热电器件的界面稳定性是决定其服役可靠性和寿命的关键因素。对于方钴矿热电器件,为了抑制高温电极与方钴矿材料之间的相互扩散,需要在两者之间加入阻挡层。本工作选用Ti_(88)Al_(12)作为阻挡层,利用一步法热压烧结制备n型Yb_(0.3)Co_4S...热电器件的界面稳定性是决定其服役可靠性和寿命的关键因素。对于方钴矿热电器件,为了抑制高温电极与方钴矿材料之间的相互扩散,需要在两者之间加入阻挡层。本工作选用Ti_(88)Al_(12)作为阻挡层,利用一步法热压烧结制备n型Yb_(0.3)Co_4Sb_(12)/Ti_(88)Al_(12)/Yb_(0.3)Co_4Sb_(12)和p型CeFe3.85Mn0.15Sb12/Ti_(88)Al_(12)/CeFe3.85Mn0.15Sb12样品,研究Ti_(88)Al_(12)阻挡层与热电材料间的界面接触电阻率及微结构在加速老化实验中的演化规律。结果表明:在相同的老化条件下,n型样品的界面接触电阻率增加速度比p型样品慢,其激活能分别为84.1 k J/mol和68.8 k J/mol。对于n型样品,由元素扩散反应生成的金属间化合物中间层的增长及最终AlCo/TiCoSb层的开裂是导致界面接触电阻率增加的主要原因;而p型热电材料与Ti_(88)Al_(12)的热膨胀系数的差异加速了p型样品中界面裂纹的产生。展开更多
Thermoelectric power generation provides us the unique capability to explore the deep space and holds promise for harvesting the waste heat and providing a battery-free power supply for IoTs.The past years have witnes...Thermoelectric power generation provides us the unique capability to explore the deep space and holds promise for harvesting the waste heat and providing a battery-free power supply for IoTs.The past years have witnessed massive progress in thermoelectric materials,while the module-level development is still lagged behind.We would like to shine some light on the module-level design and characterization of thermoelectric power generators(TEGs).In the module-level design,we review material selection,thermal management,and the determination of structural parameters.We also look into the module-level characterization,with particular attention on the heat flux measurement.Finally,the challenge in the optimal design and reliable characterization of thermoelectric power generators is discussed,together with a calling to establish a standard test procedure.展开更多
文摘采用熔融法结合放电等离子烧结(SPS)技术合成了P型填充方钴矿化合物Sr_(0.5)Co_(4-x)Fe_xSb_(12),并研究了Fe掺杂对该化合物高温热电性能的影响。采用X-射线衍射(XRD)及电子探针(EPMA)表征了化合物的物相及化学成分,在300～850 K温度范围内测试了化合物的电导率、赛贝克系数和热导率,采用Van de Pauw方法测试了化合物的室温载流子浓度。实验结果表明,化合物的主要相组成为Sr_(0.5)Co_(4-x)Fe_xSb_(12)方钴矿相,同时含有少量FeSb_2和CoSb_2杂质相。化合物的赛贝克系数均为正值,表明为空穴导电。随着Fe掺杂量的增加,化合物的载流子浓度及电导率增加,赛贝克系数降低,晶格热导率降低,最小室温晶格热导率为1.97 Wm^(-1)K^(-2)。对于化合物Sr_(0.52)Co_(2.32)Fe_(1.68)Sb_(12),在850K时获得的最大热电性能指数ZT约为0.60。
文摘热电器件的界面稳定性是决定其服役可靠性和寿命的关键因素。对于方钴矿热电器件,为了抑制高温电极与方钴矿材料之间的相互扩散,需要在两者之间加入阻挡层。本工作选用Ti_(88)Al_(12)作为阻挡层,利用一步法热压烧结制备n型Yb_(0.3)Co_4Sb_(12)/Ti_(88)Al_(12)/Yb_(0.3)Co_4Sb_(12)和p型CeFe3.85Mn0.15Sb12/Ti_(88)Al_(12)/CeFe3.85Mn0.15Sb12样品,研究Ti_(88)Al_(12)阻挡层与热电材料间的界面接触电阻率及微结构在加速老化实验中的演化规律。结果表明:在相同的老化条件下,n型样品的界面接触电阻率增加速度比p型样品慢,其激活能分别为84.1 k J/mol和68.8 k J/mol。对于n型样品,由元素扩散反应生成的金属间化合物中间层的增长及最终AlCo/TiCoSb层的开裂是导致界面接触电阻率增加的主要原因;而p型热电材料与Ti_(88)Al_(12)的热膨胀系数的差异加速了p型样品中界面裂纹的产生。
基金supported by Shenzhen DRC project(Grant No.[2018]1433)。
文摘Thermoelectric power generation provides us the unique capability to explore the deep space and holds promise for harvesting the waste heat and providing a battery-free power supply for IoTs.The past years have witnessed massive progress in thermoelectric materials,while the module-level development is still lagged behind.We would like to shine some light on the module-level design and characterization of thermoelectric power generators(TEGs).In the module-level design,we review material selection,thermal management,and the determination of structural parameters.We also look into the module-level characterization,with particular attention on the heat flux measurement.Finally,the challenge in the optimal design and reliable characterization of thermoelectric power generators is discussed,together with a calling to establish a standard test procedure.
