不同背反射结构在硅异质结太阳电池中的应用研究

该文旨在利用银纳米颗粒（Ag NPs）和SiO_x/Ag背反射结构提升硅异质结（SHJ）太阳电池在900~1200nm波段红外光谱响应。研究在SHJ太阳电池背光侧分别制备Ag、SiO_x/Ag和嵌入Ag NPs的SiO_x/Ag几种背反射结构,以最大限度提升SHJ太阳电池红外光谱响应。结果表明：SiO_x/Ag背反射结构可有效减少红外光的逃逸损失,提升太阳电池红外光谱响应,使得双面制绒SHJ太阳电池短路电流密度从37.74 mA/cm²提升到38.07 mA/cm²;但嵌入Ag NPs并不能帮助SiO_x/Ag背反射结构进一步提升双面制绒SHJ电池红外光谱响应,证明了基于其局域表面等离激元共振效应仅对陷光能力较差的平面太阳SHJ电池有一定提升。     

铁基载氧体的污泥化学链气化过程中氮迁移热力学模拟与实验研究

基于吉布斯自由能最小化原理,采用HSC Chemistry 6.0软件,对污泥化学链气化过程中NO_x前驱物（NH₃和HCN）与Fe₂O₃载氧体的氧化还原行为进行了热力学模拟。基于污泥热解实验中NO_x前驱物的含量,计算载氧体与污泥的摩尔比（OC/SS）对NH₃、HCN以及NH₃和HCN混合气氧化过程的影响。热力学模拟结果表明：Fe₂O₃能显著促进NO_x前驱物的氧化和裂解,主要生成N₂,几乎无NO_x生成;当NH₃、HCN以及混合气（NH₃和HCN）分别作为还原剂时,其最优OC/SS分别为0.02、0.04和0.05;由于HCN还原性强于NH₃,其氧化速率较快。基于Fe₂O₃/Al₂O₃混合物（FeAl）载氧体,实验对比了污泥化学链气化与污泥热解过程中NO_x前驱物的释放特性,发现Fe₂O₃能显著降低烟气中NO_x前驱物的产率,NH₃和HCN产率分别下降32%和62%。实验结果与热力学模拟结果一致。     

Capacitive performance and cycling stability of NixCo1-x(OH)2 xerogels

研究了Ni_xCo_1-x(OH)₂干凝胶中钴含量对其电性能及循环稳定性的影响。用溶胶-凝胶法制备了Ni_xCo_1-x(OH)₂干凝胶材料,用液氮吸附、XPS和XRD研究了含钴Ni(OH)₂干凝胶的组成和结构,用恒电流技术研究了它们的电容性能。结果表明,Ni_xCo_1-x(OH)₂干凝胶具有较高的比表面积和丰富的中孔;添加钴改善了Ni_xCo_1-x(OH)₂干凝胶的倍率性能,当钴含量达到24%时效果最佳;充放电后Co_xNi_1-x(OH)₂干凝胶的晶态结构仍是β-Ni(OH)₂晶相结构,钴含量20%以上的Co_xNi_1-x(OH)₂干凝胶充放电后微晶尺寸变化不明显;组成的活性炭/ Ni_0.76Co_0.24(OH)₂干凝胶电容器20 mA/cm²充放电循环时,库仑效率达到95%以上,循环100000次以上,电容器的比容量仍保持在90%以上。在长循环过程中,Ni_0.76Co_0.24(OH)₂干凝胶的微晶尺寸变化不大,微晶晶胞a轴逐渐变大、c轴逐渐缩小,晶胞参数趋向理想的β-Ni(OH)₂晶体。     

氢等离子体处理钝化层对高效晶硅异质结太阳电池性能的影响

研究不同时间氢等离子体处理（HPT）氢化非晶硅a-Si:H（i）钝化层对高效晶硅异质结太阳电池（效率>23％）性能的影响。发现适当时间的HPT可改善钝化效果提升电池性能,但过长时间的HPT可导致薄膜钝化效果变差,有效少数载流子寿命降低。分析认为HPT时间过长,H原子进入到a-Si:H（i）薄膜层中,导致薄膜内部SiH₂增多,微结构因子（R）增大,薄膜质量变差。并且,适当时间的HPT改善太阳电池性能的幅度有限,而过长时间的HPT导致电池性能下降却很明显。因此,针对高效率的晶硅异质结太阳电池,应对钝化层沉积之后的HPT工艺进行谨慎控制。     

