Intercalation and delamination behavior of Ti3C2Tx and MnO2/Ti3C2Tx/RGO flexible fibers with high volumetric capacitance
Intercalation and delamination behavior of Ti3C2Tx and MnO2/Ti3C2Tx/RGO flexible fibers with high volumetric capacitance
复制标题
具有高体积电容的 Ti3C2TX 和 MnO2/Ti3C2TX/RGO 柔性纤维的插层和分层行为
DOI：
10.1039/c9ta01993f
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发表时间：
2019
影响因子：
11.9
通讯作者：
Liu Zong-Huai
中科院分区：
文献类型：
--
作者：
Lu Meng;Zhang Zhiyan;Kang Liping;He Xuexia;Li Qi;Sun Jie;Jiang Ruibin;Xu Hua;Shi Feng;Lei Zhibin;Liu Zong-Huai
用不同链长的烷基氢氧化铵(TAAOH)系统地研究了Ti3C2Tx的插层和分层过程。TAA+离子对Ti3C2Tx纳米片材的插层反应起着关键作用，不同阶段TAA+插层Ti3C2Tx的层间距和晶相与插层的TAA+离子的大小密切相关，并且它们几乎不受Ti3C2Tx每摩尔TAAOH摩尔当量的加入和干燥条件的影响。此外，插层过程非常迅速，仅需4h即可完成插层。TAA+插层的Ti3C2Tx可以通过握手或反复洗涤的方法脱层成Ti3C2Tx纳米片。将石墨烯氧化物纳米片悬浮液引入Ti3C2Tx纳米片悬浮液中，采用湿法纺丝法制备了Ti3C2Tx/RGO纤维，然后在HI/CH3COOH溶液中还原Ti3C2Tx/GO纤维。然后在室温下将Ti3C2Tx/RGO纤维浸泡在不同浓度的KMnO4溶液中，制得具有良好柔韧性和电容的MnO2/Ti3C2Tx/RGO三元混杂纤维。MnO2/Ti3C2Tx/RGO三元杂化光纤电极在1MNa2SO4电解液中的体积电容最大，达到851F cm−3，且具有良好的柔韧性。将这两个光纤电极扭转在一起，组装成PVA-LiCl凝胶电解质全固态对称MnO2/Ti3C2Tx/RGO//MnO2/Ti3C2Tx/RGO光纤超级电容器。它不仅表现出24F cm−3的体积电容和10 000次循环后92%的循环稳定性，而且还表现出优异的柔韧性和力学性能，其中体积电容在90°1000次弯曲后没有明显变化。此外，组装的对称型超级电容器在体积功率密度为8.16 mW cm−3时的最大体积能量密度为2.13 mW h cm−3。这将为具有良好能量密度和柔韧性的新型可穿戴式储能装置开辟新的应用领域。
The intercalation and delamination processes of Ti3C2Tx are systematically investigated by using alkylammonium hydroxides (TAAOH) with different chain lengths. TAA+ cations have a key function for the intercalation reaction of Ti3C2Tx nanosheets, and the basal spacing and the crystal phase of TAA+-intercalated Ti3C2Tx at different stages are closely related to the size of the intercalated TAA+ ions, and they are hardly changed with the addition of molar equivalents of TAAOH per mole of Ti3C2Tx and the drying conditions. Moreover, the intercalation process is very rapid and it can be carried out by just 4 h treatment. TAA+-intercalated Ti3C2Tx can be delaminated into Ti3C2Tx nanosheets by hand shaking or repeated washing. By introducing a graphene oxide nanosheet suspension into the Ti3C2Tx nanosheet suspension, Ti3C2Tx/RGO fibers are firstly prepared by a wet-spinning method followed by reducing Ti3C2Tx/GO fibers in HI/CH3COOH solution. Then the Ti3C2Tx/RGO fiber is soaked in KMnO4 solution with different concentrations at room temperature, and a MnO2/Ti3C2Tx/RGO ternary hybrid fiber with good flexibility and capacitance is prepared. The MnO2/Ti3C2Tx/RGO ternary hybrid fiber electrode shows the largest volumetric capacitance of 851 F cm−3 in 1 M Na2SO4 electrolyte and good flexibility. By twisting two of these fiber electrodes together, an all-solid-state symmetric MnO2/Ti3C2Tx/RGO//MnO2/Ti3C2Tx/RGO fiber supercapacitor with PVA–LiCl gel electrolyte is assembled. It not only exhibits a volumetric capacitance of 24 F cm−3 and superior cycle stability of 92% after 10 000 cycles, but also shows outstanding flexibility and mechanical properties in which the volumetric capacitance has no obvious change after bending the supercapacitor at 90° 1000 times. Furthermore, the assembled symmetric supercapacitor shows the maximum volumetric energy density of 2.13 mW h cm−3 at a volumetric power density of 8.16 mW cm−3. This work will open a new application field of Ti3C2Tx-based fibers for new wearable energy storage devices with good energy density and flexibility.