LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) has received widespread attention due to its high discharge specific capacity. However, poor cycling performance and rate capacity limit its large-scale commercial applications. Here, we develop 4,5-Dicyano-1,3-dithiol-2-one (DDO) as a new type additive to enhance the cycling performance and rate capacity of NCM811/Li⁺ half cell. Electrochemical tests show that the discharge capacity retention rate of cell is 75.59% after 200 cycles with 0.1 wt% DDO-containing electrolyte, while the cell with blank electrolyte is only 15.11%. The initial coulomb efficiency and rate capacity with 0.1 wt% DDO are higher than the blank one. Through scanning electron microscope (SEM) analysis, the particle of NCM811 is smooth and integral after 50th cycled, while the particle ruptures in blank electrolyte. The outstanding electrochemical performance of NCM811 is attributed to the stable and uniform cathode electrolyte interphase (CEI) film formed by DDO. Moreover, X-ray photoelectron spectroscopy (XPS) reveals that DDO prevents the decomposition of carbonate solvents and nickel element dissolution of NCM811. Other tests also confirm that the robust CEI layer can reduce the polarization and internal resistance of the cell during cycles.

LiNi _0.8 Co _0.1 Mn _0.1 O ₂（NCM811）由于其高放电比容量而受到广泛关注。然而，不良的循环性能和速率能力限制了其大规模的商业应用。在这里，我们开发4,5-Dicyano-1,3-dithiol-2-one（DDO）作为新型添加剂，以增强NCM811 / Li ⁺的循环性能和倍率容量半格。电化学测试表明，使用0.1 wt％含DDO的电解液进行200次循环后，电池的放电容量保持率为75.59％，而带有空白电解液的电解液仅为15.11％。DDO为0.1 wt％时的初始库仑效率和速率容量要高于空白值。通过扫描电子显微镜（SEM）分析，NCM811的颗粒在第50次循环后是光滑且完整的，而该颗粒则在空白电解液中破裂。NCM811出色的电化学性能归因于DDO形成的稳定且均匀的阴极电解质中间相（CEI）膜。此外，X射线光电子能谱（XPS）显示DDO可以防止NCM811的碳酸盐溶剂分解和镍元素溶解。