Experimental and Theoretical Analysis of Synthesized Poly(Pthalazinone Ether Sulfone Ketone) Copolymer‐Modified Separators for Li−S Batteries. Issue 20 (17th October 2022)

• Record Type: Journal Article
• Authors: Mathivanan, Tamilarasan; Dolui, Subrata; Nandhini, Panjulingam; Rajkumar, Kanakaraj; Lakshmipathi, Senthilkumar; Banerjee, Sanjib; Kalai Selvan, Ramakrishnan
• Is Part Of: ChemElectroChem. Volume 9:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-17
• Subjects: DFT analysis -- Li−S battery -- Modified Separator -- PPESK -- Shuttling effect; Electrochemistry -- Periodicals; 541.37
• DOI: 10.1002/celc.202200561
• Languages: English
• ISSNs: 2196-0216

Abstract

Abstract: Lithium‐Sulfur (Li−S) batteries have become an undoubtful choice for future high‐energy applications due to their high theoretical capacity and energy density. However, the "Shuttle Effect" is a phenomenon that hinders the practical application of Li−S batteries. The present work reports a facile synthesis of poly(phthalazinone ether sulfone ketones) (PPESK) as a surface modifier for the conventional glass fiber separator to arrest the shuttle effect. PPESK is prepared by aromatic nucleophilic substitution (SNAr) with 4‐(4‐hydroxyphenyl) phthalazin‐1(2H)‐one, bis (4‐chlorophenyl methanone), and 4, 4′‐sulfinyl‐bis (chlorobenzene). The Li−S cells with PPESK@GF separators deliver a high initial discharge capacity of 1054.2 mAh g −1 at 0.2 C than GF (991.5 mAh g −1 at 0.2 C). Density functional theory (DFT) calculations are performed to determine the interaction between the PPESK with lithium polysulfides, Li2 Sn (n=1, 2, 4, 6, and 8). The results indicate that all the lithium polysulfides strongly bind with the sulfone nitrogen site of the PPESK structure with high binding energy, particularly Li2 S6 has −492.58 kcal/mol. The atoms‐in‐molecules analysis (AIM) shows the presence of ionic bonds between PPESK and lithium polysulfides. Gibb's free energy, the thermodynamical parameter, indicates that the reaction is exergonic and spontaneous. Overall, the theoretical findings augment the observed experimental results. Abstract : The cost‐effective and straightforward aromatic nucleophilic substitution method is adopted for the synthesis of PPESK. The PPESK‐modified glass fiber membrane separator effectively improves the cycling stability and specific capacity of Li−S batteries. PPESK has a higher binding energy and higher ability to reduce the shuttle mechanism in Li−S batteries confirmed by DFT simulation.