Collaborative Research: CDS&E: Computational Exploration of Electrically Conductive Metal-Organic Frameworks as Cathode Materials in Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) consisting of a lithium metal anode and an earth-abundant sulfur cathode have attracted much attention as a promising candidate for energy storage. To date, several challenges and technical hurdles prevent the development of LSBs. In this collaborative project, Professors Farnaz Shakib (New Jersey Institute of Technology) and Mohammad Momeni (University of Missouri–Kansas City) will investigate the design and application of electrically-conductive metal-organic frameworks (EC-MOFs) as cathode materials for LSBs. EC-MOFs are a new class of nanoporous materials with exceptionally high surface area and layered structures that can tolerate mechanical deformations during battery operation. This project will advance science by employing novel computational techniques to design and investigate the functionality of a new class of materials as cathodes. This will lead to the design of more efficient clean energy resources. During this project, graduate students will be trained as the skilled workforce for the future of STEM. Undergraduate and K-12 level students will learn the fundamentals of computational chemistry through full-day workshops and Summer Schools, which will help their growth in STEM fields. Despite intensive research on lithium-sulfur batteries (LSBs), finding a porous cathode material with a high electrical conductivity that can prevent sulfur shuttling to the anode is still a pressing challenge. The project will address the unique structural and electronic properties of Pi(𝜋)-stacked layered 2D electrically conductive metal-organic frameworks (EC-MOFs) as optimal cathode materials in LSBs. Apart from the apparent advantage of electrical conductivity, the layered architecture of EC-MOFs can endure extreme deformations without mechanical collapse. At the same time, their porous nature allows for efficient encapsulation of the active sulfur material in the cathode providing enhanced resistance toward its dissolution into the electrolyte solution (the shuttling effect). The primary goal of this project is to probe the virtually unlimited chemical space of EC-MOFs to introduce ideal candidates as cathode materials. Since a case-by-case analysis of thousands of EC-MOFs as potential cathode materials is impractical, this research follows two main objectives: (i) creating a comprehensive and expandable database of EC-MOFs with an automated crystal structure creation tool which will be followed by high-throughput screening discovery of EC-MOFs with desired structural and electrical properties; and (ii) investigating sulfur (S8) and its lithium-polysulfide derivatives’ encapsulation and possible transport at the electrode-electrolyte interface from advancedmolecular dynamics simulations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.