Salez Thomas J, Huang Bo Tao, Rietjens Maud, Bonetti Marco, Wiertel-Gasquet Cécile, Roger Michel, Filomeno Cleber Lopes, Dubois Emmanuelle, Perzynski Régine, Nakamae Sawako
Service de Physique de L'État Condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
Laboratoire Physicochimie des Electrolytes et Nanosystèmes interfaciaux, UMR CNRS 8234, Université Pierre et Marie Curie - Paris 6, 4 place Jussieu, F-75009 Paris 5, France and Grupo de Fluidos Complexos - Instituto de Quimica, Universidade de Brasilia, CP 04478, 70904-970 Brasilia (DF), Brazil.
Phys Chem Chem Phys. 2017 Apr 5;19(14):9409-9416. doi: 10.1039/c7cp01023k.
Currently, liquid thermocells are receiving increasing attention as an inexpensive alternative to conventional solid-state thermoelectrics for low-grade waste heat recovery applications. Here we present a novel path to increase the Seebeck coefficient of liquid thermoelectric materials using charged colloidal suspensions; namely, ionically stabilized magnetic nanoparticles (ferrofluids) dispersed in aqueous potassium ferro-/ferri-cyanide electrolytes. The dependency of thermoelectric potential on experimental parameters such as nanoparticle concentration and types of solute ions (lithium citrate and tetrabutylammonium citrate) is examined to reveal the relative contributions from the thermogalvanic potential of redox couples and the entropy of transfer of nanoparticles and ions. The results show that under specific ionic conditions, the inclusion of magnetic nanoparticles can lead to an enhancement of the ferrofluid's initial Seebeck coefficient by 15% (at a nanoparticle volume fraction of ∼1%). Based on these observations, some practical directions are given on which ionic and colloidal parameters to adjust for improving the Seebeck coefficients of liquid thermoelectric materials.
目前，作为传统固态热电材料在低品位废热回收应用中的廉价替代品，液体热电池正受到越来越多的关注。在此，我们提出了一种利用带电胶体悬浮液提高液体热电材料塞贝克系数的新途径；即分散在铁氰化钾/亚铁氰化钾水性电解质中的离子稳定磁性纳米颗粒（铁磁流体）。研究了热电势对纳米颗粒浓度和溶质离子类型（柠檬酸锂和柠檬酸四丁铵）等实验参数的依赖性，以揭示氧化还原对的热电流电势以及纳米颗粒和离子转移熵的相对贡献。结果表明，在特定的离子条件下，加入磁性纳米颗粒可使铁磁流体的初始塞贝克系数提高15%（纳米颗粒体积分数约为1%时）。基于这些观察结果，给出了一些关于调整哪些离子和胶体参数以提高液体热电材料塞贝克系数的实际指导方向。
