Bi_（0.5）Sb_（1.5）Te_3/Cu core/shell powders were prepared by electroless plating and hydrogen reduction, and then sintered into bulk by spark plasma sintering. After electroless plating, with increasing the Cu cont...Bi_（0.5）Sb_（1.5）Te_3/Cu core/shell powders were prepared by electroless plating and hydrogen reduction, and then sintered into bulk by spark plasma sintering. After electroless plating, with increasing the Cu content, the electrical conductivity keeps enhancing significantly. The highest electrical conductivity reaches 3341 S/cm at room temperature in Bi0.5Sb1.5Te3 with 0.67 wt% Cu bulk sample. Moreover, the lowest lattice thermal conductivity reaches 0.32 W/m·K at 572.2 K in Bi0.5Sb1.5Te3 with 0.67 wt% Cu bulk sample, which is caused by the scattering of the rich-copper particles with different dimensions and massive grain boundaries. According to the results, the ZT values of all Bi0.5Sb1.5Te3/Cu bulk samples have improved in a high temperature range. In Bi0.5Sb1.5Te3 with 0.15 wt% Cu bulk sample, the highest ZT value at 573.4 K is 0.81. When the Cu content increases to 0.67 wt%, the highest ZT value reaches 0.85 at 622.2 K. Meanwhile, the microhardness increases with increasing the Cu content.展开更多
Bi2Te2.7Se0.3/Cu core/shell powders were prepared by electroless plating and hydrogen reduction, and then sintered into bulk by spark plasma sintering in order to improve the thermoelectric and mechanical properties o...Bi2Te2.7Se0.3/Cu core/shell powders were prepared by electroless plating and hydrogen reduction, and then sintered into bulk by spark plasma sintering in order to improve the thermoelectric and mechanical properties of n-type Bi-Te thermoelectric material. After electroless plating, with the increasing of Cu content, Seebeck coefficient keeps increasing and power factor enhances significantly. The highest power factor increases by three times and reaches 23.8 W·cm^-1·K^-2 at room temperature in Bi2Te2.7Se0.3 with 0.22 wt%Cu sample, which means electrical transport properties of Bi2Te2.7Se0.3/Cu samples have been improved.Meanwhile, the ZT values of Bi2Te2.7Se0.3/Cu samples can be enhanced at different temperature zone by adjusting the Cu content. Bi2Te2.7Se0.3 with 0.05 wt% Cu sample has the best thermoelectric properties in high temperature zone, and the ZT peak value increases from 0.35 to 0.85 at 623 K. When the Cu content increases to 0.15 wt%,the ZT peak value moves to the low temperature(373 K) and increases from 0.24 to 0.71. At the same time, the mechanical properties increases with the increasing of Cu content.展开更多
In order to improve the thermoelectric and mechanical properties of p-type Bi_(2)Te_(3) thermoelectric material,Bi_(0.5)Sb_(1.5)Te_(3)/Ni&Cu core/shell powders were electroless plated with the same content of Ni a...In order to improve the thermoelectric and mechanical properties of p-type Bi_(2)Te_(3) thermoelectric material,Bi_(0.5)Sb_(1.5)Te_(3)/Ni&Cu core/shell powders were electroless plated with the same content of Ni and different content of Cu,and then reduced by hydrogen,and finally sintered into bulk by spark plasma sintering.After composite electroless plating with Ni&Cu,for the bulk sample with 0.3 wt% Ni and 0.15 wt% Cu,the power factor rises significantly and the highest value increases from 25 to 33 μW·cm^(-1)· K^(-2) at room temperature.Meanwhile,the thermal conductivity decreases to about 0.80 W·m^(-1)·K^(-1) at 623 K.Therefore,the composite electroless plating with Ni&Cu can obviously improve the electrical and thermal transport performance of p-type Bi_(2)Te_(3) based thermoelectric materials.Thus,the ZT value enhances significantly and the highest value increases over 3 times,from 0.35 to 1.16 at 473 K in Bi_(0.5)Sb_(1.5)Te_(3) with 0.3 wt% Ni and 0.15 wt% Cu bulk sample.At the same time,the mechanical properties have also been improved after composite electroless plating with Ni&Cu.展开更多
