Amine- and Amide-Functionalized Mesoporous Carbons: A Strategy for Improving Sulfur/Host Interactions in Li-S Batteries
Journal article, 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

Author

Samuel Joseph Fretz

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Marco Agostini

Chalmers, Physics, Materials Physics

Piotr Jankowski

Chalmers, Physics, Materials Physics

Patrik Johansson

Chalmers, Physics, Materials Physics

Aleksandar Matic

Chalmers, Physics, Materials Physics

Anders Palmqvist

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

BATTERIES & SUPERCAPS

2566-6223 (eISSN)

Vol. 3 8 757-765

Next generation batteries for hybrid and electric vehicles

Swedish Energy Agency, 2013-12-01 -- 2017-12-31.

Areas of Advance

Energy

Materials Science

Subject Categories

Materials Chemistry

Other Chemical Engineering

Other Chemistry Topics

DOI

10.1002/batt.202000027

More information

Latest update

10/8/2020