High Power Density Thermoelectric Generators with Skutterudites

Abstract

Thermoelectric generators (TEGs) offer a versatile solution to convert low‐grade heat into useful electrical power. While reducing the length of the active thermoelectric legs provides an efficient strategy to increase the maximum output power density pmax, both the high electrical contact resistances and thermomechanical stresses are two central issues that have so far prevented a strong reduction in the volume of thermoelectric materials integrated. Here, it is demonstrated that these barriers can be lifted by using a nonconventional architecture of the legs which involves inserting thick metallic layers. Using skutterudites as a proof‐of‐principle, several single‐couple and multi‐couple TEGs with skutterudite layers of only 1 mm are fabricated, yielding record pmax ranging from 3.4 up to 7.6 W cm−2 under temperature differences varying between 450 and 630 K. The highest pmax achieved corresponds to a 60‐fold increase per unit volume of skutterudites compared to 1 cm long legs. This work establishes thick metallic layers as a robust strategy through which high power density TEGs may be developed.

GaAs-Based Near-Field Thermophotonic Devices: Approaching The Idealized Case With One-Dimensional PN Junctions

“…It even exceeds what was obtained with the DB method for a quasi-ideal NF-TPX device with an IQE of 0.9, and reaches values obtained for FF-TPV with emitters at more than 1400 K [11]. The order of magnitude of the power output is similar to what is found for NF-TPV for 700 K temperature difference [46], and only one order below what is obtained for thermoelectric devices for 300 K temperature difference [47]. This result is essential for the development of NF-TPX device: it shows that even when getting rid of idealizing approximations, we can reach really high electrical power densities by improving both the contacts at the boundaries of the LED and the PV cell and their geometries for efficient charge carrier management.…”

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

“…However, the efficiency of current commercial TE modules composed of state-of-the-art materials with ZT > 1 remains below ≈8% which strongly limits their use to niche applications [1,2]. With the aim to increase the applicability of this technology, many attempts to improve the overall performance of TE modules have been reported recently in the literature and consist of using newly developed materials with an improved ZT [3][4][5][6][7], the development of alternative architectures [8][9][10][11][12][13], or fabrication process [14]. However, two important challenges remain: (i) the use of less toxic and expensive elements than those comprising the majority of current high-performance materials (Pb, Te, Bi.…”

Vibrational and structural properties of the $R$Fe$_{4}$Sb$_{12}$ ($R=$Na, K, Ca, Sr, Ba) filled skutterudites

“…Concerning the latter topic, research on the filled skutterudites is indeed triggered mostly by the presence of an unusual vibrational dynamics that makes the filled skutterudites good candidates for thermoelectric applications [5][6][7]. In this regard, earlier contributions proposed that the R fillers behave as independent, non dispersive and low energy oscillators (or rattlers), that scatter the cage derived phonons, giving rise to a phonon glass.…”