TiO2‐Coated Interlayer‐Expanded MoSe2/Phosphorus‐Doped Carbon Nanospheres for Ultrafast and Ultralong Cycling Sodium Storage
TiO2‐Coated Interlayer‐Expanded MoSe2/Phosphorus‐Doped Carbon Nanospheres for Ultrafast and Ultralong Cycling Sodium Storage
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DOI：
10.1002/advs.201801222
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发表时间：
2018-11
期刊：
影响因子：
15.1
通讯作者：
Yuyu Wang;Yun-Xia Wang;Wenpei Kang;Dongwei Cao;Chenxu Li;Dongxu Cao;Zixi Kang;Daofeng Sun;
中科院分区：
文献类型：
--
作者：
Yuyu Wang;Yun-Xia Wang;Wenpei Kang;Dongwei Cao;Chenxu Li;Dongxu Cao;Zixi Kang;Daofeng Sun;
基于多电子转换反应，层状过渡金属二硫属化物被认为是用于钠离子电池的有前景的电极材料，但由于其低固有电导率和严重的体积变化而具有差的循环性能和倍率性能。在这里，层间扩展的MoSe 2/磷掺杂的碳杂化纳米球包覆的TiO 2（表示为MoSe 2/P-C @ TiO 2）通过简单的水解反应制备，其中TiO 2包覆的聚吡咯-磷钼酸被用作一种新的前体，随后通过硒化过程。得益于MoSe 2、磷掺杂碳和TiO 2的协同效应，混合纳米球表现出前所未有的循环稳定性和超快赝电容钠存储能力。MoSe 2/P-C @ TiO 2在5.0 A g−1下8000次循环的可逆容量为214 mAh g − 1，在10.0 A g−1下10000次循环的可逆容量为154 mAh g−1，以及在0.5-3.0 V电压范围内高达20.0 A g− 1的卓越倍率容量，容量为175 mAh g−1。全电池成功地证实了在0.5A g-1下100次循环的242.2mAh g-1的可逆容量，库仑效率超过99%。
Based on multielectron conversion reactions, layered transition metal dichalcogenides are considered promising electrode materials for sodium‐ion batteries, but suffer from poor cycling performance and rate capability due to their low intrinsic conductivity and severe volume variations. Here, interlayer‐expanded MoSe2/phosphorus‐doped carbon hybrid nanospheres coated by anatase TiO2 (denoted as MoSe2/P‐C@TiO2) are prepared by a facile hydrolysis reaction, in which TiO2 coating polypyrrole‐phosphomolybdic acid is utilized as a novel precursor followed by a selenization process. Benefiting from synergistic effects of MoSe2, phosphorus‐doped carbon, and TiO2, the hybrid nanospheres manifest unprecedented cycling stability and ultrafast pseudocapacitive sodium storage capability. The MoSe2/P‐C@TiO2 delivers decent reversible capacities of 214 mAh g−1 at 5.0 A g−1 for 8000 cycles, 154 mAh g−1 at 10.0 A g−1 for 10000 cycles, and an exceptional rate capability up to 20.0 A g−1 with a capacity of ≈175 mAh g−1 in a voltage range of 0.5–3.0 V. Coupled with a Na3V2(PO4)3@C cathode, a full cell successfully confirms a reversible capacity of 242.2 mAh g−1 at 0.5 A g−1 for 100 cycles with a coulombic efficiency over 99%.