Current large-scale production of flexible solar devices delivers cells with lowefficiency. In this paper we present an alternative path to organic or inorganicthin films. Our cells combine the remarkable surface passivation properties ofthe silicon heterojunction solar cells design, and the quality of n-type Czwafers. The cells were manufactured on 50-70 µm-thick wafers. The cellshave and efficiency of 17.8-19.2%, open-circuit voltages of 735-742 mV,short-circuit currents of 34.5-35.5 mA/cm2, and fill-factors of72-75%. The cells are not as flexible as bare wafers. Thin cells are particularsensitive to the additional stress introduced by the busbars and the solderedribbons. For radiuses of curvature over 8cm the cells efficiency remains thesame, for radius equal to 6cm the cell efficiency drops less than 2%, and forradius equal to 4cm the drop is less than 3%. The broken fingers due to smallerbend radius lead to higher series resistance and subsequently lowerfield-factors.

Development of transparent electrodynamic screens (EDS) printed on ultrathinflexible glass film substrates for retrofitting on solar panels and solarmirrors to perform self cleaning function is reviewed. Large-scale solar plantsare generally installed in semi-arid and desert areas where dust layers build upon solar collectors causes major energy-yield loss. Maintaining designed plantcapacities requires more than 90% reflectivity for CSP mirrors and 90%transmission efficiency for PV modules; solar collectors must therefore becleaned at a frequency depending on the rate of dust deposition. Scarcity ofwater in these regions requires a cleaning method that drastically reduces oreliminates water and the associated labor costs for high efficiency operation oflarge-scale solar plants. An EDS film consists of rows of interdigitated,transparent conducting parallel electrodes embedded within a flexible ultrathinglass film and an optically clear adhesive film used for retrofitting the filmon the surface of solar collectors. When phased voltage pulses activate theelectrodes, the dust particles are first electrostatically charged, thenrepelled and removed from the surface of the solar collectors by Coulomb force,restoring transmission efficiency greater than 90%. The electrodes of EDS areeither made from silver nanowire or another conductive transparent materialprinted on a highly transparent, ultrathin (100-μm thick), flexibleborosilicate glass film. Applications of different conducting transparentelectrodes and methods of printing are reviewed for optimizing self-cleaningfunction of solar panels and mirrors.

We report in this study the dissociation conditions for the carbon dioxidehydrate in the presence of additive materials. We measured thehydrate-water-vapor (H-Lw-V) three-phase equilibrium data using the isochoricmethod. Examples of these phase equilibrium data for the additive materials of1,3,5-trioxane, 2,5-dihydrofuran, 1,3-dioxolane, and 3,4-dihydro-2H-pyran arepresented. The experimental pressure range is from 1.6 to 3.3 MPa, and theconcentration of each additive is at 10 wt%. The experimental results indicatethat cyclic ethers of 1,3,5-trioxane, 2,5-dihydrofuran, and 1,3-dioxolanepromote the formation of carbon dioxide hydrate. Their promotion effects at agiven pressure are up to 5 K, 6.9 K, and 4.2 K, respectively, The additivematerial of 3,4-dihydro-2H-pyran, however, shows the inhibitor behavior. Theaverage inhibition effect is about 1.3 K at a given pressure.

We report a simple and scalable process to synthesize the core–shellnanostructure of MoS2@N-doped carbon nanosheets (MoS2@C),in which polydopamine is coated on the MoS2 surface and thencarbonized. Transmission electron microscopy reveals that the as-synthesizedMoS2@C possesses a nanoscopic and ultrathin layer ofMoS2 sheets with a thin and conformal coating of carbon layers(∼5 nm). The MoS2@C demonstrates a superiorelectrochemical performance as an anode material for lithium ion batteriescompared to exfoliated MoS2 sample. This unique core–shellstructure is capable of excellent delivery of Li+ ion incharging–discharging process: a specific capacity as high as 1239 mAh g−1, a high rate of charging-discharging capability evenat a high current rate of 10 A g−1 while retaining 597 mAh g−1, and a good cycle stability over 70 cycles at a highcurrent rate of 2 A g−1.

Removing residual moisture in lithium-ion battery electrodes is essential fordesired electrochemical performance. In this manuscript, the residual moisturein LiNi0.5Mn0.3Co0.2O2 cathodesproduced by conventional solvent-based and aqueous processing is characterizedand compared. The electrochemical performance has also been investigated forvarious residual moisture contents. It has been demonstrated that the residualmoisture lowers the first cycle coulombic efficiency, but its effect on shortterm cycle life is insignificant.

