Integrated lithium metal anode protected by composite solid electrolyte film enables stable quasi-solid-state lithium metal batteries

Lithium (Li) metal, possessing an extremely high theoretical specific capacity (3860 mAh/g) and the most negative electrode potential (−3.040 V vs. standard hydrogen electrode), is one the most favorable anode materials for future high-energy-density batteries. However, the poor cyclability and safety issues induced by extremely unstable interfaces of traditional liquid Li metal batteries have limited their practical applications. Herein, a quasi-solid battery is constructed to offer superior interfacial stability as well as excellent interfacial contact by the incorporation of Li@composite solid electrolyte integrated electrode and a limited amount of liquid electrolyte (7.5 μL/cm²). By combining the inorganic garnet Al-doped Li_6.75La₃Zr_1.75Ta_0.25O₁₂ (LLZO) with high mechanical strength and ionic conductivity and the organic ethylene-vinyl acetate copolymer (EVA) with good flexibility, the composite solid electrolyte film could provide sufficient ion channels, sustained interfacial contact and good mechanical stability at the anode side, which significantly alleviates the thermodynamic corrosion and safety problems induced by liquid electrolytes. This innovative and facile quasi-solid strategy is aimed to promote the intrinsic safety and stability of working Li metal anode, shedding light on the development of next-generation high-performance Li metal batteries.     

轻质三维多孔泡沫铝用作高性能锂金属负极骨架

将轻质、三维多孔且亲锂的泡沫铝用作锂(Li)金属负极骨架,通过简单的机械挤压方法,将泡沫铝与金属Li复合,制得Al@Li复合负极。泡沫铝自身的高亲锂性,能够为Li金属成核提供丰富且均匀的活性位点,诱导Li在泡沫铝内部的快速成核和均匀电沉积。同时,泡沫铝的三维多孔结构,可以容纳Li金属负极在充放电过程中的巨大体积应变,降低局部电流密度,从而有效抑制Li枝晶的生长。因此,与纯Li金属负极相比,所获得的Al@Li复合负极在对称电池和LiFePO₄||Al@Li半电池中,均表现出了更加优异的循环稳定性。     

轻质三维多孔泡沫铝用作高性能锂金属负极骨架

将轻质、三维多孔且亲锂的泡沫铝用作锂(Li)金属负极骨架,通过简单的机械挤压方法,将泡沫铝与金属 Li复合,制得Al@Li复合负极。泡沫铝自身的高亲锂性,能够为Li金属成核提供丰富且均匀的活性位点,诱导Li在泡沫铝内部的快速成核和均匀电沉积。同时,泡沫铝的三维多孔结构,可以容纳Li金属负极在充放电过程中的巨大体积应变,降低局部电流密度,从而有效抑制Li枝晶的生长。因此,与纯Li金属负极相比,所获得的Al@Li复合负极在对称电池和LiFePO₄||Al@Li半电池中,均表现出了更加优异的循环稳定性。     

Wave formation by heating in thin metal film on an elastomer

Wave formation by heating rather than the usual cooling in a thin metal film on an elastomer is presented. A simple model is used to relate the wavelength of the waves thus formed to the heating temperature. An indirect method of estimating Young's modulus at elevated temperatures emerges from the analysis. The waves formed by heating can be made to appear or not to appear by the selection of the temperature to which the sample is heated. A relationship is given for the critical temperature that determines the appearance or nonappearance of the waves. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1122–1128, 2001     

LiFe0.98 Pt0.02 PO4薄膜的光学及气敏性研究

为提高LiFePO_4敏感薄膜元件的灵敏度,以铂(Pt)作为掺杂元素,用水热法一步合成出LiFe_(0.98)Pt_(0.02)PO_4粉末;利用旋涂法将其固定在锡掺杂玻璃光波导表面,制备了LiFe_(0.98)Pt_(0.02)PO_4薄膜/锡掺杂玻璃光波导元件。将敏感薄膜在不同温度下热处理,通过比较各个敏感薄膜元件对苯类挥发性有机气体的响应讨论薄膜处理温度对LiFe_(0.98)Pt_(0.02)PO_4薄膜元件光学特性及气敏性的影响。结果显示,在450℃下处理的薄膜因具有光学透明性好、折射率高、光传播损失小等特点对苯类气体显出较大的响应,能够检测出浓度为1×10~(-7)~1×10~(-3)V/V_0的二甲苯气体。当气体浓度小于1×10~(-6)V/V_0时,其他苯类气体不会对二甲苯的检测产生影响。     

Electrochemical kinetics and cycling performance of nano Li[Li0.23Co0.3Mn0.47]O2 cathode material for lithium ion batteries

