Systematic Molecular Design of Ketone Derivatives of Aromatic Molecules for Lithium-Ion Batteries: First-Principles DFT Modeling.

The thermodynamic and electrochemical redox properties for a set of ketone derivatives of phenalenyl and anthracene have been investigated to assess their potential application for positive electrode materials in rechargeable lithium-ion batteries. Using first-principles DFT, it was found that 1) the thermodynamic stabilities of ketone derivatives are strongly dependent on the distribution of the carbonyl groups and 2) the redox potential is increased when increasing the number of the incorporated carbonyl groups. The highest values are 3.93 V versus Li/Li+ for the phenalenyl derivatives and 3.82 V versus Li/Li+ for the anthracene derivatives. It is further highlighted that the redox potential of an organic molecule is also strongly correlated with its spin state in the thermodynamically stable form.