound of the maximum density from 0.5 to 1.0 electrons per monomer depending on the structure, processing, and ionic species used in charging and discharging of the polymers. Several recent examples have also implied that more stable, reversible charge-discharge cycling is being observed in n-doped polymers. These observations suggest that the performance metrics of this class of electronically conducting polymer may ultimately reach the levels required for practical battery applications. Further efforts are essential to perfect practical large-scale electrode fabrication to move toward greater compatibility in the methods used for solar cells and those used in producing batteries. A better understanding must also be developed to elucidate the effects of molecular structure and polymer architecture on these materials.

Mechanical alloying of Ti45Zr38–xNi17+x and Ti45–xZr38Ni17+x (0 ≤ x ≤ 8) elemental powders produced an amorphous phase, but subsequent annealing converted the amorphous phase into an icosahedral quasicrystal phase, along with a Ti2Ni-type phase. The discharge capacities, measured in a three-electrode cell at room temperature for both the amorphous and quasicrystal electrodes, increased with increasing Ni substitution for Zr or Ti. The highest discharge capacities, which were about 60 mAh/g for the amorphous electrode and 100 mAh/g for the quasicrystal electrode, were obtained from (Ti45Zr30Ni25) after substitution of Ni for Zr. For the Ti45Zr30Ni25 composition, the discharge performance of the quasicrystal electrode was stable over charge/discharge cycling, but that of the amorphous electrode gradually decreased with cycling. The structure of the quasicrystal phase in the electrodes was stable, even after 15 charge/discharge cycles, but the amorphous phase converted to a (Ti, Zr)H2 f.c.c. hydride.

Three different types of HT-LiCoO2/lithium lanthanum titanate (LLT) assemblies were produced by depositing an HT-LiCoO2 cathode on polycrystalline LLT with various surface finishes, to investigate the effects of the HT-LiCoO2/LLT interface structure on the electrochemical properties of the assemblies. An amorphous layer is confirmed to be introduced by Ar ion irradiation to crystalline LLT. The HT-LiCoO2/LLT assembly composed of the ion-irradiated LLT exhibits good cycle stability and relatively low apparent interface resistivity. These results indicate that the introduction of an amorphous LLT layer by surface modification of crystalline LLT is very effective in improving the structural stability and lithium-ion conductivity of the interface between HT-LiCoO2 and crystalline LLT.

A simple and environmentally benign three-step hydrothermal method was developed for growing oriented single-crystalline TiO2-B and/or anatase TiO2 nanowire arrays on titanium foil over large areas. These nanowire arrays are suitable for use as the anode in lithium ion batteries; they exhibit specific capacities ranging from 200–250 mAh/g at charge-discharge rates of 0.3 C where 1 C is based on the theoretical capacity of 168 mAh/g. Batteries retain this capacity over as many as 200 charge-discharge cycles. Even at high charge-discharge rates of 0.9 C and 1.8 C, the specific capacities were 150 mAh/g and 120 mAh/g, respectively. These promising properties are attributed to both the nanometer size of the nanowires and their oriented alignment. The comparable electrochemical performance to existing technology, improved safety, and the ability to roll titanium foils into compact three-dimensional structures without additional substrates, binders, or additives suggest that these TiO2 nanowires on titanium foil are promising anode materials for large-scale energy storage.

Superhydrophobic membranes have the potential to protect devices from incidental exposure to water. This paper reports on the processing of Teflon AF fluoropolymers through electrospinning. Teflon AF is difficult to electrospin due to its low dielectric constant and the low dielectric constants of the liquids in which it is soluble. The two approaches that have been utilized to produce fibers are direct electrospinning in Novec engineering liquids and core-shell electrospinning. Both methods produced superhydrophobic membranes. Fibers with an average diameter of 290 nm and average water contact angle of 151° were obtained by core-shell electrospinning. One suggested application for electrospun superhydrophobic membranes is the lithium-air battery.

The complexity of layered-spinel yLi2MnO3·(1 – y)Li1+xMn2–xO4 (Li:Mn = 1.2:1; 0 ≤ x ≤ 0.33; y ≥ 0.45) composites synthesized at different temperatures has been investigated by a combination of x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). While the layered component does not change substantially between samples, an evolution of the spinel component from a high to a low lithium excess phase has been traced with temperature by comparing with data for pure Li1+xMn2–xO4. The changes that occur to the structure of the spinel component and to the average oxidation state of the manganese ions within the composite structure as lithium is electrochemically removed in a battery have been monitored using these techniques, in some cases in situ. Our 6Li NMR results constitute the first direct observation of lithium removal from Li2MnO3 and the formation of LiMnO2 upon lithium reinsertion.

