Voltage increase of aqueous lithium-ion batteries by Li-ion conducting Li1.5Al0.5Ge1.5(PO4)3 glass-ceramic

  In this research, a lithium ion conducting lithium aluminum germanium phosphate (LAGP) glass-ceramic with a formula of Li1.5Al0.5Ge1.5(PO4)3 was synthesized by melt-quenching method and subsequent crystallization at 850 °C for 8 h. The prepared glass-ceramic was characterized using X-ray diffraction analysis (XRD) and field emission scanning electron microscopy (FESEM). The XRD patterns exhibited the existence of LiGe2(PO4)3 as the dominant phase with a little impurity phase of GeO2. SEM images revealed the presence of large cubic LAGP grains. Also, the prepared glass-ceramic was used as protective membrane in aqueous lithium ion batteries for their voltage increase. The prepared batteries with graphite as anode, LiMn2O4 as cathode and saturated aqueous solution of lithium nitrate as the electrolyte with assistance of protective membrane exhibited discharge voltage of 3.64 V and discharge capacity of 117 mAh g-1, which are comparable with those in organic-based lithium ion batteries.