Li[Li_0.23Co_0.3Mn_0.47]O₂ cathode material was prepared by a sol–gel method. The material had a primary particle size of about 100 nm, covered by a 30 Å of Li₂CO₃ layer. The material showed promising electrochemical performance when cycled up to 3C rate. The electrochemical kinetics of the first charge was much slower than that of the second charge, due to the complex electrochemical process which involved not only Li⁺ diffusion but also release of oxygen. By taking account of this, the material was pre-charged very slowly (C/50) in the first cycle. This led to excellent electrochemical performance in the following cycles. For instance, the 1C-rate capacity increased to 168 mA h g⁻¹ after 50 cycles, comparing with the 145 mA h g⁻¹ obtained without pre-charging.     

Solid film at the anode influences the process of polyvalent metal electrorefining: theoretical bifurcation analysis of the problem

A theoretical study of polyvalent metal anodic electrorefining has been carried out, and the decisive influence of surface film on the long-term process has been shown. A mathematical model of the long-term continuous electrorefining process in the form of non-linear differential equations is proposed. The developed model was investigated by the methods of the bifurcation theory. The model predicts the following types of electrolytic system: 1. The low-valence compound of the anodic film does not form. 2. A steady-state process with a stationary thickness of the anodic deposit. 3. An unlimited accumulation of low-valence compounds at the anode. 4. An unstable steady state: a bifurcation with a transition to case 3 or to the regime of undamped oscillations. The model provides satisfactory explanations of the experimental results related to long-term continuous electrorefining processes in molten salts. Received: 19 February 1997 / Accepted: 18 August 1997     

Film growth and interface reaction of ultra thin 3d-transition metal oxide/metal layer structures

The interface reactions between transition metal oxide substrates and ultra thin metal layers of different thickness (<15 nm) have been investigated by using x-ray photoelectron spectroscopy (XPS). To a different extent oxidation of deposited metal and reduction of the oxidic substrate is visible for complementary layer systems. For the interface nickel oxide/manganese an enhanced reaction is found compared to the system manganeseoxide/nickel. Based on the experimental data a model of the evolving interface is proposed.     

Preparation of Fe3O4 thin film by the sol-gel method and its magnetic properties

Films consisting of magnetite particles were prepared by the sol-gel method using iron (III) nitrate dissolved in ethylene glycol and 2-methoxyethanol as a new precursor with the aim of decreasing the processing temperatures. Films were annealed under the mixture of hydrogen and nitrogen at various temperatures. Magnetite formation was found to be influenced both by temperature and atmosphere during firing and hydrogenation processes. Typical values of magnetization in saturation and coercive force of films were 440 mT and 196 kA/m, respectively.     

Multiscale dewetting of triblock copolymer thin film induced by solvent vapor

Multiscale dewetting of poly(styrene‐b‐ethylene/butylenes‐b‐styrene) (SEBS) triblock copolymer thin films induced by volatile solvent vapor treatment were observed in this study. Film rupture occurred at first and produced macroscopic holes. Near‐regular droplets (which represented a compromise between complete disorder and perfect order) could be formed at the last stage. The mechanism of solvent‐driven dewetting was discussed by comparing with that of thermal‐induced dewetting. Similar to thermal‐induced dewetting, the block copolymer thin films initially break up through the nucleation of holes that perforated the films. The rapid growing holes became unstable and formed nonequilibrium fingering patterns. The films exhibit autophobic or autodewetting phenomena. The velocity of the holes growth was nearly a constant (3.3 μm/min). The stages of the dewetting were quite similar to that found for homopolymer and block copolymer thin films dewetting on solid or liquid substrates under thermal treatment. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2874–2884, 2005     

四氢呋喃预处理对吡咯修饰金属锂电极性能的影响

采用四氢呋喃对金属锂电极进行预处理, 以减少电极表面杂质和吡咯化锂钝化膜形成过程中产生的气体, 从而提高电极表面钝化膜的致密性和电极的充放电循环性能. 实验结果表明: 采用四氢呋喃对金属锂电极预处理后, 电极表面杂质显著减少, 能在电极表面形成一层更加均匀而致密的吡咯化锂钝化膜. 该钝化膜使得电极界面阻抗降低, 界面稳定, 金属锂溶解沉积过程的可逆性增加. 金属锂呈“海绵”状均匀沉积, 有效抑制或减少了锂枝晶或“死锂”的产生, 提高了金属锂的循环效率.     

