Electrical and electrochemical properties of niobium disulphide

The electrical conductivity and thermoelectric power measurements of NbS2 pure and electrochemically doped with lithium, LixNbS2, were done as a function of temperature (77 to 300 K). The high absolute values of conductivity and their dependence on temperature together with low absolute values of thermoelectric power and their linear increase with temperature indicate metallic properties of niobium disulphide. In case of LixNbS2 the obtained values of electrical conductivity are significantly lower as compared with the starting NbS2. The temperature dependence of the thermoelectric power of intercalated niobium disulphide also indicates that metallic properties get worse as the concentration of lithium increases. The modification of the electronic structure of NbS2 due to lithium intercalation was proposed. The character of the discharge curves in the electrochemical Li/Li+/LixNbS2 systems was correlated with the electronic properties of niobium disulphide.