导电碳浆用掺杂低电阻石墨的制备

以 1μm天然鳞片石墨作主体材料 ,在溶液中采用不同的掺杂剂制备了不同的掺杂石墨层间化合物 ,并将其制成导电碳浆 ,再采用标准薄膜开关线路板印刷成标准线路测定其电阻。实验结果表明制备出的掺杂石墨层间化合物电阻比未经处理的石墨降低了 1～ 3倍 ,导电性能稳定。其中 ,电阻值最小的是高碘酸钾作掺杂剂的石墨层间化合物 ,其电阻值仅为 2 2kΩ/0 8mm× 10 0cm。

Effect of KOH treatment on structural and photovoltaic properties of ZnO nanorod arrays

ZnO nanorod arrays （NRs） were synthesized on the fluorine-doped SnO2 transparent conductive glass （FTO） by a simple chemical bath deposition （CBD） method combined with alkali-etched method in potassium hydroxide （KOH） solution. X-ray diffraction （XRD）, scanning electron microscopy （SEM） and current-voltage （I-V） curve were used to characterize the structure, morphologies and optoelectronic properties. The results demonstrated that ZnO NRs had wurtzite structures, the morphologies and photovoltaic properties of ZnO NRs were closely related to the concentration of KOH and etching time, well-aligned and uniformly distributed ZnO NRs were obtained after etching with 0.1 mol/L KOH for 1 h. ZnO NRs treated by KOH had been proved to have superior photovoltaic properties compared with high density ZnO NRs. When using ZnO NRs etched with 0.1 mol/L KOH for 1 h as the anode of solar cell, the conversion efficiency, short circuit current and open circuit voltage, compared with the unetched ZnO NRs, increased by 0.71%, 2.79 mA and 0.03 V, respectively.

Study of the Conductance Characteristic of Doped Polymer by Monte Carlo Method

The conduct mechanism of the doped polymer is considered. In an asymmetrysystem composed of high polymer and doping conductive matte, chain or congeries framework will beformed between the conductive particles to improve the conductance characteristic. In thisprocession, the conductive particles interact to each other. In this paper, we describe theconductance of the doped polymer by Monte Carlo method. The results accord with the experimentsquite well. It can be concluded that there is an evident change of doped polymer from nonconductorto metal.

Preparation of low-temperature sintered high conductivity inks based on nanosilver self-assembled on surface of graphene

Finer nanoplates of silver are prepared by self-assembly on the surface of graphene,and the low-temperature sintered high conductivity ink containing the silver nanoplates is prepared.Most importantly,graphene is added to the solution before the chemical reduction reaction occurs.Firstly,it is found that silver nanoplates have self-assembly phenomenon on the surface of graphene.Secondly,the Ag nano hexagonal platelets(AgNHPs)with small particle sizes(10 nm),narrow distribution and good dispersion are prepared.Especially,smaller sizes(10 nm)and narrower particle size distribution of AgNHPs particles can be easily controlled by using this process.Finally,the conductivity of the ink is excellent.For example,when the printed patterns were sintering at 150℃,the resistivity of the ink(GE:0.15 g/L)reached the minimum value of 2.2×10^-6 cm.And the resistivity value was 3.7×10^-6Ωcm,when it was sintered at 100℃ for 30 min.The conductive ink prepared can be used for the field of printing electronics as ink-jet printing ink.

