Thermal investigations of transitional metal oxide cathodes in Li-ion cells

Accelerating rate and differential scanning calorimeters were used to investigate the thermal behavior of LiCoO2 and LiNi0.8Co0.2O2 cathodes in fully charged Li-ion cells. The heat flow for LiNi0.8Co0.2O2 was observed to be three times higher than that for LiCoO2. The net heat transferred out of the cell fabricated with a LiNi0.8Co0.2O2 cathode was found to be 51% higher than the net heat transferred out of the cell fabricated with LiCoO2. Although LiNi0.8Co0.2O2 was found to be thermally less stable than LiCoO2, the electrochemical performance of the LiNi0.8Co0.2O2 cathode under high power discharge was found superior to LiCoO2.