La2Ni7和LaMgNi7储氢合金电子结构的研究

采用密度泛函理论研究了La2Ni7和LaMg-Ni7储氢合金的电子结构,探讨了微观结构和合金宏观性能之间的关联性.结果表明,含Mg元素的LaMgNi7体系形成成键作用的Ni-Mg键,体系稳定性高于纯La2Ni7体系.同时LaMgNi7体系中的Ni-Ni键强度弱于La2Ni7体系中的相应键,降低了H进入体系的能量壁垒,改...     

Mg-Ni基储氢合金的研究进展与发展趋势

系统阐述了近年来Mg-Ni基储氢合金的研究开发概况,指出Mg-Ni基储氢合金具有放电容量高、资源丰富、价格低廉等突出优点,分析了影响Mg-Ni基储氢合金储氢性能的主要因素,总结了近年来采用的行之有效的改进方法,主要有制备非晶/纳米晶、元素替代、添加催化剂等,并对Mg-Ni基储氢合金今后的发展方向进行了探讨与展望,指出Mg-Ni基储氢合金虽然前景可观,但是要实现实际应用仍然存在一些问题需要解决。     

Characterization of CuInS2 thin films prepared by sulfurization of Cu-In precursor

CuInS2 thin films were prepared by sulfurization of Cu-In precursors. The influences of the deposition sequence of Cu and In layers, such as Cu/In, Cu/In/In, and In/Cu/In, on structure, topography, and optical properties of CuInS2 thin films were investigated. X-ray diffraction results show that the deposition sequence of Cu and In layers affects the crystalline quality of CuInS2 films. Atomic force microstructure images reveal that the grain size and surface roughness are related to the deposition sequence used. When the deposition sequence of precursor is In/Cu/In, the CuInS2 thin films show a single-phase chalcopyrite structure with （112） preferred orientation. The surface morphology of CIS films is uniform and compacted. The absorption coefficient is larger than 10^4 cm^-1 with optical band gap Egclose to 1.4 eV.     

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 为考察具有Cu7In3相结构的Cu In前驱膜对CuInS2薄膜微结构的影响，采用电沉积法制备了Cu In薄膜，并对制备态Cu In薄膜在380 ℃进行真空退火处理制备Cu7In3前驱膜。采用硫化法对制备态Cu In薄膜和Cu7In3薄膜进行硫化处理制备了CIS薄膜。结果表明,两种前驱膜经硫化处理均在表面生成CuxS偏析相，经KCN刻蚀处理发现以Cu7In3为前驱膜制备的CuInS2薄膜高质量结晶，具有(112)择优取向，适合于制备CIS薄膜太阳能电池吸收层。     

衬底温度对CuI薄膜微结构与性能的影响

采用喷射沉积技术，探讨不同的衬底温度对CuI薄膜的微结构与性能的影响。通过x射线衍射谱，场发射扫描电子显微镜，霍尔测试仪和紫外．可见光分光光度计等测试了CuI薄膜的微结构、表面形貌和光电性能。研究结果表明，衬底温度为120℃时CuI薄膜的结晶性较好，薄膜表面相对均匀致密。可见光透过率随着衬底温度升高先增大后减小，在衬底温度为120℃时最高，近76％，适合作Al：ZnO／p-CuI／n-CIS薄膜太阳能电池的缓冲层。     

硫化温度对CuInS2吸收层薄膜微结构的影响

采用电沉积-硫化法制备了CuInS2(CIS)薄膜.用X射线衍射仪(XRD)、原子力显微镜(AFM)和能谱仪(EDS)等实验手段对CIS薄膜的晶体结构、形貌和组分进行了表征.结果表明:在500～560℃硫化温度范围内制备的CIS薄膜表面均生成金属性CuxS二元相,后续的KCN刻蚀处理CuxS二元相可去除.硫化温度为540℃制得的CIS薄膜高质量结晶、具有[112]择优取向,适合于制备CIS薄膜太阳能电池吸收层.     

铸态及退火态La（0.75）Mg（0.25）Ni（3.5）Si（0.10）储氢合金相结构和高温电化学性能的研究

研究了铸态及退火（940℃、8h）La0.75Mg0.25Ni3.5Si0.10储氢合金相结构,及在30、45、55和70℃环境温度下电化学性能,包括放电容量、寿命、高倍率和自放电行为。X射线衍射分析表明,两合金均为La-Ni5、（La,Mg）2Ni7和（La,Mg）Ni3相组成的多相结构,退火处理使LaNi5和（La,Mg）Ni3相减少,（La,Mg）2Ni7相增多,但两合金主相均为LaNi5。研究发现,铸态和退火态合金活化性能都较优异,最大放电容量均随测试温度升高而减小,并且退火处理能提高每个温度点的放电容量,70℃高温下最为显著,合金放电容量从238.4mAh/g增加到342.5mAh/g。随温度升高,铸态合金的高倍率放电性先增大后减小,而退火合金高倍率放电性随温度升高单调增加。合金的荷电保持率随温度升高而降低,退火处理可提高各个温度点的荷电保持率。     

Structure and high-temperature electrochemical properties of La_（0.60）Nd_（0.15）Mg_（0.25）Ni_（3.3）Si_（0.10） hydrogen storage alloys

The structure and high-temperature electrochemical properties of the as-cast and annealed (940 °C, 8 h) La0.60Nd0.15Mg0.25Ni3.3Si0.10 hydrogen storage alloys were investigated. The X-ray diffraction revealed that the multiphase structure of the as-cast alloy with LaNi5 phase as the main phase was converted into a double-phase structure with La2Ni7 phase as the main phase after annealing. The surface morphology studied by scanning electronic microscope (SEM) showed that the annealed alloy had a much higher anti-corrosion ability than the as-cast alloy. Both alloys presented excellent activation characteristics at all test temperatures. The maximum discharge capacity of the as-cast alloy decreased when the test temperature increased, while the temperature almost had no effect on the annealed alloy. As the test temperature increased, the cyclic stability and charge retention of both alloys decreased, and these properties were improved significantly by annealing.     

硫化对Cu-In预制膜微结构的影响

采用电沉积-硫化法制备了CuInS2薄膜,考察了硫源温度对CuInS2薄膜微结构的影响,并分析了硫化过程中的反应动力学.采用扫描电子显微镜(SEM)和能潜仪(EDS)观察并分析了薄膜的表面形貌和组分,采用X射线衍射仪(XRD)表征了薄膜的组织结构.结果表明,硫化过程的生长动力学不同于硒化过程,CuInS2薄膜的生长遵循扩散机制,当硫源温度在300～340℃之间,均可制得单一黄铜矿相结构且沿(112)面择优取向生长的CuInS2薄膜,且硫源温度为340℃制备的CuInS2薄膜均匀、致密,晶粒尺寸约为1μm,适合于制备CIS薄膜太阳能电池吸收层.     

CIS薄膜太阳能电池Cu-In前驱膜结构相变研究

为考察CIS薄膜太阳能电池Cu-In前驱膜结构相变规律, 采用电沉积法制备Cu-In前驱膜, 并对前驱膜进行真空退火热处理. 采用SEM和EDS观察并分析了薄膜的表面形貌和成分, 采用XRD表征薄膜组织结构. 结果表明, Cu-In前驱膜以CuIn, CuIn2和Cu混合相存在; 157 ℃真空退火10 min, 发生第一次相变生成Cu11In9相; 310 ℃真空退火10 min, 发生第二次相变生成Cu7In3相. 富Cu的Cu-In前驱膜结构相变受动力学边界条件所控制.