A Modification of LiMn2O4 by Ionic Conductive Agent and Electronic Conductive Agent Coating

Carbon was used as electronic conductive agent, and metasilicic acid lithium (Li2SiO3) as ionic conductive agent, the two factors were investigated cooperatively. We evaluated their effect by using spherical spinel LiMn2O4 which prepared ourselves as cathode material. Then Li2SiO3/carbon surface coating on LiMn2O4 (LMO/C/LSO) which Li2SiO3 inside and carbon/Li2SiO3 coated LiMn2O4 (LMO/LSO/C) were prepared, All of materials were characterized by X-ray diffraction (XRD) and electrochemical test;spherical LiMn2O4 was characterized by scanning electron microscopy (SEM);and coated materials were characterized by transmission electron microscopy (TEM). While uncoated spinel LiMn2O4 maintained 72% of capacity in 60 cycles by the rate of 0.2C, and LMO/LSO/C showed the best electrochemical performance, 89% of the initial capacity remained after 75 cycles at 0.2C. Furthermore, the rate performance of LMO/LSO/C also improved obviously, about 30 mAh·g-1 of capacity attained at the rate of 5C, higher than LMO/C/LSO and bare LiMn2O4.

A review on electronically conducting polymers for lithium-sulfur battery and lithium-selenium battery:Progress and prospects

Lithium-sulfur(Li-S) batteries and lithium-selenium(Li-Se) batteries,as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities,have become the hotspots of current researches.Besides,elemental S(Se) raw materials are widely sourced and their production costs are both low,which make them considered one of the new generations of high energy density electrochemical energy storage systems with the most potential for development.However,poor conductivity of elemental S/Se and the notorious "shuttle effect" of lithium polysulfides(polyselenides) severely hinder the commercialization of Li-S/Se batteries.Thanks to the excellent electrical conductivity and strong absorption of lithium polysulfide(polyselenide) about electronically conducting polymer,some of the above thorny problems have been effectively alleviated.The review presents the fundamental studies and current development trends of common electronically conducting polymers in various components of Li-S/Se batteries,which involves polyaniline(PANI) polypyrrole(PPy),and polythiophene(PTh) with its derivatives,e.g.polyethoxythiophene(PEDOT) and poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS).Finally,the review not only summarizes the research directions and challenges facing the application of electronically conducting polymers,but also looks forward to the development prospects of them,which will provide a way for the practical use of electronically conducting polymers in Li-S/Se batteries with outstanding electrochemical properties in the short run.

Study on Electronic Conductivity of CaO-SiO2-Al2O3-FeOx Slag System

A study on electronic conductivity of CaO-SiO2-Al2O3-FeOxslag system with Wagner polarization technique was carried out.The experimental data show that electronic conductivity is consisted of free electron conductivity and electron hole conductivity and both are related to the content of Fe3+and Fe2+.Free electron conductivity is decreasing and electron hole conductivity is increasing while Fe3+changes to Fe2+.There is a maximum electronic conductivity at some ratio of ferric ions Fe3+to total ion content.Under the experimental conditions,the electronic conductivity is in the range of 10-4—10-2S/cm.

Effect of ZrO_2 (9mol% Y_2O_3) coating thickness on the electronic conductivity of Mg-PSZ oxygen sensors

The ZrO2 (9mol% Y2O3) coating was prepared evenly on the surface of MgO partially stabilized zirconia (Mg-PSZ) tube (oxygen sensor probe) by dipping the green Mg-PSZ tube in a ZrO2 (9mol% Y2O3) slurry and then co-firing at 1750°C for 8 h. The double-cell method was employed to measure the electronic conductivity parameter and exam the reproducibility of the coated Mg- PSZ tube. The experimental results indicate that the good thermal shock resistance of the Mg-PSZ tube can be retained when the coating thickness is not more than 3.4 μm. The ZrO2 (9mol% Y2O3) coating reduces the electronic conductivity parameter remarka- bly, probably due to the lower electronic conductivity of Y2O,-stabilized ZrO2 than that of MgO-stabilized ZrO2. Moreover, the ZrO2 (9mol% Y2O3) coating can improve the reproducibility and accuracy of the Mg-PSZ tube significantly in the low oxygen measure- ment. The smooth surface feature and lower electronic conductivity of the coated Mg-PSZ tube should be responsible for this im- provement.

