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A theoretical model is suggested to describe the dislocation-mediated mechanisms for the nucleation and growth of nanoscale deformation twins in hexagonal-close-packed materials. In the framework of the model, the nanoscale deformation twins nucleate and grow through the glide of glissile Shockley partial dislocations which are generated due to the nonplanar dissociation of the leading dislocation in a pile-up of 〈a〉 slip dislocations on the basal plane. Here, the pile-up of 〈a〉 dislocations on the basal plane was produced by preceding plastic deformation processes. The energy and stress conditions of the nanoscale deformation twin nucleation and growth through the dislocation-mediated mechanisms are calculated and discussed in detail. The results indicate that, when the pre-existent pile-up on the basal plane is 10–5, the nanoscale deformation { 1 ¯ 0 1 2 } twin nucleation stress is about 466.97–519.51 MPa. If take the shear stress applied to the pre-existent dislocation pile-up into account, the results are consistent with the experimental and molecular dynamic simulation results in literature. Besides, the twin is connected to grain boundary, and the longitudinal section of the twin is an approximately rectangular shape.

The a 0 / 2 〈 111 〉 screw dislocation glides through the nucleation and propagation of the kink-pair which dominates the plastic deformation of the BCC iron. A continuum model and the corresponding numerical methods are developed to investigate the kink mechanism on an arbitrary shape Peierls potential and subject to an external stress field. This model gives a link between the Landau theory of phase transitions and the line tension theory of string models. The order parameter is associated with the screw dislocation in BCC iron for describing the relative slip between adjacent Peierls valley. The kink configurations on the different Peierls potentials, such as the sinusoidal, Eshelby, anti-parabolic and camel-hump potential, are derived. By considering the motion of the screw dislocation on a 2-D Peierls potential surface, the 3-D saddle-point configuration of a non-planar kink-pair is obtained. The configuration is directly related to the details of the 2-D potential surface and it changes along with the applied stress tensor. A parameterized constitutive equation is derived for describing the temperature dependence of the flow stress which is compared with the experimental data from literature. The twinning/anti-twinning (T/AT) asymmetry and the tension-compression (T/C) asymmetry are reproduced in the model. The results rule out the possibility that the non-Schmid plasticity of the BCC iron is ascribed to split configuration.

The alumina contains plenty of Li2O and K2O as a result of using low-grade bauxite in China. Thus, LiF and KF will be enriched in the electrolytes with the operation of the cell, so that the composition and physicochemical properties of electrolytes have been changed. The effects of LiF, KF, and CR on the liquidus temperature of electrolytes based on the xNaF·AlF3-5 wt pct CaF2-2.5 wt pct Al2O3-0.5 wt pct MgF2 system have been investigated in this study. The results show that the liquidus temperature decreases by 5.13 K to 10.74 K (5.13 °C to 10.74 °C) per 1 wt pct addition of LiF and that the liquidus temperature decreases by 1.63 K to 3.8 K (1.63 °C to 3.8 °C) with per 1 wt pct addition of KF. When adding LiF and KF together, it has the interplay between LiF and KF. Under different electrolyte systems, the interplay between LiF and KF is complex. The effect of CR on liquidus temperature has been related to the concentration of LiF and KF.

MgAl 2 O 4 MgAlON materials as potential candidate sidewalls were prepared by using AlN, MgO, Al 2 O 3 , and nanosized MgAl 2 O 4 powder as starting materials. The reaction sintering of the MgAl 2 O 4 MgAlON materials was investigated by means of X-ray diffraction and scanning electron microscope. All the specimens were corroded in a Na 3 AlF 6 AlF 3 CaF 2 Al 2 O 3 bath to assess the electrolyte corrosion resistance. The results show that reaction sintering occurs in the MgAl 2 O 4 MgO Al 2 O 3 AlN system at 1830 °C and 5 MPa in flowing nitrogen for 5 h. The MgAl 2 O 4 MgAlON specimens are obtained and have high bulk density. The flexural strength increases from 202 ± 6 MPa to 248 ± 8 MPa and the Vickers hardness increases from 9.5 ± 0.2 GPa to 12.6 ± 0.4 GPa with increasing MgAlON content from 10 wt% to 40 wt%. The MgAl 2 O 4 MgAlON materials exhibit a good corrosion resistance to the Na 3 AlF 6 AlF 3 CaF 2 Al 2 O 3 bath owing to their high-density and the formation of the composite spinel in the specimens. The corrosion mechanisms of MgAl 2 O 4 MgAlON composites in molten electrolyte are mainly proposed by the dissolution of MgAl 2 O 4 and the diffusion of fluoride. Corrosion kinetic obeys a nearly parabolic law and the corrosion rate decreases with increasing MgAlON content.

