High-Energy-Density Rechargeable Lithium–NickelChloride Aqueous Solution Batteries

摘要

High-energy-density rechargeable batteries with performance beyond that of lithium-ion batteries are required for next-generation electric vehicles. We propose a novel rechargeable battery with a lithium anode and a NiCl2 aqueous cathode that is separated Li1.4Al0.4Ge0.2Ti1.4(PO4)3 as a water-stable lithium-ion-conducting solid electrolyte. The cell was discharged up to 93% of the theoretical cathode capacity at 0.5 mA cm^–2 and 25 °C. The calculated energy density, based on the weights of NiCl2 and Li, and the average discharge voltage of 2.4 V at 0.5 mA cm^–2, was 852 Wh kg^–1, which is more than twice as high as that of conventional lithium-ion batteries. The cell was successfully cycled for 50 cycles without any degradation of the charge and discharge voltages at 0.5 mA cm^–2 and 25 °C for 5 h charge and 5 h discharge, where the utilization of NiCl2 was 80%.