Sulfur/CuxS hybrid material for Li/S primary battery with improved discharge capacity

Abstract Sulfur is potential for primary lithium battery with high power and energy. However, the discharge capacity is limited due to the low electrochemical activity of sulfur. In this work, Cu x S is incorporated into sulfur cathode synergistically to improve discharge specific capacity for primary lithium battery. For the sulfur/Cu x S hybrid cathodes, discharge capacity is higher than the sulfur cathode. With the Cu x S in hybrid cathodes varying from 40% to 60 wt %, the discharge capacity increases and then decreases when Cu x S reaches 80 wt %. An enhanced discharge capacity of 1618.5 mAh g −1 (S) at the current rate of 0.1 C , energy density of 1107 Wh kg −1 (CuS+S) and power density of 2827 W kg −1 (CuS+S) are obtained when Cu x S reaches 60 wt %. The good discharge performance is derived from trapping of polysusfides through chemical redox of sulfiphilic Cu x S and capacity contribution of semi–conductive Cu x S. And, the self–discharge is limited of the sulfur/Cu x S hybrid cathodes. This new cooperation provides a promising approach to significantly enhance the discharge performance of primary lithium batteries.