Li-S batteries are among the more auspicious candidates as next-generation batteries, owing to the abundance and inexpensive cost of raw sulfur, environmental benignity, theoretical capacity of 1675 mAh g^-1 for sulfur cathodes, and theoretical energy density of 2500 Wh kg^-1. Yet, in spite of their benefits, Li-S batteries have not been successfully commercialized so far, since they suffer from several problems: 1) Li-sulfides dissolution and their shuttle reactions that avoid full oxidation of the Li-sulfides to sulfur in the cathodes, 2) volatility of the conventional ether-based electrolyte solutions, and 3) only a partial utilization of sulfur at the cathodes due to the low sulfur conductivity of 5 x 10^-30 S cm^-1.

A mixture of graphene and Li₂S is pelletized by a volume reduction of 220% to synthesize a high energy density cathode for Li–S batteries. The pelletized Li₂S/graphene cathode represents a breakthrough in Li−S battery technology, providing the high energy and high-power density promised by the technology, while ensuring the required battery lifetime. Which plots the gravimetric energy density against the active mass loading for the Li₂S/carbon batteries reported in the literature and for the state-of-the-art commercial Li-ion battery. (Panasonic NCR18650B) At present, the cathode fabrication technology is applied to Sulfur and S-PAN as well as Li₂S batteries.

With sulfur, Li₂S and S-PAN, we are doing research on cathode materials of Li-S battery, and we are presenting achievements in all fields. Each positive electrode has different characteristics, and the development of Li-S battery, one of the next generation batteries, requires even development and comparative analysis in each cathode material.