Alkali metal-sulfur batteries having high volumetric and gravimetric energy densities

摘要

Provided is an alkali metal-sulfur battery, comprising: (a) an anode; (b) a cathode having (i) a cathode active material slurry comprising a cathode active material dispersed in an electrolyte and (ii) a conductive porous structure acting as a 3D cathode current collector having at least 70% by volume of pores and wherein cathode active material slurry is disposed in pores of the conductive porous structure, wherein the cathode active material is selected from sulfur, lithium polysulfide, sodium polysulfide, sulfur-polymer composite, sulfur-carbon composite, sulfur-graphene composite, or a combination thereof; and (c) a separator disposed between the anode and the cathode; wherein the cathode thickness-to-cathode current collector thickness ratio is from 0.8/1 to 1/0.8, and/or the cathode active material constitutes an electrode active material loading greater than 15 mg/cm2, and the 3D porous cathode current collector has a thickness no less than 200 μm (preferably thicker than 500 μm).