During the activation and charge process, vacancies are generated in theLi2MnO3 component in lithium-rich layered cathodematerials. The chemical expansion coefficient tensor associated with oxygenvacancies, lithium vacancies and a Li-O vacancy pair were calculated forLi2-xMnO3-δ. The chemical expansioncoefficient was larger for oxygen vacancies than for lithium vacancies in mostdirections. Additionally, the chemical expansion coefficient for a Li-O vacancypair was shown to not be a linear sum of the chemical expansion coefficients ofthe two vacancy types, suggesting that the oxygen vacancies and lithiumvacancies in Li2-XMnO3-δ exhibit a couplingeffect.

Phase transformation enthalpies are determined using the recently developedmeasurement technique Thin-Film Calorimetry (TFC), which is based onpiezoelectric resonators vibrating in thickness shear mode. They are applicableup to at least 1000 °C. To the best of our knowledge, no comparable TFCsystems for such high temperatures exist.

The experimental part is divided into two subsections. The first is addressed toa thermodynamic investigation on piezoelectric langasite crystals (LGS,La3Ga5SiO14) which are the key component ofthe TFC system. The specific heat capacity is measured on LGS crystals of threedifferent manufacturers. It ranges from about 0.45 J g-1K-1 at 40 °C to about 0.60 J g-1 K-1at 1000 °C. Thereby, deviations of up to 5 % between the differentcrystals are detected. Thermal diffusivity data for Y-cut LGS crystals aredetermined as well. Here, a constant decrease with temperature is detectedranging from 0.48 mm2 s-1 at room temperature to 0.38mm2 s-1 at 700 °C.

The second part presents thin-film calorimetric investigation on thin films ofthe family Li-Ni-Mn-Co-Al-Oxide (NMC/NMCA). These cathode materials areinvestigated and compared when annealed in ambient air or 0.5 % H2/Arup to 860 °C. Three stoichiometries are chosen:Li(Ni1/3Mn1/3Co1/3)O2,Li(Ni0.6Mn0.2Co0.2)O2, andLi(Ni0.6Mn0.2Co0.15Al0.05)O2.The samples show three or four phase transformations. In air, the samplescrystallize in the range of 250-350 °C. In 0.5 % H2/Ar, thetransformations occur at higher temperatures. Especially in air, stoichiometricNMC crystallizes at lower temperatures compared to Ni-rich compositions.Additional doping with Al enhances the thermal stability which shifts all phasetransformations to higher temperatures in both atmospheres.

Recently, molybdenum oxide (MoO2) has been found to be a chemicallystable and relatively inexpensive material for the application as the anode in alithium ion battery [1-5]. We believe the use of MoO2 in batteryapplications has been hindered due to a long, complicated, and multistepsynthesis process. We present a simple one-pot hydrothermal technique tosynthesize MoO2 nanoparticles directly onto a copper (Cu) substrate.

We believe this is a first report of the synthesis of MoO2 directlyonto a Cu substrate, and could lead to the ability to both fabricate othermaterials in a similar manner as well as depositing MoO2 onto othersubstrates. This technique can reduce anode production time by eliminating thecoating process, and also decrease the total amount of chemicals used whencompared to a typical powder synthesis and coating processes. TheMoO2 coated Cu electrode was characterized using Raman Spectroscopy,Grazing Incident X-ray Diffraction (GIXRD) and scanning electron microscopy(SEM) techniques to confirm the composition, crystallinity and structure of thesynthesized MoO2 nanomaterial.

Multiphysics simulations (COMSOL) of core-shell nanoarchitectures show that theycan operate at 3 times the C-rate of micron scale thin film materials whilestill accessing 90% of an additive free cathode oxide material. A highperformance Ge anode DC sputtered onto a Cu nanotube current collector ischaracterised. Volume expansion of Ge is alleviated and mechanical stability isenhanced due to the Cu nanotubes current collector.

A nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt(CoO/Co) core-shell nanoparticles (NPs), was structurally and chemicallycharacterized with transmission electron microcopy (TEM) while itselectrochemical response for Lithium ion battery (LIB) applications wasevaluated as well. The results herein show that the nanoporous C material wasuniformly functionalized with the CoO/Co core-shell NPs. Further the NPs werecrystalline with fcc-type lattice on the Co2+ oxide shelland hcp-type core of metallic Co0. The electrochemical study wascarried out by using galvanostatic charge/discharge cycling at a current densityof 1000 mA g−1. The potential of this hybrid material forLIB applications was confirmed and it is attributed to the successful dispersionof the Co2+/ Co0 NPs in the C support.