Perylenetetracarboxylic diimide as a high-rate anode for potassium-ion batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 7; no. 42; pp. 24454 - 24461
• Main Authors: Bai, Yunfei, Fu, Wenbin, Chen, Wenhao, Chen, Zhichun, Pan, Xiaojun, Lv, Xiaoxia, Wu, Jincai, Pan, Xiaobo
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2019
• Subjects: Anodes; Batteries; Charge transfer; Density functional theory; Diffusion rate; Diimide; Electrode materials; Electrodes; Infrared spectroscopy; Ion diffusion; Organic compounds; Potassium; Rechargeable batteries; Specific capacity; X-ray diffraction
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c9ta07605k

Organic compounds are appealing electrode materials for potassium-ion batteries (PIBs) owing to their economical and eco-friendly nature. Here, we report an important organic semiconductor, 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), as a high-rate anode for PIBs. The PTCDI electrode is found to deliver a high average specific capacity of 310 mA h g −1 at 0.5 A g −1 and a remarkable rate performance (in the range from 0.5 to 5.0 A g −1 ), which can be attributed to the fast K ion diffusion (up to ∼10 −8 cm 2 s −1 ) and low charge-transfer resistance (93 ohm). The proposed six-electron storage mechanism for the PTCDI electrode during the discharge/charge process has been revealed by ex situ infrared (IR) spectroscopy and ex situ X-ray diffraction (XRD), as well as density functional theory (DFT) calculations. This study could pave the way for developing advanced PIB anodes with low cost and high performance. Benefitting from large space and semiconductor properties of PTCDI, a PTCDI electrode was constructed for PIBs. The electrode displays an excellent performance in optimized electrolytes which can be attributed to fast electron and ion transport kinetics.