科学者たちは熱から電気を生成する決定をします

既存の熱電素子は高価で有毒な元素を使用している。 科学者たちは、熱を電気に効率的に変換できる銅、マンガン、ゲルマニウム、硫黄からなる安価な結晶を作りました。

熱電特性を持つ合成硫化物鉱物

熱を電気に効率的に変換する努力の一環として、無害な原料から容易にアクセスできる材料は、安全で安価ないわゆる熱電材料開発の新しい視点を開きます。 合成銅鉱物は、構造の単純な変化によって複雑な構造と微細構造を獲得し、所望の特性の基礎を築くという研究結果が最近、ジャーナルに発表されました。 Angewandte ケミ。

今回の研究の交信著者であるフランス・カンCRISMAT研究所のCNRS研究員である材料科学者Emmanuel Guilmeauは、新しい合成物質は銅、マンガン、ゲルマニウム、硫黄で構成され、やや単純な工程で生産されると説明しています。 。 「粉末はボールミリングによって単に機械的に合金化され、予め結晶化された相を形成し、次いで６００度まで緻密化される。[{” attribute=””>Celsius. This process can be easily scaled up,” he says.

Thermoelectric materials convert heat to electricity. This is especially useful in industrial processes where waste heat is reused as valuable electric power. The converse approach is the cooling of electronic parts, for example, in smartphones or cars. Materials used in these kinds of applications have to be not only efficient, but also inexpensive and, above all, safe for health.

However, thermoelectric devices used to date make use of expensive and toxic elements such as lead and tellurium, which offer the best conversion efficiency. To find safer alternatives, Emmanuel Guilmeau and his team have turned to derivatives of natural copper-based sulfide minerals. These mineral derivatives are mainly composed of nontoxic and abundant elements, and some of them have thermoelectric properties.

Now, the team has succeeded in producing a series of thermoelectric materials showing two crystal structures within the same material. “We were very surprised at the result. Usually, slightly changing the composition has little effect on the structure in this class of materials,” says Emmanuel Guilmeau describing their discovery.

The team found that replacing a small fraction of the manganese with copper produced complex microstructures with interconnected nanodomains, defects, and coherent interfaces, which affected the material’s transport properties for electrons and heat.

Emmanuel Guilmeau says that the novel material produced is stable up to 400 degrees Celsius (750 degrees Fahrenheit), a range well within the waste heat temperature range of most industries. He is convinced that, based on this discovery, novel cheaper, and nontoxic thermoelectric materials could be designed to replace more problematic materials.

Reference: “Engineering Transport Properties in Interconnected Enargite-Stannite Type Cu_2+xMn_1−xGeS₄ Nanocomposites” by Dr. V. Pavan Kumar, S. Passuti, Dr. B. Zhang, Dr. S. Fujii, K. Yoshizawa, Dr. P. Boullay, Dr. S. Le Tonquesse, Dr. C. Prestipino, Prof. B. Raveau, Prof. P. Lemoine, Dr. A. Paecklar, Dr. N. Barrier, Prof. X. Zhou, Prof. M. Yoshiya, Dr. K. Suekuni, Dr. E. Guilmeau, 13 September 2022, Angewandte Chemie International Edition.
DOI: 10.1002/anie.202210600

Funding: Agence Nationale de la Recherche, Horizon 2020 Framework Programme, Japan Society for the Promotion of Science