Quinone Electrode for Long Lifespan Potassium-Ion Batteries Based on Ionic Liquid Electrolytes
Weisheng Zhang, Hao Tian, Jiawen Wang, Jiawen Wang, Huimin Sun, Jing Wang, Jing Wang, Weiwei Huang
Abstract
As a class of flexible and designable materials, organic electrode materials would greatly facilitate the progress of potassium-ion batteries (PIBs), especially when the dissolution issue is ameliorated. Ionic liquid electrolytes (ILEs) do not merely alleviate the dissolution of organic materials but provide reliable security. Herein, Pillar[5]quinone (P5Q) as the cathode of PIBs is demonstrated for the first time, and the electrochemical performance of two common ILEs is investigated. In the 0.3 M KFSI-PY13FSI electrolyte with better conductivity, the P5Q cathode maintains a large reversible capacity of 232 mAh g–1 (450 Wh kg–1) after 100 cycles at 0.2C at 1.2–4.0 V. When a current density of 2.0C is applied, the cell retains a capacity of 101 mAh g–1 (211 Wh kg–1) after 1000 cycles and 61 mAh g–1 (125 Wh kg–1) even over 5000 cycles. This research would inspire research on organic electrodes and advance the application of PIBs.