The thickening mechanism of the deformation twinning (DT) has been frequently studied in numerous researches and the transverse propagation of that is beginning to trigger the attention of scholars. Recently, some researchers report that the twin front of { 10 1 ¯ 2 } mode of Magnesium is composed of a conjugate twin plane and prismatic/basal (PB) planes, and the combined mobility of these planes rule the overall kinetics of twin propagation. Focusing on that, a continuum phase field model is proposed to investigate the equilibrium shape of tensile twins and the kinetics of the twin front. A new form of surface free energy is introduced in this model for the purpose of describing the orientation-dependent properties of twin boundaries. The simulations well reproduce the PB interfaces and the results indicate that the anisotropic surface energy plays a dominant role in forming the irregular facets on the twin front. A generalized energy-momentum tensor is derived and analyzed for shear loading in order to investigate the equilibrium and mobility of twin boundaries, and the simulations show that the configurational forces distributed on the PB interfaces are smaller than that on the other twin planes, which implies that the growth of twin is beneficial for the formation of PB interfaces. The simulations also indicate that the anisotropic twin boundary energy is not responsible for the large aspect ratio nature of twins, which may be governed by the competition between thickening mechanism and transverse propagation mechanism of the DT.

The corrosion and oxygen evolution behaviors of cast and rolled Pb–Ag–Nd anodes were investigated by metalloscopy, environmental scanning electron microscopy, X-ray diffraction analysis, and various electrochemical measurements. The rolled anode exhibits fewer interdendritic boundaries and a dispersed distribution of Pb–Ag eutectic mixtures and Nd-rich phases in its cross-section. This feature inhibits rapid interdendritic corrosion into the metallic substrate along the interdendritic boundary network. In addition, the anodic layer formed on the rolled anode is more stable toward the electrolyte than that formed on the cast anode, reducing the corrosion of the metallic substrate during current interruption. Hence, the rolled anode has a higher corrosion resistance than the cast anode. However, the rolled anode exhibits a slightly higher anodic potential than the cast anode after 72 h of galvanostatic polarization, consistent with the larger charge transfer resistance. This larger charge transfer resistance may result from the oxygen-evolution reactive sites being blocked by the adsorption of more intermediates and oxygen species at the anodic layer/electrolyte interfaces of the rolled anode than at the interfaces of cast anode.

Kesterite Cu 2 ZnSnS 4 (CZTS) thin films have been fabricated by an electrodeposition route via sulfurizing sequentially electrodeposited Cu–Zn and Cu–Sn stacked binary alloy layers. The CZTS films exhibit densely packed grains with only minor ZnS secondary phase. Photovoltaic device with the structure of ITO/i-ZnO/CdS/CZTS/Mo/Glass shows the highest power conversion efficiency of 3.67%. The limiting factors of the efficiency are the high series resistance and recombination rate. The ZnS phase, voids at the Mo/CZTS interface and high resistance MoS 2 layer have been considered to lead to high series resistance and thereby low J SC and FF.

A (Cu,Ni)/(10NiO-NiFe2O4) cermet was tested as an inert anode for aluminum electrolysis in Na3AlF6-K3AlF6-AlF3 melt at 1173 K (900 °C), and its corrosion behavior was studied. The results show that the low-temperature Na3AlF6-K3AlF6-AlF3 bath is beneficial, improving the service conditions. With the combined effects of the electrolyte composition and the nascent oxygen during electrolysis, the metal phase (Cu,Ni) at the surface of anode will not be leached preferentially, but be transferred into the aluminates including FeAl2O4, NiAl2O4 and CuAl2O4. This is helpful for the anode to improve its corrosion resistance.

Cu 2 FeSnSe 4 (CFTSe) nanocrystals have been synthesized by a hot-injection method. The structure of prepared CFTSe nanocrystals is determined by XRD, high resolution TEM image, and SAED pattern. The composition of the CFTSe nanocrystals is confirmed from the results of EDS and XPS. Results clearly prove the formation of CFTSe nanocrystals using the hot-injection method in this study. A band gap of 1.60±0.02 eV for CFTSe nanocrystals is obtained from the UV–vis–NIR data. Moreover, the corresponding CFTSe nanocrystals-film shows a clear photoresponse in photoelectrochemical measurement. Our work illustrates that CFTSe nanocrystals have potential application in the field of solar energy conversion.

Co0.85Se nanocrystals were synthesized via the hot-injection method using oleylamine (OLA) as solvent. The experimental results indicate that the reaction temperature plays an important role in the formation of Co0.85Se nanocrystals. Meanwhile, it is also found that the source of cobalt (CoCl2) should be excessive to obtain pure Co0.85Se nanocrystals. The obtained nanocrystals exhibit particulate shape and pure hexagonal Co0.85Se phase based on transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) analyses. Optical and optoelectronic properties of the film drop-coated by Co0.85Se nanocrystals ink were also characterized. The obtained sample shows an optical band gap value of 1.16 eV and remarkable photo-electrical response, suggesting that the prepared Co0.85Se nanocrystals have the great potential in photo-electrical conversion application.

Furan, epoxy, and their composites were used to modify pitch binder for TiB2/C composite cathode in aluminum electrolysis. The physical-chemical properties of the cathodes have been investigated. When the pitch is modified by furan and epoxy composite, the cathode exhibits the lowest electrolysis expansion (0.60 pct), open porosity (28.80 pct), and electrical resistivity (35.91 μΩ·m); the highest bulk density (2.54 g·cm–3); and compressive strength (44.90 MPa). Results of the semicokes from a scanning electron microscope show that cohesion and toughness are effectively improved, especially in the case of the furan and epoxy composite-modified pitch semicokes. Studies using Fourier transform infrared spectroscopy indicate that an aromaticity index of 0.845 and a condensed degree Abs880/Abs1600 of 0.927 of polynuclear aromatic hydrocarbons are obtained, suggesting that a more complete reaction of the cross-linked curing takes place in the pitch binder modified by furan and epoxy composite, which improves cohesion and toughness of the binder and, thus, enhances the performances of TiB2/C composite cathode.

