Cathode materials for rechargeable rocking chair or lithium-ion batteries, are reviewed. The emphasis is placed on the comparison between specific capacities and rechargeability of lithium-containing high voltage cathode materials such as manganese oxides and LiMO(2) compounds, where M is Co or Ni. It is generally found that the maximum reversible capacities for the most promising materials fall in the range 100-120 mAh/g, and decaying to around 75 mAh/g after several hundred cycles. The rechargeability is similar for the most commonly considered materials : LiMn2O4, LiCoO2, and LiNiO2. No improvements in capacity or rechargeability, beyond what have been found for these materials, is observed by substitution of other elements into these compounds.