Thermodynamic definition of the thermoelectric figure of merit of an anisotropic medium

Buda, I. S.; Lutsyak, V. S.; Khamets, U. M.; Shcherbina, L. A.

doi:10.1002/pssa.2211230231

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…Previous attempts of solving the above equations [7,18,24] have ended up with very complicated calculations and discussions. This is because for a N × N Onsager matrix, there are N (N + 1)/2 independent response coefficients (if the Onsager matrix is symmetric).…”

Section: Optimizing Efficiency and Power For Systems With Symmetmentioning

confidence: 99%

“…( 3) was derived for isotropic systems, where, by choosing a proper set of coordinate axes, the problem can be reduced to correlated transport for two scalar currents: one heat current and one electric current. Quite often in anisotropic materials, the complete description of thermoelectric transport must involve six scalar currents as both the electric and heat currents consist of three scalar components (e.g., the electrical current j = (j x , j y , j z ) with j x , j y , and j z being the components in the x, y, and z directions) [15,18]. For piezoelectric energy conversion in an anisotropic material, the full description of responses involves nine scalar "currents": three of them are electric displacements and the other six are strains [19].…”

Section: Introductionmentioning

confidence: 99%

“…Quite often Ioffe's derivation of optimal energy efficiency cannot be directly applied to those practical systems. In those situations the (global) maximum efficiency is rather difficult to find, although one can always easily find certain optimal efficiencies under restrictions [7,15,18,19,23].…”

Section: Introductionmentioning

confidence: 99%

“…Finding the optimal exergy efficiency and power for complex thermodynamic systems has stimulated a number of studies [7,18,24]. It becomes increasingly important as researches reveal more cross-correlated responses and realize their applications [10,25,26].…”

Section: Introductionmentioning

confidence: 99%

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Thermodynamic bounds and general properties of optimal efficiency and power in linear responses

Jiang

2014

Phys. Rev. E

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We study the optimal exergy efficiency and power for thermodynamic systems with Onsager-type "current-force" relationship describing the linear-response to external influences. We derive, in analytic forms, the maximum efficiency and optimal efficiency for maximum power for a thermodynamic machine described by a N × N symmetric Onsager matrix with arbitrary N . The figure of merit is expressed in terms of the largest eigenvalue of the "coupling matrix" which is solely determined by the Onsager matrix. Some simple but general relationships between the power and efficiency at the conditions for (i) maximum efficiency and (ii) optimal efficiency for maximum power are obtained. We show how the second law of thermodynamics bounds the optimal efficiency and the Onsager matrix, and relate those bounds together. The maximum power theorem (Jacobi's Law) is generalized to all thermodynamic machines with symmetric Onsager matrix in the linear-response regime. We also discuss systems with asymmetric Onsager matrix (such as systems under magnetic field) for a particular situation and we show that the reversible limit of efficiency can be reached at finite output power. Cooperative effects are found to improve the figure of merit significantly in systems with multiply cross-correlated responses. Application to example systems demonstrates that the theory is helpful in guiding the search for high performance materials and structures in energy researches.

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Section: Optimizing Efficiency and Power For Systems With Symmetmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermodynamic bounds and general properties of optimal efficiency and power in linear responses

Jiang

2014

Phys. Rev. E

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“…Furthermore, the system is characterized by the material parameters: the thermal conductivity κ for zero current, the Peltier coefficient $\Pi = TS$ , the Seebeck coefficient S , the isothermal electrical conductivity σ , or the resistivity ρ = 1/ σ as well as the Seebeck conductivity Θ = σS . Note that in general all the material parameters are symmetric tensors of 2nd rank, which have to be modified in the presence of magnetic fields 16–24.…”

Section: Thermoelectric Equationsmentioning

confidence: 99%

Green's function approach in the classical theory of thermoelectricity

Achilles

Seifert

Trimper

2011

Physica Status Solidi (b)

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The Green's function (GF) method is a powerful technique to describe non-equilibrium processes under inclusion of a broad class of boundary and initial conditions. Based on the Onsager theory of non-equilibrium the applicability of GFs is demonstrated to find the steady-state solution for the thermoelectric behaviour in one dimension. The spatial temperature profile is represented by the GF even if the Onsager transport coefficients are likewise coordinate dependent. The method can be directly used to study situations which are realized experimentally. The method can be extended to construct a systematic perturbation theory where the GF obeys a Dyson equation.

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