Metallic lithium plays an important role in the national economy and national defense construction. With the growing demand and exhausted lithium mineral resources, it is of great significance to extract lithium from abundant liquid lithium resources such as seawater and brines. Active exploration of lithium extraction methods and technologies have been carried out. Spinel-type manganese oxide has attracted much attention because of its remarkably high selectivity for lithium ions in the aqueous phase, and it is called ion-sieve adsorbent. Being environmentally friendly and efficient, the ion-sieve adsorption method is regarded as the most promising one for extracting lithium from seawater and brines. In this revieal, the structure of LiMn2O4 is presented, and the development of lithium-ion insertion/extraction mechanisms is introduced as well. The synthesis method and modification of the ion-sieve precursor are also summarized in details. Moreover, the granule/membrane formation and application of lithium ion-sieves are discussed. Finally, the existing problems and the prospects of the lithium ion-sieve are put forward.

Novel cathode material Li₃V_2-2x/3Mnx(PO₄)₃/C was successfully synthesized by Sol-Gel method using CH₃COOLi·2H₂O, V₂O₅, Mn(CH₃COO)₂·4H₂O, (NH₄)₂HPO₄ and sucrose as raw materials. The as-prepared products were characterized by XRD, XPS, SEM.The results show that a small amount of Mn2+doping do not alter the structure of Li₃V₂(PO₄)₃ materials with a monoclinic structure (space group P21/n), and the valence states of V and Mn in Li₃V_1.94Mn_0.09(PO₄)₃/C are +3 and +2, respectively. The Li₃V_1.94Mn_0.09(PO₄)₃ particle with uniform shape of sphere and diameter less than 200 nm, shows the best cyclic stability and rate performance. Controlling the charge and discharge voltage range from 3.0 to 4.8 V at the rate of 0.1C, the first charge and discharge capacity of Li₃V_1.94Mn_0.09(PO₄)₃ are up to 182.1 and 168.8 mAh/g, respectively, and its discharge efficiency is up to 92.69%. After 100 cycles, its discharge capacity can also retain 77.4% of the first one.

The homogeneous distribution of FeOOH/SiO₂ precursor material was prepared from FeCl₂•4H₂O and Na₂SiO₃•9H₂O by low-heating solid-state reaction. Then Li₂FeSiO₄/C composites were prepared by microwave assisted solid reaction method, with prepared precursor FeOOH/SiO₂ and Li₂CO₃ as the starting materials, PVA and super-P   carbon as carbon sources. The prepared samples were characterized by X-ray diffractometry, SEM, TEM, and galvanostatic charge-discharge test. Highly pure Li₂FeSiO₄/C material with uniform and fine particle size was obtained at 650℃ in 12 min. Under the selective microwave synthesis system, super-P carbon powder and pyrolyzed amorphous carbon not only effectively provided the high temperature to induce the complete reaction but also formed the conductive network to enhance the electronic conductivity. The optimum Li₂FeSiO₄/C composite displayed discharge capacity of 129.6 mAh/g at 0.05C rate and 107.5 mAh/g at 0.5C rate at 60℃. After 15 cycles the discharge capacity maintained 104.8 mAh/g at 0.5C, indicating good electrochemical capacity and cycling stability. Consequently, the results show that microwave assisted solid synthesis process is a promising method for preparing Li₂FeSiO₄/C composite.

LiFePO4/Al/C composite cathode materials were synthesized by two-step solid-state method. The crystalline structure, morphology, the particle size and the coated state of the samples were characterized by XRD, SEM and TEM. The effect of the amounts of Al powder on the electrochemical properties of the composite was investigated. The results show that the interface reaction occurs between metal Al and LiFePO₄, resulting in the formation of several by-products and the passive film on the surface of LiFePO₄. The surface of LiFePO₄ particles are coated by the irregularly shaped metal Al and a thin carbon layer of 1-2 nm. The LiFePO₄/Al/C containing 3wt% Al shows the best electrochemical performances, with discharge specific capacity of 117.8 mAh/g at 25℃ and 10C rate, and discharge specific capacity of 105.6 mAh/g at -20℃ and 0.1C rate, and discharge capacity of samples at -20℃ is 73.8% of that of samples at 25℃.

