Electrochemical and thermal behaviour of Li[Li _x(Ni _0.3Co _0.1Mn _0.6) _1-x]O ₂ (x = 0.09, 0.11) cathode materials for lithium rechargeable batteries

High rate capable Mn-rich layered Li[Li _x(Ni _0.3Co _0.1Mn _0.6) _1-x]O ₂ (x = 0.09, 0.11) cathode materials that are fully charged are investigated with respect to st tability. Differential scanning calorimetry is used to determine the thermal stability of cathode material compositions together with PVdF binder and a conductive agent by heating from 30°C to 400 °C at 10 °C/min. In the Li[Li _x(Ni _0.3Co _0.1Mn _0.6) _1-x]O ₂ (x = 0.09, 0.11) cathode materials, the exothermic reaction started at 100 °C. Due to thermal runway, a sharp peak was observed at 279.25 °C for the material of x = 0.09 with exothermic heat generation of 168.4 J/g. For the Mn-rich cathode material, where x = 0.11, two relatively smaller peaks appeared at 250.72 °C and 268.60 °C with heat evolution of 71.49 J/g and 93.67 J/g, respectively. These layered cathode materials are thermally stable. The x = 0.09 composition shows huge heat flow occurrence when compared to the x = 0.11. It is concluded from a heat generation analysis that the two Mn-rich cathode materials are thermally stable for lithium rechargeable batteries.