Ultrathin, flexible, solid polymer composite electrolyte enabled with aligned nanoporous host for lithium batteries

Lithium-ion batteries raise safety, environmental, and cost concerns, which mostly arise from their nonaqueous electrolytes. The use of aqueous alternatives is limited by their narrow electrochemical stability window (1.23 volts), which sets an intrinsic limit on the practical voltage and energy output. We report a highly concentrated aqueous electrolyte whose window was expanded to ~3.0 volts with the formation of an electrode-electrolyte interphase. A full lithium-ion battery of 2.3 volts using such an aqueous electrolyte was demonstrated to cycle up to 1000 times, with nearly 100% coulombic efficiency at both low (0.15 coulomb) and high (4.5 coulombs) discharge and charge rates.

Garnet-type electrolytes are attractive for lithium metal batteries due to their high ionic conductivity. A strategy to decrease interfacial impedance between a lithium metal anode and garnet electrolyte is found promising for all-solid-state batteries.