S. Tian

Porous LiMn2O4 as cathode material with high power and excellent cycling for aqueous rechargeable lithium batteries

A porous LiMn2O4 consisting of nano grains was prepared by using polystyrene as template. It was studied as a cathode material for aqueous rechargeable lithium batteries (ARLBs) using 0.5 mol l−1Li2SO4 aqueous solution as the electrolyte. Charge and discharge capacities at a current density of 10 A g−1 (about 90C) were 76% and 95% of the total capacity (118 mAh g−1), respectively. The power density can be up to 10000 W kg−1 and the cycling behavior is excellent. After 10000 cycles at 9C with 100% DOD (depth of discharge), the capacity retention of porous LiMn2O4 is 93%, which indicates that it can be used for a lifetime without maintenance. The main reasons for its excellent electrochemical performance are due to the nano grains, porous morphology and high crystalline structure. In addition, the acid-free aqueous electrolyte prevents Mn2+ from dissolution. These excellent results suggest a great promise for the development of aqueous rechargeable lithium batteries (ARLBs) in practical application.

IMPROVING ELECTROCHEMICAL PERFORMANCE OF LiCoO2 BY TiO2 COATING AS CATHODE FOR AQUEOUS RECHARGEABLE LITHIUM BATTERIES

Modified LiCoO2 was prepared via a sol–gel method followed by a TiO2 coating and characterized by X-ray diffraction analysis, transmission electronic microscopy and various measurements of charge/discharge behavior. Its cycling performance and rate capability were greatly improved compared to the original LiCoO2. The initial capacity of the TiO2-coated LiCoO2 is 134 mAh g-1 at the current density of 5000 mA g-1. When the current density increases to 10,000 mA g-1, the cathode displays an initial capacity of 128 mAh g-1, much higher than that (<101 mAh g-1) for the virginal LiCoO2, and shows no evident capacity fading after 100 cycles.

LiV3O8 NANOMATERIAL AS ANODE WITH GOOD CYCLING PERFORMANCE FOR AQUEOUS RECHARGEABLE LITHIUM BATTERIES

LiV3O8 nanorod material was prepared by a simple sol–gel method. The electrochemical properties of the as-prepared LiV3O8 in 0.5 M Li2SO4 aqueous electrolyte were studied through cyclic voltammograms (CV) and discharge–charge measurements. Experiments show that this nanorod material can deliver the capacities of 72, 62 and 53 mAh/g at 20, 50, 100 mA/g, respectively. After 50 cycles, it can maintain 64, 47 and 40 mAh/g, corresponding to 88%, 76% and 77% of the initial capacities, which suggest that this nanorode material presents good cycling performance as anode material for aqueous rechargeable lithium batteries.