Fundamental thermodynamic features of metal selenides electrodeposition have been investigated in this paper. Based on thermodynamic calculation, the reaction equilibriums and potential–pH formulas of Me–Se–H2O system at 298 K are obtained, and the general potential–pH diagram of this system is drawn for the first time. The potential–pH diagram for some typical selenides is also presented. The analysis results show that the electrodeposition of metal selenides generally proceeds under weak acidic conditions (pH 1–3) via Kroger mechanism, and the deposition potential should be more positive than that of individual metal ions. It is also found that for different metal selenides, the deposition potential and pH ranges are different. Usually, the more positive the standard redox potential of the metal element is, the more positive the deposition potential of selenide corresponds to, and the broader the optional pH range can be.

The effect of thermal treatment on the microstructure and properties of pitches and thermal-treated, pitch-based TiB2/C composite cathodes were investigated. Thermal treatments were performed at 473 K, 523 K, 573 K, 623 K, and 673 K (200 °C, 250 °C, 300 °C, 350 °C, and 400 °C), respectively. The results show that the aromaticity of the treated pitches increases with an increasing thermal treatment temperature, and subsequently, the coking value and quinoline-insoluble (QI) content increase from 60.62 wt pct to 79.09 wt. pct and from 8.97 wt pct to 32.54 wt pct when the treatment temperature increases from 473 K to 623 K (200 °C to 350 °C). The volume fraction of coalesced mesophase in semicoke decreases with an increasing thermal treatment temperature, and after 673 K (400 °C) is reached, the coalesced mesophase is almost invisible. The bulk density and compressive strength of modified pitch-based cathodes increase with an increasing thermal treatment temperature from 2.24 g cm−3 to 2.39 g cm−3 and from 24.21 MPa to 54.85 MPa, whereas open porosity decreases from 34.62 pct to 27.06 pct. Both electrical resistivity and electrolysis expansion ratio first decrease and then increase with an increasing thermal treatment temperature, and the lowest values (45.63 μΩ m and 0.65 pct) are achieved at 573 K (300 °C). Compared with those of the parent pitch-based cathode, the properties of the modified pitch-based cathodes had improved significantly. The mechanisms of the improvements are discussed in the text.

Cu(In,Ga)Se2 thin films were prepared from aqueous solution by pulse electrodeposition. It was found that the co-deposition of the species occurred under a 3D growth with instantaneous nucleation. The morphology of the pulse-electrodeposited film can be improved by adjusting the duty cycle. The significant loss of indium and reduction of In–Se compound(s) accordingly were observed with decrease of duty cycle. Chalcopyrite structure Cu(In,Ga)Se2 films with p-type behavior and enhancement in crystallinity were obtained after annealing treatment in Ar atmosphere.

A Cu 2 ZnSnS 4 (CZTS) ultrathin film counter electrode (CE) was prepared in situ by the sol–gel method. As the film was only 200 nm thickness, it showed a degree of transparence. The dye-sensitized solar cell (DSSC) with the prepared CE was the bifacially active transparent cell, which exhibited η of 5.63% and 1.60% corresponding to front- and back-side illumination respectively. It showed improved performance compared to DSSC with Pt CE, Electrochemical impedance spectroscopy (EIS) and Cyclic voltammetry (CV) measurements indicated the CZTS ultrathin film CE had a superior electrocatalytic activity than Pt CE.

The effect of Cr-sources on the performance of Li 1.05 Cr 0.04 Mn 1.96 O 4 prepared by slurry spray drying method was studied by adopting three different chromic compounds, Cr 2 O 3 , Cr 2 (SO 4 ) 3 and Cr(CH 3 COO) 3 , respectively. The prepared powder materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), laser particle size analyzer and Brunauer–Emmett–Teller (BET) specific surface area test. Electrochemical performances of these cathode materials were investigated by electrochemical impedance spectroscopy (EIS) and charge–discharge tests with Li/LiCr x Mn 2− x O 4 coin-type batteries. The results indicate that porous spherical particles with average particle size of about 24 μm can be obtained by slurry spray drying process. Using Cr(CH 3 COO) 3 as Cr-source resulted in the better mixing properties, which can make the as-prepared CA-Li 1.05 Cr 0.04 Mn 1.96 O 4 having smaller lattice parameter, smaller grain size and better structure stability, and consequently the obtained sample showed low charge transfer impedance and electrochemical polarization, and exhibited good electrochemical performance at elevated temperature.

