Amine- and Amide-Functionalized Mesoporous Carbons: A Strategy for Improving Sulfur/Host Interactions in Li-S Batteries
Artikel i vetenskaplig tidskrift, 2020

Lithium-sulfur (Li-S) batteries are of great interest due to their potentially high energy density, but the low electronic conductivity of both the sulfur (S-8) cathode active material and the final discharge product lithium sulfide (Li2S) require the use of a conductive host. Usually made of relatively hydrophobic carbon, such hosts are typically ill-suited to retain polar discharge products such as the intermediate lithium polysulfides (LiPs) and the final Li2S. Herein, we propose a route to increase the sulfur utilization by functionalizing the surface of ordered mesoporous carbon CMK3 with polar groups. These derivatized CMK3 materials are made using a simple two-step procedure of bromomethylation and subsequent nucleophilic substitution with amine or amide nucleophiles. We demonstrate that, compared to the unfunctionalized control, these modified CMK3 surfaces have considerably larger binding energies with LiPs and Li2S, which are proposed to aid the electrochemical conversion between S-8 and Li2S by keeping the LiPs species in close proximity to the carbon surface during Li-S battery cycling. As a result, the functionalized cathodes exhibit significantly improved specific capacities relative to their unmodified precursor.

Li-S batteries

high gravimetric energy density

polysulfides

bromomethylation

density functional theory

Författare

Samuel Joseph Fretz

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Marco Agostini

Chalmers, Fysik, Materialfysik

Piotr Jankowski

Chalmers, Fysik, Materialfysik

Patrik Johansson

Chalmers, Fysik, Materialfysik

Aleksandar Matic

Chalmers, Fysik, Materialfysik

Anders Palmqvist

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

BATTERIES & SUPERCAPS

2566-6223 (eISSN)

Vol. 3 8 757-765

Nästa generation batterier för hybrid- och elfordon

Energimyndigheten, 2013-12-01 -- 2017-12-31.

Styrkeområden

Energi

Materialvetenskap

Ämneskategorier

Materialkemi

Annan kemiteknik

Annan kemi

DOI

10.1002/batt.202000027

Mer information

Senast uppdaterat

2020-10-08