A Quinone-Based Electrode for High Performance Rechargeable Aluminum Ion Batteries with Low-cost AlCl3-urea Ionic Liquid Electrolyte.

Intensive energy demand urges state-of-the-art rechargeable batteries. Rechargeable aluminum ion batteries (AIBs) are promising candidates with suitable cathode materials. Owing to high abundance of carbon, hydrogen and oxygen and rich chemistry of organics (structural diversity and flexibility), small organic molecules are good choices as the electrode materials for AIB. Herein, a series of small-molecule quinone derivatives (SMQD) as cathode materials for AIB was investigated. Nonetheless, dissolution of small organic molecule into liquid electrolytes remains a fundamental challenge. To nullify the dissolution problem effectively, 1,4-benzoquinone was integrated with four bulky phthalimide groups to form 2,3,5,6-tetraphthalimido-1,4-benzoquinone (TPB) as the cathode materials and assembled to be AI/TPB cell. As a result, Al/TPB cell delivered capacity as high as 175 mAh/g over 250 cycles in the urea electrolyte system. Theoretical studies also have been carried out to reveal and understand the storage mechanism of TPB electrode.