Mo2C/Al2O3的制备及其催化二甲醚水蒸气重整性能研究

通过浸渍沉淀法结合程序升温碳化法制备了Mo₂C/Al₂O₃复合催化剂,并应用于二甲醚水蒸气重整催化体系的研究。考察了二甲醚水解催化载体、水解功能组分Al₂O₃与重整功能组分Mo₂C的比例、反应物浓度对复合催化剂活性的影响。结果表明,β-Mo₂C与γ-Al₂O₃载体以Mo/Al = 1/1耦合后能够高效催化二甲醚重整制氢,其最佳进料水醚比为5,最适反应温度为400℃。     

加热和水处理共同调控PbI2薄膜形貌及其在钙钛矿太阳电池中的应用研究

该文研究加热和水处理共同作用对PbI₂薄膜形貌的调控和对钙钛矿太阳电池性能的影响。使用的钙钛矿体系为（FAPbI₃）_1-x（MAPbBr₃）_x,并在两步法工艺基础上对PbI₂薄膜进行不同时间加热和短时间水处理可将PbI₂薄膜制备成多孔结构。将双重处理后的PbI₂薄膜制备成钙钛矿薄膜后,可发现钙钛矿薄膜质量明显提升,表现在：钙钛矿的晶粒尺寸明显增大、结晶性增强、吸光能力提升、载流子传输更快。且此种方式能有效调控钙钛矿薄膜中的PbI₂残留量。在器件效率方面,只对PbI₂薄膜进行加热处理制备的电池的开路电压、短路电流、填充因子和效率分别为1.05 V、23.12 mA/cm²、73.81%和17.92%,而在最优双重处理工艺下制备的电池的这4个相应的参数分别为1.09 V、24.75 mA/cm²、77.85%和21.10%。     

Ag/Al2O3(Li2O)/g-C3N4光催化乙醇制取环氧乙烷

本文制备了一系列Ag/Al₂O₃(Li₂O)/g-C₃N₄复合催化剂,考察了其可见光催化乙醇制取环氧乙烷的性能。Li₂O可调变Al₂O₃表面的酸性,从而降低了主要副产物乙醛的选择性。Ag/Al₂O₃(Li₂O) 在g-C₃N₄上的负载量对产物环氧乙烷的选择性有较大影响,当Ag/Al₂O₃(Li₂O) 负载量为5wt%时,乙醇具有较高的转换率,且环氧乙烷的选择性高达100%。     

Rb掺杂Li4Ti5O12作为锂离子电池负极材料的合成及电化学性能

合成了不同Rb掺杂量的钛酸锂（Li_4-xRb_xTi₅O₁₂; x = 0.010, 0.015, 0.020）作为锂离子电池的负极材料。测试结果显示,Rb离子掺杂有效增强了钛酸锂的电子电导率。相同的测试条件下,相比于未掺杂样品和高Rb含量掺杂样品（x = 0.015, 0.020）,适量的Rb掺杂钛酸锂（Li_3.99Rb_0.01Ti₅O₁₂; x = 0.010）表现出最优的电化学性能。Li_3.99Rb_0.01Ti₅O₁₂材料表现出161.2 mA∙h/g的初始容量,且在1 C下经过1000次循环后容量保持率可达90.9%。此外,全电池Li_3.99Rb_0.01Ti₅O₁₂ // LiFePO₄在0.5 C条件下首次放电容量为144 mA∙h/g,经过150次循环后,容量保持率为78.8%。     

多晶PERC太阳电池的背面与正面结构性能优化

多晶硅太阳电池以其价格低廉的优势成为低成本太阳电池的首选,但其光电转换效率提升空间有限。钝化发射极和背面电池（PERC）技术是当前晶硅太阳电池提效的主要途径。多晶PERC电池结合了多晶硅电池的低成本和PERC电池的高效,是当前多晶硅电池的研究热点。本文研究了多晶PERC电池的背面和正面结构优化与设计,提出了提高多晶PERC电池效率的产业化技术方法。通过在硅片背面用三层SiN_x:H薄膜来代替常规双层SiN_x:H薄膜,在保证优良的背面钝化的同时,使电池长波响应得到改善,电池光电转换效率由20.19% 提升至20.26%。优化多晶PERC电池的背面激光开窗工艺,使多晶电池效率较常规工艺提升0.11%。而在多晶PERC电池的正面叠加选择性发射极技术,可较常规工艺提升电池效率0.10%。综合运用多种提效手段有利于保持多晶PERC电池的竞争力。     

“SE+PERC”单晶硅太阳电池发射极方阻均匀性提升工艺的研究

针对“SE+PERC”单晶硅太阳电池制备过程中,管式扩散炉扩散后硅片发射极方阻均匀性差的问题,在扩散工艺的“预沉积”步骤设计小氮气(N₂)流量、氧气(O₂)流量、炉内压强参数变化实验,研究小N₂流量、O₂流量和炉内压强变化对发射极方阻、方阻均匀性及太阳电池电性能的影响。研究结果表明：通过调整小N₂流量、O₂流量及扩散过程中的炉内压强可以有效提高发射极方阻均匀性,并提高太阳电池的光电转换效率。在小N₂流量为1000 sccm、O₂流量为600 sccm、炉内压强为80 kPa的工艺条件下可实现发射极的方阻均匀性最佳,均值为4.94%;此时“SE+PERC”单晶硅太阳电池的光电转换效率为23.11%。     

