Kish Graphite Flakes as a Cathode Material for an Aluminum Chloride–Graphite Battery

High Resolution Image Download MS PowerPoint Slide Nonaqueous, ionic liquid-based aluminum chloride–graphite batteries (AlCl 3 –GBs) are a highly promising post-Li-ion technology for low-cost and large-scale storage of electricity because these batteries feature exclusively highly abundant chemical elements and simple fabrication methods. In this work, we demonstrate that synthetic kish graphite, which is a byproduct of steelmaking, can be used as a cathode in AlCl 3 –GB and exhibits high capacities of ≤142 mAh g –1 . The comprehensive characterization of kish graphite flakes and other forms of graphite by X-ray diffraction, Raman spectroscopy, and Brunauer–Emmett–Teller surface area analysis provides solid evidence that the exceptional electrochemical behavior of kish graphite flakes is mainly determined by the high structural order of carbon atoms, a low level of defects, and a unique “crater morphology”. In view of the nonrocking chair operation mechanism of AlCl 3 –GB, we have tested the achievable energy densities as a function of the composition of chloroaluminate ionic liquid (AlCl 3 content) and have obtained energy densities of up to 65 Wh kg –1 . In addition, the kish graphite flakes can rapidly charge and discharge, offering high power densities of up to 4363 W kg –1 .