Abstract Secondary(S-NCM) and monocrystalline (M-NCM) LiNi0.5Co0.2Mn0.3O2 cathode materials were prepared via synthesizing Ni-Co-Mn hydroxide precursors following by heat treatment operations. The materials of S-NCM and M-NCM are characterized by various means in order to describe the microstructure in detail, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The results of the physical characterization and electrochemistry measurement identify that the 3-4 μm thick monocrystalline cathode materials exhibit lower cation mixture and avoid the cracks of the particles. Electrochemical performance tests were taken at the various voltage of 3.0–4.3/4.4 V under different temperatures (25 °C and 45 °C) respectively. The electrodes of S-NCM always show higher discharge capacity than that of M-NCM at 0.1–2 C, while the electrochemical performances of M-NCM electrode become better at a high rate (5 C), especially at a high temperature (45 °C). The M-NCM electrode reaches 101.4 mAh g−1 (61.9%, 3.0–4.3 V, 258 cycles), 112.7 mAh g−1 (63.4%, 3.0–4.4 V, 258 cycles), which exhibits better electrochemistry performance than that of S-NCM sample, demonstrating the expected properties of the micron-sized single crystal cathode. In addition, the single crystal cathode materials can alleviate side reactions and keep up the layered structures stability during the charging/discharging process. It is testified that the M-NCM cathode materials are propitious for LIBs with long-life and high-rate, and the S-NCM cathode has better performances at 3C digital products.

中文翻译：

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高性能锂离子电池单晶与二次LiNi0.5Co0.2Mn0.3O2正极材料对比

摘要 通过热处理合成Ni-Co-Mn氢氧化物前驱体，制备了二次(S-NCM)和单晶(M-NCM)LiNi0.5Co0.2Mn0.3O2正极材料。S-NCM 和 M-NCM 的材料通过各种手段进行表征以详细描述微观结构，例如 X 射线衍射 (XRD)、X 射线光电子能谱 (XPS)、扫描电子显微镜 (SEM)、和透射电子显微镜（TEM）。物理表征和电化学测量的结果表明，3-4 μm 厚的单晶正极材料表现出较低的阳离子混合物并避免了颗粒的裂纹。电化学性能测试分别在不同温度（25°C 和 45°C）下在 3.0-4.3/4.4 V 的各种电压下进行。S-NCM 的电极在 0.1-2 C 时总是表现出比 M-NCM 更高的放电容量，而 M-NCM 电极的电化学性能在高倍率（5 C）下变得更好，特别是在高温（45 ℃）。M-NCM 电极达到 101.4 mAh g-1（61.9%，3.0-4.3 V，258 次循环），112.7 mAh g-1（63.4%，3.0-4.4 V，258 次循环），其电化学性能优于S-NCM 样品，展示了微米级单晶阴极的预期特性。此外，单晶正极材料在充放电过程中可以减轻副反应并保持层状结构的稳定性。证明M-NCM正极材料有利于长寿命、高倍率的LIBs，S-NCM正极在3C数码产品中具有更好的性能。