<p>Efficient thermoelectric (TE) materials require simultaneous optimization of electrical conductivity and Seebeck coefficient while minimizing thermal conductivity, a challenge limiting widespread application of thermoelectric devices. Ni doping offers a promising strategy to optimize carrier concentration in Cu₇Te₄ while introducing phonon scattering centres. Here, we synthesize Cu_{7 − <i>x</i>}Ni_<i>x</i>Te₄ (<i>x</i> = 0–0.06) nanorods (NRs) via a surfactant-free polyol method, yielding single-phase hexagonal structures with 22–28 nm crystallite sizes. Rietveld refinement confirms Ni²⁺ substitution at Cu⁺ sites, inducing systematic lattice contraction and electronic band structure modifications. The optimal composition (<i>x</i> = 0.06) exhibits a 330% power factor enhancement (23.45 μW m⁻¹ K⁻²) through increased Seebeck coefficient (37.24 μV K⁻¹) while maintaining reasonable conductivity. Simultaneously, point-defect and interface scattering reduces thermal conductivity by 40% (1.25 W m⁻¹ K⁻¹), yielding a 5.6-fold <i>ZT</i> improvement (0.0056) at 300 K. The key innovation of this work lies in the surfactant-free polyol synthesis that enables clean and controlled Ni incorporation without secondary phases, resulting in simultaneous carrier-density tuning and enhanced phonon scattering.These results demonstrate that controlled Ni doping provides a viable pathway for enhancing room-temperature TE performance in earth-abundant copper tellurides, with potential applications in waste heat recovery and micro-power generation.</p>