Wang Wenqing, He Shu-Ang, Cui Zhe, Liu Qian, Yuen Muk Fung, Zhu Jinqi, Wang Hao, Gao Mengluan, Luo Wei, Hu Junqing, Zou Rujia
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, International Joint Laboratory for Advanced Fiber and Low-dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, P. R. China.
College of Science, Donghua University, Shanghai, 201620, P. R. China.
Small. 2022 Oct;18(41):e2203948. doi: 10.1002/smll.202203948. Epub 2022 Sep 9.
The poor conductivity, inert charge transmission efficiency, and irreversible Na trapping of Na Ti O result in retardant electrons/ions transportation and deficient sodium-ion storage efficiency, leading to sluggish reaction kinetics. To address these issues, an urchin-like Ti CT /Na Ti O (Ti C/NTO) heterostructure sphere consisting of Ti C/NTO heterostructure nanobelts array is developed via a facile one-step in situ hydrothermal strategy. The Ti C/NTO heterostructure can obviously decrease Na diffusion barriers and increase electronic conductivity to improve reaction kinetics due to the built-in electric field effect and high-quantity interface region. In addition, the urchin-like vertically aligned nanobelts can reduce the diffusion distance of electrons and ions, provide favored electrolyte infiltration, adapt large volume expansion, and mitigate the aggregation to maintain structural stability during cycles, further enhancing the reaction kinetics. Furthermore, the Ti C/NTO heterostructure can effectively suppress many unwanted side reactions between reactive surface sites of NTO and electrolyte as well as irreversible trapping of Na . As a result, systematic electrochemical investigations demonstrate that the Ti C/NTO heterostructure as an anode material for record sodium-ion storage delivers the highest reversible capacity, the best cycling stability with 0.0065% decay rate for 4500 cycles at 2.0 A g , and excellent rate capability of 172.1 mAh g at 10.0 A g .
NaTi₂O₅的低导电性、惰性电荷传输效率和不可逆的Na捕获导致电子/离子传输迟缓以及钠离子存储效率低下，从而使反应动力学缓慢。为了解决这些问题，通过简便的一步原位水热策略制备了一种由Ti₂C/NTO异质结构纳米带阵列组成的海胆状Ti₂C/NaTi₂O₅（Ti₂C/NTO）异质结构球体。由于内置电场效应和大量界面区域，Ti₂C/NTO异质结构可以显著降低Na扩散势垒并提高电子导电性，从而改善反应动力学。此外，海胆状垂直排列的纳米带可以缩短电子和离子的扩散距离，提供良好的电解质浸润性，适应大体积膨胀，并减轻聚集以在循环过程中保持结构稳定性，进一步增强反应动力学。此外，Ti₂C/NTO异质结构可以有效抑制NTO活性表面位点与电解质之间的许多不必要的副反应以及Na的不可逆捕获。结果，系统的电化学研究表明，Ti₂C/NTO异质结构作为用于钠离子存储的阳极材料，具有最高的可逆容量、最佳的循环稳定性，在2.0 A g⁻¹下4500次循环的衰减率为0.0065%，以及在10.0 A g⁻¹下172.1 mAh g⁻¹的优异倍率性能。
