Bromination of Aromatic Carbonyl Derivate As an Organic Anode Material for Sodium Ion Battery

The sodium battery has the potential to be the next generation battery system which utilizes cheaper and more abundant sodium material but affords nearly the same power as lithium batteries. The key issue to realize such sustainable batteries is to develop suitable organic electrode materials with sufficient redox capacity and cycling stability. Organic molecules are intriguing candidates for electrode materials for use in rechargeable Na ion batteries, organic electrode with aromatic carbonyl derivate structure has gained much attention because of its low cost, no need for rare metals, low safety risks compared to transition metal oxides, and design flexibility at the molecular level. Among possible organic materials, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) with aromatic carbonyl derivate structure is a promising candidate anode material for lithium rechargeable batteries due to its demonstrate that each carbon in a C₆ ring can accept a Li ion to form a Li₆/C₆ additive complex through a reversible electrochemical lithium addition reaction. In contrast, in this case of sodium addition reaction, NTCDA can insert ~7.5 Na ion in the initial discharge process but with poor cyclability. Recently, the substituents on a phenyl ring can affect the thermodynamic and kinetic properties of aromatic carbonyl derivate structure. In this work, we tried to selectively substitution the functional groups of NTCDA by a bromination, and thus we dramatically enhanced the electrochemical performance of NTCDA.