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To obtain a rapid processible LED encapsulant that leads to high and stable light extraction efficiency (LEE), UV curable ZrO2/phenyl-siloxane nano-composite (ZSC) double-layer encapsulants were prepared and optimized. The highly crystalline ZrO2 nanoparticles with a diameter of ∼14 nm were synthesized through a modified hydrothermal method at mild conditions, and a UV curable methacryl-diphenyl-polysiloxane (MDPS) with a refractive index (RI) of 1.54 (at 633 nm) was synthesized from self-condensation of diphenylsilanediol and an end-capping reaction. High refractive indexes (RIs) from 1.54–1.61 have been obtained for ZSC composites by adding 0–20 wt% ZrO2. Before and after sulfur vapor erosion, the double-layer encapsulated sample (M-10/M) showed 11.2% and 64.8% higher LEE respectively than that of Dow Corning OE-7662. Meanwhile, the variation of LED light color temperature (Tc) was less than 1%. The effect of the ZrO2 nanoparticle content on LEE of double-layer and single-layer encapsulation were compared and discussed based on Fresnel loss and Rayleigh scattering theories. The double-layered UV curing processing took only 1/6 of the time needed for common thermal curing.

The surface properties of nanoparticles have a significant influence on the properties of the gel electrolytes. Herein, the surface NH2-rich nanoparticle (A-SiO2), with a tightening network, is synthesized by silanizing SiO2 nanoparticles with pre-polymerized aminopropyltriethoxysilane, which is further employed to prepare ionic-liquid gel electrolytes for dye-sensitized solar cells. The addition of a small amount of A-SiO2 can effectively solidify the ionic-liquid, whereas a large number of NH2 groups on the SiO2 surface leads to a large negative shift of the TiO2 conduction band edge, and can react with I3− in the form of a Lewis complex, resulting in an increase in the concentration of I− and a decrease in the concentration of I3− in the electrolyte. In addition, the ionic-liquid gel electrolyte possesses thixotropic behavior, which allows it to easily penetrate into the inner part of the TiO2 mesoporous film. As a result, large improvements of the photovoltage from 695 mV to 785 mV and of the photocurrent from 13.3 mA cm−2 to 14.9 mA cm−2 are achieved. This leads to significant enhancement of the power conversion efficiency, from 6.2% to 8.1%, for the cell with A-SiO2 compared to that of the pristine ionic-liquid electrolyte.

A new kind of carboxyl group-functionalized silica nanoparticles were synthesized and employed as framework to form “soggy sand” electrolyte for dye-sensitized solar cells. The property of this electrolyte has been evaluated by studying the effect of the carboxyl group-functionalized silica nanoparticles content on the performance of dye-sensitized solar cells. The cells based on electrolyte containing the carboxyl group-functionalized silica nanoparticles show better performance owing to the increased short-circuit photocurrent than that of the liquid device and yield the energy conversion efficiency of 7.1% under AM 1.5 illumination at 100 mV cm−2 when the content of the carboxyl group-functionalized silica is 15 wt.%. Keywords: Functionalized silica, Ionic liquid, Soggy sand electrolyte, Dye-sensitized solar cells

The acidic ionic liquid polymer P [((3-(4-vinylpyridine) propanesulfonic acid) iodide)-co-(acrylonitrile)], which is named as P-HI for short, has been employed in ionic liquid electrolyte for dye-sensitized solar cells. The novel acidic ionic liquid polymer/ionic liquid composite polymer electrolyte does not contain iodine, and the performance of this electrolyte has been evaluated by studying the content of P-HI and the iodine concentration on the performance of dye-sensitized solar cells. The cell based on electrolyte containing 20 wt.% P-HI yields an overall energy conversion efficiency of 6.95% under AM 1.5 illumination at 100 mW cm−2. Keywords: Acidic ionic liquid polymer, Ionic liquid, Electrolyte, Dye-sensitized solar cells

A series of all-solid polymer electrolytes were prepared by cross-linking new designed poly(organophosphazene) macromonomers. The ionic conductivities of these all-solid, dimensional steady polymer electrolytes were reported. The temperature dependence of ionic conductivity of the all-solid polymer electrolytes suggested that the ionic transport is correlated with the segmental motion of the polymer. The relationship between lithium salts content and ionic conductivity was discussed and investigated by Infrared spectrum. Furthermore, the polarity of the host materials was thought to be a key to the ionic conductivity of polymer electrolyte. The all-solid polymer electrolytes based on these poly(organophosphazenes) showed ionic conductivity of 10−4 S cm−1 at room temperature.

