An overview of positive-electrode materials for advanced lithium-ion batteries

Positive-electrode materials for lithium and lithium-ion batteries are briefly reviewed in chronological order. Emphasis is given to lithium insertion materials and their background relating to the “birth” of lithium-ion battery. Current lithium-ion batteries consisting of LiCoO₂ and graphite are approaching a critical limit in energy densities, and new innovating materials are needed in order to continue the advance of lithium-ion batteries. In particular, the recent trends on material researches for advanced lithium-ion batteries, such as layered lithium manganese oxides, lithium transition metal phosphates, and lithium nickel manganese oxides with or without cobalt, are described. Trials on new applications of lithium insertion materials for high-power lithium-ion batteries as well as hybrid capacitors leading for 12 V lead-free accumulators are also highlighted.