High-Voltage Performance of Li[Ni(0.55)Co(0.15)Mn(0.30)]O(2) Positive Electrode Material for Rechargeable Li-Ion Batteries

Abstract

The electrochemical properties and thermal stabilities of a new positive electrode material for Li-ion batteries, Li[Ni 0.55 Co 0.15 Mn 0.30 ]O 2 Li[Ni0.55Co0.15Mn0.30]O2 , were investigated over a wide potential window. This electrode material was synthesized via a coprecipitation method. X-ray diffraction studies indicated that the synthesized material crystallized into an α-NaFeO 2 α-NaFeO2 layered structure (R3 ? m) (R3?m) . The Li[Ni 0.55 Co 0.15 Mn 0.30 ]O 2 Li[Ni0.55Co0.15Mn0.30]O2 positive electrode has a discharge capacity of 202mAhg ?1 202mAhg?1 in the voltage range of 2.7?4.5V 2.7?4.5V . This high capacity was retained throughout cycling. The thermal stability of Li[Ni 0.55 Co 0.15 Mn 0.30 ]O 2 Li[Ni0.55Co0.15Mn0.30]O2 was measured by differential thermal calorimetry and found to be comparable to that of Li[Ni 1?3 Co 1?3 Mn 1?3 ]O 2 Li[Ni1?3Co1?3Mn1?3]O2 . This positive electrode material was also characterized in a full cell configuration (graphite negative electrode) by the hybrid pulse power characterization tests following the FreedomCAR battery test manual for plug-in hybrid electric vehicles (PHEVs). The pulse power capability and available energy met the goals for PHEVs.