Formation and Effect of Residual Lithium Compounds on Li-Rich Cathode Material Li-1.35[Ni0.35Mn0.65]O-2
Formation and Effect of Residual Lithium Compounds on Li-Rich Cathode Material Li-1.35[Ni0.35Mn0.65]O-2
复制标题
富锂正极材料Li-1.35[Ni0.35Mn0.65]O-2中残留锂化合物的形成及其影响
DOI：
10.1021/acsami.9b01806
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发表时间：
2019
影响因子：
9.5
通讯作者：
Zheng Jun-chao
中科院分区：
文献类型：
--
作者：
Zhou Chun-xian;Wang Peng-bo;Zhang Bao;Tang Lin-bo;Tong Hui;He Zhen-jiang;Zheng Jun-chao
富锂正极材料因其优异的电化学容量而被认为是理想的正极材料。然而，通过与环境气氛中的水分和二氧化碳反应而在材料表面上形成的残余锂化合物会损害表面结构，损害容量，并阻碍使用富锂材料的电极制造。暴露于空气中会导致残留锂化合物的形成;此类化合物的形成被认为与处理和储存期间的湿度、温度和时间有关。在这项研究中，我们首次展示了一种控制时间、温度和湿度以加速暴露的人工策略。系统研究了富锂正极材料Li 1. 35 [Ni 0. 35 Mn 0. 65] O2中残余锂化合物的形成及其影响。所形成的残余锂化合物主要具有无定形结构，并且部分地涂覆在表面上。这些化合物包括LiOH、Li 2 O和Li 2CO 3。Li 2CO 3是残余锂化合物的主要成分。材料表面残留锂化合物的存在导致了高的放电容量损失和大的放电电压衰减。了解残余锂化合物的形成和抑制其影响将有助于防止其不利影响并改善电化学性能。
Li-rich cathode materials are regarded as ideal cathode materials, owing to their excellent electrochemical capacity. However, residual lithium compounds, which are formed on the surface of the materials by reacting with moisture and carbon dioxide in ambient atmosphere, can impair the surface structure, injure the capacity, and impede the electrode fabrication using Li-rich materials. Exposure to air atmosphere causes the formation of residual lithium compounds; the formation of such compounds is believed to be related to humidity, temperature, and time during handling and storage. In this study, we demonstrated for the first time an artificial strategy for controlling time, temperature, and humidity to accelerate exposure. The formation and effect of residual lithium compounds on Li-rich cathode material Li1.35[Ni0.35Mn0.65]O2were systematically investigated. The residual lithium compounds formed possessed primarily an amorphous structure and were partially coated on the surface. These compounds include LiOH, Li2O, and Li2CO3. Li2CO3is the major component in residual lithium compounds. The presence of residual lithium compounds on the material surface led to a high discharge capacity loss and large discharge voltage fading. Understanding the formation and suppressing the effect of residual lithium compounds will help prevent their unfavorable effects and improve the electrochemical performance.