A combustion synthesis technique was used to prepare nanoparticulate LiMgxMn1−xPO4 (x = 0, 0.1, 0.2)/carbon composites. Powders consisted of carbon-coated particles about 30 nm in diameter, which were partly agglomerated into larger secondary particles. The utilization of the active materials in lithium cells depended most strongly on the post-treatment and the Mg content and was not influenced by the amount of carbon. Best results were achieved with a hydrothermally treated LiMg0.2Mn0.8PO4/C composite, which exhibited close to 50% utilization of the theoretical capacity at a C/2 discharge rate.

Over the last dozen years, studies at the cell and tissue level have demonstrated that the function and fate of all cells, stem cells in particular, are affected by the collective physical properties of their microenvironments. Meanwhile, biophysical studies at the single molecule level have taught us a great deal about how mechanical forces affect the structure and function of proteins involved in the assembly of cells into tissues. Together, these molecular, cellular, and tissue studies provide insight into the process and importance of mechanotransduction, which is the process by which mechanical forces are transduced into biological signals. This insight should motivate biomimetic approaches to better control cell fate and tissue function.

The thin film electrolyte known as Lipon (lithium phosphorous oxynitride) has proven successful for planar thin film battery applications. Here, the sputter deposition of the amorphous LiPON electrolyte onto more complex 3D structures is examined. The 3D structures include off-axis alignment of planar substrates and also 10–100 μm arrays of pores, columns, and grooves. For magnetron sputtering in N2 gas at 2.6 Pa, the Lipon film deposition is not restricted to be line-of-sight to the target, but forms conformal and dense films over the 3D and off-axis substrates. The deposition rate decreases for areas and grooves that are less accessible by the sputtered flux. The composition varies, but remains within the range that gives sufficient Li+ ionic conductivity, 2 ± 1 μS/cm.

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.

Tetrakis(diethylamino)phosphonium tetrafluoroborate (TDENPBF4), tetrakis(diethylamino)phosphonium hexafluorophosphate (TDENPPF6), and tetrakis(dimethylamino)phosphonium tetrafluoroborate (TDMNPBF4) in acetonitrile (AN) have been studied as electrical double-layer capacitor electrolytes in a two-electrode test cell using titanium carbide derived carbon, C(TiC), as an electrode material. Electrochemical characteristics for C(TiC)|1 M TDENPBF4 + AN, C(TiC)|1 M TDENPPF6 + AN, and C(TiC)|1 M TDMNPBF4 + AN interfaces have been obtained by cyclic voltammetry, constant current charging/discharging, and electrochemical impedance spectroscopy. High-capacitance (85 °F/g) and gravimetric power (269 kW/kg) have been achieved at cell voltage 3.2 V. Data obtained have been compared with results published previously.

This review represents recent research on using chemical prelithiation to improve cycling performance of nanostructured electrode materials for lithium ion batteries in our group. We focus on two typical cathode materials, MoO3 nanobelts and FeSe2 nanoflowers. Methods of direct or secondary hydrothermal lithiation of MoO3 nanobelts and FeSe2 nanoflowers are described first, followed by electrochemical investigation of the samples before and after lithiation. Compared with pristine materials, lithiated samples exhibit better cycling capability. Prelithiation of other kinds of materials, such as V2O5, MnO2, etc. is also briefly reviewed. This demonstrates that prelithiation can be a powerful general approach for improving cycling performance of Li-ion battery electrode materials.

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.

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.

This article reviews polymer behavior at the air-water interface with a focus on the Langmuir technique and spreading processes to gain insight into this interface. The influence of the solvent and the water subphase on some polymer monolayers is discussed. The surface pressure–area isotherms (π–A) are described in terms of the chemical structure and the hydrophilic-hydrophobic balance of selected polymeric systems, with an emphasis on the behavior of the specific diblock copolymer films at the air-water interface. In some cases, molecular dynamic simulation studies can be used to visualize the organization and orientation of polymers at the air-water interface and to identify the main molecular interactions involved in such processes.

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.