Micro-expanded?flake?graphite (MEFG) and micro-expanded?spherical?graphite (MESG) were prepared from two kinds of natural graphite by intercalation reaction and rapid heating processes. Then carbon nanotubes/   micro-expanded?graphite (CNTs/MEG) composites were prepared by chemical vapor deposition (CVD) process, for which CNTs were grown in the pores of micro-expanded?graphite. Electrochemical test results?show that first discharge/ charge capacities of CNTs/MEFG and CNTs/MESG could respectively accommodate up to 443 and 477 mAh/g. Both of the prepared CNTs/MEG composites keep more than 95% capacities after 30 cycles at the rate of 0.2C and their capacities are stable at?259 and 195 mAh/g after 50 cycles at 1C rate, respectively. The nanoporous structure and the CNTs network can improve the discharge capacities and effectively?buffer the volumetric change of the composite electrode materials in the charge/discharge process. The diffusion path of Li+ can be reduced because of the electrolyte solution that filled in the nanopores, which significantly improves the rate capability of the electrodes. In addition, the growing ivy-like CNTs could improve the electric conductive property of the composites in the charge/discharge process.

(1–x)(0.9462K_0.5Na_0.5NbO₃-0.0498LiSbO₃-0.004BiFeO₃)-xCo_0.85Cu_0.15Fe₂O₄((1–x)(KNN-LS-BFO)-xCCFO) (x=0.1, 0.2, 0.3, 0.4, 0.5) multiferroic magnetoelectric ceramics were prepared by solid phase method. The presence of perovskite and spinel in the sintered composites were proved by XRD patterns and no impurity phase existed. SEM images show that particle size of KNN-LS-BFO is big and complete, while the particle size of CCFO is small. When x increases from 0.1 to 0.5, the piezoelectric coefficient of the composites decreases from 120 pC/N to 33 pC/N, While saturation magnetization and remanent magnetization increase and saturation magnetostriction constant increases from 18×10^–6 to 52×10^–6 approximately. When the applied magnetic field increases, the magnetoelectric properties of the composites increase to the maximum and then decrease. When the alternating magnetic field frequency is 1 kHz and x=0.3, the magnetoelectric voltage coefficient attains maximum value 20.6 mV/A.

The cycle fatigue of PZT ceramic under different stress was investigated by modified small punch (MSP) tests. The research results show that residual strength and piezoelectric constant decrease with increasing cycle stress, which is attributed to crack propagation during cyclic stress process. The value of fatigue crack propagation (n) is calculated to be 395 according to the relationship between maximum stress and fatigue life. The fatigue life under series cycle maximum stress can be induce by fatigue crack propagation. Below the maximum strength of 79.1 MPa, the PZT ceramics can be used over 5 years.

The multiferroic materials BiFeO₃ nanopowders of dispersion uniformity were synthesized by the citric acid Sol-Gel method, using the iron(Ⅲ) nitrate and bismuth nitrate as the reactants and dilute nitric acid as the catalyst. The physical and chemical characteristics, such as structure, morphology and purity of BiFeO₃ nanopowders were investigated by TG-DSC, XRD, FT-IR, SEM and AFM, respectively. The results indicate that the preparation and purity of BiFeO₃ nanopowders have a profound influence on the precursor solution pH value of sol process and the calcined temperature of the xerogel. The optimum reaction conditions are the precursor solution pH=7–8 and calcined temperature of 600℃. It is found that BiFeO₃ nanopowders with 100 nm in size, good dispersion and without Bi₂₅FeO₄₀ and Bi₂Fe₄O₉ impurity phase are synthesized under the optimum reaction conditions. The saturation magnetization (Ms), the remanent magnetization (Mr) and the coercivity (Hc) of BiFeO₃ nanopowders under the optimum reaction conditions are 1.08 A·m²/kg, 0.13 A·m²/kg and 15.76 kA/m, respectively.