CdS thin films were deposited onto glass substrates by the chemical bath deposition (CBD). The influence of the deposition temperature varied from 55 °C to 85 °C in a step of 5 °C on the crystallographic structure, morphology as well as optical and electrical properties was investigated in detail. Increasing deposition temperature can promote phase transformation from cubic to hexagonal and improvement of crystallinity in CdS films. CdS film deposited at 75 °C shows compact and smooth surface, and excellent transmission in visible light range. The band gaps are found to decrease from 2.56 eV to 2.38 eV with the increase of deposition temperature, and the sub-band gap of about 2.32 eV is noticed at low deposition temperature of 55–70 °C. All CdS films are of n-type conductivity and the carrier concentration is in the order of 10 12 –10 13 cm −3 . The lowest resistivity and highest mobility obtained are in the case of 85 °C.

A three-layer process and apparatus have been developed for electrorefining of silicon for solar cell application. The anode is solidified from a hypereutectic solution of copper and MG silicon. At the temperature of operation (1223 K (950 °C)), elements that have an electronegativity greater than that of silicon will remain at the anode (e.g., Cu, B, P, etc.) and then the Cu-Si phase can be used under certain conditions as a filter for purifying silicon with an electrorefining process. According to the stable liquid electrode reactive surface, high current density is possible during electrorefining and such advantages obviously improve the rate of deposition, which is a key point to reach commercial development. Deposited silicon particles are found embedded in electrolyte. Furthermore, with increasing operation time and current density, recombination of silicon particles is revealed and yields silicon balls with a diameter of 2 cm. The analysis of the anode feed and refined silicon shows a remarkable reduction of B and P concentrations, from 12.7 to 2.4 ppmw and 98.6 to 4.3 ppmw, respectively. Besides, particular mention should be made of efficient removal of impurities such as Fe, Mn, and Ti, which are present in significant quantities in the anode feed.

The activated carbon wound supercapacitors with TEABF4/propylene carbonate (PC) and TEABF4/acetonitrile (AN) electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior were investigated by cyclic voltammetry (CV) and constant current charge-discharge. Compared with the PC-based supercapacitor, the AN-based supercapacitor has higher capacitance and lower equivalent serial resistance (RES) at discharge currents ranging from 5 to 1 000 mA and 25 °C. Moreover, temperature effects are more prominent for PC-based supercapacitor than for AN-based supercapacitor. When the measurement temperature ranges from 60 °C to −40 °C the capacitance changes from 5.1 to 2.5 F and RES changes from 135 to 876 mΩ for the PC-based supercapacior, while the AN-based supercapacitor shows less change in capacitance and RES. Thus AN-based supercapacitor exhibits excellent power characteristics and temperature property.

A new anodic material of ternary Pb-0.8%Ag-(0–5.0%)Bi alloy for zinc electrowinning was obtained by doping Bi. The anodic oxygen evolution potential, corrosion rate, surface products after polarization, and microstructures before and after polarization were studied and compared with those of Pb-0.8%Ag anode used in industry. The results show the anodic overpotential decreases with the increase of Bi content in the alloys. When the content of Bi is 1.0% (mass fraction), the anodic overpotential is 40–50 mV lower than that of Pb-0.8%Ag anode. While the corrosion rate decreases and then increases with the increase of Bi content. The Pb-0.8%Ag-0.1%Bi anode has the lowest corrosion rate (0.090 6 mg/(h·cm2). Doping Bi influences the structure of the anodic layer, but does not change the phase. The Pb-0.8%Ag-1.0%Bi anode layer is of a more fine-grained structure compared with Pb-0.8%Ag anode.

A process was proposed based on the combination of chemical and physical activation for the production of activated carbons used as the electrode material for electric double layer capacitor (EDLC). By material characterization and electrochemical methods, the influences of the activitation process on the specific surface area, pore structure and electrochemical properties of the activated carbons were investigated. The results show that specific surface area, the mesopore volume, and the specific capacitance increase with the increase of the mass ratio of KOH to char (m(KOH)/m(char)) and the activation time, respectively. When m(KOH)/m(char) is 4.0, the specific surface area and the mesopore volume reach the maximum values, i.e. 1 960 m2/g and 0.308 4 cm3/g, and the specific capacitance is 120.7 F/g synchronously. Compared with the chemical activation, the activated carbons prepared by chemical-physical activation show a larger mesopore volume, a higher ratio of mesopore and a larger specific capacitance.

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 constant (CVCC) technique. The results show that the conductivities of melts increase with the increase of temperature, but by different extents. Every increasing 10 °C 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 °C 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 °C, 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.

Lithium difluoro(axalato)borate (LiODFB) was synthesized in dimethyl carbonate (DMC) solvent and purified by the method of solventing-out crystallization. The structure characterization of the purified LiODFB was performed by Fourier transform infrared (FTIR) spectrometry and nuclear magnetic resonance (NMR) spectrometry. The electrochemical properties of the cells using 1 mol/L LiPF6 and 1 mol/L LiODFB in ethylene carbonate (EC)/DMC were investigated, respectively. The results indicate that LiODFB can be reduced at about 1.5 V and form a robust protective solid electrolyte interface (SEI) film on the graphite surface in the first cycle. The graphite/LiNi1/3Mn1/3Co1/3O2 cells with LiODFB-based electrolyte have very good capacity retention at 55 °C, and show very good rate capability at 0.5C and 1C charge/discharge rate. Therefore, as a new salt, LiODFB is a most promising alternative lithium salt to replace LiPF6 for lithium ion battery electrolytes in the future.

