A novel AlCl3-[EMIM][TF2N] electrolyte for rechargeable aluminum-ion battery

Abstract

Owing to the high theoretical capacity, low price, easy availability of aluminum, the rechargeable aluminum-ion battery (AIB) is very suitable as an electrochemical energy storage device for large-scale power storage. High preference of rechargeable AIBs is depended on the suitable electrolytes. In this paper, a kind of novel ionic liquid electrolyte is prepared by mixing aluminum chloride (AlCl3) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TF2N]). This electrolyte possesses high electrical conductivity and a satisfactory oxidation voltage (2.50 V vs. Al/Al3+), which are more excellent than conventional AlCl3-based electrolytes. The Al|1.7AlCl3-[EMIM][TF2N]|carbon paper battery exhibits a stable discharge specific capacity of ~75 mAh·g-1 at 100 mA·g-1 with a near 100% coulombic efficiency, indicating that AlCl3-[EMIM][TF2N] ionic liquid is a promising electrolyte for high-voltage and high-performance aluminum-ion batteries.