Towards the Stable 4.6V LiCoO₂ CathodesviaAluminum and Lanthanum Doping
DescriptionThe commercial lithium cobalt oxide (LiCoO2) can only exhibit a maximum capacity of 165 mAh g-1with the cut-off voltage of 4.35 V. Simply cycling LiCoO2at a higher voltage than 4.35 V can extract more capacity, but will also cause significant capacity fade mainly due to the harmful order-disorder phase transition and O3-(H1-3) phase transition. In our previous collaboration work with Huawei, we successfully pushed the cut-off voltage of LiCoO2to 4.5 V for a reversible capacity of ~190 mAh g-1by completely inhibiting the order-disorder transition. Here in this project, we try to tackle this long-standing issue of instability at 4.6 V and further pursue the 4.6 V-LCO with a capacity ~ 220 mAh g-1by using a novel multi-element bulk-doping strategy. The high-valance elements (such as Al) for replacing Co can be used to disturb the potential well for fluctuation, therefore suppressing the order-disorder transition. Synergistically, the uniform bulk-doping of lanthanide series (La) can serve as pillars in the framework, neutralize the weakened O-O repulsion, therefore suppressing the O3-(H1-3) phase transition.
|Effective start/end date||1/05/22 → …|