Motivated by the newly synthesized mixed-valent spinel LiRh2O4 for which a large thermopower is observed in the metallic cubic phase above 230K [Okamoto {\it et al.} (arXiv:0806.2504)], we calculate the Seebeck coefficient by the combination of local density approximation and dynamical mean field theory (LDA+DMFT). The experimental values are well reproduced not only by LDA+DMFT but also by the less involved Boltzmann equation approach. A careful analysis of the latter shows unexpectedly that the origin of the large thermopower shares a common root with a very different oxide: NaxCoO2. We also discuss how it is possible to further increase the powerfactor of LiRh2O4 through doping, which makes the material even more promoising for technological applications.
@article{arxiv.0806.2506,
title = {Origin of large thermopower in LiRh$_2$O$_4$},
author = {R. Arita and K. Kuroki and K. Held and A. V. Lukoyanov and S. Skornyakov and V. I. Anisimov},
journal= {arXiv preprint arXiv:0806.2506},
year = {2008}
}