This work describes a series of novel Eucommia ulmoides gum (EUG)-based damping materials with excellent damping properties by using the interpenetrating polymer network (IPN) method for the first time; this is an innovative application of EUG. The novel core-shell structure of an EUG-based multicomponent latex interpenetrating polymer network (LIPN) can be controlled by selecting a suitable initiator system, emulsification method, and polymeric sequence and by regulating the miscibility among the components. The damping properties and morphology of multicomponent LIPNs were investigated by dynamic mechanical analysis (DMA) and transmission electron microscope (TEM) in order to reveal the relationship between structure and performance. The results show that some LIPNs that use EUG as the seed in the multicomponent core-shell structure have a high damping factor (tanδ) at a broader temperature range. For example, the EUG/PS/PBA LIPN (1/1/1 by weight) possesses excellent damping properties; its temperature range for tanδ>0.3 extends to almost 130°C. EUG-based LIPNs, particularly the trinary EUG-based LIPNs are novel damping materials with good potential for development.

All solid-state comb-like network polymer electrolytes (CNPE) based on poly(methylsiloxane) with pendant PEO chains as internal plasticizing chains (IPC) have been designed and synthesized. Ultraviolet (UV) polymerization method was applied for the curing of CNPEs. Effects of the network structure on the conductive properties and mechanical properties were discussed in details. Ionic conductivity of the prepared CNPE is one order of magnitude larger than those without IPCs, which suggests that the expected drop of conductivity caused by crosslinking has been well compensated by the introduction of IPCs. Maximum conductivity of 1.01 × 10−4 S cm−1 and maximum tensile strength of 0.66 MPa were obtained at 30 °C. Electrochemical stability and electrolyte/electrodes interfacial stability properties were evaluated by cyclic voltammetry and ac impedance, respectively.

Novel surface modification approach for graphite anode of lithium ion batteries was developed in this study. Poly(acrylonitrile) was in situ encapsulated on the surface of natural graphite (N-graphite) particles via radiation-initiated polymerization. The graphite obtained shows a large improvement in electrochemical performance such as initial Coulombic efficiency and cycleability compared with the original N-graphite. The structural stability of graphite surface is enhanced due to the fact that encapsulated poly(acrylonitrile) can depress the co-intercalation of solvated lithium ion.

An amorphous carbon doped with sulfur to be used as anode material for lithium ion batteries is prepared by heat-treatment of a mixture of polyacrylonitrile (PAN) and sulfuric acid. With X-ray photoelectron spectroscopy (XPS), elemental analysis, X-ray powder diffraction (XRD), scanning electron microscopy, and electrochemical capacity measurements effects of sulfur on properties of the carbon anode are investigated. The added sulfur favorably increases the charge capacity in close correlation with an increase of the size of graphite crystallites, L c , the interlayer distance, d 0 0 2 , and the number of micropores, and the doping of sulfur in the state of CSC. On the other hand, it also causes detrimental changes, for example the formation of amine-group nitrogen, sulfate/sulfonate deposits, and macropores. Nevertheless, as a result, both reversible and irreversible capacities are enhanced. This clearly shows, that added heteroatoms may have opposite influences, good and bad, on electrochemical performance of carbonaceous anode materials. Approaches towards suppressing the unfavorable ones in the application in lithium ion batteries are discussed.

