High performance lithium-ion batteries with pillar[5]quinone/ion-liquid system

Abstract The capacity of cathode is a short slab issue of lithium-ion batteries (LIBs). Organic quinone cathode materials with high theoretical capacities could effectively solve the problem. Here, pillar[5]quinone (P5Q) with high theoretical capacity of 446 mAh g−1 is chosen as the cathode, while it is puzzled over fast dissolution rate in traditional organic electrolytes. Recently, ionic liquids have been reported the weak dissolution towards organic compounds. At the same time, their peculiarities of non-volatilization and non-combustibility could reduce the safety risk of using traditional organic electrolytes in LIBs. In this work, LIBs combined with LiPF6/[PY13][TFSI] (Lithium Hexafluorophosphate/N-methyl-N-propylpyrrolidiniumbis(trifluoromethanesulfonyl)amide) electrolyte and P5Q cathode show excellent electrochemical performance, principally reflected in stable cycling performance (maintain at 284 mAh g−1 at 0.2 C current density after 200 cycles with capacity retention of 70%) and high rate property (reach 220 mAh g−1 at 2 C). This strategy would further realize the practical application of organic LIBs.