Enhanced structural and electrochemical stability of LiNi0.83Co0.11Mn0.06O2 cathodes by zirconium and aluminum co-doping for lithium-ion battery

A series of Zr4+ and/or Al3+ doped LiNi0.83Co0.11Mn0.06O2 are synthesized via a solid phase method. TEM shows that the co-doped specimen consists of a layered core and a coherent interface cation-mixed shell. XRD and XPS results clarify that Zr4+ doping increases the Li+/Ni2+ cation site exchange degree and the concentration of Ni2+. The morphology and structural integrity of the co-doped electrode maintains well, and it provides a higher cycle retention (89.7%) than blank (60.1%) after 150 cycles and a superior capacity of 152.8 mAh g(-1) at 7C (only 57.7 mAh g(-1) for blank) and an enhanced elevated temperature cycle retention (83.0%) than blank (33.7%) after 100 cycles at 55 degrees C. Generally, Zr4+ raises the concentration of Ni2+ to keep electric neutrality and then reconstruct a stable interfacial structure to inhibit side reactions, the structural stability could be also enhanced by the strong Zr-O and Al-O bonds. Meanwhile, Al3+ served as centers of positive charge can suppress the phase transformation. Benefiting from the synergistic effect of Zr4+/Al3+, as well as the induced coherent interface cationmixed shell, co-doped specimen shows enhanced structural stability and the superior electrochemical performance. This study provides a route to prepare advanced layered cathodes for lithium-ion batteries.