Stanley Abbey - Academia.edu (original) (raw)
Papers by Stanley Abbey
Advanced science, Apr 16, 2024
Advanced science, Jun 1, 2024
Energies, Mar 2, 2020
The conversion efficiency of the thermoelectric generator (TEG) is adversely affected by the qual... more The conversion efficiency of the thermoelectric generator (TEG) is adversely affected by the quality of thermal contact between the module and the heat source. TEGs with the planar substrate are not suitable for the curved heat sources. Several attempts have been made to tackle this issue by fabricating complex tubular-shaped TEGs; however, all efforts have been limited to low-temperature applications. Furthermore, the electrical contact resistance of the module is critical to achieving a high-power output. In this work, we developed the tubular TEG with significantly low specific contact resistance by optimizing the joining process. We show that the modified resistance welding (MRW) performed by spark plasma sintering (SPS) is an efficient joining method for the fabrication of the TE module, with high feasibility and scalability. This research seeks to suggest important design rules to consider when fabricating TEGs.
ACS Applied Materials & Interfaces, Jan 3, 2022
The alloy Zn 41 Sb 59 was synthesized by high-pressure techniques and its bulk amorphous nature a... more The alloy Zn 41 Sb 59 was synthesized by high-pressure techniques and its bulk amorphous nature at ambient conditions confirmed by X-ray powder diffraction and electron microscopy studies. Electrical resistivity, thermopower, and thermal conductivity of Zn 41 Sb 59 were measured in a temperature range from 6 to 350 K. Zn 41 Sb 59 is a semiconductor and resistivity data suggest an activation energy of about 0.25 eV above 250 K. The thermopower is positive and increases with increasing temperature. Roomtemperature values for the resistivity and thermopower are 8 Ω cm and 300 µV/K, respectively. The temperature dependence of the thermal conductivity is characteristic for amorphous solids and continuously increasing from 0.08 W/(m K) at 6 K to 0.19 W/(m K) at room temperature. Comparison of the thermal conductivity of Zn 41 Sb 59 with the thermal lattice conductivity of the crystalline thermoelectric material-Zn 4 Sb 3 reveals a remarkable resemblance, justifying the classification of the latter as a phonon-glass material.
International Journal of Nanotechnology, 2018
Determination of thermoelectric properties of NaxCoO2 (x = 0.5, 0.6, 0.7, 0.8, 0.85, and 0.9) fab... more Determination of thermoelectric properties of NaxCoO2 (x = 0.5, 0.6, 0.7, 0.8, 0.85, and 0.9) fabricated by polymerised complex (PC) method has been investigated in the temperature range 300-773 K. The single phase of NaxCoO2 was identified in samples with higher Na concentration (x > 0.7), while the second phase of Co3O4 was detected in that of lower Na concentration. The data from the measurement of Seebeck coefficients of all the samples suggest that they are p-type, which means that the major carrier concentrations are holes. The lowest electrical resistivity was obtained from sample x = 0.8. A fine microstructure was observed and is due to the PC method of fabrication, leading to low thermal conductivity. The maximum dimensionless figure of merit (ZT) of 0.25 at 773 K was evident in sample x = 0.8, which was mainly due to its lower electrical resistivity.
International Journal of Nanotechnology, Nov 30, 2018
Energy & Environmental Science
A twisted grain boundary is introduced in the tellurium crystal to effectively block phonon propa... more A twisted grain boundary is introduced in the tellurium crystal to effectively block phonon propagation while maintaining high electron mobility for superior thermoelectric properties.
RSC Advances, 2022
The silver paste was synthesized by a hydrometallurgical method from waste catalyst.
Journal of Materials Chemistry A
The AgBiSe2–CuBiSe2 system shows band nestification at high temperatures, resulting in heavy DOS ... more The AgBiSe2–CuBiSe2 system shows band nestification at high temperatures, resulting in heavy DOS effective mass while preserving electron mobility.
Graphene/Bi 2 Te 3 thermoelectric materials were prepared by spark plasma sintering (SPS) using h... more Graphene/Bi 2 Te 3 thermoelectric materials were prepared by spark plasma sintering (SPS) using hydrothermal synthesis of the powders as starting materials. The X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) were used to investigate the phase composition and microstructure of the as-prepared materials. Electrical resistivity, Seebeck coefficient, and thermal conductivity measurement were applied to analyze the thermoelectric properties. The effect of graphene on the performance of the thermoelectric materials was studied. The results showed that the maximum dimensionless figure of merit of the graphene/Bi 2 Te 3 composite with 0.2 vol.% graphene was obtained at testing temperature 475 K, 31% higher than the pure Bi 2 Te 3 .
