Xi Chen1
City University of Hong Kong1
Xi Chen1
City University of Hong Kong1
<br/>Single-crystalline Ni-rich cathodes are promising for the next generation of high-energy-density Li-ion batteries due to their better capacity retention than their polycrystalline counterparts. However, there is still much room for improving the electrochemical performances when considering their surface degradation and severe kinetic hindrance during cycling. Herein, we report a strategy to construct an <i>in situ</i> formed robust Li-conductive Li<sub>3</sub>PO<sub>4</sub> layer on the surface of the single crystalline LiNi<sub>0.83</sub>Co<sub>0.12</sub>Mn<sub>0.05</sub>O<sub>2 </sub>cathode particles. This Li-conductive layer significantly increases the Li-ion diffusion coefficients and suppresses detrimental surface phase transformation. <i>In situ</i> XRD reveals that the improved kinetics alleviate the local stress at high voltage. The as-prepared single-crystalline LiNi<sub>0.83</sub>Co<sub>0.12</sub>Mn<sub>0.05</sub>O<sub>2</sub> delivers good durability (96.8 % after 100 cycles at 1 C) and excellent rate capability (177.08 mAh g<sup>-1</sup> at 5 C). This work provides a facile and efficient strategy to improve the cyclic performance and boost the rate capability of single-crystalline Ni-rich cathodes.