Activated carbon Norit R3-ex (demineralized) was annealed at various temperatures (950–2700 °C) in an argon atmosphere. The changes of the porosity of the products were characterized on the basis of N2 adsorption isotherms (at 77 K). The texture of the samples was investigated by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The presence of surface oxygen (Fourier transform infrared) and its content in the surface layer (from energy dispersive spectroscopy) were determined. The electrical resistivity of powdered samples was measured. Cyclovoltammetry of carbon (powdered electrodes) were carried out and the electrical double-layer capacitances were estimated from the cyclic voltammetry curves. Heat treatment increased the degree of crystallization of the samples, which was correlated with changes in their conductivity. A rapid drop in porosity (at 1800–2100 °C) took place in parallel with a decrease in the electrical double layer capacity. The presence of surface oxygen as a result of oxygen chemisorption on freshly annealed carbon samples was confirmed using several methods.

The electrical and physical properties of atomic-layer-deposited EryHf1-yOx thin films have been investigated with different stoichiometries of erbium oxide (Er2O3) and hafnium oxide (HfO2). The as-deposited and annealed EryHf1-yOx films exhibit much higher dielectric constants than the reported k-values of the corresponding binary oxides. The highest k-value of 37.6 ± 1 is achieved with 13 at.% of erbium in the film. The enhancement in dielectric constant is due to the formation of the cubic HfO2 phase stabilized by erbium, as revealed by x-ray diffraction experiments. The annealed mixed oxide films exhibit remarkably low oxide charges, low interface states, low leakage, and good breakdown electric fields.

Recent advancements using carbon nanotube electrodes show the ability for multifunctionality as a lithium-ion storage material and as an electrically conductive support for other high capacity materials like silicon or germanium. Experimental data show that replacement of conventional anode designs, which use graphite composites coated on copper foil, with a freestanding silicon-single-walled carbon nanotube (SWCNT) anode, can increase the usable anode capacity by up to 20 times. In this work, a series of calculations were performed to elucidate the relative improvement in battery energy density for such anodes paired with conventional LiCoO2, LiFePO4, and LiNiCoAlO2 cathodes. Results for theoretical flat plate prismatic batteries comprising freestanding silicon-SWCNT anodes with conventional cathodes show energy densities of 275 Wh/kg and 600 Wh/L to be theoretically achievable; this is a 50% improvement over today's commercial cells.

Graphite nanosheets (GNs) were introduced into polyvinylidene fluoride (PVDF) via the solution mixing technique. The nanocomposites were then subjected to compression molding for electrical measurements. Solution mixing enabled homogeneous dispersion of GN within the PVDF matrix. The electrical transport behavior of such nanocomposites was studied by means of the impedance spectroscopy in a wide frequency range from 102 to 107 Hz. The results showed that the permittivity and conductivity of the composites are frequency dependent and well obeyed with the scaling law (ε′ ∝ ωu and σ′ ∝ ω−v) in the vicinity of percolation threshold (Φc ≈ 2.5 wt%). A large dielectric constant of 173 was observed in the PVDF/GN 2.5 wt% composites at 1 kHz.

The aligned freestanding nanorods (NR) of Co3O4 and nanoporous hollow spheres (NHS) of SnO2 and Mn2O3 were investigated as the anodes for Li-ion rechargeable batteries. The Co3O4 nanorods demonstrated 1433 mAh/g of reversible capacity initially and then decreased gradually. The NHS of SnO2 and Mn2O3 delivered energy densities as 400 and 250 mAh/g, respectively, in multiple galvonastatic discharge–charge cycles. The morphologic changes of the nanostructure anodes were investigated. It was found that Co3O4 NR broke down during cycles, but SnO2 NHS still maintained their structural integrity in multiple cycles resulting in sustainable high capacity. The nanostructured metal oxides exhibit great potential as the new anode materials for Li-ion rechargeable batteries with high energy density, low cost, and inherent safety.

High energy and power density lithium iron phosphate was studied for hybrid electric vehicle applications. This work addresses the effects of porosity in a composite electrode using a four-point probe resistivity analyzer, galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The four-point probe result indicates that the porosity of composite electrode affects the electronic conductivity significantly. This effect is also observed from the cell's pulse current discharge performance. Compared to the direct current (dc) methods used, the EIS data are more sensitive to electrode porosity, especially for electrodes with low porosity values.

Self-assembly bioinspired peptide nanotubes (PNT) demonstrate diverse physical properties such as optical, piezoelectric, fluidic, etc. In this work, we present our research on environmentally clean bioinspired peptide nanostructured material, to be applied to energy storage devices-supercapacitors (SC). Such an application is based on our recently developed PNT physical vapor deposition technology. It has been found that PNT fine structure and its wettability in electrolytes are the critical factors for a strong variation of the SC capacitance. We show that PNT-coated carbon electrodes enlarge the double-layer capacitance by dozens of times; reaching 800 μF/cm2 in a sulfuric acid (normalizing to the electrode geometric surface area of carbon background electrode). The discovered effect is provided by hollow PNT possessing numerous hydrophilic nanoscale-diameter channels, elongated along the PNT axis, which dramatically increase the functional area of carbon electrodes. Another type of the observed PNT morphology is fiberlike highly hydrophobic PNT rods, which do not contribute to the SC capacitance.