Phosphorus-containing carbon has been prepared by the pyrolysis of phenolic resin containing chemically bonded phosphorus atoms, which is synthesized through the esterification of phenolic hydroxyl group by phosphoric acid. The electrochemical insertion of lithium in as-prepared carbon is also investigated. It is found that, at a pyrolysis temperature of 500°C, the addition of phosphoric acid in the precursor lowers the reversible capacity of the resultant carbon, but at 900°C, the addition of phosphoric acid in the precursor resin increases the reversible capacity of resultant carbon. Especially, the phosphorus-containing carbon prepared by the above method at 900°C gives a capacity beyond the theoretical value of graphite and reasonable discharge/charge curves. The phosphorus-containing carbon prepared by the pyrolysis at 500°C shows a similar electrochemical behavior to that of pure carbon and the effect of phosphorus atoms is little. Its reversible capacity is mainly determined by the content of hydrogen atoms rather than phosphorus atoms. However, at a relatively high pyrolysis temperature, 900°C, more phosphorus atoms are bonded with carbon atoms and are introduced to the microcrystallite structure of carbon. Hence, phosphorus element exerts a strike effect on the electrochemical behavior of carbon and, because of its different electronic effect from carbon element, more lithium species are inserted into carbon matrix.

Disordered polyacenes were prepared from poly(styrene-co-divinylbenzene). The structures and electrochemical properties of these samples were studied. The result shows that the crosslinking unit of divinylbenzene in copolymer is beneficial to the charge capacity of the resultant polyacene. The change capacity of polyacene increases with the increase of the content of divinylbenzene (DVB), and finally surpasses the theoretical capacity of graphite (372 mA hr/g) when the content of DVB goes up to 5 wt%. Moreover, the charge curves have a potential plateau at approximately 1 V v. Li/Li+, and the increase of charge capacity mainly results from the lengthening of this plateau. Copyright © 1999 John Wiley & Sons, Ltd.

Through the measurement of electrochemical properties of carbon anodes based on copolymers of 4-VP and AN with crosslinker DVB, it is found that the introduction of crosslinker DVB can favor the enhancement of reversible capacity, and the highest can be up to 600 mAh g− 1. Measurements of Thermal gravity analysis, elemental analysis, X-ray powder diffraction, scanning electron microscopy and specific surface area indicate that the incorporation of DVB into polymer PAN can not only affect the contents of nitrogen and hydrogen, but also favor the carbonization process. In addition, it can result in improvement of the regularity of the obtained carbon structure, i.e. the formation of graphite structure, and the number of micropores is increased. By virtue of all these factors, charge capacity below and above 0.9 V enhances and charging voltages decrease with the addition amount of DVB.

Carbon anode materials for a lithium secondary battery based on polyacrylonitrile (PAN) are studied by using elemental analysis, X-ray powder diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The reversible lithium capacity and charging voltage curves of carbons from PAN are affected by the heat-treatment temperature the rate of temperature rise and the soak time. These factors lead to a change in nitrogen content, cyclization and cross-linking processes, the carbon structure, and the number of micropores. The reversible capacity reaches 426 mAh g−1 at 600°C; the lower the rate of temperature rise, the higher the reversible capacity. The addition of phosphoric acid can favour the cyclization process of PAN, and can increase the number of micropores in the resulting carbon. It can also act as setting agent for graphene molecules and can improve the regularity of the carbon structure. In addition, the doped phosphorus is bonded with C and O, and dispersed homogeneously in the bulk carbon structure. This results in an increase in d002. Such doping can enhance the reversible capacity above and below 0.9 V.

Through observation of the binding energy spectra of V 2p ( S =3/2) and C 1s , and ESR measurements, we suggest that the nucleation agent formed during heat-treatment of a mixture of V 2 O 5 and melamine-formaldehyde resin (polymeric carbon) is the complex VO(graphene) 2 . First, this complex enables the carbon structure to become more ordered and increases its d 002 value. Second, the VO displays electron-absorbing ability. Third, the content of the imperfect carbon structure is decreased. All of these effects result in increased capacity and improved cycling behaviour of lithium secondary batteries using such material as the anode.

The electrochemical properties of carbon anodes in lithium secondary batteries are improved by the addition of vanadium as V2O5. The action of the added V2O5 is different from that obtained by incorporating a nonmetallic element such as nitrogen, boron, phosphorous or silicon. Because it can increase the distance between the 002 planes of the carbon and act as nucleating agent that promotes the formation of a layer-like carbon structure, V2O5, not only enlarges the carbon anode's reversible capacity of lithium storage but also improves the cycling behavior.