天然石墨经过浓H_3PO_4插层处理、有机胺热解碳包覆后形成具有"核-壳"结构的碳包覆插层石墨负极材料。利用X射线衍射仪、扫描电子显微镜、拉曼光谱仪和恒流充放电仪对改性天然石墨的晶体结构、表面形貌和电化学性能进行了分...天然石墨经过浓H_3PO_4插层处理、有机胺热解碳包覆后形成具有"核-壳"结构的碳包覆插层石墨负极材料。利用X射线衍射仪、扫描电子显微镜、拉曼光谱仪和恒流充放电仪对改性天然石墨的晶体结构、表面形貌和电化学性能进行了分析和表征。结果表明:改性后的天然石墨晶面间距增大,表面成功地包覆了一层无定型碳;其首次充电比容量为366.42 m A·h/g,在1 C倍率下循环20周后容量保持率为87.13%,而在同样条件下,天然石墨的容量保持率仅为78.13%。该改性方法有效地改善了天然石墨的倍率性能和循环性能。展开更多
Improvement of the heat transfer effect of cold side of a thermoelectric generator(TEG) is one of the approaches to enhance the performance of the TEG systems.As a new type of heat transfer media,nanofluids can enhanc...Improvement of the heat transfer effect of cold side of a thermoelectric generator(TEG) is one of the approaches to enhance the performance of the TEG systems.As a new type of heat transfer media,nanofluids can enhance the heat transfer performance of working liquid significantly.In this study,the performance of a commercial TEG with graphene-water(GW) nanofluid as coolants in a minichannel heat exchanger is investigated experimentally at low temperatures.The results show that the output power of TEG increases with the flow rate under 950 mL/min.However,the fluid flow rate has no influence on the output power of TEG with higher flow rate(larger than 950 mL/min) when the heat transfer dynamic balance state of the system is reached.The optimal concentration and flow rate of nanofluid are 0.1 wt%and 950 mL/min,respectively.At the optimal conditions,the improved voltage,output power and conversion efficiency with GW nanofluid applied in the cooling system are increased by11.29%,21.55%and 3.5%in comparison with those with only water applied,respectively.展开更多
近年来,随着能源危机的加剧,可以将热能与电能进行直接转换的热电材料得到了广泛的关注。在众多热电材料体系中,有机无机纳米复合热电材料具有独特优势。相比于无机材料,有机材料成本低、质量轻、机械柔韧性好、热导率较低。添加不同类...近年来,随着能源危机的加剧,可以将热能与电能进行直接转换的热电材料得到了广泛的关注。在众多热电材料体系中,有机无机纳米复合热电材料具有独特优势。相比于无机材料,有机材料成本低、质量轻、机械柔韧性好、热导率较低。添加不同类型的添加材料构成纳米复合材料后,额外引入的声子-界面散射能进一步降低热导率,同时有机无机材料能带不匹配引起的载流子筛选效应进一步提升塞贝克(Seebeck)系数。因此,目前大量工作证明有机无机纳米复合热电材料有潜力获得高的热电优值(Figure of merit,ZT),在微型热电制冷器件、柔性可穿戴发电设备、温度传感器等领域均具有光明的应用前景。本文聚焦聚(3,4-乙烯二氧噻吩)∶聚(苯乙烯磺酸盐)(PEDOT∶PSS)热电材料及以其为基底构成的纳米复合材料热电性能的研究工作,综述了提升PEDOT∶PSS热电性能的物理方法、化学试剂改性法等。进一步重点讨论了加入不同类型的无机填料的PEDOT∶PSS基纳米复合材料热电性质的研究进展,并揭示了其热电性能提升的内在机制。展开更多
文摘天然石墨经过浓H_3PO_4插层处理、有机胺热解碳包覆后形成具有"核-壳"结构的碳包覆插层石墨负极材料。利用X射线衍射仪、扫描电子显微镜、拉曼光谱仪和恒流充放电仪对改性天然石墨的晶体结构、表面形貌和电化学性能进行了分析和表征。结果表明:改性后的天然石墨晶面间距增大,表面成功地包覆了一层无定型碳;其首次充电比容量为366.42 m A·h/g,在1 C倍率下循环20周后容量保持率为87.13%,而在同样条件下,天然石墨的容量保持率仅为78.13%。该改性方法有效地改善了天然石墨的倍率性能和循环性能。
基金supported by the National Natural Science Foundation of China(Grant Nos.51590902&51476095)the Natural Science Foundation of Shanghai(Grant No.14ZR1417000)+1 种基金the Key Subject of Shanghai Polytechnic University(Material Science and Engineering,Grant No.XXKZD1601)the Program for Professor of Special Appointment(Young Eastern Scholar,Grant No.QD2015052)at Shanghai Institutions of Higher Learning
文摘Improvement of the heat transfer effect of cold side of a thermoelectric generator(TEG) is one of the approaches to enhance the performance of the TEG systems.As a new type of heat transfer media,nanofluids can enhance the heat transfer performance of working liquid significantly.In this study,the performance of a commercial TEG with graphene-water(GW) nanofluid as coolants in a minichannel heat exchanger is investigated experimentally at low temperatures.The results show that the output power of TEG increases with the flow rate under 950 mL/min.However,the fluid flow rate has no influence on the output power of TEG with higher flow rate(larger than 950 mL/min) when the heat transfer dynamic balance state of the system is reached.The optimal concentration and flow rate of nanofluid are 0.1 wt%and 950 mL/min,respectively.At the optimal conditions,the improved voltage,output power and conversion efficiency with GW nanofluid applied in the cooling system are increased by11.29%,21.55%and 3.5%in comparison with those with only water applied,respectively.
文摘近年来,随着能源危机的加剧,可以将热能与电能进行直接转换的热电材料得到了广泛的关注。在众多热电材料体系中,有机无机纳米复合热电材料具有独特优势。相比于无机材料,有机材料成本低、质量轻、机械柔韧性好、热导率较低。添加不同类型的添加材料构成纳米复合材料后,额外引入的声子-界面散射能进一步降低热导率,同时有机无机材料能带不匹配引起的载流子筛选效应进一步提升塞贝克(Seebeck)系数。因此,目前大量工作证明有机无机纳米复合热电材料有潜力获得高的热电优值(Figure of merit,ZT),在微型热电制冷器件、柔性可穿戴发电设备、温度传感器等领域均具有光明的应用前景。本文聚焦聚(3,4-乙烯二氧噻吩)∶聚(苯乙烯磺酸盐)(PEDOT∶PSS)热电材料及以其为基底构成的纳米复合材料热电性能的研究工作,综述了提升PEDOT∶PSS热电性能的物理方法、化学试剂改性法等。进一步重点讨论了加入不同类型的无机填料的PEDOT∶PSS基纳米复合材料热电性质的研究进展,并揭示了其热电性能提升的内在机制。