Selective removal of CO from hydrogen-rich stream over CuO/CexSn1−xO2–Al2O3 catalysts

The solid solutions of Ce_xSn_1−xO₂ incorporated with alumina to form Ce_xSn_1−xO₂–Al₂O₃ mixed oxides, by the suspension/co-precipitation method, were used to prepare CuO/Ce_xSn_1−xO₂–Al₂O₃ catalysts for the selective oxidation of CO in excess hydrogen. Incorporating Al₂O₃ increased the dispersion of Ce_xSn_1−xO₂, but did not change their main structures and did not weaken their redox properties. Doping Sn⁴⁺ into CeO₂ increased the mobility of lattice oxygen and enhanced the activity of the 7%CuO/Ce_xSn_1−xO₂–Al₂O₃ catalyst in the selective oxidation of CO. The selective oxidation of CO was weakened as the doped fraction of Sn⁴⁺ exceeded 0.5. Incorporating appropriate amounts of Sn⁴⁺ and Al₂O₃ could obtain good candidates 7%CuO/Ce_xSn_1−xO₂–Al₂O₃(20%), 1–x=0.1–0.5, for a preferential oxidation (PROX) unit in a polymer electrolyte membrane fuel cell system for removing CO. Its activity was comparable with, and its selectivity was much larger than, that of the noble catalyst 5%Pt/Al₂O₃.     

Electrochemical characteristics of metal oxide-coated lithium manganese oxide (spinel type): Part II. In the range of 3.0–4.4 V

Metal oxide-coated spinel was investigated with respect to electrochemical characteristics. Metal oxide coating on commercial spinel powder (LiMn_2−xM_xO₄, M=Zr, Nikki, Japan) was carried out using the sol–gel method. Al₂O₃/CuO_x-coated spinel exhibited stable cycle performance in the range from 3.0 to 4.4 V, and it had lower charge transfer resistance and higher double layer capacitance than bare spinel in later cycles. In the SEM image of the powder after the cell test, bare spinel showed abnormal surfaces formed by decomposition of the electrolyte, while Al₂O₃/CuO_x-coated spinel displayed a normal surface covered with a surface film. Therefore, it is expected that an Al₂O₃/CuO_x layer coated on the spinel powder can function as a protective film, which supresses the reaction between electrolyte and active material.     

Electrochemical characteristics and cycle performance of LiMn2O4/a-Si microbattery

A LiMn₂O₄ thin film and an amorphous Si (a-Si) thin film were prepared by radio-frequency (rf) magnetron sputtering. Each thin film was electrochemically evaluated by cyclic voltammetry (CV) and galvanostatic cycling. The rate of capacity fade on cycling was monitored as a function of the voltage window and current density. This was compared with the cycle performance of cathode and anode using two kinds of electrolyte, 1 M LiPF₆ in EC/DMC and PC, for 100 cycles. It was found that the discharge capacity of optimized LiMn₂O₄/a-Si full-cell reached 24 μAh/(cm²-μm) in the first cycle, and a reversible capacity of about 16 μAh/(cm² μm) was still maintained after 100 cycles. In a voltage window of 3.0–4.2 V, LiMn₂O₄/a-Si full-cell exhibits relatively stable cycle performance compared to a voltage window of 2.75–4.2 V.     

A screen-printed Ce0.8Sm0.2O1.9 film solid oxide fuel cell with a Ba0.5Sr0.5Co0.8Fe0.2O3−δ cathode

Screen-printing technology was developed to fabricate Ce_0.8Sm_0.2O_1.9 (SDC) electrolyte films onto porous NiO–SDC green anode substrates. After sintering at 1400 °C for 4 h, a gas-tight SDC film with a thickness of 12 μm was obtained. A novel cathode material of Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ was subsequently applied onto the sintered SDC electrolyte film also by screen-printing and sintered at 970 °C for 3 h to get a single cell. A fuel cell of Ni–SDC/SDC (12 μm)/Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ provides the maximum power densities of 1280, 1080, 670, 370, 180 and 73 mW cm⁻² at 650, 600, 555, 505, 455 and 405 °C, respectively, using hydrogen as fuel and stationary air as oxidant. When dry methane was used as fuel, the maximum power densities are 876, 568, 346 and 114 mW cm⁻² at 650, 600, 555 and 505 °C, respectively. The present fuel cell shows excellent performance at lowered temperatures.