The available capacity of Mg hybrid batteries is closely related to the number of charge carriers within electrolyte solutions. Therefore, in this study, a dual-salt composition capable of supplying high Li + concentration was prepared. A dual-salt electrolyte consisting of a LiAlCl 4 complex (LACC) and LiN(SO 2 CF 3 ) 2 (LiTFSI) was found to be an excellent candidate, providing 2.2 M Li + concentration along with anodic stability up to 3 V (vs Mg/Mg 2+ ). However, the LACC moiety of the above composition first had to undergo a two-step modification procedure comprising "Mg powder treatment" and "conditioning process" to properly implement Mg deposition and stripping at the Mg anode. Spontaneous substitutions of oxidation states between the anionic Al 3+ complex and metallic Mg induced by these processes resulted in the generation of Mg 2+ complex species within the LACC solutions. The modified LACC was compatible even with 2 M of LiTFSI, the concentration with which we achieved 150 mA h g -1 capacity of a FePO 4 cathode at 1.5 mg cm -2 loading density, when using an electrolyte volume of only 25.5 μL cm -2 .
Bibliographical noteFunding Information:
This work was supported by the institutional program of the Korea Institute of Science and Technology (project no. 2E27870 and 2E28142) and by a grant from the National Research Foundation of Korea (NRF-2011-C1AAA001-0030538).
© 2018 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films