A series of lateral structural photoconductive semiconductor switches (PCSS) were fabricated on V-doped semi-insulating 6H-SiC substrate with the Ni/Au contacts. These PCSS were measured with different bias voltages, excitation energies and excitation wavelengths. The photoelectric absorption effect and photoelectric response of SiC PCSS were investigated. It is found that the absorption coefficient is between 0.601 and 0.692 mm^–1 for semi-insulating 6H-SiC substrate when it is excited by 532 nm laser, and the corresponding pulse signal is much smaller than that excited by 1064 nm laser. Nanosecond-pulse signal is obtained for 6H-SiC PCSS excited by 532 nm laser. The peak current flowing through the switch is increased with increasing the bias voltage and excitation energy, while it is decreased with the increase in substrate thickness.

TiO₂ thin films were deposited on heavily doped silicon wafer by DC magnetron sputtering and the Au electrodes were evaporated on TiO₂/n⁺-Si by electric beam evaporation to get Au/TiO₂/n⁺-Si structured resistive random access memory (ReRAM). The effects of annealing temperatures on the crystalline structure of the TiO₂ thin films and the resistive switching characteristics of the fabricated device were investigated. Au/TiO₂/n⁺-Si structured device exhibits reversible and steady unipolar resistive switching behaviors. The values of set voltage, reset voltage, reset current and reset power vary with the annealing temperatures. The resistive switching mechanism is discussed based on the filamentary model. The results reveal that the fabricated device annealed at 500℃ has good nonvolatile property. The average ratio of resistances between high resistance state (HRS) and low resistance state (LRS) is larger than 10³ and the devices could maintain a sufficient margin of memory for more than 10 years. The resistive switching characteristic is remained after 100 switching cycling tests.

Flower-like titania nanocrystals were synthesized by hydrolysis of titanium (IV) chloride at a low temperature of 70℃ in 4–6 h, employing nanocrystal cellulose (NCC) as a morphology controlling agent. The obtained nanocrystals were characterized by transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD) and FTIR. TEM and HRTEM investigations reveal that the morphologies of the nancrystals are flower-like, and each flower is composed of several nanoneedles with a diameter of 15–20 nm and a length of 100–200 nm. The XRD results show that the crystalline phase of the nanocrystals have a strong dependence on the mole ratio of TiCl₄ to H₂O and the reaction time. FTIR result shows that a chemical bond is formed between NCC and TiO₂. A possible growth mechanism is proposed based on the characteristic results. The NCC whose surface is full of hydrophilic groups can establish hydrogen bonding with TiO₂ to promote the nucleation and crystal growth of TiO₂ at low temperature. Moreover, the selective adsorption of NCC molecules on the crystal face of TiO₂ varies the growth rate of different crystal planes, and the anisotropic crystal growth leads to the formation of nanoneedles. Then these nanoneedles aggregate together to assemble into a flower-like secondary structure. TiO₂ prepared at low temperature exhibites high activity in the photocatalytic degradation of methyl orange in aqueous solution under metal halide lamp.

The Co-BiVO₄ photocatalyst was prepared by hydrothermal method and characterized by X-ray diffraction, scanning electron microscope, UV-Vis absorption spectroscope, and low-temperature N₂ adsorption. The characterized results indicate that highly crystalline monoclinic scheelite structure of Co-BiVO₄ is obtained at pH=7 and the Co dopant does not change the crystal phase of BiVO₄. The Co-BiVO₄ has a significant red-shift in the absorption band in the visible region, and its absorption intensity increases greatly for the doped catalyst compared with pure BiVO₄. Low-temperature N₂ adsorption result reveals that the pore size of the Cu-BiVO₄(pH=7) mostly distributes at 2.67 nm. The desulfurization ability of Co-BiVO₄ was researched by photocatalytic oxidation of thiophene in visible light. The results show that the Co-BiVO₄ photocatalysts exhibit higher photocatalytic activities for degradation of thiophene under visible light irradiation. When pH value is 7.0 and the hydrothermal synthesize time is 8 h, the photocatalytic activities reach the maximum. Under the conditions of 150 mL/min air flow, 1.0 mg/L catalyst amount, and visible light irradiation for 3 h in 400 W xenon lamp light, the desulfurization rate by Co-BiVO₄ at 600 mg/L initial concentration increases to 86%.