Electrical conductivity of (Na_3AlF_6-40%K_3AlF_6)-AlF_3-Al_2O_3 melts

The effects of contents of AlF3 and Al2O3, and temperature on electrical conductivity of （Na3AlF6-40%K3AlF6）- AlF3-Al2O3 were studied by continuously varying cell censtant （CVCC） technique. The results show that the conductivities of melts increase with the increase of temperature, but by different extents. Every increasing 10 ℃ results in an increase of 1.85 × 10^-2, 1.86× 10^-2, 1.89 × 10^-2 and 2.20 × 10^-2 S/cm in conductivity for the （Na3AlF6-40%K3AlF6）-AlF3 melts containing 0%, 20%, 24%, and 30% AlF3, respectively. An increase of every 10 ℃ in temperature results an increase about 1.89× 10^-2, 1.94 × 10^-2, 1.95 × 10^-2, 1.99× 10^-2 and 2.10× 10^-2 S/cm for （Na3AlF6-40%K3AlF6）-AlF3-Al2O3 melts containing 0%, 1%, 2%, 3% and 4% Al2O3, respectively. The activation energy of conductance was calculated based on Arrhenius equation. Every increasing 1% of AlF3 results in a decrease of 0.019 and 0.020 S/cm in conductivity for （Na3AlF6-40%K3AlF6）-AlF3 melts at 900 and 1 000 ℃, respectively. Every increase of 1% Al2O3 results in a decrease of 0.07 S/cm in conductivity for （Na3AlF6-40%K3AlF6）-AlF3-Al2O3 melts. The activation energy of conductance increases with the increase in content of AlF3 and Al2O3.

Electrochemical study on semiconductive properties of the passive film on rebar in concrete

The electrochemical behavior of metallic passive film on rebar in concrete is characterized by its semiconductive nature. The charge distribution at the interface between a semiconductor and an electrolyte is often determined by measuring the capacitance of the space-charge layer （Csc） as a function of the electrode potential （E）. When the space charge-layer serves as the depletion layer, the relation of Csc^-2 vs E resembles a Mott-Schottky plot （M-S plot）. The semiconductive properties of the passive film on rebar in concrete were analyzed with M-S plots to study the effect of chloride ions and mineral admixtures on rebar passive films. Some rebar electrodes were immersed in simulated concrete pore solutions, while others were embedded in concrete with/without mineral admixtures. In saturated Ca（OH）, solutions, the relation of Csc^-2-E of rebar electrodes shows linear MottSchottky relationship indicating that the passive film on rebar is a highly disordered n-type semiconductor, with donor density （ND） in the order of 10^26m^-3. After adding chloride ions （Cl wt%〈0.2%） in system solutions, the M-S plot slopes significantly decreased and ND increased, suggesting that chloride ion will cause passive film corrosion and breakdown. The M-S plots of the passive film on rebar electrodes embedded in concrete were similar to those immersed in simulated system solution. However, ND of those in concrete with mineral admixtures tended to be a little smaller, indicating that introducing proper quantity admixtures into concrete could make the rebar passive film have a thicker space-charge layer and therefore a thicker passive film layer.

Effect of surface treatment for aluminum foils on discharge properties of lithium-ion battery

Aluminum foils having thicknesses of 10-20 μm are commonly employed as current collectors for cathode electrodes in Li-ion batteries. The effects of the surface morphology of the foil on battery performance were investigated by using a foil with roughened surface by chemical etching and a plain foil with smooth surface on both sides. For high-conductivity LiCoO2 active materials with large particle size, there are no significant differences in battery performance between the two types of foils. But for low-conductivity LiFePO4 active materials with small particle size, high-rate discharge properties are significantly different. The possibility shows that optimizing both the surface morphology of the aluminum foil and particle size of active material leads to improvement of the battery performance.

Characteristic Analysis of the Solid Oxide Fuel Cell with Proton Conducting Ceramic Electrolyte

An electrolyte model for the solid oxide fuel cell (SOFC) with proton conducting perovskite electrolyte is developed in this study, in which four types of charge carriers including proton, oxygen vacancy (oxide ion), free electron and electron hole are taken into consideration. The electrochemical process within the SOFC with hydrogen as the fuel is theoretically analyzed. With the present model, the effects of some parameters, such as the thickness of electrolyte, operating temperature and gas composition, on the ionic transport (or gas permeation) through the electrolyte and the electrical performance, i.e., the electromotive force (EMF) and internal resistance of the cell, are investigated in detail. The theoretical results are tested partly by comparing with the experimental data obtained from SrCe0.95M0.05O3-α, (M=Yb, Y) cells.

