Sepiolite-sulfur as a high-capacity, high-rate performance, and low-cost cathode material for lithium sulfur batteries

Lithium sulfur batteries have the theoretical energy density of up to 2600 Wh/kg, though its commercialization is limited by high material cost and poor cyclic performance. In this work, we show that sepiolite-sulfur is a high-capacity, high-rate performance, and low-cost cathode material for lithium -sulfur batteries. Sepiolite is a porous mineral with specific structure, outstanding physical and chemical adsorption characteristics, and excellent ion exchange capability, making it an ideal matrix material for lithium-sulfur batteries. It is shown that the first specific discharge capacity of sepiolite-sulfur cathode is about 1436 mAh g(-1) at 0.2 C current rate, and it remains as high as 901 mAh g(-1) after 300 cycles. Under 1 C current density, the first discharge capacity is 1206 mAh g(-1), and maintains a high value of 601 mAh g(-1) after 500 cycles. The raw materials are abundant and low cost, and the manufacturing process is simple and scalable, making it promising for the commercialization of lithium sulfur batteries. (C) 2015 Elsevier B.V. All rights reserved.