We report the electrical transport and H(2)S sensing properties of single beta-AgVO(3) nanowire device. beta-AgVO(3) nanowires were successfully prepared by ultrasonic treatment followed by hydrothermal reaction using V(2)O(5) sol. The individual beta-AgVO(3) nanowire exhibits a "threshold switching" phenomenon. High bias (i.e., 6 V for Au contacts) is required to initially switch the individual nanowire device from nonconductive to conductive, and it may be related to the formation of nanoscale metallic Ag when enough voltage is applied between the two electrodes. This novel nanomaterial shows good H(2)S sensing performances with short response and recovery time within 20 s, relatively low response concentration of 50 ppm, and good selectivity.

and fair theoretical specifi c capacity (197 mAh g −1 for complete extraction of three lithium ions when charged to 4.8 V, 133 mAh g −1 when cycled between the potential window of 3.0-4.3 V). [12][13][14] In particular, because of its sodium super ionic conductor (NASICON) structure, monoclinic Li 3 V 2 (PO 4 ) 3 provides a 3D pathway for Li + insertion/ extraction, which results in a very high ion diffusion coeffi cient (from 10 −9 to 10 −10 cm 2 s −1 ). [15][16][17][18][19] However, Li 3 V 2 (PO 4 ) 3 suffers a poor electronic conductivity (2.4 × 10 −7 S cm −1 at room temperature) due to the nature of its separated VO 6 octahedral arrangement, which significantly limits its rate performance and the further commercialization. [20][21][22][23][24] Carbon coating is an economic and feasible technique that is widely used to improve the electronic conductivity. [ 14,17,[25][26][27][28] However, the common carbon coating could only provide an electron pathway on the nanoscale for individual particles. In comparison, the architecture combining the nanoscale carbon coating and the microscale carbon network could provide hierarchical pores for the electrolyte to pass through, which may supply a highly conductive network for both electrons and lithium ions, promoting the fast charge/discharge processes. [ 6,[29][30][31][32] In addition, the fast kinetics enabled by this architecture would be benefi cial for the battery performance at low temperature, which is a key issue in the application.Here, we propose a feasible and environmentally friendly one-pot method utilizing glucose as both the carbon source and the reducing agent (functioned by the aldehyde group). Via the optimization of the interface reaction, hierarchical carbon (nanoscale amorphous carbon coating and microscale carbon network) decorated Li 3 V 2 (PO 4 ) 3 is obtained (Schematic, Figure 1 ). This unique architecture can provide the following three important features simultaneously: 1) continuous electron conduction enabled by hierarchical carbon, 2) rapid ion transport enabled by electrolyte-fi lled macro/ mesopore network, and 3) a buffered protective carbon shell. The obtained cathode material achieved an enhanced rate capability (121 mAh g −1 at rate up to 30 C), superior cycling stability Developing rechargeable lithium ion batteries with fast charge/discharge rate, high capacity and power, long lifespan, and broad temperature adaptability is still a signifi cant challenge. In order to realize the fast and effi cient transport of ions and electrons during the charging/discharging process, a 3D hierarchical carbon-decorated Li 3 V 2 (PO 4 ) 3 is designed and synthesized with a nanoscale amorphous carbon coating and a microscale carbon network. The Brunauer-Emmett-Teller (BET) surface area is 65.4 m 2 g −1 and the porosity allows for easy access of the electrolyte to the active material. A specifi c capacity of 121 mAh g −1 (91% of the theoretical capacity) can be obtained at a rate up to 30 C. When cycled at a rate of 20 C, the capacity retention is 77...

Rational assembly of unique complex nanostructures is one of the facile techniques to improve the electrochemical performance of electrode materials. Here, a substrate-assisted hydrothermal method was designed and applied in synthesizing moundlily like radial β-AgVO(3) nanowire clusters. Gravitation and F(-) ions have been demonstrated to play important roles in the growth of β-AgVO(3) nanowires (NWs) on substrates. The results of cyclic voltammetry (CV) measurement and X-ray diffraction (XRD) characterization proved the phase transformation from β-AgVO(3) to Ag(1.92)V(4)O(11) during the redox reaction. Further electrochemical investigation showed that the moundlily like β-AgVO(3) nanowire cathode has a high discharge capacity and excellent cycling performance, mainly due to the reduced self-aggregation. The capacity fading per cycle from 3rd to 51st is 0.17% under the current density of 500 mA/g, which is much better than 1.46% under that of 20 mA/g. This phenomenon may be related to the Li(+) diffusion and related kinetics of the electrode. This method is shown to be an effective and facile technique for improving the electrochemical performance for applications in rechargeable Li batteries or Li ion batteries.

Olivine-type LiMnPO4 has been extensively studied as a high-energy density cathode material for lithium-ion batteries. To improve both the ionic and electronic conductivities of LiMnPO4, a series of carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposites are synthesized by a facile sol-gel method combined with the conventional solid-state method. The optimized composite presents a three-dimensional hierarchical structure with active nanoparticles well-embedded in a conductive carbon matrix. The combination of the nanoscale carbon coating and the microscale carbon network could provide a more active site for electrochemical reaction, as well as a highly conductive network for both electron and lithium-ion transportation. When cycled at 20 C, an initial specific capacity of 103 mA h g(-1) can be obtained and the capacity retention reaches 68% after 3000 cycles, corresponding to a capacity fading of 0.013% per cycle. The stable capacity and excellent rate capability make this carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposite a promising cathode for lithium-ion batteries.

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