Mg2＋-ion Conducting Polymer Electrolytes： Materials Characterization and All-Solid-State Battery Performance Studies

For All-Solid-State battery applications, Mg2＋-ion conducting polymer electrolytes and Mg-metal electrode are currently considered as alternate choices in place of Li＋-ion conducting polymer electrolytes/Li-metal electrode. Present paper reports fabrication of All-Solid-State battery based on the following Mg2＋-ion conducting nano composite polymer electrolyte （NCPE） films： [85PEO： 15Mg（C104）2] ＋ 5% TiO2 （〈 100 nm）, [85PEO： 15Mg（CIO4）2] ＋ 3% SiO2（-8 nm）. [85PEO： 15Mg（CIO4）2] ＋ 3% MgO （〈 100 nm）, [85PEO：15Mg（C1O4）2] ＋ 3% MgO （-44 μm）. NCPE films were prepared by hot-press technique. Solid Polymer Electrolyte （SPE） composition： [85PEO： 15Mg（CIO4）2], identified as high conducting film at room temperature, has been used as ISt--phase host and nano/micro particles of active （MgO）/passive （SiO2, TiO2） fillers as IInd-phase dispersoid. Filler particle dependent conductivity studies identified above mentioned NCPE films as optimum conducting composition （OCC） at room temperature. Ion transport behavior of SPE/NCPE film materials was investigated previously. Present paper reports materials characterization and cell performance studies on All-Solid-State batteries： Mg （Anode） Ⅱ SPE or NCPE films tt C＋MnO2＋Electrolyte （Cathode）. Open circuit voltage （OCV） obtained was in the range： 1.79-1.92 V. The batteries were discharged at room temperature under different load conditions and some important battery parameters have been evaluated from plateau region of cell-potential discharge profiles. All the batteries performed quite satisfactorily specially under low current drain states.

Research progress of transparent conducting ZnO:Al (ZAO) films

Owing to both of its high carrier concentration and large band gap, ZnO:Al (ZAO) films which is an n-type degenerate semiconductor, exhibits low resistance and high transmittance in the visible range. This work studies the crystal structure, optical and electrical properties and preparation methods of ZAO films, and discusses the existing problems and application prospective of ZAO films.

Effect of Screw-Dislocation on Electrical Properties of Spiral-Type Bi2Se3 Nanoplates

We systematically investigated the electrical nanoplates through field effect transistor and properties of spiral-type and smooth Bi2Se3 conductive atomic force microscopy （CAFM） measurement. It is observed that both nanoplates possess high conductivity and show metallic-like behavior. Compared to the smooth nanoplate, the spiral-type one exhibits the higher carrier concentration and lower mobility. CAFM characterization reveals that the conductance at the screw-dislocation edge is even higher than that on the terrace, implying that the dislocation can supply excess carriers to compensate the low mobility and achieve high conductivity. The unique structure and electrical properties make the spiral-type Bi2 Se3 nanoplates a good candidate for catalysts and gas sensors.

Fast-ionic conductor Li_(2.64)(Sc_(0.9)Ti_(0.1))_(2)(PO_(4))_(3) doped PVDF-HFP hybrid gel-electrolyte for lithium ion batteries

With increasing demand on energy density of lithium-ion battery,wide electrochemical window and safety performance are the crucial request for next generation electrolyte.Gel-electrolyte as a pioneer for electrolyte solidization development aims to solve the safety and electrochemical window problems.However,low ionic conductivity and poor physical performance prohibit its further application.Herein,a fast-ionic conductor(Li_(2.64)(Sc_(0.9)Ti_(0.1))_(2)(PO_(4))_(3))(LSTP)was added into poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)base gel-electrolyte to enhance mechanical properties and ionic conductivity.Evidences reveal that LSTP was able to weaken interforce between polymer chains,which increased the ionic conductibility and decreased interface resistance during the cycling significantly.The obtained LiFePO_(4)/hybrid gel-electrolyte/Li-metal coin cell exhibited excellent rate capacity(145 mA·h/g at 1C,95 mA·h/g at 3C,28℃)which presented a potential that can be comparable with commercialized liquid electrolyte system.

