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.