Li-rich layered oxides are the most promising cathode candidate for lithium ion batteries with high specific energy. In this work, Li_1.13Mn_0.47Ni_0.2Co_0.2O₂-coated Li [Li_0.2Mn_0.52Ni_0.13Co_0.13 V_0.02]O₂ cathode materials were synthesized via a sol–gel method, and their electrochemical performance was evaluated. Structural and morphological characterizations of the materials demonstrate that Li[Li_0.2Mn_0.52Ni_0.13Co_0.13V_0.02]O₂ particles are covered by Li_1.13Mn_0.47Ni_0.2Co_0.2O₂ particles. Moreover, the Li_1.13Mn_0.47Ni_0.2Co_0.2O₂ coating has no obvious effect on the crystal structure of Li-rich materials. The specific capacity, cycle performance, and rate capability of Li-rich materials are significantly improved with the coating of Li_1.13Mn_0.47Ni_0.2Co_0.2O₂. Materials coated with 1 wt% to 3 wt% Li_1.13Mn_0.47Ni_0.2Co_0.2O₂ exhibit the highest capacity retention of 93% after 100 cycles at 1 C, which is 10% higher than that of the uncoated one. The specific capacity of 3 wt% Li_1.13Mn_0.47Ni_0.2Co_0.2O₂-coated material is 115.9 mAh g⁻¹ at 5 C, and that of the blank sample is 89.8 mAh g⁻¹ under the same condition. The cyclic voltammetry and electrochemical impedance spectra reveal that the enhanced cycle performance and rate capability of the surface-modified Li-rich materials are due to the presence of the Li_1.13Mn_0.47Ni_0.2Co_0.2O₂ coating layer, which restrains structural transformation with cycling and decreases the charge-transfer resistance of the materials.

中文翻译：

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Li 1.13 Mn 0.47 Ni 0.2 Co 0.2 O 2涂层增强了锂离子电池正极材料的富Li [Li 0.2 Mn 0.52 Ni 0.13 Co 0.13 V 0.02] O 2正极材料的电化学性能

富含锂的层状氧化物是具有高比能的锂离子电池最有希望的阴极候选材料。在这项工作中，通过溶胶-凝胶法合成了Li _1.13 Mn _0.47 Ni _0.2 Co _0.2 O ₂包覆的Li [Li _0.2 Mn _0.52 Ni _0.13 Co _0.13  V _0.02 ] O ₂正极材料，并评估了它们的电化学性能。材料的结构和形态表征表明，Li [Li _0.2 Mn _0.52 Ni _0.13 Co _0.13 V _0.02 ] O_2个颗粒通过李覆盖_1.13锰_0.47镍_0.2钴_0.2 Ò ₂颗粒。此外，Li _1.13 Mn _0.47 Ni _0.2 Co _0.2 O ₂涂层对富锂材料的晶体结构没有明显影响。使用Li _1.13 Mn _0.47 Ni _0.2 Co _0.2 O ₂涂层可以显着提高富Li材料的比容量，循环性能和倍率性能。涂有1wt％至3wt％Li _1.13 Mn _0.47 Ni的材料_0.2 Co _0.2 O ₂在1 C下进行100次循环后，显示出最高的容量保持率，为93％，比未镀膜的高出10％。3wt％的Li _1.13 Mn _0.47 Ni _0.2 Co _0.2 O ₂包覆材料的比容量在5℃下为115.9 mAh g ^-1，空白样品在相同条件下的比容量为89.8 mAh g ^-1。循环伏安法和电化学阻抗谱表明，表面改性的富锂材料的增强的循环性能和速率能力是由于存在Li _1.13 Mn _0.47 Ni _0.2 Co_0.2 O ₂涂层，可抑制循环的结构转变并降低材料的电荷转移阻力。