Self-templating preparation and electrochemical performance of LiMnPO4 hollow microspheres
Self-templating preparation and electrochemical performance of LiMnPO4 hollow microspheres
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LiMnPO4空心微球的自模板制备及其电化学性能
DOI：
10.1016/j.jallcom.2018.12.348
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发表时间：
2019-04-30
影响因子：
6.2
通讯作者：
Yi, Rongxi
中科院分区：
文献类型：
--
作者：
Pan, Xiaoliang;Gao, Zhi;Yi, Rongxi
由纳米粒子制成的空心微球由于其振实密度高、Li+扩散长度短和良好的循环稳定性而被认为是储能装置中最具吸引力的结构之一。然而，很难完全评估控制空心微球参数（例如其结构和尺寸）的有效性。这是由于所应用的处理的不利影响，特别是在用于能量存储的锂基微球的情况下。在本研究中，使用沉淀的 Li3PO4 空心微球作为牺牲模板，通过简便的溶剂热法合成了具有可演化结构（空心、海胆状和蛋黄壳结构）和可调尺寸（600 nm、1.5 μm 和 3 μm）的 LiMnPO4 空心微球。本文根据时间相关实验的观察结果提出了一种可能的形成机制。研究发现添加剂 ((NH4)(2)SO4)、溶剂中二甘醇 (DEG) 与 H2O 的体积比以及 Li3PO4 模板尺寸等工艺参数对产品的最终物相、结构和尺寸有明显影响。与3μm海胆状和600nm空心微球相比，3μm空心微球表现出优异的电化学性能，包括高倍率性能和良好的循环稳定性，这可归因于亚基纳米尺寸和微球稳定结构之间的协同作用。 (C) 2019 Elsevier B.V. 保留所有权利。
Hollow microspheres fabricated from nanoparticles are considered as one of the most attractive architectures for energy storage devices owing to their high tap density, short Li+ diffusion length, and good cycling stability. It is, however, difficult to fully assess the effectiveness of controlling the parameters of hollow microspheres, such as their structure and size. This is due to the adverse effects of the applied treatments, especially in the case of lithium-based microspheres used for energy storage. In the present study, LiMnPO4 hollow microspheres with evolvable structures (hollow, urchin-like, and yolk-shell architectures) and tuneable sizes (600 nm, 1.5 mu m, and 3 mu m) were synthesised via a facile solvothermal process using precipitated Li3PO4 hollow microspheres as the sacrificial templates. A possible formation mechanism is proposed in this paper based on observations from time-dependent experiments. The process parameters such as the additive ((NH4)(2)SO4), diethylene glycol (DEG)-to-H2O volume ratio of the solvent, and Li3PO4 template size were found to distinctly impact the final phase, structure, and size of the products. Compared with the 3-mu m urchin-like and 600-nm hollow microspheres, the 3-mu m hollow microspheres exhibited excellent electrochemical properties including a high rate capability and good cycling stability, which can be attributed to the synergy between the nano-size of the subunits and the stable structure of the microspheres. (C) 2019 Elsevier B.V. All rights reserved.