One-pot synthesis and multifunctional surface modification of lithium-rich manganese-based cathode for enhanced structural stability and low-temperature performance.
One-pot synthesis and multifunctional surface modification of lithium-rich manganese-based cathode for enhanced structural stability and low-temperature performance.
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DOI：
10.1016/j.jcis.2022.01.176
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发表时间：
2022-01
影响因子：
9.9
通讯作者：
Cheng-guo Shen;Yiqian Liu;Wenrong Li;Xiaoyu Liu;Jingwei Xie;Jinlong Jiang;Yong Jiang;B. Zhao;Jiujun Zhang
中科院分区：
文献类型：
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作者：
Cheng-guo Shen;Yiqian Liu;Wenrong Li;Xiaoyu Liu;Jingwei Xie;Jinlong Jiang;Yong Jiang;B. Zhao;Jiujun Zhang
高能量密度富锂Li1.2Ni0.13Co0.13Mn0.54O2被认为是最有前途的锂离子电池正极材料之一。但其临界动力学缺陷和低温电化学性能差限制了其实际应用。采用一锅法溶胶-凝胶法制备了表面包覆有Li 7 La 3 Zr 2 O 12（LLZO）层的La/Zr共掺杂的Li1.2Ni0.13Co0.13Mn0.54O2亚微米粉体。几个纳米的涂层LLZO层能够为相邻颗粒建立快速的锂离子传输通道，并抑制活性材料和电解质之间的严重副反应。此外，大半径La/Zr阳离子共掺杂可以拓宽锂离子的扩散路径，阻碍有害的结构转变，提高阴极在重复循环过程中的电化学结构稳定性。由于这种多功能表面改性策略的众多优点，改性后的Li 1. 2Ni 0. 13 Co 0. 13 Mn 0. 54 O2复合材料表现出显著降低的界面阻抗，增强的Li+扩散动力学和减轻的相变，以及优异的低温电化学性能。在-10 ℃和-20 ℃时，其比容量分别为173.8 mAh g− 1和134.1 mAh g− 1，显示了富锂正极材料的巨大应用前景。
High-energy–density lithium-rich Li1.2Ni0.13Co0.13Mn0.54O2is regarded as one of the most promising cathode materials for lithium-ion batteries. However, its practical application is restricted by critical kinetics drawbacks and poor low-temperature electrochemical performances. In this research, Li1.2Ni0.13Co0.13Mn0.54O2submicron particles coated by a Li7La3Zr2O12(LLZO) layer and co-doped by La/Zr cations has been fabricated via a facile one-pot sol–gel technique and subsequent heat treatment. The coating LLZO layer with a few nanometers is able to build a rapid lithium-ion transport channel for adjacent particles and suppress severe side reactions between active material and the electrolyte. Moreover, large-radius La/Zr cations co-doping can broaden the diffusion paths of lithium ions, hinder the detrimental structural transformation, and improve the electrochemical structure stability of the cathode during repeated cycles. Owing to numerous merits from this multifunctional surface modification strategy, the modified Li1.2Ni0.13Co0.13Mn0.54O2composite exhibits the significantly decreased interface impedance, enhanced Li+diffusion kinetics and mitigated phase transformation, as well as excellent low-temperature electrochemical performance. It can contribute ultrahigh capacities of 173.8 mAh g−1at −10 ℃ and 134.1 mAh g−1at −20 ℃, respectively, displaying great application prospects of Li-rich cathode materials.