TiO₂/SiO₂ composite aerogels were prepared by Sol-Gel method at ambient pressure and heat-treated at different temperatures. The microstructure of TiO₂/SiO₂ composite aerogels was characterized by X-ray diffraction (XRD), thermo gravimetric analyzer (TGA) and N₂ adsorption-desorption. The photocatalytic activity was evaluated by means of photocatalytic degradation of methyl orange under UV irradiation. The effects of heat treatment temperatures on microstructure and photocatalytic activity were investigated. With the increase of heat treatment temperature, the crystallization of anatase and the anatase grain size increase, however, the specific surface area decreases. As a result, the photocatalytic activity of TiO₂/SiO₂ composite aerogels is enhanced initially, then decreases with the increase of heat treatment temperature. When the heat treatment temperature is set at about 700℃, the degradation ratio of methyl orange on the TiO₂/SiO₂ composite aerogels reaches 95.4% after irradiated by ultraviolet light for 20 min.

Lead evaporation and recovery of nanoparticle materials from waste cathode-ray tube (CRT) glass using the self-propagating high-temperature synthesis (SHS) method was investigated. The reaction temperature and combustion velocity of the mixture of Fe₂O₃-Mg-CRT in the SHS process were studied in detail. Then the lead extraction ratio, phase compositions as well as the micromorphology of extracted PbO nanoparticles were examined. The thermodynamics of lead evaporation and nanocrystallization mechanism were also analyzed. It can be found that the SHS reaction temperature and combustion velocity decrease with increasing CRT glass content, and the addition of CRT glass as a diluent can be used to control the SHS lead extraction behavior to obtain PbO nanoparticles with good desperation and morphology. With 40wt% CRT glass addition, about 93% of lead can be recovered from CRT glass as nano-sized PbO with high purity. The collected PbO nanoparticles are almost spherical in shape with particle sizes ranging from 40 nm to 50 nm, which are mainly from the volatilization and rapid condensation during the SHS process. The study indicates a novel method to recycle and reuse waste CRT glass．

Cu²⁺-doped ZnO nano-rod powders (0–6mol%) were prepared via solvothermal method. The crystal and micro-morphology of the doped ZnO nano-rods were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of Cu²⁺ dopant and the thermal condition (reaction temperature and duration) on the gas sensitivities of ZnO nano-rods were studied. The gas sensing properties of pure ZnO nanorod sensor and 3mol% Cu²⁺-doped ZnO nano-rod sensors to formaldehyde, acetic acid, toluene, ethanol, acetone and trimethylamine were also studied. The results show that the micro-morphology of ZnO powders are nano-rods, the lengths and diameters of ZnO nanorods change with the variation of the Cu²⁺ concentration. The sensor based on 3mol% Cu²⁺-doped ZnO nano-rods exhibits high response and good selectivity to dilute ethanol, the responses to 1×10^-3 ethanol and 1×10^–6 ethanol reach 380.5 and 4.2 when it works at 395℃, respectively, and its response time and recovery time are 16 s and 40 s, respectively.

