Electrolyte-Induced Morphology Evolution to Boost Potassium Storage Performance of Perylene-3,4,9,10-tetracarboxylic Dianhydride
Yuqing Zhao, Simi Sui, Qian Yang, Jiaxin Li, Shenxu Chu, Mengjia Gu, Lin Li, Shuo Shi, Yuxin Zhang, Zhuo Chen, Shulei Chou, Kaixiang Lei
Abstract
Organic materials have attracted extensive attention for potassium-ion batteries due to their flexible structure designability and environmental friendliness. However, organic materials generally suffer from unavoidable dissolution in aprotic electrolytes, causing an unsatisfactory electrochemical performance. Herein, we designed a weakly solvating electrolyte to boost the potassium storage performance of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). The electrolyte induces an in situ morphology evolution and achieves a nanowire structure. The weakly dissolving capability of ethylene glycol diethyl ether-based electrolyte and unique nanowire structure effectively avoid the dissolution of PTCDA. As a result, PTCDA shows excellent cycling stability (a capacity retention of 89.1% after 2000 cycles) and good rate performance (70.3 mAh g –1 at 50C). In addition, experimental detail discloses that the sulfonyl group plays a key role in inducing morphology evolution during the charge/discharge process. This work opens up new opportunities in electrolyte design for organic electrodes and illuminates further developments of potassium-ion batteries.