采用机械研磨和固相烧结制备高电压的镍锰酸锂材料 (LNMO),并包覆氧化铝 (AO)、钛酸锂 (LTO)、氧化锆 (ZO)来改善材料的充放电倍率和循环性能,并通过扫描电子显微镜 (SEM)和激光颗粒粒度分析检测材料的微观形貌和宏观颗粒。结果表明:钛酸锂包覆改性的镍锰酸锂样品LNMO/LTO颗粒表面光滑,呈现为多面体形状,结晶度更好。包覆改性处理后的LNMO/AO、LNMO/ZO和LNMO/LTO在大倍率2C时的放电比容量有显著提高,相应的放电比容量分别为72mAh/g、95mAh/g和72mAh/g,均高于初始样品LNMO的51mAh/g。氧化锆包覆改性的LNMO/ZO材料的电荷转移阻抗显著降低,为404Ω,初始LNMO的电荷转移阻抗为1851Ω,可能是材料电化学性能得以改善的原因之一。

High-voltage lithium nickel manganate material LNMO was prepared by mechanical grinding and solid phase sintering,and coated with alumina AO,lithium titanate LTO,zirconia ZO to improve the material's rate and cycle performance.Scanning electron microscopy (SEM) and laser particle size analysis were used to detect the microscopic morphology and macroscopic particles of the material.The results shown that the particle morphology of LNMO/LTO sample modified by lithium titanate was significantly changed.The surface of the particle was smooth and appeared as a polyhedral shape with better crystallinity.The LNMO/AO,LNMO/ZO and LNMO/LTO had a significant increase in the discharge specific capacity at a large rate of 2C,and the corresponding discharge specific capacities were 72mAh/g,95mAh/g and 72mAh/g,respectively,both higher than 51mAh/g of the initial sample LNMO.The charge transfer resistance of the LNMO/ZO was significantly reduced to 404Ω,and the charge transfer resistance of the initial LNMO was 1851Ω,which may be one of the reasons for the improved electrochemical performance of the material.