LiNi0.8Co0.15Al0.05O2 (LNCA) is a highly promising cathode material for lithium-ion batteries, but the low-rate capability and poor cycling stability of LNCA limit the expansibility of its commercial applications. Herein, Li4SiO4 with a small amount of Al is introduced to modify LNCA by combined wet-chemical and solid-state methods and improve its rate and cycle performance. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscope (HRTEM), and Energy Disperse Spectroscopy (EDS) results confirm that a Li4SiO4 coating layer (2–5 nm) is firmly wrapped on the LNCA surface. The modified LNCA shows surprising rate performance and excellent cycle retention. Specifically, the LNCA material coated with 3 mol% Li4SiO4 displays a discharge capacity of 156.5 mAh g−1 at 10 C and exhibits a capacity retention of 88% after 100 cycles at 1 C rate(2.7–4.3 V). The excellent electrochemical performance of the LNCA@Li4SiO4 is due to the incorporation of the Li4SiO4 layer. This layer enhances the lithium-ion diffusion between electrode and electrolyte and suppresses the side reaction produced by direct contact between the active material and electrolyte during repeated charge–discharge cycles. All these findings indicate the high potential of this material for application in advanced lithium-ion batteries.