A series of CaSi₂O₂N₂: 0.05Eu²⁺, xDy³⁺, xLi+ (0≤x≤0.03) phosphors were prepared through high-temperature solid-state reaction method. The phosphors were characterized by X-ray diffraciton (XRD) and fluorescence spectrophotometer (PL). XRD patterns revealed that the samples maintained CaSi₂O₂N₂ single phase after doping Dy³⁺ or Li⁺ ions. The PL results showed that the excitation spectra of samples were all located in the UV to blue spectral region. The emission spectra for 400 nm excitation showed the typical broad band of Eu²⁺ peaking at about 545 nm (5d-4f). In addition, the emission intensity could be greatly enhanced through doping Dy³⁺ in CaSi₂O₂N₂:Eu²⁺ phosphors. Furthermore, the effect of the Li⁺ doping was studied. Li⁺ ions could be used as charge compensation in CaSi₂O₂N₂:Eu²⁺, Dy³⁺ phosphors. Thus the doping of Li+ ions could further improve the emission intensity of CaSi₂O₂N₂:Eu²⁺, Dy³⁺ phosphor. When the doping concentrations of Dy³⁺ and Li+ were 1mol%, the emission intensity reached a maximum, which was about 157% of that of the sample without doping Dy³⁺ or Li+.

Ti₃SiC₂ bonded diamond materials were fabricated by spark plasma sintering using Ti/Si/TiC/diamond abrasive as the raw materials. The result showed that displace, dispalce rate and vaccum degree of Ti-Si-2TiC sample sintered by SPS were obviously changed. The Ti/Si/TiC powders were obviously sintered and transformed to TiC and Ti₃SiC₂ at 1200℃ during the sintering process. With increasing sintering temperature, Ti₃SiC₂ content in the samples increased. Ti₃SiC₂ content in the samples were 65.9%, 79.97%, 87.5% and 90.1%, respectively. Addition of (5% and 10%) appropriate amounts of diamond did not inhibit the reaction synthesis of Ti₃SiC₂. SEM observation showed that diamond had one close combination with the matris, and Ti₃SiC₂ grains grew on the surface of diamond. One formation mechanism of Ti₃SiC₂ on the surface of diamond was proposed, C on the surface of diamond reacted with Ti and formed TiC firstly, then TiC reacted with Ti-Si phase and formed Ti₃SiC₂.

A seeded growth procedure was used to successfully prepare continuous and well inter-grown zeolitic imidazolate framework-8 (ZIF-8) membranes on porous α-alumina tubes. The effects of some parameters including the content of seeds and PEI in seeding solution, the concentration of sodium formate in synthesis solution and synthesis temperature on the formation of ZIF-8 membranes were investigated in detail. The characterization of SEM, XRD and single gas permeation showed that PEI added in the seeding solution can improve the adhesion between the seed crystals and the support surface. Moreover, sodium formate used in synthesis solution could prevent the seed layer from peeling off during the membrane growing process. The as-synthesized ZIF-8 membrane is well inter-grown and continuous. Single gas permeation shows that the separation factors of H₂/CO₂ and H₂/CH₄ are 5.4 and 2.56, respectively, indicating that Knudsen diffusion plays a controlling role in the gas permeation through the ZIF-8 membrane.

Al-doped ZnO (AZO) films were deposited on the glass substrates by direct current magnetron sputtering using different sputtering pressures ranging from 0.2 Pa to 2.2 Pa. Microstructure, phase, electrical and optical properties of AZO films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), four-point probe and UV-Vis spectrophotometer, respectively. The results revealed that the deposition rate decreased with the increasing sputtering pressure according to Keller-Simmons model; the crystalline phase of all films was hexagonal wurtzite and the preferred orientation changed with the sputtering pressure; the surface morphology greatly depended on the sputtering pressure and the film deposited at 1.4 Pa showed low resistivity (8.4×10^-4 Ω·cm), high average transmission and the highest Q, a criterion factor as the film figure of merit, which was the ratio between the normalized average transmission and the normalized resistivity.

Transparent and thermal insulation coatings were prepared from antimony doped nano-SnO₂/waterborne polyurethane composite emulsion. It’s found that thermal insulation is resulted from the absorbance of the infrared light by antimony doped nano-SnO₂ particles in the composite coatings. Thermal insulation measurement results show that under illumination of sunlight, the temperature of the coated glass surface increases, while the temperature inside the measurement box decrease as much as 17.5℃. Therefore, antimony doped nano-SnO₂/waterborne polyurethane composite coatings are cost effective thermal insulating coating due to many advantages such as low cost, chemically stable, and easy in process.