Understanding the Electrochemical Properties of Naphthalene Diimide: Implication for Stable and High-Rate Lithium-Ion Battery Electrodes

Redox-active organic molecules have attracted much attention as alternatives to transition-metal-based electrodes for lithium-ion batteries due to their low cost and large abundance. However, the relatively low cycling stability still prevents some of the most promising molecules to be used as lithium-ion electrodes. Herein, we used 1,4,5,8-naphthalene diimide (NDI) as a model molecule to systematically investigate its intrinsic electrochemical property, including its electrolyte compatibility, maximum capacity, cycling stability, and rate capability in different organic electrolytes. Extensive physicochemical characterization, electrochemical measurement, and density function theory (DFT) calculation together show that the electrode-electrolyte interaction is the key factor determining its specific capacity and proper selection of electrolytes, NDI molecule, which was considered to be not stable for lithium storage, theoretical capacity (based on two-electron reaction), very high rate capability, and high cycling stability. This study suggests the importance of understanding the fundamental electrode-electrolyte interactions in designing high-performance organic electrodes.