Enabling Dual‐Ion Batteries via the Reversible Storage of Pyr14+ Cations into Coronene Crystal

Abstract

Dual‐ion batteries with pure ionic liquid electrolyte (IL‐DIBs) have received increasing interest due to their sustainability, high operating voltage, and environmental friendliness. However, owing to the insertion/extraction of large‐size ionic liquid cations, the conventional IL‐DIBs with a graphite anode suffer from severe volume expansion and graphite exfoliation on the anode, causing a poor cycling performance. Herein, a novel IL‐DIB is constructed by introducing a bulk organic material (coronene) as the anode, against a natural graphite cathode. The results show that, in a voltage window range from 1.0 to 4.4 V, the battery has a high discharge specific capacity of ≈73.3 mA h g−1 and exhibits a good cycling performance for 450 cycles with a lower capacity loss of 0.061 mA h g−1 per cycle at a current density of 300 mA g−1 (3 C). Notably, it still maintains a considerable capacity of ≈55.8 mA h g−1 at a high rate of 10 C. In addition, the reversible intercalation/de‐intercalation of the Pyr14+ cations into/from the coronene anode is investigated by ex situ X‐ray diffraction and Fourier transform infrared spectroscopy, showing an excellent structure stability of the coronene crystal during the charge–discharge process.