Spaced-Resolved Electron Density of Aluminum Plasma Produced by Frequency-Tripled Laser

By using the space-resolved spectrograph, the K-shell emission from laser-produced plasma was investigated. Electron density profiles along the normal direction of the target surface in aluminum laser-plasmas were obtained by two different diagnostic methods and compared with the profiles from the theoretical simulation of hydrodynamics code MULTI1D. The results corroborate the feasibility to obtain the electron density above the critical surface by the diagnostic method based on the Stark-broadened wings in the intermediately coupled plasmas.

Laser X-ray Conversion and Electron Thermal Conductivity

The influence of electron thermal conductivity on the laser x-ray conversion in the coupling of 3w. laser with Au plane target has been investigated by using a non-LTE radiation hydrodynamic code. The non-local electron thermal conductivity is introduced and compared with the other two kinds of the flux-limited Spitzer-Harm description. The results show that the non-local thermal conductivity causes the increase of the laser x-ray conversion efficiency and important changes of the plasma state and coupling feature.

Electron states and electron Raman scattering in semiconductor double cylindrical quantum well wire

The differential cross section for an electron Raman scattering process in a semiconductor GaAs/AlGaAs double quantum well wire is calculated,and expressions for the electronic states are presented.The system is modeled by considering T = 0 K and also with a single parabolic conduction band,which is split into a subband system due to the confinement.The gain and differential cross-section for an electron Raman scattering process are obtained.In addition,the emission spectra for several scattering configurations are discussed,and interpretations of the singularities found in the spectra are given.The electron Raman scattering studied here can be used to provide direct information about the efficiency of the lasers.

Electronic Transport of Uranium Mononitride

We investigated the electronic heat capacity, thermal conductivity, and resistivity of UN using Quantum Espresso and EPW code. GGA, PBEsol functional was used. The calculated electronic heat coefficient was found to be significantly reduced (0.0176 J⋅mol-1⋅K-2 versus 0.0006 J⋅mol-1⋅K-2) when the non-local hybrid functional (B3LYP) was used. Furthermore, we calculated electrical resistivity using a very transparent Ziman’s formula for metals with the Eliashberg transport coupling function as implemented in EPW code for non-spin-polarized calculations. The number of mobile electrons in UN, as a function of temperature, was derived from the ratio of the calculated resistivity and available experimental data. The electronic thermal conductivity was evaluated from the calculated electronic resistivity via Wiedemann-Franz law with the number of mobility electrons (nav) incorporated (averaged over the temperature range 300 K - 1000 K). Both the electronic thermal conductivity and resistivity, as calculated using newly evaluated nav, compare well with experimental data at ~700 K, but to reproduce the observed trend as a function of temperature, the number of mobile electrons must decrease with the temperature as evaluated.

Electron Transport under the Influence of Two Kinds of Friction in an Electron-Deuteron Plasma

We discuss an electron transport in an ideal plasma which consists of electrons and deuterons. With respect to a frictional force to suppress an unlimited increase of a drift velocity, the Boltzmann equation with the Fokker-Planck collision term takes into consideration only a dynamical frictional force coming from the many-body collisions through the Coulomb force. However, we here bring forward a problem that there may be another frictional force besides the dynamical frictional force. Another frictional force was found in the weakly ionized plasma and appears only in the case where free paths (nearly straight lines in no external force field) can be defined. Then, we have inquired into the existence of physical quantities like free paths (or free times) in the field of the scattering through the Coulomb force and the existence of an effective radius of the Coulomb force of a deuteron.

