Cu-Ni-Based Alloys from Nanopowders as Potent Thermoelectric Materials for High-Power Output Applications

Abstract

A new approach for the development of thermoelectric materials, which focuses on a high-power factor instead of a large figure of merit zT, has drawn attention in recent years. In this context, the thermoelectric properties of Cu-Ni-based alloys with a very high electrical conductivity, a moderate Seebeck coefficient, and therefore a high power factor are presented as promising low-cost alternative materials for applications aiming to have a high electrical power output. The Cu-Ni-based alloys are prepared via an arc melting process of metallic nanopowders. The heavy elements tin and tungsten are chosen for alloying to further improve the power factor while simultaneously reducing the high thermal conductivity of the resulting metal alloy, which also has a positive effect on the zT value. Overall, the samples prepared with low amounts of Sn and W show an increase in the power factor and figure of merit zT compared to the pure Cu-Ni alloy. These results demonstrate the potential of these often overlooked metal alloys and the utilization of nanopowders for thermoelectric energy conversion.

Precision Interface Engineering of CuNi Alloys by Powder ALD Toward Better Thermoelectric Performance

“…However, it is important to consider that CuNi alloys with finer grains and a more optimized composition (such as Cu 55 Ni 45 ) and doping (with Se) have the potential to yield even higher initial zT values. Therefore, it is reasonable to anticipate that by employing the same pristine material conditions reported in studies like Yuan et al.’s, or others, [ 38–44 ] further enhancements in zT values are potentially achievable.…”

“…For the sample modified with Z44/A11/Z44 multilayers, due to decoupling thermoelectric parameters by ALD, a maximum figure of merit (zT) of 0.22 was achieved at 673 K, ≈128% higher than that of pristine CuNi and is a bit higher than the previously reported vaules [38][39][40][41][42][43][44] (Figure 2).…”

“…In high cycle number coating (>50 cycles), the multilayer coatings maintained the high PF while significantly reducing the thermal conductivity. For the sample modified with Z44/A11/Z44 multilayers, due to decoupling thermoelectric parameters by ALD, a maximum figure of merit ( zT ) of 0.22 was achieved at 673 K, ≈128% higher than that of pristine CuNi and is a bit higher than the previously reported vaules [ 38–44 ] ( Figure ).…”

“…Comparison of temperature-dependent zT among other optimized CuNi works. [[38][39][40][41][42][43][44]…”

High thermoelectric performance in metallic NiAu alloys via interband scattering

“…Similarly, an unusually high Seebeck effect is found in isovalent NiCu alloys, exploited in thermocouples. Over the last few years, there have been several attempts to enhance the TE properties of NiCu alloys (17)(18)(19)(20)(21), yet a clear strategy to effectively optimize the electronic structure and thereby boost the TE performance is still lacking. Thus, with some exceptions (22)(23)(24), metals have been largely overlooked by the majority of the TE community, dismissing interband scattering as a potential route to design thermoelectrics.…”