Composite number

Engineering

Electrochemistry

Metallurgy

Materials science

Cathode

Carbon fibers

Inorganic chemistry

Chemical engineering

Electrocatalyst

Dissolution

Physical chemistry

Nanotechnology

Carbon nanotube

Sodium sulfide

Composite material

Sulfur

Nanocrystal

Chemistry

Electrode

Polysulfide

Sulfide

Electrolyte

Nickel sulfide

Nature Communications

Polysulfide dissolution and slow electrochemical kinetics of conversion reactions lead to low utilization of sulfur cathodes that inhibits further development of room-temperature sodium-sulfur batteries. Here we report a multifunctional sulfur host, NiS 2 nanocrystals implanted in nitrogen-doped porous carbon nanotubes, which is rationally designed to achieve high polysulfide immobilization and conversion. Attributable to the synergetic effect of physical confinement and chemical bonding, the high electronic conductivity of the matrix, closed porous structure, and polarized additives of the multifunctional sulfur host effectively immobilize polysulfides. Significantly, the electrocatalytic behaviors of the Lewis base matrix and the NiS 2 component are clearly evidenced by operando synchrotron X-ray diffraction and density functional theory with strong adsorption of polysulfides and high conversion of soluble polysulfides into insoluble Na 2 S 2 /Na 2 S. Thus, the as-obtained sulfur cathodes exhibit excellent performance in room-temperature Na/S batteries.

Nickel sulfide nanocrystals on nitrogen-doped porous carbon nanotubes with high-efficiency electrocatalysis for room-temperature sodium-sulfur batteries