Cobalt-free nickel-rich layered LiNi0.9Al0.1-xZrxO2 cathode for high energy density and stable lithium-ion batteries

To meet the challenges of limited resources and the toxicity of cobalt, cobalt freed Ni-rich layered cathode materials for high energy density power batteries have become a hot spot. However, the poor stability upon cycling hindered their applications. A layered Zr-introduced Ni-Al based Co-free cathode material LiNi0.9Al0.1-xZrxO2 (NAZ) is designed and synthesized with a sol-gel method. The prepared Co-free cathode material exhibits perfect crystal structure stability and electrochemical performance, which are attributed to the incorporation of Zr4+ with high-valence and strong Zr-O bond energy. The obtained LiNi0.9Al0.08Zr0.02O2 (NAZ-2) shows a first discharge capacity of 177.5 mAh g−1 at 1 C, and maintains about 92.45 % after 100 charge / discharge cycles. It also displays a high specific capacity of 160 mAh g−1 at 5 C. Furthermore, compared to the pure sample, LiNi0.9Al0.08Zr0.02O2 (NAZ-2) shows a lower charge transfer impedance of 57.90 Ω and larger diffusion coefficient of lithium ions of 5.70217 × 10−9 cm2 S−1, which is conducive to the migration of Li+ and the inhibiting of the polarization.