Efficient Si Doping Promoting Thermoelectric Performance of Yb-Filled CoSb₃-Based Skutterudites

Abstract

Nanocomposites have become a widely popular way to assist in the enhancement of thermoelectric performance for filled skutterudites. Herein, we unveil the distinctive effect of Si doping on the classic Yb 0.3 Co 4 Sb 12 . On the one hand, the reduced Yb filling fraction is accompanied by the in-situ precipitated CoSi nanoparticles, which not only enhances the power factor in the intermediate−low temperature range but also reduces electronic thermal conductivity for decreasing the carrier concentration. On the other hand, CoSi nanoparticles intensively disrupt the phonon transport, hiding the increased lattice thermal conductivity due to reduced Yb filling fraction. Although the residual YbSb 2 second phases have an adverse effect on the thermoelectric properties, the integration effects achieve a peak ZT value of 1.37 at 823 K and increase ZT ave by 21% for the Yb 0.3 Co 4 Sb 12 /0.1Si sample.

Wearable Thermoelectric Generators: Materials, Structures, Fabrications, and Applications

“…[ 44 ] However, most of the thermoelectric materials that have been mentioned earlier achieve their highest ZT values at high temperature range (normally >600 K), limiting the applications for energy harvesting from low‐temperature scenarios, making them good candidates in harvesting industrial waste heat but less ideal in wearable devices at room‐temperature range. [ 45–54 ]…”

“…[44] However, most of the thermoelectric materials that have been mentioned earlier achieve their highest ZT values at high temperature range (normally >600 K), limiting the applications for energy harvesting from low-temperature scenarios, making them good candidates in harvesting industrial waste heat but less ideal in wearable devices at room-temperature range. [45][46][47][48][49][50][51][52][53][54] Since wearable devices require working at room-temperature range, solid-state TE materials with satisfying TE performances at low temperature have attracted more research interests these years. As good represents, metal chalcogenides and Bi 2 Te 3 -based tellurides have become good candidates for wearable TEGs.…”

Ce‐filled Ni1.5Co2.5Sb12 Skutterudite Thin Films with Record‐High Figure of Merit And Device Performance

“…[39][40][41][42][43]47,49,50,[54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] The S 2 𝜎 of bulk skutterudites are also provided for a comparison. [35,[69][70][71] The inset shows the photo of as-deposited thin films. e) Comparison of asachieved maximum ZT (ZT max ) between this work and reported CoSb 3 -based thin films.…”

“…d) Comparison of as-achieved maximum power factors S 2 𝜎 between this work and reported CoSb 3 -based thin films [39][40][41][42][43]47,49,50,[54][55][56][57][58][59][60][61][62][63][64][65][66][67][68]. The S 2 𝜎 of bulk skutterudites are also provided for a comparison [35,[69][70][71]. The inset shows the photo of as-deposited thin films.…”

Structure Optimization and Multi-frequency Phonon Scattering Boosting Thermoelectrics in Self-Doped CoSb3-Based Skutterudites

“…As a commercial thermoelectric material in the mid-temperature region, the CoSb 3 -based skutterudites have attracted broad attention for the symmetric body-centered cubic crystal structure, high band degeneracy, as well as high thermal stability. , However, its application is plagued by the ultra-high κ L (∼7.5 W m –1 K –1 at room temperature), thus poor zT (∼0.05 at 723 K) and low thermoelectric efficiency . Recently, attempts have been made to advance its thermal performance including introduction of solid solution alloy by doping, − filling atom (such as alkaline-earth atoms, − rare-earth atoms, − alkaline metals, , and group IIIA elements − ), special structures (dislocation arrays, micro-/nanopores, and nano-core–shell structures), − and the nanoscale second phase (such as InSb, GaSb, AgSbTe 2 , and Bi 0.5 Sb 1.5 Te 3 ). Based on the insights gained into the above strategies, as well as the electronic and phonon transport of CoSb 3 materials, excellent thermoelectric properties have been achieved, including zT of ∼1.9 at 835 K in (R, Ba, Yb) y Co 4 Sb 12 (R = Sr, La, Mm, DD, SrMm, SrDD) and ∼1.8 at 823 K in (In, Sr, Ba,Yb) y Co 4 Sb 12 …”