Materials and Technologies for Metal-Sulfur Batteries

As a cathode material, sulfur (S) owns high capacity and energy density (1675 mAh g ⁻¹ , 2600 Wh kg ⁻¹) when coupled with lithium metal anode. Thus, lithium-sulfur (Li-S) batteries have attracted significant attention over the past decades for the next-generation high energy density rechargeable batteries. Inspired by the remarkable progress of Li-S batteries, other metal-sulfur battery systems with potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), or aluminum (Al) have also been studied. Na, Mg, and Al elements are more abundant on the earth and cheaper than Li. In addition, the Na-S, Mg-S, and Al-S batteries also show high gravimetric and volumetric energy densities. However, the research on Na-S, Mg-S, and Al-S chemistries is far behind the Li-S chemistry due to some challenges. This chapter summarizes and analyzes the electrochemical mechanisms and research progress of the four metal-sulfur systems. Other emerged metal-sulfur systems, including aqueous zinc-sulfur (Zn-S) and anode-free metal-sulfur, are also introduced briefly.