Surface-Phosphided Metal Oxide Microspheres as Catalytic Host of Sulfur to Enhance the Performance of Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are one of the most promising high-energy density secondary batteries due to their high theoretical energy density of 2600 Wh kg. However, the sluggish kinetics and severe "shuttle effect" of polysulfides are the well-known barriers that hinder their practical applications. A carefully designed catalytic host of sulfur may be an effective strategy that not only accelerates the conversion of polysulfides but also limit their dissolution to mitigate the "shuttle effect.

High Volumetric Energy Density Sulfur Cathode with Heavy and Catalytic Metal Oxide Host for Lithium-Sulfur Battery.

For high-energy lithium-sulfur batteries, the poor volumetric energy density is a bottleneck as compared with lithium-ion batteries, due to the low density of both the sulfur active material and sulfur host. Herein, in order to enhance the volumetric energy density of sulfur cathode, a universal approach is proposed to fabricate a compact sulfur cathode with dense materials as sulfur host, instead of the old-fashioned lightweight carbon nanomaterials. Based on this strategy, heavy lanthanum strontium manganese oxide (LaSrMnO), with a high theoretical density of up to 6.

Synthetic and structural studies on new diiron azadithiolate (ADT)-type model compounds for active site of [FeFe]hydrogenases.

A series of new diiron azadithiolate (ADT) complexes (1-8), which could be regarded as the active site models of [FeFe]hydrogenases, have been synthesized starting from parent complex [(μ-SCH(2))(2)NCH(2)CH(2)OH]Fe(2)(CO)(6) (A). Treatment of A with ethyl malonyl chloride or malonyl dichloride in the presence of pyridine afforded the malonyl-containing complexes [(μ-SCH(2))(2)NCH(2)CH(2)O(2)CCH(2)CO(2)Et]Fe(2)(CO)(6) (1) and [Fe(2)(CO)(6)(μ-SCH(2))(2)NCH(2)CH(2)O(2)C](2)CH(2) (2). Further treatment of 1 and 2 with PPh(3) under different conditions produced the PPh(3)-substituted complexes [(μ-SCH(2))(2)NCH(2)CH(2)O(2)CCH(2)CO(2)Et]Fe(2)(CO)(5)(PPh(3)) (3), [(μ-SCH(2))(2)NCH(2)CH(2)O(2)CCH(2)CO(2)Et]Fe(2)(CO)(4)(PPh(3))(2) (4), and [Fe(2)(CO)(5)(PPh(3))(μ-SCH(2))(2)NCH(2)CH(2)O(2)C](2)CH(2) (5).