Controllable engineering of new ZnAl2O4-decorated LiNi0·8Mn0·1Co0·1O2 cathode materials for high performance lithium-ion batteries

Fast and continuous growth in the market of energy storage systems has increased the demand for powerful cathode materials with excellent electrochemical characteristics. In this scene, the micron-sized particles of commercial NMC811 electrode were decorated with ZnAl2O4 nanoparticles via facile coprecipitation method. The slight shifts in XRD peaks to higher angles and in FTIR bands to lower frequencies confirm the formation of ZnAl2O4 coating film surrounding NMC811 particles. The morphological features of ZAO@NMC811 core-shell particles were deeply investigated by FESEM/EDS and HRTEM/SAED techniques. XPS results of the coated sample revealed the co-existence of Zn2+ and Al3+ ions on the surface of NMC811 structure. The charge and discharge capacities of modified NMC811 were significantly increased by 5.7 and 9% achieving about 221 and 188.5 mAhg−1, respectively after first cycle. The reduction in the separation potentials of both anodic and cathodic CV scans gives a strong indication for enhancing the structure stability and lowering the polarization between NMC811 particles after coating. The modified NMC811 exhibited higher capacity retention ∼82% than that ∼ 60.2% of pristine NMC811 after 100 cycles upon 1 C. EIS results of both types of cells elucidated the enhancement of electronic and ionic conductivity as well as Li+ ions diffusion for ZAO@NMC811 cell after cycling. The suggested ZAO coating material is cheaper, easily fabricated and considerably improved the electrochemical performance of pure NMC811 cathode compared to the reported coating materials.