基金the National Natural Science Foundation of China(No.51371073)
文摘Bi_（0.5）Sb_（1.5）Te_3/Cu core/shell powders were prepared by electroless plating and hydrogen reduction, and then sintered into bulk by spark plasma sintering. After electroless plating, with increasing the Cu content, the electrical conductivity keeps enhancing significantly. The highest electrical conductivity reaches 3341 S/cm at room temperature in Bi0.5Sb1.5Te3 with 0.67 wt% Cu bulk sample. Moreover, the lowest lattice thermal conductivity reaches 0.32 W/m·K at 572.2 K in Bi0.5Sb1.5Te3 with 0.67 wt% Cu bulk sample, which is caused by the scattering of the rich-copper particles with different dimensions and massive grain boundaries. According to the results, the ZT values of all Bi0.5Sb1.5Te3/Cu bulk samples have improved in a high temperature range. In Bi0.5Sb1.5Te3 with 0.15 wt% Cu bulk sample, the highest ZT value at 573.4 K is 0.81. When the Cu content increases to 0.67 wt%, the highest ZT value reaches 0.85 at 622.2 K. Meanwhile, the microhardness increases with increasing the Cu content.
基金Funded by the National Natural Science Foundation of China(No.51371073)
文摘Bi2Te2.7Se0.3/Cu core/shell powders were prepared by electroless plating and hydrogen reduction, and then sintered into bulk by spark plasma sintering in order to improve the thermoelectric and mechanical properties of n-type Bi-Te thermoelectric material. After electroless plating, with the increasing of Cu content, Seebeck coefficient keeps increasing and power factor enhances significantly. The highest power factor increases by three times and reaches 23.8 W·cm^-1·K^-2 at room temperature in Bi2Te2.7Se0.3 with 0.22 wt%Cu sample, which means electrical transport properties of Bi2Te2.7Se0.3/Cu samples have been improved.Meanwhile, the ZT values of Bi2Te2.7Se0.3/Cu samples can be enhanced at different temperature zone by adjusting the Cu content. Bi2Te2.7Se0.3 with 0.05 wt% Cu sample has the best thermoelectric properties in high temperature zone, and the ZT peak value increases from 0.35 to 0.85 at 623 K. When the Cu content increases to 0.15 wt%,the ZT peak value moves to the low temperature(373 K) and increases from 0.24 to 0.71. At the same time, the mechanical properties increases with the increasing of Cu content.
基金Funded by the National Natural Science Foundation of China (No.51371073)。
文摘In order to improve the thermoelectric and mechanical properties of p-type Bi_(2)Te_(3) thermoelectric material,Bi_(0.5)Sb_(1.5)Te_(3)/Ni&Cu core/shell powders were electroless plated with the same content of Ni and different content of Cu,and then reduced by hydrogen,and finally sintered into bulk by spark plasma sintering.After composite electroless plating with Ni&Cu,for the bulk sample with 0.3 wt% Ni and 0.15 wt% Cu,the power factor rises significantly and the highest value increases from 25 to 33 μW·cm^(-1)· K^(-2) at room temperature.Meanwhile,the thermal conductivity decreases to about 0.80 W·m^(-1)·K^(-1) at 623 K.Therefore,the composite electroless plating with Ni&Cu can obviously improve the electrical and thermal transport performance of p-type Bi_(2)Te_(3) based thermoelectric materials.Thus,the ZT value enhances significantly and the highest value increases over 3 times,from 0.35 to 1.16 at 473 K in Bi_(0.5)Sb_(1.5)Te_(3) with 0.3 wt% Ni and 0.15 wt% Cu bulk sample.At the same time,the mechanical properties have also been improved after composite electroless plating with Ni&Cu.
