Development of alternative cathode materials is of highly desirable for sustainable and cost-efficient lithium-ion batteries (LIBs) in energy storage fields. In this study, for the first time, we report tunable nitrogen-doped graphene with active functional groups for cathode utilization of LIBs. When employed as cathode materials, the functionalized graphene frameworks with a nitrogen content of 9.26 at% retain a reversible capacity of 344 mAh g after 200 cycles at a current density of 50 mA g. More surprisingly, when conducted at a high current density of 1 A g, this cathode delivers a high reversible capacity of 146 mAh g after 1000 cycles. Our current research demonstrates the effective significance of nitrogen doping on enhancing cathode performance of functionalized graphene for LIBs.

To achieve low thermal conductivity, polythiophene (PTh)/bismuth telluride (Bi 2 Te 3 ) nanocomposite has been prepared by spark plasma sintering using a mixture of nanosized Bi 2 Te 3 and PTh powders. Bi 2 Te 3 powder with sphericalshaped particles of 30 nm diameter and PTh nanosheet powder were first prepared by hydrothermal synthesis and chemical oxidation, respectively. X-ray diffraction analysis and scanning electron microscopy observations revealed that the hybrid composite consists of PTh nanosheets and spherical Bi 2 Te 3 . The organic PTh acts as an adhesive in the composite. Transport measurements showed that the PTh in the Bi 2 Te 3 matrix can reduce its thermal conductivity significantly, but also dramatically reduces its electrical conductivity. As a result, the figure of merit of the composite is lower than that of pure Bi 2 Te 3 prepared under the same conditions. The maximum value of ZT for the sample with 5% PTh (by weight) was 0.18 at 473 K, which is rather high compared with other polymer/inorganic thermoelectric material composites.

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The ZnO nanostructures were synthesized on Si(100) substrates by chemical vapor deposition (CVD) method. Different Morphologies of ZnO nanostructures, such as nanoparticle film, micro-pillar and micro-nano multi-structure, were obtained with different conditions. The results of XRD and TEM showed the good quality of ZnO crystal growth. Selected area electron diffraction analysis indicates the individual nano-wire is single crystal. The wettability of ZnO was studied by contact angle admeasuring apparatus. We found that the wettability can be changed from hydrophobic to super-hydrophobic when the structure changed from smooth particle film to single micro-pillar, nano-wire and micro-nano multi-scale structure. Compared with the particle film with contact angle (CA) of 90.7 degrees, the CA of single scale microstructure and sparse micro-nano multi-scale structure is 130-140 degrees, 140-150 degrees respectively. But when the surface is dense micro-nano multi-scale structure such as nano-lawn, the CA can reach to 168.2 degrees . The results indicate that microstructure of surface is very important to the surface wettability. The wettability on the micro-nano multi-structure is better than single-scale structure, and that of dense micro-nano multi-structure is better than sparse multi-structure.