Use of anti-solvent to enhance thermoelectric response of hybrid-halide perovskite thin films

Hybrid halide perovskite has been recently focused on thermoelectric energy harvesting due to the cost-effective fabrication approach and ultra-low thermal conductivity. To achieve high performance, tuning of electrical conductivity is a key parameter that is influenced by grain boundary scattering and charge carrier density. The fabrication process allows tuning these parameters. We report the use of anti-solvent to enhance the thermoelectric performance of lead-free hybrid halide perovskite, CH3NH3SnI3, thin films. Thin films with anti-solvent show higher connectivity in grains and higher Sn+4 oxidation states which results in enhancing the value of electrical conductivity. Thin films were prepared by a cost-effective wet process. Structural and chemical characterizations were performed using x-ray diffraction, scanning electron microscope, and x-ray photoelectron spectroscopy. The value of electrical conductivity and the Seebeck coefficient were measured near room temperature. The high value of power factor (1.55 µW/m.K2 at 320 K) was achieved for thin films treated with anti-solvent.

Intercalation Electrochemistry for Thermoelectric Energy Harvesting from Temperature Fluctuations

The effective use of energy from sustainable sources is considered a crucial step on the way to a CO2-neutral economy. Low-grade waste heat (< 100°C) is widely and ubiquitously available,...

Thermoelectric energy harvesting using vapour chamber coolers for aerospace applications

Thermoelectric generators (TEGs) have shown great potentials to supply low-power sensor nodes in aerospace applications due to their relatively small size, adequate output power and reliability. TEGs convert waste heat available at aircraft locations into a usable potential difference. However, TEGs’ performance greatly depends on the use of passive cooling systems such as heatsinks to enhance their energy supply. This paper reports the first proof-of-concept use of vapour chambers coupled to traditional circular pin-fin heatsinks to enhance the output power of TEGs. Vapour chambers are compact and small capillary-driven heat spreaders that incorporate a cavity in their volume containing a working fluid to provide a high effective thermal conductivity. Numerical simulations and experimental tests revealed that the use of vapour chambers provided significant increase of the output power, with a maximum produced power of 28.2 W and a relative difference of 6.27 W against conventional energy scavenging configurations. Results demonstrate the high thermal cooling performance of vapour chambers to efficiently support thermal energy harvesting solutions designed for condition and structural health monitoring.

Energy Harvesting Materials and Structures for Smart Textile Applications: Recent Progress and Path Forward

A major challenge with current wearable electronics and e-textiles, including sensors, is power supply. As an alternative to batteries, energy can be harvested from various sources using garments or other textile products as a substrate. Four different energy-harvesting mechanisms relevant to smart textiles are described in this review. Photovoltaic energy harvesting technologies relevant to textile applications include the use of high efficiency flexible inorganic films, printable organic films, dye-sensitized solar cells, and photovoltaic fibers and filaments. In terms of piezoelectric systems, this article covers polymers, composites/nanocomposites, and piezoelectric nanogenerators. The latest developments for textile triboelectric energy harvesting comprise films/coatings, fibers/textiles, and triboelectric nanogenerators. Finally, thermoelectric energy harvesting applied to textiles can rely on inorganic and organic thermoelectric modules. The article ends with perspectives on the current challenges and possible strategies for further progress.

Analysis of Thermoelectric Energy Harvesting with Graphene Aerogel-Supported Form-Stable Phase Change Materials

Graphene aerogel-supported phase change material (PCM) composites sustain the initial solid state without any leakage problem when they are melted. The high portion of pure PCM in the composite can absorb or release a relatively large amount of heat during heating and cooling. In this study, these form-stable PCM composites were used to construct a thermoelectric power generator for collecting electrical energy under the external temperature change. The Seebeck effect and the temperature difference between the two sides of the thermal device were applied for thermoelectric energy harvesting. Two different PCM composites were used to collect the thermoelectric energy harvesting due to the different phase transition field in the heating and cooling processes. The graphene nano-platelet (GNP) filler was embedded to increase the thermal conductivities of PCM composites. Maximum output current was investigated by utilizing these two PCM composites with different GNP filler ratios. The thermoelectric energy harvesting efficiencies during heating and cooling were 62.26% and 39.96%, respectively. In addition, a finite element method (FEM) numerical analysis was conducted to model the output profiles.