Acta Phys. -Chim. Sin. ›› 2000, Vol. 16 ›› Issue (08): 735-740.doi: 10.3866/PKU.WHXB20000812

• ARTICLE • Previous Articles     Next Articles

Lithiation Behavior of α-Fe2O3 in LiOH Electrolyte Solution

Li Ming, Yang Hua-Quan   

  1. Department of Chemistry,Peking University,Beijing 100871
  • Received:1999-12-23 Revised:2000-04-07 Published:2000-08-15
  • Contact: Yang Hua-Quan

Abstract:

The lithiation behavior of a-Fe_2O_3, is investigated at ambient-temperature in LiOH solutions by methods of cyclic voltammetry, IR and tracking XRD and ICP analyses. The results reveal that lithiation can take place to a small extent in α-Fe_2O_3 and its electrochemically synthesized product is Fe_3O_4 but lithiation process is limited by the unavoidable extrusion of iron in alkaline solutions. It is suggested that Li+ intercalation promotes iron's extrusion from α-Fe_2O_3 and Fe_3O_4, and that a coordination effect occurs between lithiation and iron extrusion, which shortens the steps of cyclic curves and improves the capacity significantly. These results are compared with experiments, in which α-Fe_2O_3 electrodes cycled in KOH solutions are tested by CV, XRD and ICP.

Key words: α-Fe2O3, Fe3O4, Aqueous secondary lithium batteries, Ni-Fe batteries