Abstract The efficient and economical conversion of low-grade waste heat into electricity has promising potential to combat the greenhouse effect expedite shift towards sustainable development. This study presents an innovative appealing approach through utilization lignin, abundant product derived from paper pulp industry, develop hydrogels as compelling materials for application in ionic thermoelectricity. Various compositions were evaluated examine impacts varying lignin concentrations,...

We investigate the effect of a thin alumina coating nanocrystalline TiO2 films on recombination dynamics dye-sensitized solar cells. Both coated and uncoated cells were measured by combination techniques: transient absorption spectroscopy, electrochemical impedance open-circuit voltage decay. It is found that barrier reduces photoinjected electrons to both dye cations oxidized redox couple. proposed this observed retardation can be attributed primarily two effects: almost complete...

The electrochemical behaviour of nanoporous TiO2 in a room temperature ionic liquid (RTIL), 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)amide (EMITFSI), was investigated by cyclic voltammetry (CV) and impedance spectroscopy. Exponentially rising currents were attributed to the charging/discharging electrons film charge transfer mechanism. main features followed same trends as other organic solvents also aqueous electrolytes. In presence lithium ions, onset potential...

A remarkable 2.6 times improvement in the power factor is achieved a porous thermoelectric oxide presence of polyelectrolyte.

This paper analyses the use of impedance spectroscopy as a characterization tool applied to thermoelectric materials. The function system under adiabatic conditions and Peltier mode operation is calculated by solving heat equation in frequency domain. analysis, focused on complex plane, provides required equivalent circuit elements interpret measurements. Using this approach, all relevant parameters thermal properties can be potentially extracted at given temperature from spectra, i.e.,...

Thermo-electrochemical cells (or thermogalvanic or thermocells, TECs) have gained attention as devices able to convert low temperature heat into electricity. Within TECs, Pt is one of the most employed electrodes, since it exhibits a fast transfer electrons with redox couple in electrolyte. However, its high price represents serious drawback. Here, we analyze use nanostructured and porous antimony-doped tin oxide (Sb:SnO2) electrode material. Electrodes different thickness (320, 550 1550 nm)...

Nanocrystalline TiO2 electrodes were prepared using binder-free paste on conductive ITO-PEN substrates by the doctor-blade method at significantly low temperature (140 °C), and further processed under different compressions (10–60 MPa) in order to improve interparticle connections adhesion between nanoparticles substrate. compressed 30 40 MPa had relatively less cracks with crack width. Electrode showed highest internal surface area. this compression best dye-sensitized solar cell (DSC)...

Abstract Managing heat through working fluids is essential in many applications, as well the development of new with improved properties. Therefore, characterization their thermal properties, which usually a laborious task, necessary to design and model systems. In this study, we show proof concept method capable determining conductivity, diffusivity, specific capacity liquids from single simple measurement, provided density known (a property easy measure). The based on use thermoelectric...

A window of opportunity: The ligand-centred redox activity complex 1 (depicted) is exploited to make an electrochromic window, which demonstrates rapid and reversible changes in optical transmission at 940 nm. made by adsorbing onto a nanocrystalline Sb-doped SnO2 film attached transparent conducting substrate cycling the applied potential through catecholate/semiquinone couple.

We discuss the interpretation of usually broad oxidation peaks observed in electronically conducting polymers, terms statistical distributions functions polarons and bipolarons. The analysis is based on examining chemical capacitance, that relates change concentration to a modification potential given species, for different models. first review standard models single energy species provide nernstian dependence, limitations these are discussed. A new model assumes Gaussian distribution...

Impedance spectroscopy has been shown as a promising method to characterize thermoelectric (TE) materials and devices. In particular, the possibility determine thermal conductivity λ, electrical σ, dimensionless figure of merit ZT TE element, if Seebeck coefficient S is known, reported, although so far for high-performance material (Bi2Te3) at room temperature. Here, we demonstrate capability this approach temperatures up 250 °C with modest properties. Moreover, compare results obtained...

Silicon is a promising alternative to current thermoelectric materials (Bi2Te3). nanoparticle based show especially low thermal conductivities due their high number of interfaces, which increases the observed phonon scattering. The major obstacle with these maintaining electrical conductivity. Surface functionalization phenylacetylene shows an conductivity 18.1 S m−1 and Seebeck coefficient 3228.8 μV K−1 as well 0.1 W m−1. This gives ZT 0.6 at 300 K significant for bulk silicon material...

Thermoelectric (TE) devices can convert heat into electricity and have gained great interest as energy harvesters in many applications, such self-powered sensors, solar TE generators industrial waste recovery. Not techniques are usually available for their characterization under operating conditions. Consequently, only current-voltage (power output) curves typically reported to account performance, which provide limited information. Impedance spectroscopy, has been mainly applied the study...

The Harman method is used extensively for the characterization of dimensionless figure merit ZT thermoelectric (TE) materials and devices. However, its accuracy has often been questioned, since in many cases there are relatively high errors associated with method. impedance spectroscopy technique, which recently shown as a suitable tool to also characterize TE devices, some similarities can directly provide ZT. In order obtain reliable measurements both methods, common critical points that...

A synergistic photovoltaic and thermoelectric effect takes place in a single heterojunction solar cell that consists of p-type CdTe nanorod array n-type Bi₂Te₃ nanostructures.

An apparatus capable of rapid measurement the Seebeck coefficient and electrical resistivity at room temperature is reported. The novel aspect this use 4 multifunctional probes that comprise a junction two conductors tip serve as both thermocouples contacts. In addition, one has built-in heater can establish gradient in sample for measurement. technique does not require special geometries or preparation contacts suitable bulk thin film materials. Together with automated stage data...

Understanding the dynamics of thermoelectric (TE) phenomena is important for detailed knowledge operation TE materials and devices. By analyzing impedance response both a single element device under suspended conditions, we provide new insights into thermal these systems. The analysis performed employing parameters such as penetration depth, characteristic diffusion frequency time. It shown that in systems governed by how Peltier heat production/absorption at junctions evolves. In...

Aging-induced degradation of commercial Li-ion pouch cells with lithium nickel-manganese‑cobalt-oxide-based cathodes and graphite anodes is studied at various operating conditions (temperature voltage) by galvanostatic measurements in situ electrochemical impedance spectroscopy (EIS). A detailed equivalent electrical circuit model, capable to fit the measured EIS spectra, developed validated. The work also confirms capacity fade dependence calendar-aged on stress factors such as temperature...