Surface-Coated NaNi<sub>0.815</sub>Co<sub>0.15</sub>Al<sub>0.035</sub>O<sub>2</sub> Cathode-Based Sodium-Ion Batteries with Enhanced Performance
Dipika Meghnani, Nitin Srivastava, Rupesh K. Tiwari, Raghvendra Mishra, Anupam Patel, Anurag Tiwari, Samriddhi, Shitanshu Pratap Singh, Vikas Yadav, Rajendra Kumar Singh
Abstract
The cathode material is the main component for stabilizing sodium-ion batteries, and there is an urgent need for cathode materials with long-term cyclability and better capacity retention. Surface stabilization is one approach that can improve the performance of the cathode materials. This study focuses on modifying the surface of NaNi 0.815 Co 0.15 Al 0.035 O 2 (Na-NCA) cathode materials using the hydrothermal method with different amounts (0.5, 1.0, and 1.5 wt %) of Na-ion conducting Na 3 PO 4 by the liquid precipitation method and its impact on the electrochemical performance of Na-NCA has been investigated. Transmission electron microscopy analysis confirms the coating layer of Na 3 PO 4 with thicknesses ∼2.2 and 20 nm for Na 3 PO 4 @0.5 and Na 3 PO 4 @1, respectively, and varying thicknesses (∼20–10 nm) is observed for Na 3 PO 4 @1.5 cathodes. Electrochemical testing indicates that the sample with a thickness of ∼2.2 nm shows a uniform coating layer, high discharge capacity, better kinetics of Na + ions, and capacity retention than that of pristine Na-NCA.