Current State-of-the-Art in the Interface/Surface Modification of Thermoelectric Materials

Thermoelectric (TE) materials are prominent candidates for energy converting applications due to their excellent performance and reliability. Extensive efforts for improving their efficiency in single-/multi-phase composites comprising nano/micro-scale second phases are being made. The artificial decoration of second phases into the thermoelectric matrix in multi-phase composites, which is distinguished from the second-phase precipitation occurring during the thermally equilibrated synthesis of TE materials, can effectively enhance their performance. Theoretically, the interfacial manipulation of phase boundaries can be extended to a wide range of materials. High interface densities decrease thermal conductivity when nano/micro-scale grain boundaries are obtained and certain electronic structure modifications may increase the power factor of TE materials. Based on the distribution of second phases on the interface boundaries, the strategies can be divided into discontinuous and continuous interfacial modifications. The discontinuous interfacial modifications section in this review discusses five parts chosen according to their dispersion forms, including metals, oxides, semiconductors, carbonic compounds, and MXenes. Alternatively, gas- and solution-phase process techniques are adopted for realizing continuous surface changes, like the core–shell structure. This review offers a detailed analysis of the current state-of-the-art in the field, while identifying possibilities and obstacles for improving the performance of TE materials.

Atomic layer deposition onto fabrics of carbon and silicon carbide fibers: Preparation of multilayers comprising alumina, titania-furfuryl alcohol hybrid, and titanium phosphate

High temperature-resistant fabrics can be used as a reinforcement structure in ceramic matrix composites. They often need a coating for oxidation protection and mechanical decoupling from the matrix. Atomic layer deposition (ALD) provides very thin conformal coatings even deep down into complex or porous structures and thus might be a suitable technique for this purpose. Carbon fiber fabrics (size 300mm× 80mm) and SiC fiber fabrics (size 400mm× 80mm) were coated using ALD with a multilayer system: a first layer made of 320 cycles of alumina (Al2O3) deposition, a second layer made of 142 cycles of titania-furfuryl alcohol hybrid (TiO2-FFA), and a third layer made of 360 cycles of titanium phosphate (TixPOy).

ALPIN Kick-Off & Workshop 2021

Wir konnten zum ALPIN Kick-Off Workshop 2021 am 21. und 22. September 72 Teilnehmer in Dresden begrüßen und das positive Feedback sowohl zu ALPIN als auch zum Workshop hat uns sehr gefreut. Die Arbeit hat sich also gelohnt und der Weg für unser Netzwerk ist geebnet. Wir werden diese Art von Workshop ab sofort jährlich durchführen (2022 treffen wir uns voraussichtlich in Bochum), um das Netzwerk zu stärken, die Möglichkeit zum Austausch zu bieten und neue gemeinsame Aktivitäten zu initiieren.