新型多孔导电陶瓷负载银阴极在锌空气电池中的应用

锌空气电池具有能量密度高、成本低及环保等优势, 其空气电极的优劣对电池的输出性能起到决定性的作用。本研究采用一种新型的多孔钙钛矿氧化物La_0.7Sr_0.3CoO_3-δ(LSC)作为陶瓷基底, 负载银纳米颗粒作为催化剂, 研究其作为锌空电池空气电极的性能。β通过调整制备过程中造孔剂(淀粉)的含量, 优选出性能最佳的Ag-LSC空气电极(阴极), 与锌阳极组装成锌空气电池, 进行电化学性能测试。β结果表明, 当LSC基底的孔隙率为~32%且银含量30 mg/cm²时, 制备的多孔陶瓷负载银阴极组装的锌空气电池功率密度最高(141 mW/cm²)。β在Ag-LSC空气电极表面涂一层聚四氟乙烯(PTFE)疏水材料后, 锌空气电池的使用寿命得到显著延长。     

Na0.7Co1-xFexO2（x=0,0.03,0.07,0.10）的制备及其电学性能

采用固相反应法制备了Na0.7CoO2和Na0.7Co1-xFexO2（x=0.03,0.07,0.10）。X射线衍射显示Fe部分取代Co掺入了Na0.7CoO2的晶格中,Fe的掺入使晶胞参数c变大。电学性能测试表明,Fe的掺杂使电导率σ随温度的变化趋势发生了改变,并且使电导率降低。Fe的掺杂使Seebeck系数α有一定的提高,但其变化幅度较电导率低。功率因子α2σ的计算结果表明Fe的掺杂引起了材料功率因子的降低。     

激光蒸凝法工艺参数对Co/CoO 纳米粒子性能的影响

采用激光蒸凝法制备出Co/CoO纳米粒子.用X射线衍射、透射电镜、振动样品磁强计等技术对纳米粒子的性能进行了表征.实验结果表明,激光功率密度决定反应区温度,激光功率密度越高,反应区温度越高;反应压力、载气流量主要影响形成的粒子的形貌;反应气体的种类改变粒子的组成,在惰性气氛、氧气气氛和还原气氛下,产物均为Co/CoO,但钴的相对含量不同.最后确定了Co/CoO纳米粒子的较佳制备条件.     

氢镍电池闭口化成中的正极活化

采用BET ,DTA及XRD等手段研究了闭口化成条件下氢镍电池发泡式正极的活化。结果表明 ,以添加了氧化亚钴的球形氢氧化镍作为正极活性物质 ,在闭口化成条件下经适当活化可获得大于 90 %的正极活性物质利用率。添加了锌及镉和镁的球形氢氧化镍作为正极活性物质 ,可在较大的放电电流条件下获得高的电池容量。正极是通过CoO溶解 /沉积 /覆盖过程发挥其导电效果而活化的。     

Influence of cobalt oxide on the structure,optical transitions and ligand field parameters of lithium phosphate glasses

The influences of cobalt oxide (CoO) additions on the structure, optical transitions, ligand field parameters and stability of lithium phosphate glasses have been investigated. A series of glass systems (LiPhCo-glasses) was successfully prepared through the melt quenching approach. The amorphous nature was confirmed from X-ray diffraction measurements. The density and molar volume followed the typical opposite behavior, where the latter showed a decreasing behavior with CoO additions. Furthermore, it was found that the LiPhCo-glasses gradually changed their color from colorless (Co-free sample) into bluish glasses with CoO additions, thereby evidencing the presence of Co²⁺ ions. This is consistent with the absorption band identified in the optical absorption spectra at ~562–572 nm, which is related to ⁴A₂(⁴F) →⁴T₁(⁴P) electronic transitions of Co²⁺ (3d⁷ electronic configuration) in tetrahedral symmetry. Additional absorption band is detected at ~1412–1448 nm, which is correlated to ⁴A₂(⁴F) →⁴T₁(⁴F) transitions of Co²⁺ ions in tetrahedral symmetry. These two absorption bands were employed to study the ligand field splitting ($10D{q}_{\mathrm{t}}$)and Racah parameter (B), which sheds the light into the bonding character between Co ions and its ligands. The analysis showed that $10D{q}_t$ (B) is increased (reduced) indicating more covalency and less stability within the glass matrix with Co additions.     