Structural,Electrical,and Optical Properties of Transparent Conductive Al-Doped ZnO Films Prepared by RF Magnetron Sputtering

Highly conductive transparent Al-doped zinc oxide （AZO） films with highly （002）-preferred orientation were successfully deposited on glass substrates at room temperature by RF magnetron sputtering. Optimization of deposition parameters was based on sputtering RF power and Ar pressure in the vacuum chamber. AZO films of 180nm with an electrical resistivity as low as 2.68 × 10^-3 Ω· cm and an average optical transmission of 90% in the visible range were obtained at RF power of 250W and Ar pressure of 1.2Pa. The effect of chemisorption of oxygen on the grain boundary would capture electrons from conduction band and lead the formation of potential barriers among the crystallites,which will influence the electric property of the AZO thin films. The films have satisfactory properties of low resistance and high transmittance for application as transparent conductive electrodes in light emitting diodes （LEDs） and solar cells.

Iron oxide encapsulated in nitrogen-rich carbon enabling high-performance lithium-ion capacitor

Lithium-ion capacitors(LICs)could combine the virtues of high power capability of conventional supercapacitors and high energy density of lithium-ion batteries.However,the lack of high-performance electrode materials and the kinetic imbalance between the positive and negative electrodes are the major challenge.In this study,Fe3O4 nanoparticles encapsulated in nitrogen-rich carbon(Fe3O4@NC)were prepared through a self-assembly of the colloidal Fe OOH with polyaniline(PANI)followed by pyrolysis.Due to the well-designed nanostructure,conductive nitrogen-rich carbon shells,abundant micropores and high specific surface area,Fe3O4@NC-700 delivers a high capacity,high rate capability and long cycling stability.Kinetic analyses of the redox reactions reveal the pseudocapacitive mechanism and the feasibility as negative material in LIC devices.A novel LIC was constructed with Fe3O4@NC-700 as the negative electrode and expanded graphene(EGN)as the positive electrode.The wellmatched two electrodes effectively alleviate the kinetic imbalance between the positive and negative electrodes.As a result,Fe3O4@NC-700//EGN LIC exhibits a wide operating voltage window,and thus achieves an ultrahigh energy density of 137.5 W h kg^-1.These results provide fundamental insights into the design of pseudocapacitive electrode and show future research directions towards the next generation energy storage devices.

Nanowire-based transparent conductors for flexible electronics and optoelectronics

As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.

Identifying the genes of unconventional high temperature superconductors

We elucidate a recently emergent framework in unifying the two families of high temperature （high To） superconductors, cuprates and iron-based superconductors. The unification suggests that the latter is simply the counterpart of the former to realize robust extended s-wave pairing symmetries in a square lattice. The unification identifies that the key ingredients （gene） of high Tc superconductors is a quasi two dimensional electronic environment in which the d-orbitals of cations that partic- ipate in strong in-plane couplings to the p-orbitals of anions are isolated near Fermi energy. With this gene, the superexchange magnetic interactions mediated by anions could maximize their contributions to superconductivity. Creating the gene requires special arrangements between local electronic structures and crystal lattice structures. The speciality explains why high Tc superconductors are so rare. An explicit prediction is made to realize high Tc superconductivity in Co/Ni-based materials with a quasi two dimensional hexagonal lattice structure formed by trigonal bipyramidal complexes.

Nanostructuring the electronic conducting La_(0.8)Sr_(0.2)MnO_(3-δ) cathode for high-performance in proton-conducting solid oxide fuel cells below 600℃

Proton-conducting oxides offer a promising electrolyte solution for intermediate temperature solid oxide fuel cells（SOFCs） due to their high conductivity and low activation energy. However, the lower operation temperature leads to a reduced cathode activity and thus a poorer fuel cell performance. La_（0.8）Sr_（0.2）MnO_（3-δ）（LSM） is the classical cathode material for high-temperature SOFCs, which lack features as a proper SOFC cathode material at intermediate temperatures.Despite this, we here successfully couple nanostructured LSM cathode with proton-conducting electrolytes to operate below600℃ with desirable SOFC performance. Inkjet printing allows depositing nanostructured particles of LSM on Y-doped Ba ZrO_3（BZY） backbones as cathodes for proton-conducting SOFCs, which provides one of the highest power output for the BZY-based fuel cells below 600 ℃. This somehow changes the common knowledge that LSM can be applied as a SOFC cathode materials only at high temperatures（above 700 ℃）.

