Xu Mengyao, Liang Lin, Qi Jing, Wu Tianli, Zhou Dan, Xiao Zhubing
Henan Key Laboratory of Photovoltaic Materials, Henan University, Kaifeng, 475004, China.
Small. 2021 Apr;17(17):e2007446. doi: 10.1002/smll.202007446. Epub 2021 Mar 17.
The distinguishable physicochemical properties of MXenes render them attractive in electrochemical energy storage. However, the strong tendency to self-restack owing to the van der Waals interactions between the MXene layers incurs a massive decrease in surface area and blocking of ions transfer and electrolytes penetration. Here, in situ generated Ti C T MXene-carbon nanotubes (Ti C T -CNTs) hybrids are reported via low-temperature self-catalyzing growth of CNTs on Ti C T nanosheets without the addition of any catalyst precursors. With combined spectroscopic studies and theoretical calculation results, it is certified that the intralayered Ostwald ripening-induced Ti C T nanomesh structure contributes to the uniform precipitation of ultrafine metal Ti catalysts on Ti C T , thus giving rise to the in situ CNTs formation on the surface of Ti C T with high integrity. Taking advantages of intimate electrolyte penetration, unobstructed 3D Li /e transport, and rich electroactive sites, the Ti C T -CNTs hybrids are confirmed to be ideal 3D scaffolds for accommodating sulfur and regulating the polysulfides conversion for high-loaded lithium-sulfur batteries.
MXenes独特的物理化学性质使其在电化学储能领域颇具吸引力。然而，由于MXene层间的范德华相互作用，其强烈的自堆叠倾向导致表面积大幅减小，离子传输和电解质渗透受阻。在此，通过在TiCT纳米片上低温自催化生长碳纳米管（CNTs），在不添加任何催化剂前驱体的情况下，原位生成了TiCT MXene-碳纳米管（TiCT-CNTs）杂化物。结合光谱研究和理论计算结果，证实层内奥斯特瓦尔德熟化诱导的TiCT纳米网结构有助于超细金属Ti催化剂在TiCT上均匀沉淀，从而在TiCT表面原位形成具有高完整性的CNTs。利用良好的电解质渗透、畅通无阻的三维Li+/e-传输以及丰富的电活性位点，TiCT-CNTs杂化物被证实是用于容纳硫和调节多硫化物转化的高负载锂硫电池的理想三维支架。
