Mesocrystalline effect in a NiTiO<sub>3</sub>/TiO<sub>2</sub> nanocomposite for enhanced capacity of lithium-ion battery anodes
Mesocrystalline effect in a NiTiO<sub>3</sub>/TiO<sub>2</sub> nanocomposite for enhanced capacity of lithium-ion battery anodes
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NiTiO<sub>3</sub>/TiO<sub>2</sub>纳米复合材料的介晶效应增强锂离子电池负极容量
DOI：
10.1039/d1qi01501j
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发表时间：
2022
影响因子：
7
通讯作者：
Feng Qi
中科院分区：
文献类型：
--
作者：
Wang Xing;Cheng Weijie;Hu Jiaqiao;Su Ying;Kong Xingang;Uemura Shinobi;Kusunose Takafumi;Feng Qi
H2O2 改性的层状钛酸酯 H1.07Ti1.73O4 (H2O2-HTO) 是拓扑化学合成的优异前体，但其剥离反应尚不清楚。在此，我们首次报道了 H2O2-HTO 的剥离反应以及 H2O2-HTO 及其纳米片在合成 NiTiO3/TiO2 纳米复合材料作为锂离子电池（LIB）负极材料中的应用。 H2O2-HTO 层间空间中的 H2O2 可以增强离子交换能力和剥离反应动力学。通过与Ni2+溶液反应，H2O2-HTO纳米片组装成HTO/Ni(OH)2三明治层状结构，通过热处理可转化为具有片状形貌和高NiTiO3含量的多晶NiTiO3/TiO2纳米复合材料。通过对 Ni2+ 交换的 H2O2-HTO 进行热处理，获得了具有片状形貌的介晶 NiTiO3/TiO2 纳米复合材料。电化学结果表明，这些 NiTiO3/TiO2 纳米复合材料作为锂离子电池负极材料，表现出 TiO2 和 NiTiO3 的协同效应，可增强可逆放电-充电比容量。此外，由于Li+在介晶纳米复合材料中的快速迁移，即介晶效应，介晶NiTiO3/TiO2纳米复合材料中的NiTiO3纳米晶表现出比多晶材料大得多的容量。
A H2O2-modified layered titanate H1.07Ti1.73O4 (H2O2-HTO) is an excellent precursor for topochemical synthesis but its exfoliation reaction is unclear. Herein, we report the first study on the exfoliation reaction of H2O2-HTO and applications of H2O2-HTO and its nanosheets in the synthesis of NiTiO3/TiO2 nanocomposites as anode materials for lithium-ion batteries (LIBs). H2O2 in the interlayer space of H2O2-HTO can enhance ion-exchange capacity and exfoliation reaction kinetics. By reaction with Ni2+ solution, H2O2-HTO nanosheets were assembled into a HTO/Ni(OH)2 sandwich layered structure which could be transformed into a polycrystalline NiTiO3/TiO2 nanocomposite with a sheetlike morphology and high NiTiO3 content by heat-treatment. A mesocrystalline NiTiO3/TiO2 nanocomposite with a plate-like morphology was obtained by heat-treatment of a Ni2+-exchanged H2O2-HTO. The electrochemical results suggested that these NiTiO3/TiO2 nanocomposites exhibit a synergistic effect of TiO2 and NiTiO3 for the enhanced reversible discharge–charge specific capacity as anode materials for LIBs. Furthermore, the NiTiO3 nanocrystals in the mesocrystalline NiTiO3/TiO2 nanocomposite show a much larger capacity than those in the polycrystalline one due to the fast passage for the Li+ migration in the mesocrystalline nanocomposite, namely the mesocrystalline effect.