碳纸负载钴氧化物的制备及电催化析氧性能研究

高效且廉价的电催化析氧反应（OER）电极材料的制备对其在电化学能源转化和储存系统中的应用具有重要的研究意义。通过溶剂热法和不同气氛焙烧,分别制得碳纤维纸（碳纸）负载的两种钴氧化物（一氧化钴和四氧化三钴）,并将其用作OER电极的催化剂。运用X射线衍射仪（XRD）、场发射扫描电镜（FESEM）和X射线光电子能谱（XPS）技术分别对两种材料的物相、形貌和表面价态进行了表征及分析。结果表明：在氮气气氛下焙烧得到一氧化钴纳米片,而在空气下焙烧得到四氧化三钴纳米片。通过线性扫描伏安法（LSV）、循环伏安曲线（CV）、电化学交流阻抗测试（EIS）和计时电位法对两种材料的电催化析氧性能进行了研究。结果表明：一氧化钴电极比四氧化三钴电极具有更优异的析氧反应催化活性和稳定性。在1 mol/L 氢氧化钾电解液中,一氧化钴和四氧化三钴电极在10 mA/cm ²电流密度下对应的电位分别为1.568 V和1.617 V。     

Role of supported metals in the selective reduction of nitrogen monoxide with hydrocarbons over metal/alumina catalysts

The promoting effect of supported metals on alumina catalyst was investigated for the reduction of nitrogen monoxide in oxygen-rich atmospheres. For NO reduction with propene over impregnated CoO/A1₂O₃, the first reaction step was found to be the oxidation of NO to NO₂ probably catalyzed by dispersed cobalt species. The next reaction step, which is the reaction of NO₂ with propene to form N₂, was considered to take place on the alumina surface. Although the activity of impregnated FeO/A1₂O₃ was low because of the presence of large iron oxide particles catalyzing propene oxidation with dioxygen, FeO/A1₂O₃ prepared with sol-gel method showed excellent deNO_x activity.     

CoO AS ADDITIVE IN POSITIVE ELECTRODE OF NICKEL-METAL HYDRIDE BATTERY

A series of positive electrodes for Ni/MH battery were fabricated by addition of CoO.The morphology and microstructure of the electrodes were examined by SEM and EDS, and electrochemical behavior was investigated in three-compartment appliances at room temperature.The electrochemical performance of the positive electrodes with CoO was improved. Under the same charge-discharge cycle, the electrodes with CoO showed higher specific capacity, lower charge mean voltage and higher discharge mean voltage. But further increasing the content of CoO in the electrodes contributed negative effect on the overall performance. Addition of 8% (mass) CoO was suggested to be a suitable content for the positive electrode.     

Solvent-controlled synthesis of mesoporous CoO with different morphologies as binder-free anodes for lithium-ion batteries

The solvent-controlled synthesis of mesoporous CoO with different morphologies was investigated through a facile route including hydrothermal reaction and subsequent calcination. By altering the solvent of reaction, CoO nanowires (CoO-NWs) and CoO polyhedron (CoO-PHn) were favorably loaded on nickel foam with robust adhesion. Compared with CoO-PHn, CoO-NWs for lithium storage has enhanced electrochemical performance in term of high reversible capacity and extraordinary rate capability. After 80 cycles, an outstanding reversible specific capacity for CoO-NWs was 1398?mA?h/g at a current density of 200?mA/g. Furthermore, a reversible specific capacity was up to 1175?mA?h/g even at a current density of 1000?mA/g. The extraordinary electrochemical property was owing to the presence of free voids, which significantly buffered the mechanical stress during the insertion/de-insertion process. In addition, one-dimensional (1D) morphology ensured a relatively short transmission route to accelerate electron transport.     

Influence of Ca content and oxygen partial pressure on microstructural evolution of (Co,Ca)O at elevated temperatures

Ca‐doped (1, 1.7, 5 and 10 mol% CaO) cobalt oxide single‐crystal samples, with an [001] orientation, were annealed at elevated temperatures of 1000–1200 °C for different times and at different oxygen partial pressures. The microstructure was examined by means of transmission light and electron microscopy. High‐temperature X‐ray diffractometry was used, with the aim of determining the temperature of the CoO ? Co₃O₄ transition in these materials. Extensive precipitation of Ca‐free Co₃O₄ spinel crystals was observed with increasing Ca content and oxygen activity. It is suggested that the electrical conductivity changes in this material may be related to this precipitation, because it changes the electronic state of cobalt cations.