title: Advanced rechargeable aluminium ion battery with a high-quality natural graphite cathode.
abstract: Recently, interest in aluminium ion batteries with aluminium 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. Here, an aluminium ion battery cell made using pristine natural graphite flakes achieves a specific capacity of ∼110 mAh g-1with Coulombic efficiency ∼98%, at a current density of 99 mA g-1(0.9 C) with clear discharge voltage plateaus (2.25-2.0 V and 1.9-1.5 V). The cell has a capacity of 60 mAh g-1at 6 C, over 6,000 cycles with Coulombic efficiency ∼ 99%. Raman spectroscopy shows two different intercalation processes involving chloroaluminate anions at the two discharging plateaus, while C-Cl bonding on the surface, or edges of natural graphite, is found using X-ray absorption spectroscopy. Finally, theoretical calculations are employed to investigate the intercalation behaviour of choloraluminate anions in the graphite electrode.
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.|Department of Chemistry, Tunghai University, Taichung 40704, Taiwan.|Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Di-Yan
authors.initials: DY
authors.lastname: Wang
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.|Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chuan-Yu
authors.initials: CY
authors.lastname: Wei
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.|College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, China.
authors.forename: Meng-Chang
authors.initials: MC
authors.lastname: Lin
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.|Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
authors.forename: Chun-Jern
authors.initials: CJ
authors.lastname: Pan
authors.affiliation: Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
authors.forename: Hung-Lung
authors.initials: HL
authors.lastname: Chou
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Hsin-An
authors.initials: HA
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Gong
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Yingpeng
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Chunze
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Angell
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.
authors.forename: Yu-Ju
authors.initials: YJ
authors.lastname: Hsieh
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.
authors.forename: Yu-Hsun
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Cheng-Yen
authors.initials: CY
authors.lastname: Wen
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.|National Synchrotron Radiation Research Center (NSRRC), Hsinchu 30076, Taiwan.
authors.forename: Bing-Joe
authors.identifier: 0000-0002-3873-2149
authors.initials: BJ
authors.lastname: Hwang
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.|Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Chia-Chun
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Dai