A new type of lead-based porous anode in zinc electrowinning was prepared by negative pressure infiltration. The anodic polarization potential and corrosion rate were studied and compared with those of traditional flat anodes (Pb-0.8%Ag) used in industry. The anode corrosion rate was determined by anode actual current density and microstructure. The results show that the anodic oxygen evolution potential decreases first and then increases with the decrease of pore diameter. The anodic potential decreases to the lowest value of 1.729 V at the pore diameter of 1.25–1.60 mm. The porous anode can decrease its actual current density and thus decrease the anodic corrosion rate. When the pore diameter is 1.60–2.00 mm, the anodic relative corrosion rate reaches the lowest value of 52.1%.

Two finite element(FE) models were built up for analysis of stress field in the lining of aluminum electrolysis cells. Distribution of sodium concentration in cathode carbon blocks was calculated by one FE model of a cathode block. Thermal stress field was calculated by the other slice model of the cell at the end of the heating-up. Then stresses coupling thermal and sodium expansion were considered after 30 d start-up. The results indicate that sodium penetrates to the bottom of the cathode block after 30 d start-up. The semi-graphitic carbon block has the largest stress at the thermal stage. After 30 d start-up the anthracitic carbon has the greatest sodium expansion stress and the graphitized carbon has the lowest sodium expansion stress. Sodium penetration can cause larger deformation and stress in the cathode carbon block than thermal expansion.

The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed, and the performances of stainless steel foams prepared from precursors with different slurry loadings and different particle sizes of the stainless steel powder were also investigated. The experimental results show that the pretreatment of sponge with alkaline solution is effective to reduce the jam of cells in precursor and ensure the slurry to uniformly distribute in sponge, and it is also an effective method for increasing the slurry loading in precursor; the mass fraction of additive A and solid content in slurry greatly affect the slurry loading in precursor, when they are kept in 9%–13% and 52%–75%, respectively, the stainless steel foam may hold excellent 3D open-cell network structure and uniform muscles; the particle size of the stainless steel powder and the slurry loading in precursor have great effects on the bending strength, apparent density and open porosity of stainless steel foam; when the stainless steel powder with particle size of 44 μm and slurry loading of 0.5 g/cm3 in precursor are used, a stainless steel foam can be obtained, which has open porosity of 81.2%, bending strength of about 51.76 MPa and apparent density of about 1.0 g/cm3.

Alumina coated LiNi1/3Mn1/3Co1/3O2 particles were obtained by a simple method of solid state reaction at room temperature. The reaction mechanism of solid state reaction at room temperature was investigated. The structure and morphology of the coating materials were investigated by XRD, SEM and TEM. The electrochemical performances of uncoated and Al2O3-coated LiNi1/3Co1/3Mn1/3O2 cathode materials were studied within a voltage window of 3.00–4.35 V at current density of 30 mA/g. SEM, TEM and EDS analytical results indicate that the surface of LiNi1/3Mn1/3Co1/3O2 particles is coated with very fine Al2O3 composite, which leads to the improved cycle ability though a slight decrease in the first discharge capacity is observed. It is proposed that surface treatment by solid state reaction at room temperature is a simple and effective method to improve the cycle performance of LiNi1/3Co1/3Mn1/3O2 particles.

With citric acid as a polymeric agent layered LiNi0.8Co0.2O2 materials were synthesized by a spray pyrolysis method. The LiNi0.8Co0.2O2 particles were characterized by means of XRD, SEM and TEM. The electrochemical performances of LiNi0.8Co0.2O2 particles were studied in a voltage window of 3.00–4.35 V and at a current density of 30 mA/g. The results show that in the pilot-scale spray pyrolysis process, the morphology of particles is dependent upon the precursor concentration and flux of carrier gas. The initial discharge capacity of the LiNi0.8Co0.2O2 particles at 720 °C for 12 h °C is 187.3 mA·h/g, and the capacity remains 96.8 % with excellent cycleability after 30 cycles. The LiNi0.8Co0.2O2 samples synthesized under the optimized conditions by the spray pyrolysis method shows a good electrochemical performance.

Based on the principle of energy conservation, the applicable technique for drained cell retrofitted from conventional one was analyzed with 2D finite element model. The model employed a 1D heat transfer scheme to compute iteratively the freeze profile until the thickness variable reached the terminating requirement. The calculated 2D heat dissipation from the cell surfaces was converted into the overall 3D heat loss. The potential drop of the system, freeze profile and heat balance were analyzed to evaluate their variation with technical parameters when designing the 150 kA conventional cell based drained cell. The simulation results show that the retrofitted drained cell is able to keep thermal balance under the conditions that the current is 190 kA, the anodic current density is 0.96 A/cm2, the anode-cathode distance is 2.5 cm, the alumina cover is 16 cm thick with a thermal conductivity of 0.20 W/(m·°C) and the electrolysis temperature is 946 °C.

