Effective and uniform surface modification is very important for improving the properties of LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811). Here, we used a liquid-phase assisted method to modify the surface of NCM811 via ammonium metatungstate to synthesize 1 W@NCM811. This step reduced surface residual lithium and led to in situ WO₃/Li₂WO₄ coating. The uniform WO₃/Li₂WO₄ coating acted as an ideal protective layer and physically prevented direct contact between the NCM811 lattice and the electrolyte, thus stabilizing the cathode/electrolyte interface and passivating detrimental reactions. Moreover, the coating enhanced the electrochemical kinetics in terms of the impedance of Li⁺ through a solid electrolyte film (R_sf) and charge transfer resistance (R_ct). The strong W-O bond can effectively improve the thermal stability of the material. As a result, the 1 W@NCM811-based cathode exhibits significantly enhanced structural stability, electrochemical performance, and thermodynamic properties. At 0.5 C (1 C = 200 mAh g⁻¹) in the voltage range of 3.0–4.3 V, the 1 W@NCM811-based cathode delivers excellent capacity retention of 97.36% and 88.92% after 100 cycles at 25 °C and 55 °C, respectively. According to the analysis of 1 W@NCM811-based cathode, a better layered lattice, fewer by-products, and less heat generation prove that this approach provides an effective means for the development of NCM811.

有效且均匀的表面改性对于提高LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (NCM811)的性能非常重要。在这里，我们使用液相辅助方法通过偏钨酸铵对 NCM811 的表面进行修饰，合成 1 W@NCM811。该步骤减少了表面残留锂并导致原位WO ₃ /Li ₂ WO ₄涂层。均匀的WO ₃ /Li ₂ WO ₄涂层充当了理想的保护层，并在物理上阻止了 NCM811 晶格与电解质之间的直接接触，从而稳定了阴极/电解质界面并钝化了有害反应。此外，涂层通过固体电解质膜 (R _sf ) 和电荷转移电阻 (R _{ct ) 增强了 Li} ⁺的阻抗方面的电化学动力学。强WO键能有效提高材料的热稳定性。因此，基于 1 W@NCM811 的正极表现出显着增强的结构稳定性、电化学性能和热力学性能。在 0.5 C (1 C = 200 mAh g ^-1) 在 3.0–4.3 V 的电压范围内，基于 1 W@NCM811 的正极在 25 °C 和 55 °C 下循环 100 次后分别提供了 97.36% 和 88.92% 的出色容量保持率。根据1 W@NCM811基正极的分析，层状晶格更好、副产物更少、发热更少，证明该方法为NCM811的开发提供了有效手段。