Metal-nitrogen-doped hybrid ionic/electronic conduction triple-phase interfaces for high-performance all-solid-state lithium-sulfur batteries

The point-to-point contact mechanism in all-solid-state Li-S batteries(ASSLSBs)is not as efficient as a liquid electrolyte which has superior mobility in the electrode,resulting in a slower reaction kinetics and inadequate ionic/electronic conduction network between the S(or Li_(2)S),conductive carbon,and solid-state electrolytes(SSEs)for achieving a swift(dis)charge reaction.Herein,a series of hybrid ionic/electronic conduction triple-phase interfaces with transition metal and nitrogen co-doping were designed.The graphitic ordered mesoporous carbon frameworks(TM-N-OMCs;TM=Fe,Co,Ni,and Cu)serve as hosts for Li_(2)S and Li_(6)PS_(5)Cl(LPSC)and provide abundant reaction sites on the triple interface.Results from both experimental and computational research display that the combination of Cu-N co-dopants can promote the Li-ion diffusion for rapid transformation of Li_(2)S with adequate ionic(6.73×10^(−4)S·cm^(−1))/electronic conductivities(1.77×10^(−2)S·cm^(−1))at 25℃.The as-acquired Li_(2)S/Cu-N-OMC/LPSC electrode exhibits a high reversible capacity(1147.7 mAh·g^(−1))at 0.1 C,excellent capacity retention(99.5%)after 500 cycles at 0.5 C,and high areal capacity(7.08 mAh·cm^(−2)).

Ni-P-SBR composite-electroless-plating enables Si anode with high conductivity and elasticity for high performance Li-ion batteries application

Silica-based anode is widely employed for high energy density Li-ion batteries owing to their high theoretical specific capacity(4200 m A h g-1).However,it is always accompanied by a huge volume expansion(300%)and shrinks during the lithiation/delithiation process,further leading to low cycle stability.Efforts to mitigate the adverse effects caused by volume expansion such as robust binder matrix,Coreshell structure,etc.,inevitably affect the electronic conductivity within the electrode.Herein,a high conductivity and elasticity Si anode(Ni-P-SBR(styrene-butadiene rubber)@Si)was designed and fabricated via the Ni-P-SBR composite-electroless-plating process.In this design,the Si particles are surrounded by SBR polymer and Ni particles,where the SBR can adapt to the volume change and Ni particles can provide the electrode with high electronic conductivity.Therefore,the Ni-P-SBR@Si delivers a high initial capacity of 3470 m A h g-1and presents capacity retention of 49.4%within 200 cycles at 600 m A g-1.Additionally,a high capacity of 1153 m A h g-1can be achieved at 2000 m A g-1and can be cycled stably under bending conditions.This strategy provides feasible ideas to solve the key issues that limit the practical application of Si anodes.

Synthesis and electrochemical performance of La_(2)CuO_(4)as a promising coating material for high voltage Li-rich layered oxide cathodes

The structural transformations,oxygen releasing and side reactions with electrolytes on the surface are considered as the main causes of the performance degradation of Li-rich layered oxides(LROs)cathodes in Li-ion batteries.Thus,stabilizing the surfaces of LROs is the key to realize their practical application in high energy density Li-ion batteries.Surface coating is regarded as one of the most effective strategies for high voltage cathodes.The ideal coating materials should prevent cathodes from electrolyte corrosion and possess both electronic and Li-ionic conductivities simultaneously.However,commonly reported coating materials are unable to balance these functions well.Herein,a new type of coating material,La_(2)CuO_(4)was introduced to mitigate the surface issues of LROs for the first time,due to its superb electronic conductivity(26-35 mS·cm^(-1))and lithium-ionic diffusion coefficient(10^(-12)-10^(-13)cm^(2)·s^(-1)).After coating with the La_(2)CuO_(4),the capacity retention of Li_(1.2)Ni_(0.54)Co_(0.13)Mn_(0.13)O_(2)cathode was increased to 85.9%(compared to 79.3%of uncoated cathode)after 150 cycles in the voltage range of 2.0-4.8 V.In addition,only negligible degradations on the deliverable capacity and rate capability were observed.

