The medium produced in heavy ion collisions develops a temperature gradient between its central and peripheral regions, which can induce an electric field through the Seebeck effect. The strength of this effect is quantified by the Seebeck coefficient, defined as the induced electric field per unit temperature gradient in the absence of electric current. We calculate the Seebeck coefficient of the quark-gluon plasma (QGP) medium using the relativistic Boltzmann transport equation within a recently developed novel relaxation time approximation (RTA) model. Contributions from individual quark flavors as well as from the QGP medium are analyzed, with particular emphasis on their dependence on the temperature and chemical potential. For fixed current quark masses, we find that the magnitude of the Seebeck coefficient decreases with increasing temperature and increases with chemical potential. Partonic interactions are further incorporated through perturbative thermal QCD within a quasiparticle framework. Comparison with the standard RTA model shows a noticeable suppression of the Seebeck coefficient in the novel RTA model, implying a weaker thermally induced electric field in the QGP medium. Additionally, while the Seebeck coefficient becomes slightly negative at high temperatures in the noninteracting case, it remains positive over the entire temperature range in the quasiparticle framework.