Voltage fade mitigation in the cationic dominant lithium-rich NCM cathode

In the archetypal lithium-rich cathode compound Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 , a major part of the capacity is contributed from the anionic (O 2−/− ) reversible redox couple and is accompanied by the transition metal ions migration with a detrimental voltage fade. A better understanding of these mutual interactions demands for a new model that helps to unfold the occurrences of voltage fade in lithium-rich system. Here we present an alternative approach, a cationic reaction dominated lithium-rich material Li 1.083 Ni 0.333 Co 0.083 Mn 0.5 O 2 , with reduced lithium content to modify the initial band structure, hence ~80% and ~20% of capacity are contributed by cationic and anionic redox couples, individually. A 400 cycle test with 85% capacity retention depicts the capacity loss mainly arises from the metal ions dissolution. The voltage fade usually from Mn 4+ /Mn 3+ and/or O n− /O 2− reduction at around 2.5/3.0 V seen in the typical lithium-rich materials is completely eliminated in the cationic dominated cathode material. At low voltages, lithium-rich cathodes can undergo a detrimental voltage fade. Here by tuning the band structure of the cathode, 85% capacity retention over 400 cycles is achieved.