2, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, , Switzerland
Aluminum-based batteries hold great promise for low-cost and large-scale stationary storage of electricity. This notion has led a surge of reports on novel batteries comprising exclusively highly abundant chemical elements. In this work, we demonstrate that the synthetic kish graphite, a large-scale byproduct of steel-making, can be used as a cathode in such aluminum chloride−graphite batteries (AlCl3−GBs), exhibiting high cathodic charge-storage capacities of up to 142 mAh g-1.
Comprehensive characterization of kish graphite flakes and of other kinds of graphite by X-ray diffraction, Raman spectroscopy and BET surface area analysis led us to the conclusion that the superior performance of the kish graphite is rooted into a high structural perfection of such graphite, low level of defects and its unique “crater morphology”. In view of non-rocking chair mechanism of AlCl3-GB and strong dependency of chloroaluminate ionic liquid composition on its energy density, in this work, we also demonstrate that kish graphite flakes enable to provide the density of 65 Wh kg-1(highest so far for such Al-based batteries) by applying 2:1 (AlCl3:EMIMCl) ionic liquid molar ratio, which compare very favorably with other battery electrochemistry suited for stationary storage of electricity (such as lead-acid or vanadium redox flow). In addition, kish graphite flakes show the unique ability for fast charge and discharge delivering a high power density of 4363 W kg-1 for AlCl3-GB, in this regard, they considerably surpass the natural graphite flakes., 
 M.-C. Lin, M. Gong, B. Lu, Y. Wu, D.-Y. Wang, M. Guan, M. Angell, C. Chen, J. Yang, B.-J. Hwang, H. Dai, Nature, 520, (2015)324-328.
 S. Wang, K. V. Kravchyk, F. Krumeich, M. V. Kovalenko, ACS Appl. Mater. Interfaces, 9, (2017)28478-28485.
 K. V. Kravchyk, S. Wang, L. Piveteau, M. V. Kovalenko, Chem. Mater., 29, (2017)4484-4492.
 D. Y. Wang, C. Y. Wei, M. C. Lin, C. J. Pan, H. L. Chou, H. A. Chen, M. Gong, Y. P. Wu, C. Z. Yuan, M. Angell, Y. J. Hsieh, Y. H. Chen, C. Y. Wen, C. W. Chen, B. J. Hwang, C. C. Chen, H. J. Dai, Nat. Commun., 8, (2017)7.