Al Doping for Mitigating the Capacity Fading and Voltage Decay of Layered Li and Mn‐Rich Cathodes for Li‐Ion Batteries

Li and Mn‐rich layered cathodes, despite their high specific capacity, suffer from capacity fading and discharge voltage decay upon cycling. Both specific capacity and discharge voltage of Li and Mn‐rich cathodes are stabilized upon cycling by optimized Al doping. Doping Li and Mn‐rich cathode materials Li 1.2 Ni 0.16 Mn 0.56 Co 0.08 O 2 by Al on the account of manganese (as reflected by their stoichiometry) results in a decrease in their specific capacity but increases pronouncedly their stability upon cycling. Li 1.2 Ni 0.16 Mn 0.51 Al 0.05 Co 0.08 O 2 exhibits 96% capacity retention as compared to 68% capacity retention for Li 1.2 Ni 0.16 Mn 0.56 Co 0.08 O 2 after 100 cycles. This doping also reduces the decrease in the average discharge voltage upon cycling, which is the longstanding fatal drawback of these Li and Mn‐rich cathode materials. The electrochemical impedance study indicat…