Preparation of bismuth telluride thin film by electrochemical atomic layer epitaxy (ECALE)

Thin-layer electrochemical studies of the underpotential deposition (UPD) of Bi and Te on cold rolled silver substrate have been performed. The voltammetric analysis of underpotential shift demonstrates that the initial Te UPD on Bi-covered Ag and Bi UPD on Te-covered Ag fitted UPD dynamics mechanism. A thin film of bismuth telluride was formed by alternately depositing Te and Bi via an automated flow deposition system. X-ray diffraction indicated the deposits of Bi₂Te₃. Energy Dispersive X-ray Detector quantitative analysis gave a 2: 3 stoichiometric ratio of Bi to Te, which was consistent with X-ray Diffraction results. Electron probe microanalysis of the deposits showed a network structure that results from the surface defects of the cold rolled Ag substrate and the lattice mismatch between substrate and deposit. Translated from Chinese Journal of Applied Chemistry, 2005, 22 (11) (in Chinese)     

Li含量对Li/MgO丙烷氧化脱氢制烯烃反应催化性能的影响

采用浸渍法制备了不同Li含量的Li/MgO催化剂,并通过TG-DTA、N_2吸附及XRD等手段对其进行了表征;对丙烷在Li/MgO催化剂表面的两种吸附状态所占据的空间体积大小进行了计算,研究了Li含量对其丙烷氧化脱氢制烯烃反应催化性能的影响。结果表明,随着Li/MgO催化剂中Li含量的增加,丙烷转化率与乙烯、甲烷、乙烷和COx的选择性均先增加,在Li物质的量分数为3%时达到最高,然后随Li含量增加而降低,而丙烯选择性则出现相反的变化趋势。丙烷在Li/MgO催化剂上的吸附和反应同时受动力学和热力学两个因素的制约;Li负载量不同,反应活性位Li+O-分散状态也不同,导致产物分布发生变化。活性位分散度高时受热力学因素影响,有利于生成丙烯;活性位分散度低时受吸附动力学影响,更趋向于生成乙烯等其他产物。     

Quantitative determination of fluoxetine in human serum by high performance thin layer chromatography

A high performance thin layer chromatographic method was developed and validated for the quantification of fluoxetine in human serum. Fluoxetine was extracted by liquid–liquid extraction method with diethyl ether as extraction solvent. Imipramine was used as internal standard. The chromatographic separation was achieved on precoated silica gel F 254 high performance thin layer chromatographic plates using a mixture of toluene/acetic acid glacial (4:5 v/v) as mobile phase. 4‐Dimethylamino‐azobenzene‐4‐sulphonyl chloride was used as derivatization reagent. Densitometric detection was done at 272 nm. The method was linear between 12.5 and 87.5 ng/spot, corresponding to 0.05 and 0.35 ng/μL of fluoxetine in human serum after extraction process and applying 25 μL to the chromatographic plates. The method correlation coefficient was 0.999. The intra‐assay and inter‐assay precisions, expressed as the RSD, were in the range of 0.70–2.01% (n=3) and 0.81–3.90% (n=9), respectively. The LOD was 0.23 ng, and the LOQ was 0.70 ng. The method proved be accurate, with a recovery between 94.75 and 98.95%, with a RSD not higher than 3.61% and was selective for the active principle tested. This method was successfully applied to quantify fluoxetine in patient serum samples. In conclusion, the method is useful for quantitative determination of fluoxetine in human serum.     

Fabrication of high performance thin films from metal fluorocomplex aqueous solution by the liquid phase deposition

The hetro-structured oxide thin films from metal fluorocomplex solution have been prepared by the liquid phase deposition (LPD) method. The Pt/Nb₂O₅ and Au/Nb₂O₅ composite films can be prepared from a mixed solution of niobium source, H₃BO₃, Pt(NH₃)₄Cl₂ and HAuCl₄ aqueous solutions under the ambient temperature and atmosphere. In the case of Au/SiO₂ composite film, (NH₄)₂SiF₆ solution is used as a mother solution. The Pt and Au ionic species are deposited in Nb₂O₅ and SiO₂ matrices. They are reduced to their metallic state after treatment above 200 °C. The size of dispersed particles can be controlled by heat treatment temperature. It is also clear that, gold nanoparticles are also found to interact with SiO₂, although the interaction is smaller than that with Nb₂O₅ showing the size of Au nanoparticles remain smaller in Nb₂O₅ that in SiO₂.     

Error minimization in the envelope method for the determination of optical constants of a thin film

The algorithm for the determination of optical constants of a weakly absorbing thin film from the envelope method has been modified to minimize the error in the estimated values of extinction coefficient (k) as a function of wavelength. The refinement procedure is based on an extension of interference order adjustment method used for improving the estimated values of film thickness d and wavelength‐dependent refractive index n from the envelope method. The proposed modification when applied to a hypothetical as well as an experimental film is found to work well over a wide spectral region. Copyright © 2010 John Wiley & Sons, Ltd.     