5Cu/(10NiO-NiFe2O4) cermet inert anodes were prepared by cold-pressing and sintering process, and the effect of superheat degree of melting K3AlF6-Na3AlF6-AlF3 on their anticorrosion performance was studied under electrolysis conditions. The results show that, the fluctuation of cell becomes small with increasing of superheat degree, which is helpful to inhibit the formation of cathodic encrustation; the concentration of impurities from inert anode in bath goes up to certain degree, but it is far smaller than those in traditional high-temperature bath. Increasing the superheat degree of melting K3AlF6-Na3AlF6-AlF3 has unconspicuous effect on the contents of impurities in cathodic aluminum. The total mass fractions of Fe, Ni and Cu in aluminum are 15.38% and 15.09% respectively under superheat degree of 95 and 195 °C. From micro-topography of anode used view, increasing the superheat degree can aggravate corrosion of metal Cu in inert anode, and has negative influence on electrical conductivity of electrode to some extent.

Ultrafine alumina power was obtained by calcining the precursor at 1 200 °C for 2 h, which was prepared by homogeneous precipitation method using aluminium salts and urea as raw materials. The effects of anions on the morphology, particle size, surface area and configuration of the precursors were studied. The results show that the reactions of urea with aluminium nitrate and aluminium chloride result in agglomerates gels with bad filtering performance, the morphology is fibrillar. Aluminium sulphate-urea reactions result in the direct formation of amorphous powders with good filtering performance, of which morphology are regular spherical particles with larger granularity and smaller surface area. The reaction of mutual compound of aluminium sulphate and aluminium nitrate with molar ratio of 40:60 with urea can produce precursor with good filtering performance, spherical morphology, and uniform granularity distribution in the particle size range of 2–3 μm.

The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders were investigated. The results show that the increase of mass ratio of phosphoric acid to aluminum hydroxide, the decrease of mass concentration of phosphoric acid and prolongation of mixing time are favorable to the improvement of thermal stability of aluminum hydroxide; when the mass ratio of phosphoric acid to aluminum hydroxide is 5:100, the mass concentration of phosphoric acid is 200 g/L and the mixing time is 10 min, the initial temperature of loss of crystal water in aluminum hydroxide rises from about 192.10 to 208.66 °C, but the dry modification results in the appearance of agglomeration and macro-aggregate in the modified powders, and the oil absorption of modified powders becomes higher than that of original aluminum hydroxide.

Mn/Ni composite oxides as active electrode materials for supercapacitors were prepared by solid-state reaction through the reduction of KMnO4 with manganese acetate and nickel acetate at low temperature. The products were characterized by X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The electrochemical characterizations were performed by cyclic voltammetry (CV) and constant current charge-discharge in a three-electrode system. The effects of different potential windows, scan rates, and cycle numbers on the capacitance behavior of Mn0.8Ni0.2Ox composite oxide were also investigated. The results show that the composite oxides are of nano-size and amorphous structure. With increasing the molar ratio of Ni, the specific capacitance goes through a maximum at molar fraction of Ni of 20%. The specific capacitance of Mn0.8Ni0.2Ox composite oxide is 194.5 F/g at constant current discharge of 5 mA.

Using the mesophase pitch as precursor, KOH and CO2 as activated agents, the activated carbon electrode material was fabricated by physical-chemical combined activated technique for supercapacitor. The influence of activated process on the pore structure of activated carbon was analyzed and 14 F supercapacitor with working voltage of 2.5 V was prepared. The charge and discharge behaviors, the properties of cyclic voltammetry, specific capacitance, equivalent serials resistance (ESR), cycle properties, and temperature properties of prepared supercapacitor were examined. The cyclic voltammetry curve results indicate that the carbon based supercapacitor using the self-made activated carbon as electrode materials shows the desired capacitance properties. In 1 mol/L Et4NBF4/AN electrolyte, the capacitance and ESR of the supercapacitor are 14.7 F and 60 mΩ, respectively. The specific capacitance of activated carbon electrode materials is 99.6 F/g; its energy density can reach 2.96 W·h/kg under the large current discharge condition. There is no obvious capacitance decay that can be observed after 5000 cycles. The leakage current is below 0.2 mA after keeping the voltage at 2.5 V for 1 h. Meanwhile, the supercapacitor shows desired temperature property; it can be operated normally in the temperature ranging from −40 °C to 70 °C.

LiFePO4 was prepared by heating the pre-decomposed precursor mixtures sealed in vacuum quartz-tube. Three kinds of cooling modes including nature cooling, air quenching, and water quenching were applied to comparing the effects of cooling modes on the microstructure and electrochemical characteristics of the material. The results indicate that the water quenching mode can control overgrowth of the grain size of final product and improve its electrochemical performance compared with nature cooling mode and air quenching mode. The sample synthesized by using water quenching mode is of the highest reversible discharge specific capacity and the best cyclic electrochemical performance, demonstrating the first discharge capacity of 138.1 mA·h/g at 0.1C rate and the total loss of capacity of 3.11% after 20 cycles.

