Abstract: LiNi_0.8Co_0.1Mn_0.1O₂(NCM 811) has been extensively researched by scholars in solid-state batteries due to its high specific capacity, low price and environmentally friendly.However, the relatively thick solid electrolyte (> 20 μm) limits its energy density.Lithium phosphorus oxynitride (LiPON), as a common thin-film solid electrolyte, has received widespread attention in the thin-film solid-state battery field.Despite is, there hasn't been any research on combining coated NCM 811 with a LiPON thin-film electrolyte to prepare a solid-state battery.Therefore, in this work, the all-solid-state lithium battery was successfully prepared by using the commercial single-side rolled NCM 811 as the cathode, a LiPON electrolyte thin film deposited via magnetron sputtering, with Li foil as the anode.Testing results showed that the NCM 811/LiPON/Li foil all-solid-state lithium battery achieved an areal capacity of 54.85 μAh cm^-2after 60 cycles at a current density of 15 μA cm^-2.Moreover, the battery exhibited excellent cycling stability and rate performance, providing evidence that the preparation of all-solid-state batteries that combine NCM 811 cathodes with LiPON electrolyte thin films is feasible, offering a new avenue for the development of NCM 811 all-solid-state batteries.