Rechargeable Lithium/Vanadium Oxide Cells Utilizing 2Me - THF / LiAsF6

Various vanadium oxide compositions were synthesized and evaluated as rechargeable lithium/vanadium oxide cell cathodes using 2Me-THF/LiAsF6. The most useful compositions were found to be: (1) VO(2.17), (2) VO(2.19), and (3) the Fe- or Cr-substituted oxide of apparent composition M(0.13)V(0.87)O(2.17). The superior rechargeability of VO(2.17) in practical high-capacity cells within cycling limits of 3.0 and 1.9 V was demonstrated by the extended cycling of a cell with an average cathode utilization of about 0.52 electrons/vanadium in over 200 cycles. Both VO(2.17) and VO(2.19) oxides require carbon in the cathode for acceptable performance, resulting in merely moderate volumetric energy densities. The incorporation of such metals as Cr or Fe into the vanadium oxide lattice is found to be useful in the synthesis of new cathode materials.