The influences of molar ratio of KOH to C and activated temperature on the pore structure and electrochemical property of porous activated carbon from mesophase pitch activated by KOH were investigated. The surface areas and the pore structures of activated carbons were analyzed by nitrogen adsorption, and the electrochemical properties of the activated carbons were studied using two-electrode capacitors in organic electrolyte. The results indicate that the maximum surface area of 3 190 m2/g is obtained at molar ratio of KOH to C of 5:1, the maximum specific capacitance of 122 F/g is attained at molar ratio of KOH to C of 4:1, and 800 °C is the proper temperature to obtain the maximum surface area and capacitance.

Cu/(10NiO-NiFe2O4) cermets containing mass fractions of Cu of 5%, 10%, 15% and 20% were prepared, and their electrical conductivities were measured at different temperatures. The effects of temperature and content of metal Cu on the electrical conductivity were investigated especially. The results indicate that the metallic phase Cu distributes evenly in 10NiO-NiFe2O4 ceramic matrix. The mechanism of electrical conductivity of Cu/(10NiO-NiFe2O4) cermets obeys the rule of electrical mechanism of semiconductor, the electrical conductivity for cermet containing 5% Cu increases from 2.70 to 20.41 S/cm with temperature increasing from 200 to 900℃. The change trend of electrical conductivity with temperature is similar with each other and it increases with increasing temperature and content of metal Cu. At 960℃, the electrical conductivity of cermet increases from 2.88 to 82.65 S/cm with the content of metal Cu increasing from 0 to 20%.

A technique of combination of vacuum firing and water quenching was applied to the synthesis of LiFePO4 powder. The sample was prepared by heating the pre-decomposed precursor mixtures sealed in vacuum quartz-tube, followed by water quenching at the sintering temperature. The synthetic conditions were optimized by orthogonal experiment. The results indicate that the fast quenching treatment can avoid the overgrowth of single crystal and improve its availability ratio of active material. The sintering temperature has the greatest effect on the electrochemical performance of sample. Next is the molar ratio of Li to Fe and the sintering time, respectively. The samples prepared in the optimized technical condition has the highest reversible discharge specific capacity of 149.8 mA·h/g.

This research focuses on the in-situ synthesis of titanium (Ti)-titanium carbide (TiC) composites by powder metallurgy (PM) technology. Newly designed Ti-1.5Fe-2.25Mo-1.2Nd-0.3Al (wt pct) alloy was chosen as the matrix, and the additive was Cr3C2. The microstructure, room/elevated temperature, tensile behavior, and sliding wear behavior of the matrix alloy and the composites are presented and discussed. Microstructural analysis of the composites reveals a uniform dispersion of the TiC reinforcements with near-equiaxed shape in the Ti matrix. Tensile property test results show that the tensile strength increases significantly at both room temperature (RT) and elevated temperature after adding Cr3C2 into matrix alloy. Results of sliding wear resistance examination indicate that the wear properties are improved through the synthesis of TiC reinforcements. High strength of the composites, with Cr3C2 added, is attributed to particle strengthening, grain refining, and solution strengthening of Cr element. Better wear resistance of the composites is attributed to strong interface between particles and Ti matrix and high hardness of the composites. Therefore, Cr3C2 is considered to be a promising additive for processing PM Ti matrix composites.

Ammonium aluminum carbonate hydroxide (AACH) precursor was synthesized by the precipitation reaction of aluminum sulfate and ammonium carbonate. Then the precursor was dealt with five drying methods including ordinary drying, alcohol exchange, vacuum freeze-drying, glycol distillation, n-butanol azeotropic distillation respectively and calcined at 1 200 °C for 2 h to get α-Al2O3. The effects of drying methods on preparation of nanometer α-Al2O3 were discussed, and the optimal drying method was confirmed. The structural properties of powders were characterized by XRD, SEM and BET measurements. The results show that vacuum freeze-drying, glycol distillation and n-butanol azeotropic distillation can prevent the powders from aggregating, and among them the n-butanol azeotropic distillation is the best method. The nanometer α-Al2O3 powder with non-aggregation can be manufactured using n-butanol azeotropic distillation and the average particle size is about 40 nm.

Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25 ± 0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.

The properties and blending recipe of petroleum cokes used to make high quality carbon anodes for aluminium electrolysis were studied. Three kinds of green cokes were selected for bench scale study to illustrate the effects of cokes properties and its blending recipe on anode performances. The results show that impurities derived mainly from cokes remarkably affect the CO2 reactivity and air reactivity of carbon anodes. Ca, Na and V can increase CO2 reactivity of calcined cokes but S has the contrary effect, and the cokes of high V level generally present high air reactivity. The anodes with good quality can be made by properly selecting and scientifically blending of cokes, some poor quality cokes can also be used to produce high quality anodes with a reasonable blending recipe. Na contaminated anodes have high CO2 reactivity and air reactivity, so the recycled anode butts should be well cleaned to reduce Na content before being introduced into anode production, which is especially important to the low S cokes.

