Electronic structure theory investigation on the electrochemical properties of cyclohexanone derivatives as organic carbonyl-based cathode material for lithium-ion batteries

Organic carbonyl-based compounds with redox-active site have recently gained full attention as organic cathode material in lithium-ion batteries (LIBs) owing to its high cyclability, low cost, high abundance, tunability of their chemical structure compared to traditionally used inorganic material. However, the utilization of organic carbonyl-based compounds in LIBs is limited to its poor charge capacity and dissolution of lower molecular weight species in electrolytes. In this study, we theoretically investigated five set of cyclohexanone derivatives (denoted as: H-1, H-2,H- H-3, H-4, and H-5) and influence of functional groups (-F and -NH2) on their electrochemical properties using advanced level density functional theory (DFT) with the Perdew-Burke-Ernzenhof hybrid functional (PBE0) at 6-31 + G(d,p) basis set. In line with the result gotten, the HOMO-LUMO results revealed that compound H5 is the most reactive among the studied cyclohexanone derivatives exhibiting energy gap values of 0.552, 0.532, 0.772 eV for free optimized structures and structurally engineered structures with electron withdrawing group (EWG) and electron donating group (EDG) respectively. Also, results from electrochemical properties of the studied compounds lithiated with only one lithium atom displayed that compound H-2 exhibited interesting redox potential and energy density for all the studied structures in free optimized state (1108.28 W h kg(-1) , 4.92 V vs Li/Li+ ), with EWG 648.22 W h kg(-1) , 3.313 V Li/Li+), and with EDG (1002.4 W h kg(-1) , 5.011 V vs Li/Li+). From our result, we can infer that compound H-2 and H-3 with corresponding redox potential, energy density and theoretical charge capacity value of 4.92 V vs Li/Li+ , 1108.28 W h kg(-1) , 225.26 mA h g(-1) and 5.168 V, 1041.61 W h kg(-1) , 201.55 mA h g(-1) lithiated with only one lithium atom in free optimized state are the most suitable compounds to be employed as organic cathode material in lithiumion batteries among all the investigated cyclohexanone derivatives. (C) 2022 The Authors. Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

Organic carbonyl-based compounds have gained attention as organic cathode materials in lithium-ion batteries (LIBs) due to their high cyclability, low cost, and tunable chemical structure. However, their utilization is limited by poor charge capacity and dissolution in electrolytes. In this study, cyclohexanone derivatives were theoretically investigated, and it was found that compound H-2 and H-3 exhibited promising electrochemical properties, making them suitable as organic cathode materials for LIBs.