Selective nitrogen doping on carbon cloth to enhance the performance of zinc anode

Metallic zinc is attractive anode material of rechargeable aqueous Zn-based batteries due to its ambient stability,high volumetric capacity,and abundant reserves.Nonetheless,Zn anodes suffer from issues such as low coulombic efficiency(CE),large polarization and dendrite formation.Herein,uniform Zn electrodeposition is reported on carbon substrates by selective nitrogen doping.Combined experimental and theoretical investigations demonstrate that pyrrolic and pyridinic nitrogen doped in carbon play beneficial effect as zinc-philic sites to direct nucleation and growth of metallic Zn,while negligible effect is observed for graphite nitrogen in Zn plating.The carbon cloth with modified amount of doped pyrrolic and pyridinic nitrogen stabilizes Zn plating/stripping with 99.3% CE after 300 cycles and significantly increases the deliverable capacity at high depth of charge and discharge compared to undoped carbon substrate and Zn foil.This work provides a better understanding of heteroatom doping effect in design and preparation of stable 3 D carbon-supported zinc anode.     

Sputter‐deposited Ni/Ti double‐bilayer thin film and the effect of intermetallics during annealing

In the present study, a double bilayer of a Ni/Ti thin film was investigated. A nanoscale NiTi thin film is deposited in a Ni–Ti–Ni–Ti manner to form a double‐bilayer structure on a Si(100) substrate. Ni and Ti depositions were carried out by using d.c. and r.f. power, respectively, in a magnetron sputtering chamber. Four types of bilayers are formed by varying the deposition time of each layer (i.e. 15, 20, 25, and 30 min). The as‐deposited amorphous thin films were annealed at 300, 400, 500, and 600 °C for 1 h to achieve the diffusion in between the layers. Microstructures were analyzed using field‐emission scanning electron microscope and high‐resolution transmission electron microscope. It was found that, with the increase in annealing temperature from 300 to 600 °C, the diffusion at the interface and atomic migration on the surface increase. Cross‐sectional micrographs exhibited the interdiffusion between the two‐layer constituents, especially at higher temperatures, which resulted in diffusion patches along the interface. Phase analyses, performed by grazing incidence X‐ray diffraction, showed the formation of intermetallic compounds with some silicide phases that enhance the mechanical properties. Nanoindentation and atomic force microscopy were carried out to know the mechanical properties and surface profiles of the films. The surface finish is better at higher annealing temperatures. It was found that for annealing temperatures varying from 300 to 600 °C, the increase in annealing temperature resulted in a gradual increase in atomic‐cluster coarsening with improved adatom mobility. Copyright © 2016 John Wiley & Sons, Ltd.     

Thermal diffusivity measurement of low-k dielectric thin film by temperature wave analysis

Thermal diffusivity of thin film with low dielectric constant (k), what is called low-k dielectric thin film, 0.31-1.14 μm, including hydrogen-silsesquioxane (HSQ), methyl-silsesquioxane (MSQ), and poly(arylen ether) was examined by temperature wave analysis. The phase shift of temperature wave was observable up to 100 kHz. Thermal diffusivity of HSQ was 4.7 × 10⁻⁷ m² s⁻¹, on the other hand it was not higher than 1.1 × 10⁻⁷ m² s⁻¹ for MSQ or poly(arylen ether) at room temperature. Temperature dependence of thermal diffusivity/thermal conductivity of MSQ was obtained, thermal diffusivity decreased but thermal conductivity increased in a heating scan at 30-150 °C. It was shown that the thermal diffusivity of low-k thin film was correlated with the chemical and the physical structures, the latter was formed in the spin-coating and the curing process.     

Molecularly imprinted TiO(2) thin film using stable ground-state complex as template as applied to selective electrochemical determination of mercury

Molecular recognition sites for mercury ions were imprinted in TiO₂ film using stable ground-state complex of 1-amino-8-naphtol-3,6-disodium sulfonate (ANDS) and mercury ions as template. The complex ratio between mercury ions and ANDS was estimated to be 2:1. Compared with the controlled and pure TiO₂ electrodes, the imprinted electrode revealed selectivity towards the imprinted ions. Linear calibration plots for mercury ions were obtained and the regression equation was I_p (μA) = 4.29 × 10⁻⁷ + 19.40 [Hg²⁺] with a detection limit of 3.06 × 10⁻⁹ mol/l. The imprinted electrode could be used for more than 1 month. Recoveries were calculated at both high and low concentrations, with a mean recovery of 99.6%.