Taking the selection of coal-tar pitch as precursor and KOH as activated agent, the activated carbon electrode material was fabricated for supercapacitor. The surface area and the pore structure of activated carbon were analyzed by Nitro adsorption method. The electrochemical properties of the activated carbons were determined using two-electrode capacitors in 6 mol/L KOH aqueous electrolytes. The influences of activated temperature and mass ratio of KOH to C on the pore structure and electrochemical property of porous activated carbon were investigated in detail. The reasons for the changes of pore structure and electrochemical performance of activated carbon prepared under different conditions were also discussed theoretically. The results indicate that the maximum specific capacitance of 240 F/g can be obtained in alkaline medium, and the surface area, the pore structure and the specific capacitance of activated carbon depend on the treatment methods; the capacitance variation of activated carbon cannot be interpreted only by the change of surface area and pore structure, the lattice order and the electrolyte wetting effect of the activated carbon should also be taken into account.

Taking the nano-sized carbon black and aniline monomer as precursor and (NH4)2S2O6 as oxidant, the well coated C/polyaniline(C/PANI) composite materials were prepared by in situ polymerization of the aniline on the surface of well-dispersed nano-sized carbon black for supercapacitor. The micro-structure of the C/PANI composite electrode materials were analyzed by SEM. The electrochemical properties of C/ PANI and PANI composite electrode were characterized by means of the galvanostatic charge-discharge experiment, cyclic voltammetric measurement and impedance spectroscopy analysis. The results show that by adding the nano-sized carbon black in the process of chemical polymerization of the aniline, the polyaniline can be in situ polymerized and well-coated onto the carbon black particles, which may effectively improve the aggregation of particles and the electrolyte penetration. What’s more, the maximum of specific capacitance of C/PANI electrode 437.6 F · g−1 can be attained. Compared with PANI electrode, C/PANI electrode shows more desired capacitance characteristics, smaller internal resistance and better cycle performance.

The precursor of ammonium aluminum carbonate hydroxide was synthesized by using aluminum sulfate (Al2(SO4)3) and ammonium carbonate((NH4)2CO3). The effects of α-Al2O3 seeds and mixture composed of α-Al2O3 and ammonium nitrate, as well as multiplex catalysts (AT) on phase transformation of alumina in sintering process were investigated respectively. The results show that the α-Al2O3 seeds and the mixture of α-Al2O3 and ammonium nitrate can lower the phase transformation temperature of α-Al2O3 to different extents while the particles obtained agglomerate heavily. AT has great potential synergistic effects on the phase transformation of alumina and reduces the phase transformation temperature of α-Al2O3 and the trends of necking-formation between particles. Therefore the dispersion of powder particles is improved significantly.

NiFe2O4-based cermet inert anodes with metallic phase compositions of Cu, Ni and 85Cu15Ni were prepared by cold pressing-sintering. Their corrosion resistance was also investigated in Na3AlF6-Al2O3 melts. The results show that the metallic phase species in cermets have no effect on the concentration of impurities in bath during electrolysis, the total steady-state concentration of impurities is almost the same, i. e. between 4.12×10−4−4.80×10−4. There exists metal preferential corrosion for the cermet inert anode with metal Ni as metallic phase. For NiFe2O4-based cermets, the cermet with metal Cu as metallic phase exhibits better corrosion resistance than the others.

A kind of complex additive mainly containing Al, Mg, F, and O was prepared. The synthetical performances of the property-modified prebaked anodes containing additives were tested in laboratory. On the basis of ideal testing results obtained, a large number of industrial prebaked property-modified anodes are prepared in a large-scale aluminum company. Further more, they are all used in 160 kA prebaked anode aluminum electrolysis cells. The statistic result show that, compared with common anodes, the property-modified ones enhance current efficiency by 0.78%, reduce energy consumption by 106.1 kW·h per ton aluminum and reduce carbon consumption by 11.6 kg per ton aluminum averagely.

The spinel LiMn2O4 used as cathode materials for lithium-ion batteries was synthesized by mechano-chemistry fluid activation process, and modified by doping rare-earth Sm. Thesting of X-ray diffraction, cyclic voltammograms, charge-discharge and SEM was carried out for LiMn2O4 cathode materials and the modified materials. The results show that the cathode materials doped rare earth LixMn2−ySmzO4 (0.95⩽x⩽1.2, 0⩽y⩽0.3, 0⩽z⩽0.2) exhibit standard spinel structure, high reversibility of electrochemistry and excellent properties of charge-discharge. In EC: DMC(1 : 1)+1 mol/L LiPF6 electrolyte with discharge capacity more than 130 mA · h/g, and its capacity is deteriorated less than 15% after 300 cycles at room temperature and less than 20% after 200 cycles at 55°C. At the same time, Crystal Field Theory was applied to explain the function and mechanism of doped rare earth element.

The contribution to the critical shear stress of nanocomposites caused by the interaction between screw dislocations and nanoscale circular cylindrical inclusions with interface stresses is derived by means of the Mott and Nabarro's model. The effect of the radius of the nanoscale inclusion and the volume fraction of inclusions as well as the interface stress on the critical shear stress is examined. The most important finding is that, when the negative interface stress is considered, a critical value of the radius of the nanoscale inclusion or the volume fraction of inclusions may exist to gain the best strengthening effects for the second-phase strengthened composites which differs from the classical solution without considering the interface stress under same external conditions.

Two kinds of biosensors for amino acids (one with nonspecific enzyme as bioelement, the other with specific enzyme(s) as bioelement), including their principles, applications, recent researches and future trends were discussed in detail. 61 references were given.