Advanced science, Apr 16, 2024
Advanced science, Jun 1, 2024
Energies, Mar 2, 2020
The conversion efficiency of the thermoelectric generator (TEG) is adversely affected by the qual... more The conversion efficiency of the thermoelectric generator (TEG) is adversely affected by the quality of thermal contact between the module and the heat source. TEGs with the planar substrate are not suitable for the curved heat sources. Several attempts have been made to tackle this issue by fabricating complex tubular-shaped TEGs; however, all efforts have been limited to low-temperature applications. Furthermore, the electrical contact resistance of the module is critical to achieving a high-power output. In this work, we developed the tubular TEG with significantly low specific contact resistance by optimizing the joining process. We show that the modified resistance welding (MRW) performed by spark plasma sintering (SPS) is an efficient joining method for the fabrication of the TE module, with high feasibility and scalability. This research seeks to suggest important design rules to consider when fabricating TEGs.
ACS Applied Materials & Interfaces, Jan 3, 2022
The alloy Zn 41 Sb 59 was synthesized by high-pressure techniques and its bulk amorphous nature a... more The alloy Zn 41 Sb 59 was synthesized by high-pressure techniques and its bulk amorphous nature at ambient conditions confirmed by X-ray powder diffraction and electron microscopy studies. Electrical resistivity, thermopower, and thermal conductivity of Zn 41 Sb 59 were measured in a temperature range from 6 to 350 K. Zn 41 Sb 59 is a semiconductor and resistivity data suggest an activation energy of about 0.25 eV above 250 K. The thermopower is positive and increases with increasing temperature. Roomtemperature values for the resistivity and thermopower are 8 Ω cm and 300 µV/K, respectively. The temperature dependence of the thermal conductivity is characteristic for amorphous solids and continuously increasing from 0.08 W/(m K) at 6 K to 0.19 W/(m K) at room temperature. Comparison of the thermal conductivity of Zn 41 Sb 59 with the thermal lattice conductivity of the crystalline thermoelectric material-Zn 4 Sb 3 reveals a remarkable resemblance, justifying the classification of the latter as a phonon-glass material.
International Journal of Nanotechnology, 2018
Determination of thermoelectric properties of NaxCoO2 (x = 0.5, 0.6, 0.7, 0.8, 0.85, and 0.9) fab... more Determination of thermoelectric properties of NaxCoO2 (x = 0.5, 0.6, 0.7, 0.8, 0.85, and 0.9) fabricated by polymerised complex (PC) method has been investigated in the temperature range 300-773 K. The single phase of NaxCoO2 was identified in samples with higher Na concentration (x > 0.7), while the second phase of Co3O4 was detected in that of lower Na concentration. The data from the measurement of Seebeck coefficients of all the samples suggest that they are p-type, which means that the major carrier concentrations are holes. The lowest electrical resistivity was obtained from sample x = 0.8. A fine microstructure was observed and is due to the PC method of fabrication, leading to low thermal conductivity. The maximum dimensionless figure of merit (ZT) of 0.25 at 773 K was evident in sample x = 0.8, which was mainly due to its lower electrical resistivity.
International Journal of Nanotechnology, Nov 30, 2018
Energy & Environmental Science
A twisted grain boundary is introduced in the tellurium crystal to effectively block phonon propa... more A twisted grain boundary is introduced in the tellurium crystal to effectively block phonon propagation while maintaining high electron mobility for superior thermoelectric properties.
RSC Advances, 2022
The silver paste was synthesized by a hydrometallurgical method from waste catalyst.
Journal of Materials Chemistry A
The AgBiSe2–CuBiSe2 system shows band nestification at high temperatures, resulting in heavy DOS ... more The AgBiSe2–CuBiSe2 system shows band nestification at high temperatures, resulting in heavy DOS effective mass while preserving electron mobility.
Graphene/Bi 2 Te 3 thermoelectric materials were prepared by spark plasma sintering (SPS) using h... more Graphene/Bi 2 Te 3 thermoelectric materials were prepared by spark plasma sintering (SPS) using hydrothermal synthesis of the powders as starting materials. The X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) were used to investigate the phase composition and microstructure of the as-prepared materials. Electrical resistivity, Seebeck coefficient, and thermal conductivity measurement were applied to analyze the thermoelectric properties. The effect of graphene on the performance of the thermoelectric materials was studied. The results showed that the maximum dimensionless figure of merit of the graphene/Bi 2 Te 3 composite with 0.2 vol.% graphene was obtained at testing temperature 475 K, 31% higher than the pure Bi 2 Te 3 .