A lithium–tin fluoride anode enabled by ionic/electronic conductive paths for garnet-based solid-state lithium metal batteries

The high energy density and stability of solid-state lithium metal batteries(SSLMBs)have garnered great attention.Garnet-type oxides,especially Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO),with high ionic conductivity,wide electrochemical window,and stability to Li metal anode,are promising solid-state electrolyte(SSEs)materials for SSLMBs.However,Li/LLZTO interface issues including high interface resistance,inhomogeneous Li deposition,and Li dendrite growth have hindered the practical application of SSLMBs.Herein,a multi-functional Li–SnF_(2) composite anode with Li,LiF,and Li-Sn alloy was specifically designed and prepared.The composite anode improves the wettability to LLZTO,constructing an intimate contact interface between it and LLZTO.Meanwhile,ionic/electronic conductive paths in situ formed at the interface can effectively uniform Li deposition and suppress Li dendrite.The solid-state symmetric cell exhibits low interface resistance(11Ω·cm^(2)) and high critical current density(1.3 mA·cm^(−2))at 25℃.The full SSLMB based on LiFePO_(4) or LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathode also shows stable cycling performance and high rate capability.This work provides a new composite anode strategy for achieving high-energy density and high-safety SSLMBs.

Fowler-Nordheim Tunneling, Photovoltaic Applications and New Band Structure Models of Electroconductive a-CNx:H Films Formed by Supermagnetron Plasma CVD

Hydrogenated amorphous carbon nitride (a-CNx:H) films were formed on Al films deposited on Si or glass (SiO2) substrates, using pulsed radio frequency (PRF) supermagnetron plasma (SMP) chemical vapor deposition (CVD) with N2/i-C4H10 mixed gases. a-CNx:H films were grown under the upper and lower electrode RF powers (13.56 MHz) of continuous and pulsed conditions, respectively, which showed low band gap of about 0.7 eV. a-CNx:H films deposited on the Al/Si or Al/SiO2 substrates showed same low threshold emission electric field (ETH) of 12 V/μm. Multiple layer of Al or ITO (anode)/50nm-SiO2/a-CNx:H/Al (cathode)/Si structures showed Fowler-Nordheim (FN) electron tunneling effect in both forward and reverse current directions. 12.5 nm a-CNx:H film on p-Si substrate showed a photoelectric conversion. Energy band structure and electron conduction models were proposed for the active states of both the field emission and FN tunneling devices and photovoltaic cells.

CNTs@S composite as cathode for all-solid-state lithium-sulfur batteries with ultralong cycle life

The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite formation.All-solid-state lithium-sulfur batteries have been proposed to solve the shuttle effect and prevent short circuits.However,solid-solid contacts between the electrodes and the electrolyte increase the interface resistance and stress/strain,which could result in the limited electrochemical performances.In this work,the cathode of all-solid-state lithium-sulfur batteries is prepared by depositing sulfur on the surface of the carbon nanotubes(CNTs@S)and further mixing with Li10GeP2S12 electrolyte and acetylene black agents.At 60℃,CNTs@S electrode exhibits superior electrochemical performance,delivering the reversible discharge capacities of 1193.3,959.5,813.1,569.6 and 395.5 mAhg^-1 at the rate of 0.1,0.5,1,2 and 5 C,respectively.Moreover,the CNTs@S is able to demonstrate superior high-rate capability of 660.3 mAhg^-1 and cycling stability of 400 cycles at a high rate of 1.0 C.Such uniform distribution of the CNTs,S and Li10GeP2S12 electrolyte increase the electronic and ionic conductivity between the cathode and the electrolyte hence improves the rate performance and capacity retention.

