High performance (ZT>1) n-type oxide thermoelectric composites from earth abundant materials

Ba1/3CoO2: A Thermoelectric Oxide Showing a Reliable ZT of ∼0.55 at 600 °C in Air

“…The specific heat capacity used for the TDTR simulation was measured using differential scanning calorimetry (DSC, DSC8500, PerkinElmer) (Supporting Information, Figure S3). The in-plane κ of the films was extracted according to the following equation as previously reported. , where φ, κ obsd , κ // and κ ⊥ are the inclination angle of the layers relative to the perpendicular of the film surface, observed thermal conductivity, in-plane κ, and cross-plane κ, respectively (Supporting Information, Figure S4). In this study, φ = 35°, which was proven by scanning transmission electron microscopy (STEM) observations in our previous study …”

“…Since most metal oxides show good chemical and thermal stability in air as well as a harmless nature compared to chalcogenide-based state-of-the-art thermoelectric materials, oxide-based thermoelectric materials that show a high ZT are promising. , Several high- ZT thermoelectric oxides have been reported thus far; Fujita et al reported that the Na x CoO 2 single crystal exhibited a ZT of ∼1.2 at 800 K. Acharya et al . reported that Nb-doped SrTiO 3 with natural graphite exhibited a ZT of ∼1.42 at 1050 K. Biswas et al reported that graphene oxide-encapsulated ZnO nanocomposites exhibited a ZT of ∼0.52 at 1100 K. However, the reliability is considerably low due to a lack of careful observation of their stability at elevated temperatures.…”

Thermoelectric Coolers: Progress, Challenges, and Opportunities

“…[ 19,51,65,77,81,82 ] Figure 2b compares reported peak ZT s of bulk TE materials reported in recent years, including Bi 2 Te 3 , [ 83 ] Bi 0.5 Sb 1.5 Te 3 (BST), [ 84 ] SnTe, [ 85 ] Mg 3 Sb 2 Zintl, [ 86 ] Cu 2 Se composites, [ 87 ] GeTe, [ 88 ] half‐Heusler, [ 89 ] PbTe, [ 90 ] skutterudite, [ 91 ] SnSe, [ 92 ] BiCuSeO, [ 93 ] and SrTiO 3 . [ 94 ] Other TE materials such as Mg 2 Si ( ZT = 1.4 at 800 K), [ 95 ] Cu 2 S 1‐ x Te x ( ZT = 2.1 at 1000 K), [ 96 ] AgSbTe 2 ( ZT = 2.1 at 573 K), [ 97 ] and clathrate ( ZT = 1.45 at 500 K), [ 98 ] and also shows their high TE potentials. Noticeably, a record‐high ZT of ≈3.1 was reported in oxide‐removed Na‐doped polycrystalline SnSe, [ 92 ] which was commented as breaking the thermoelectric performance limit.…”

“…[ 20,22,23,57,61,116–120 ] b) Reported peak ZT s of state‐of‐the‐art bulk TE materials. [ 83–94 ] Timelines for c) maximum cooling performance Δ T max and d) maximum COP (COP max ) of TECs based on bulk, film, and superlattice materials. [ 11–13,16–18,20,22,23,25–27,30,32,33,35,36,38,40,52,53,56,57,61,62,73,102–115 ]…”

High Thermoelectric Performance of ZnO by Coherent Phonon Scattering and Optimized Charge Transport

“…However, owing to low σ and high κ tot , bulk oxides usually possess poor zT compared to metal or semimetallic compounds. [ 24 ] Various studies on oxide thermoelectric materials—including p‐type Ca 3 Co 4 O 9 , [ 25 ] NaCo 2 O 4 , [ 26 ] BiCuSeO [ 27 ] as well as and n‐type ZnO, [ 28 ] SrTiO 3 , [ 29 ] and CaMnO 3 [ 30 ] —have been designed and developed. In most cases, competitive zT has been achieved through complex and rigorous synthesis procedures.…”