Surface modification by sulfated zirconia on high-capacity nickel-based cathode materials for Li-ion batteries

Sulfated zirconia was successfully synthesized and uniformly coated onto a nickel-rich layered lithium oxide (LiNi_0.8Co_0.1Mn_0.1O₂), and investigated with a view to its potential use as a cathode material in Li-ion batteries. The uniformity of this sulfated zirconia coating was confirmed through electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. Furthermore, the electrochemical properties of the sulfated-zirconia-coated LiNi_0.8Co_0.1Mn_0.1O₂ electrode were found to be greatly improved compared to those of pristine LiNi_0.8Co_0.1Mn_0.1O₂ and zirconia-coated LiNi_0.8Co_0.1Mn_0.1O₂, especially at elevated temperature (60 °C). These results are directly attributed to the sulfated zirconia coating, which is effective in reducing side reactions by preventing direct contact between the active materials and electrolyte solutions, as well as forming a more stable solid electrolyte interphase (SEI) layer on the active material surface.