Study on rare earth electrolyte of SDC-LSGM

Ce0.85Sm0.15O1.925 （SDC） and La0.9Sr0.1Ga0.5Mg0.2O2.85 （LSGM） were synthesized using Glycine-Nitrate Process （GNP）, and the composite electrolytes were prepared by mixing SDC and LSGM. An X-ray diffraction pattern indicated that the mixture of SDC and LSGM consisted of their original phases after heating at 1450 ℃ for 10 h. The electronic conductivity of SDC-LSGM composite electrolytes were measured by direct current polarization method using Hebb-Wagner ion blocking cell at 700-800 ℃ in the oxygen partial pressure range of 104-10-20 MPa and compared with the results of SDC. Typical polarization curves, which were theoretically predicted, were observed on all the samples. The slopes of lgσe-lgPo2 plot for all the composite electrolytes agreed with the theoretically predicted value of-1/4 at some intermediate oxygen partial pressures and -1/6 at low oxygen partial pressure. The electronic conductivity of SDC-LSGM composite electrolytes decreased with the increase in LSGM content, whereas the ionic transport number ti of all the samples increased with the increase in LSGM content.

Hydrogen Permeation Properties of Perovskite-type BaCe_(0.9)Mn_(0.1)O_(3-δ)Dense Ceramic Membrane

The electrical conduction properties of dense BaCe0.9Mn0.1O3-d (BCM10) membrane were investigated in the temperature range of 600-900oC. High ionic and electronic conductivities at elevated temperatures make BCM10 a potential ceramic material for hydrogen separation. Hydrogen permeation through BCM10 membranes was studied using a high- temperature permeation cell. Little hydrogen could be detected at the sweep side. However, appreciable hydrogen can permeate through BCM10 membrane coated with porous platinum black, which shows that the process of hydrogen permeation through BCM10 membranes was controlled by the catalytic decomposition and recomposition of hydrogen on the surfaces of BCM10 membranes.

Architecture engineering of carbonaceous anodes for high-rate potassium-ion batteries

The limited lithium resource in earth's crust has stimulated the pursuit of alternative energy storage technologies to lithium-ion battery.Potassium-ion batteries(KIBs)are regarded as a kind of promising candidate for large-scale energy storage owing to the high abundance and low cost of potassium resources.Nevertheless,further development and wide application of KIBs are still challenged by several obstacles,one of which is their fast capacity deterioration at high rates.A considerable amount of effort has recently been devoted to address this problem by developing advanced carbonaceous anode materials with diverse structures and morphologies.This review presents and highlights how the architecture engineering of carbonaceous anode materials gives rise to high-rate performances for KIBs,and also the beneficial conceptions are consciously extracted from the recent progress.Particularly,basic insights into the recent engineering strategies,structural innovation,and the related advances of carbonaceous anodes for high-rate KIBs are under specific concerns.Based on the achievements attained so far,a perspective on the foregoing,and proposed possible directions,and avenues for designing high-rate anodes,are presented finally.

Influence of Conductivity of Slag on Decarburization Reaction

By altering the electrochemical properties of slag, the decarburization reaction of Fe3+-based slag withFe-C droplet was studied. The results showed that a lot of free electrons and holes exist in the slag containing transition metal oxides (such as TiO2 and Fe2O3). So electronic conduction in the slag increases. Finally, it led to the increment of the decarburization reaction rate between slag and Fe-C droplet, and mass fraction of carbon remaining indroplet decreases to a lower level.

Understanding De-protonation Induced Formation of Spinel Phase in Li-rich Layered Oxides for Improved Rate Performance

Constructing layered-spinel composites is important to improve the rate performance of lithium-rich layered oxides.However,up to now,the effect of microstructure of composites on the rate performance has not been well investigated.In this study,a series of samples were prepared by a simple protonation and de-protonation for the pristine layered material(LiMnNiCoO)obtained by sol-gel method.The characterizations of XRD,Raman and oxidation-reduction potentials of charge-discharge curves demonstrated that these samples after de-protonation are layered-spinel composites.When these composites were tested as a cathode of lithium-ion batteries,the sample treated with 0.1 M of nitric acid exhibited higher discharge capacities at each current density than that of other composites.The outstanding rate performance is attributed to the high concentration of conduction electron resulting from the low average valence state(44.2%of Ni)as confirmed by its high conductivity(1.124×10??mat39800Hz)and ambient temperature magnetic susceptibility(8.40×10emu/Oe?mol).This work has a guiding significance for the synthesis of high rate performance of lithium battery cathode materials.