Advanced Rechargeable Aluminum Ion Battery with a High Quality Natural Graphite Cathode
Di-Yan Wang,1,2,3 Chuan-Yu Wei,1,4 Meng-Chang Lin,3,5Chun-Jern Pan,3,6 Hung-Lung Chou,7 Hsin-An Chen,4 Ming Gong,3 Yingpeng Wu,3 Chunze Yuan,3 Michael Angell,3 Yu-Ju Hsieh,1 Yu-Hsun Chen,1 Cheng-Yen Wen,4 Chun-Wei Chen,4 Bing-Joe Hwang,6,8* Chia-Chun Chen,1,9* and Hongjie Dai3*
Recently interest in aluminum ion batteries with aluminum anodes, graphite cathodes and ionic liquid electrolytes has increased; however much remains to be done to increase the cathode capacity and to understand details of the anion-graphite intercalation mechanism. In this study an aluminum-ion-battery cell, made using pristine natural graphite flakes,achieves a specific capacity of ~110 mAhg-1 with Coulombic efficiency~98%, at a current density of 99 mAg-1(0.9C) with clear discharge voltage plateaus (2.25 to 2.0V and 1.9 to 1.5V). The cell has a capacity of 60 mAhg-1 at 6C, over 6000 cycles with Coulombic efficiency~99%. Raman spectroscopy showes two different intercalation processes involving chloroaluminateanions at the two discharging plateaus, while C-Cl bonding on the surface, or edges of nature graphite, is found using X-ray absorption spectroscopy. Finally, theoretical calculations are employed to investigate the intercalation behavior of choloraluminate anions in the graphite electrode.