Maximizing the ion accessibility and high mechanical strength in nanoscale ion channel MXene electrodes for high-capacity zinc-ion energy storage

Two-dimensional transition-metal carbides(MXenes)have superhydrophilic surfaces and superior metal conductivity,making them competitive in the field of electrochemical energy storage.However,MXenes with layered structures are easily stackable,which reduces the ion accessibility and transport paths,thus limiting their electrochemical performance.To fully exploit the advantages of MXenes in electrochemical energy storage,this study reports the etching of large-sized MXene into nanosheets with nanoscale ion channels via a chemical oxidation method.While the resulting ion-channel MXene electrodes retain the excellent mechanical strength and electrical conductivity of large-sized MXene nanosheets,they can effectively shorten the ion transport distance and improve the overall electrochemical activity.The fabricated self-healing MXene-based zinc-ion microcapacitor exhibits a high areal specific capacitance(532.8 mF cm^(-2))at the current density of 2mA cm^(-2),a low self-discharge rate(4.4 mV h^(-1)),and high energy density of 145.1μWh cm^(-2)at the power density of 2800μW cm^(-2).The proposed nanoscale ion channel structure provides an alternative strategy for constructing high-performance electrochemical energy storage electrodes,and has great application prospects in the fields of electrochemical energy storage and flexible electronics.

Post-annealing tailored 3D cross-linked TiNb2O7 nanorod electrode: towards superior lithium storage for flexible lithium-ion capacitors

TiNb2O7 anode materials(TNO)have unique potential for applications in Li-ion capacitors(LICs)due to their high specific capacity of ca.280 mA h g^-1 over a wide anodic Li-insertion potential window.However,their highrate capability is limited by their poor electronic and ionic conductivity.In particular,studies on TNO for LICs are lacking and that for flexible LICs have not yet been reported.Herein,a unique TNO porous electrode with cross-linked nanorods tailored by post-annealing and its application in flexible LICs are reported.This binder-free TNO anode exhibits superior rate performance(~66.3%capacity retention as the rate increases from 1 to 40 C),which is ascribed to the greatly shortened ion-diffusion length in TNO nanorods,facile electrolyte penetration and fast electron transport along the continuous single-crystalline nanorod network.Furthermore,the TNO anode shows an excellent cycling stability up to 2000 cycles and good flexibility(no capacity loss after continuous bending for 500 times).Model flexible LIC assembled with the TNO anode and activated carbon cathode exhibits increased gravimetric and volumetric energy/power densities(~100.6 W h kg^-1/4108.8 W kg^-1;10.7 mW h cm^-3/419.3 mW cm^-3),more superior to previously reported hybrid supercapacitors.The device also efficiently powers an LED light upon 180°bending.

Improving the volumetric specific capacitance of flexible polyaniline electrode:solution casting method and effect of reduced graphene oxide sheets

High volumetric specific capacitance is essential for flexible supercapacitors.In this paper,a flexible composite electrode with ultrahigh volumetric specific capacitance and good rate performance is designed and prepared.The film electrode is composed of non-porous compact polyaniline as the matrix and a small amount of reduced graphene oxide sheets as the conductive filler.The film is prepared by a newly developed solution casting method,where the casting solution is obtained by self-assembly of polyaniline and graphene oxide in a blended solution.A systematical investigation on the effect of reduced graphene oxide sheets reveals that they serve as both the conductive filler and the diffusion barrier.With the optimized reduced graphene oxide content,a large volumetric specific capacitance of 1354 F cm^−3 at 2.4 A cm^−3 is achieved,and good rate performance is also obtained because of the good ionic conductivity of polyaniline.This work provides a high performance electrode for flexible supercapacitors,and the solution casting method is also valuable in fabricating other organic electrode materials.