Metal-like electrical conductivity in LaxSr2−xTiMoO6 oxides for high temperature thermoelectric power generation

2017 ◽  
Vol 46 (18) ◽  
pp. 5872-5879 ◽  
Author(s):  
Mandvi Saxena ◽  
Tanmoy Maiti

Increasing electrical conductivity in oxides, which are inherently insulators, can be a potential route in developing oxide-based thermoelectric power generators with higher energy conversion efficiency.

2021 ◽  
pp. 1-23
Author(s):  
Dandan Pang ◽  
Aibing Zhang ◽  
Zhenfei Wen ◽  
Baolin Wang ◽  
Ji Wang

Abstract Thermoelectric power generators (TEGs) have been attracted increasing attention recently due to their capability of converting waste heat into useful electric energy without hazardous emissions. This paper develops a theoretical model to analyze the thermoelectric performance of TEGs with cylindrical legs. The influence of heat convection loss between lateral surfaces of thermoelectric legs and ambient environment on the energy conversion efficiency is investigated. For the idealized model, closed-form solutions of optimal electric current, maximum power output and maximum energy conversion efficiency are obtained, a new dimensionless impact factor H is introduced to capture the heat convection effect. The impact factor H depends on the ratio of heat conductivity to heat convection coefficient and geometry size of thermoelectric legs, as well as the temperature ratio of heat sink to hot source. The performance can be evaluated by the figure of merit, impact factor H and temperature gradient across the hot source and heat sink for a well-designed TEG with cylindrical legs. For the case of considering contact resistance, it is found that there exists an optimal leg's height for maximum energy conversion efficiency due to the heat convection on lateral surfaces of thermoelectric leg. The proposed theoretical model in this paper will be very helpful in the designing of actual TEG devices.


2014 ◽  
Vol 605 ◽  
pp. 306-309
Author(s):  
Miae Kim ◽  
Ji Beom Kim ◽  
Joon Hyeon Jeon

Lithium-ammonia (Li-NH3) solutions are possible to be successfully made under the vacuum condition but there still remains a problem of undergoing stable and reliable decomposition in vacuum for high-efficiency thermoelectric power generation. This paper describes a new method, which uses a tube giving pressure equilibrium between closed ends, for improving the thermoelectric conversion efficiency of Li-NH3solutions in vacuum. Thermoelectric experimental results show that solution reaction in the tube proceeds stably and efficiently, and this potentially leads to the improved reversibility of the reaction for deriving the long-time, high-efficiency thermoelectric power.


2019 ◽  
Vol 5 (6) ◽  
pp. eaav5813 ◽  
Author(s):  
Hangtian Zhu ◽  
Jun Mao ◽  
Zhenzhen Feng ◽  
Jifeng Sun ◽  
Qing Zhu ◽  
...  

Thermoelectric modules, consisting of multiple pairs of n- and p-type legs, enable converting heat into electricity and vice versa. However, the thermoelectric performance is often asymmetrical, in that one type outperforms the other. In this paper, we identified the relationship between the asymmetrical thermoelectric performance and the weighted mobility ratio, a correlation that can help predict the thermoelectric performance of unreported materials. Here, a reasonably high ZT for the n-type ZrCoBi-based half-Heuslers is first predicted and then experimentally verified. A high peak ZT of ~1 at 973 K can be realized by ZrCo0.9Ni0.1Bi0.85Sb0.15. The measured heat-to-electricity conversion efficiency for the unicouple of ZrCoBi-based materials can be as high as ~10% at the cold-side temperature of ~303 K and at the hot-side temperature of ~983 K. Our work demonstrates that the ZrCoBi-based half-Heuslers are highly promising for the application of mid- and high-temperature thermoelectric power generation.


2016 ◽  
Vol 9 (10) ◽  
pp. 3120-3127 ◽  
Author(s):  
Feng Hao ◽  
Pengfei Qiu ◽  
Yunshan Tang ◽  
Shengqiang Bai ◽  
Tong Xing ◽  
...  

High efficiency Bi2Te3-based thermoelectric materials and devices with energy conversion efficiencies of up to 6.0% under a temperature gradient of 217 K.


2021 ◽  
Vol 271 ◽  
pp. 01023
Author(s):  
Hu Chen ◽  
Zhifei Ji ◽  
Yusheng Hu ◽  
Min Lin

This paper proposed a pulley-buoy accelerated wave energy linear power generation system, and the feasibility and effectiveness of this system were verified through experimental research. Compared with the traditional wave energy power generation system with three-stage energy conversion links, the pulley-buoy accelerated wave energy linear power generation system omits the intermediate energy transfer and conversion link, and realizes the direct gain of electric energy from the buoy movement caused by wave, and by introducing the pulley combination, the movement speed of the buoy is enlarged, the power generation of the linear power generation system is increased, thereby the wave energy conversion efficiency of the system is improved. Under laboratory conditions, a small-size pulley-buoy accelerated wave energy linear power generation system prototype and a swing-plate wave-making system were built to explore the effects of different buoy sizes on the power generation performance of the system. The test results show that within the research scope of this paper, increasing the size of the buoy can effectively increase the wave energy conversion efficiency of the system and improve the power generation performance of the accelerated wave energy power generation system. The research results in this paper provide useful experience for the practical application and efficient operation of wave energy power generation systems.


2009 ◽  
Vol 1166 ◽  
Author(s):  
Paolo Mele ◽  
Kaname Matsumoto ◽  
Takeshi Azuma ◽  
Keita Kamesawa ◽  
Saburo Tanaka ◽  
...  

AbstractPure and Al2O3(2%, 5%, 8%) doped sintered ZnO (n-type) and pure sintered Ca3Co4O9 (p-type) pellets were prepared by conventional solid state synthesis starting from the oxides. The sintered pellets were cut by a diamond saw in a pillar shape (15 mm×5 mm×5 mm) for experimental checks. The best doped sample was 2 % Al2O3 ZnO showing Seebeck coefficient S = -180 mV/K and electrical conductivity σ = 8 S/cm at 400°C, while thermal conductivity κ = 1.8 W/m×K at 600°C. Typical values for Ca3Co4O9 were S = 82.5 mV/K and σ = 125 S/cm at 800°C, while κ = 1.01 W/m×K at 600°C. Several modules fabricated by elements cut from sintered pellets were tested and the best performance was obtained in the module formed by six 2 % Al2O3ZnO/ Ca3Co4O9 couples, that generated an output power P = 300 mV at 500°C (when ΔT = 260°C).


Sign in / Sign up

Export Citation Format

Share Document