Beyond Li-Ion Chemistry for High Energy Aqueous Battery

Tuesday, 3 October 2017: 17:20
Maryland D (Gaylord National Resort and Convention Center)
C. Yang (University of Maryland), C. Wang, L. Suo (University of Maryland, College Park), and F. Wang (U.S.Army Research Lab)
Leveraging the most recent success in expanding electrochemical stability window of aqueous electrolytes, we applyed a few new aqueous chemistries of both high energy density and safety. We show that in the super-concentrated aqueous electrolyte, these electrochemistry couples can exhibit high capasity and high voltage, which depend on thermodynamically phase-separations from the super-concentrated aqueous electrolyte. Meanwhile, fast reaction kinetics and negligible active material dissolution are also shown. The aqueous Li-ion/sulfur full cell delivers record-high energy densities up to 200 Wh/(kg of total electrode mass) for >1000 cycles at ~100% coulombic efficiency. The aqueous Li-ion/graphite full cell is heading the 300 Wh/kg target. These performances already approaches that of commercial LIBs using non-aqueous electrolyte, along with intrinsic safety not possessed by the latter. The excellent performance of this new aqueous battery chemistry significantly promotes the practical possibility of aqueous LIBs in large-format applications.