2, Empa- Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, , Switzerland
Due to limited natural abundance of lithium, novel battery technologies are needed for large-scale, stationary storage of electricity.1 Such batteries can then be combined with renewable sources of electricity, for the best integration of a variety of sources into electrical grid. We will discuss the utility of graphite as cathode material in non-aqueous aluminum batteries as a highly promising post-Li-ion technology for low cost and/or large scale storage of electricity.2, 3 In particular, the focus will be on a balance between structural perfection of the graphite, its electrochemical performance and material’s synthesis costs. In this regard, we provide a balanced analysis of the overall cell-level energy density of graphite based aluminum batteries. In view of its non-rocking chair operation mechanism, we show the achievable energy densities as a function of the composition of chloroaluminate ionic liquid (AlCl3 content) and compare it with other battery electrochemistries suited for stationary storage of electricity (such as lead-acid or vanadium redox flow). We will discuss also other issues associated with this technology, one being the incompatibility of most metallic current collectors with the corrosive AlCl3-based ionic liquids. Finally, we will present a novel concept of flexible aluminum-graphite battery using current collectors from earth-abundant elements and point to further avenues to commercialization of aluminum-graphite batteries as a potential grid-level energy storage technology.4
 M.-C. Lin, et al. Nature 2015, 520, 324-328.
 K. V. Kravchyk, et al. Chem. Mater. 2017, 29, 4484-4492.
 S. Wang, et al. ACS Appl. Mater. Interfaces. 2017, 9, 28478-28485.
 S. Wang, et al. Advanced Science 2017, submitted.