The processes of extraction and insertion of lithium ions in LiCoO(2) cathode are investigated by galvanostatic cycling and electrochemical impedance spectroscopy (EIS) at different potentials during the first charge/discharge cycle and at different temperatures after 10 charge/discharge cycles. The spectra exhibit three semicircles and a slightly inclined line that appear successively as the frequency decreases. An appropriate equivalent circuit is proposed to fit the experimental EIS data. Based on detailed analysis of the change in kinetic parameters obtained from simulating the experimental EIS data as functions of potential and temperature, the high-frequency, the middle-frequency, and the low-frequency semicircles can be attributed to the migration of the lithium ions through the SEI film, the electronic properties of the material and the charge transfer step, respectively. The slightly inclined line arises from the solid state diffusion process. The electrical conductivity of the layered LiCoO(2) changes dramatically at early delithiation as a result of a polaron-to-metal transition. In an electrolyte solution of 1 mol L(-1) LiPF(6)-EC (ethylene carbonate) :DMC (dimethyl carbonate), the activation energy of the ion jump (which is related to the migration of the lithium ions through the SEI film), the thermal activation energy of the electrical conductivity and the activation energy of the intercalation/deintercalation reaction are 37.7, 39.1 and 69.0 kJ mol(-1), respectively.

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Through coordination of the Seebeck coefficient and carrier concentration in Cu3SnS4, TE performance improves significantly with the ZT value of 0.75 at 790 K.

In the present work, we report the growth of flexible SiC quasialigned nanoarrays with N dopants on carbon fabric substrate via the catalyst-assisted pyrolysis of a polymeric precursor. The resultant products are systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), highresolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDS).The as-synthesized SiC nanowires are single-crystalline and grow along the [111] direction with a uniform spatial distribution of N dopants. The effect of the distance between the SiC array and the anode on the Field emission (FE) properties was investigated. FE measurements show that these N-doped SiC nanoarrays could be an excellent candidate for field emitters with very low turn-on fields of 1.90-2.65 V mm À1 and threshold fields of 2.53-3.51 V mm À1 , respectively, which can be mainly attributed to the decrease of work function induced by the N dopants. Experimental procedureThe SiC-NWs with N dopants were synthesized by the catalystassisted pyrolysis of a polymer precursor of polysilazane (PSN,

In this project, we have successfully manipulated the lattice defects in α-In 2 Se 3 -based solid solutions (In 2-x Zn x Se 3 ) upon proper substitutions of Zn for In, via a non-equilibrium fabrication technology of materials (NEFT). The manipulation of the defects centers on reducing the number of interstitial In atoms (In i ) and Se vacancies (V Se ), and creating a new antisite defect Zn In as a donor. By such means, the lattice structure tends to be ordering, and also more stabilized than that of pure α-In 2 Se 3 . At the meantime, the carrier concentration (n) and mobility (µ) have increased by 1~2 orders of magnitude. As a consequence, the solid solution at x=0.01 gives the 10 highest TE figure of merit (ZT) of 1.23(±0.22) in the pressing direction at 916K, which is about 4.7 times that of virgin α-In 2 Se 3 (ZT=0.26). This achieved TE performance is mainly due to the remarkable improvement of the electrical conductivity that increases from 0.53×10 3 (Ω -1 m -1 ) at x=0 to 4.88×10 3 (Ω -1 m -1 ) at x=0.01 at 916K, in spite of the enhancement of the lattice thermal conductivity (κ L ) from 0.26 (wm -1 k -1 ) to 0.32 (wm -1 k -1 ).