Design of well-defined porous Ti2Nb10O29/C microspheres assembled from nanoparticles as anode materials for high-rate lithium ion batteries
Design of well-defined porous Ti2Nb10O29/C microspheres assembled from nanoparticles as anode materials for high-rate lithium ion batteries
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由纳米颗粒组装而成的清晰多孔 Ti2Nb10O29/C 微球作为高倍率锂离子电池负极材料的设计
DOI：
10.1016/j.electacta.2018.09.133
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发表时间：
2018-12-01
影响因子：
6.6
通讯作者：
Ma, Jianmin
中科院分区：
文献类型：
--
作者：
Liu, Xiaodi;Wang, Hui;Ma, Jianmin
采用溶剂热法一锅法合成了结构规整的多孔Ti 2Nb 10 O29/C微球。所制备的Ti 2Nb 10 O29/C微球具有良好的分散性，由相互连接的纳米颗粒组成。Ti 2Nb 10 O29/C微球独特的多孔结构和导电碳的改性可提供大的电极-电解质接触面积，提高Li+扩散系数和电子电导率，赋予其优异的Li+存储性能。Ti 2Nb 10 O29/C多孔微球在1、5、10、20和30 C下的放电容量分别为278.7、239.7、236.8、220.5和208.1 mAh g（-1）。相反，Ti 2Nb 10 O29多孔微球的放电容量可以从278.6 mAh g（-1）迅速降低到140.5 mAh g（-1）（1 vs. 30 C）。最重要的是，Ti 2Nb 10 O29/C微球表现出良好的倍率容量，例如1C时为276.8 mAh g（-1），10 C时为245.6 mAh g（-1），20 C时为226.7 mAh g（-1），30 C时甚至为217.9 mAh g（-1）。由此可以推断，这种优异的速率性能主要是由赝电容效应引起的。在10 C的高电流密度下，经200次循环后，Ti 2Nb 10 O29/C微球的放电容量仍保持在186.7 mAh g（-1），首次循环容量保持率为89.5%。(C)2018爱思唯尔有限公司版权所有
Well-defined porous Ti2Nb10O29/C microspheres have been synthesized by a one-pot solvothermal method. The as-formed Ti2Nb10O29/C microspheres possess good dispersity and are constructed by interconnected nanoparticles. The unique porous microstructure and modification of conduction carbon can provide large electrode-electrolyte contact areas and improve the Li+ diffusion coefficient and electronic conductivity of Ti2Nb10O29/C microspheres, endowing them with excellent Li+ storage properties. Ti2Nb10O29/C porous microspheres can deliver prominent discharge capacity of 278.7, 239.7, 236.8, 220.5 and 208.1 mAh g(-1) at 1, 5, 10, 20, and 30 C, respectively. On the contrary, the discharge capacity of Ti2Nb10O29 porous microspheres can be quickly reduced from 278.6 to 140.5 mAh g(-1) (1 vs. 30C). Most importantly, Ti2Nb10O29/C microspheres display good rate capacity, such as 276.8 mAh g(-1) at 1 C, 245.6 mAh g(-1) at 10 C, 226.7 mAh g(-1) at 20 C, and even 217.9 mAh g(-1) at 30 C. It is deduced that the excellent rate performance is mainly caused by the pseudocapacitive effect. In addition, the discharge capacity of Ti2Nb10O29/C microspheres is retained to 186.7 mAh g(-1) at a high current density of 10 C after 200 cycle, with 89.5% retention of the 1st cycle capacity. (C) 2018 Elsevier Ltd. All rights reserved.