Sodium Chemical Sources of Current with Cathods Based on Copper Sulphides

Abstract

In the work, cells consisting of sodium and copper sulfides with different composition, structure, and morphology of the cathode material were investigated as chemical current sources. A decrease in the characteristic particle size of CuS from 0.4–5 μm to 10–50 nm led to an increase in the initial operating voltage from 1.87 V to 2.55 V and capacity from 166 mAh·g^–1 to 400 mAh·g^–1. The superstoichiometric incorporation of sulfur into nanosized copper sulfide CuS_1+x leads to a decrease in the initial operating voltage of the cell by 0.23 V, while the capacity increases from 400 mAh·g^–1 to 431 mAh·g^–1. In the case of sulfide of the Cu₂S composition, the capacity of the cell with the sodium anode is 121 mAh·g^–1, in addition, this material, like microcrystalline copper sulfide of the CuS composition, is prone to surface passivation with sulfides of variable composition. A comparative analysis of the electrochemical parameters of sodium and lithium current sources with cathode materials based on copper sulfides of different composition and morphology is carried out