[en] Highlights: • Sintering TiS₂ can result in off-stoichiometry and the intercalation of Ti atoms. • Such structural changes greatly affect the thermoelectric properties of TiS₂. • S/Ti ratio decreases with sintering temperature upon the volatilization of sulphur. • Highest S/Ti ratio is obtained by high-pressure sintering at lower temperatures. • Sulphur volatilisation is restrained when using a gas tight-sintering mould. Nearly stoichiometric Ti_1.005S₂ was prepared by a solid-state synthesis of the constituent elements and consolidated under a variety of processing conditions applied using pulsed-electric-current sintering. The non-stoichiometry in the Ti_{1 + x}S₂ induced during the sintering was quantitatively determined with a Rietveld structural refinement and a thermogravimetric analysis combined with inductively coupled plasma atomic emission spectroscopy. Significant cation off-stoichiometry and sulphur losses were already observed at a sintering temperature of 700 °C, resulting in heavily self-intercalated Ti_1.076S₂, which significantly altered the thermoelectric properties in comparison with the nearly stoichiometric compound. By applying a high sintering pressure of 500 MPa the Ti_1.005S₂ could be consolidated at 500 °C with no detectable sulphur loses and with a high bulk density of 97.6%. The sulphur volatilization in the TiS₂ was also effectively suppressed up to 800 °C by using a gas-tight sintering mould, which resulted in the composition Ti_1.017S₂, prepared at 800 °C and 200 MPa, with an optimal thermoelectric figure of merit ZT equal to 0.32 at 375 °C.