Insights into Perylene-Tetra-Carboxylate Derivatives as Versatile Anode Materials for Alkali-Metal-Ion Batteries

Abstract

The use of organic molecules as novel electrode materials potentially paves the way for the design of better and more sustainable batteries. Herein, the successful synthesis and comprehensive characterization of the alkali perylene tetra-carboxylate derivatives PCT-Li4, PTC-Na4, and PTC-K4 is reported. These conjugated carbonyl compounds are among the most promising organic electrode materials at present, since they can achieve high energy and power density as well as very good cycling stability. All materials were electrochemically tested vs. Li, Na, and K metal electrodes. A capacity of up to 120 mAh g-1 matching a two-electron redox reaction was obtained in all cases. The “crossover tests” with charge carriers not present in the pristine molecules demonstrate the great versatility of such materials. Moreover, ex situ FT-IR and operando XRD measurements were conducted to gain a deeper understanding of the influence not only of the charge carrier, but also of the initial crystal structure on the different charge storage mechanisms, as simulations for PTC-Li4 vs. Li indicate a decisive role of the initial crystal structure and, thus, contribute to the further development of organic batteries. References Dühnen, S. et al. Toward Green Battery Cells: Perspective on Materials and Technologies. Small Methods 4, 2000039 (2020).Song, Z. & Zhou, H. Towards sustainable and versatile energy storage devices: an overview of organic electrode materials. Energy & Environmental Science 6, 22 80–2301 (2013).Iordache, A. et al. From an Enhanced Understanding to Commercially Viable Electrodes: The Case of PTCLi4 as Sustainable Organic Lithium-Ion Anode Material. Advanced Sustainable Systems 1, 1600032 (2017).