<p><b>Abstract</b>—Lithium–vanadium Li_1.3V₃O₈ oxide is synthesized from a mixture of initial components NH₄VO₃ and Li₂CO₃ at temperature 585°C in one case and from their melt at 620°C in another case. The crystal structures of the materials synthesized at both of these temperatures, their morphologies and microstructures are studied. The temperature dependence of the dc and ac electrical conductivities (ECs) are studied in the temperature range from 25 to 300°C. The dependence of the V⁴⁺ cation content on the heat-treatment temperature is investigated. The synthesis from the melt at elevated temperatures of 620°C allows one to form a Li_1.3V₃O₈ powder with a mean particle size of 5 μm. The temperature dependences of the electron component of EC of both Li_1.3V₃O₈ samples are linear; the activation energies of EC in these samples are approximately 12 kJ/mol (585°C) and 15 kJ/mol (620°C), respectively. The synthesis of Li_1.3V₃O₈ from the melt at 620°C is shown to be accompanied by a decrease in the content of tetravalent vanadium from 12 to 10%, a slight decrease in EC, and a decrease in its activation energy as compared to Li_1.3V₃O₈ formed at 585°C. The relation between EC and the heat-treatment temperature of lithium–vanadium Li_1.3V₃O₈ oxide is considered.</p>