Conductive and highly compressible MXene aerogels with ordered microstructures as high-capacity electrodes for Li-ion capacitors
Conductive and highly compressible MXene aerogels with ordered microstructures as high-capacity electrodes for Li-ion capacitors
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DOI：
10.1016/j.mtadv.2021.100135
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
J. Orangi;H. Tetik;P. Parandoush;E. Kayali;D. Lin;M. Beidaghi
中科院分区：
文献类型：
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作者：
J. Orangi;H. Tetik;P. Parandoush;E. Kayali;D. Lin;M. Beidaghi
将二维 (2D) 材料组装成功能性三维 (3D) 结构可以使其用于各种应用。对于储能器件，具有高离子和电子传输特性以及良好机械特性的3D电极有望促进下一代高能量和功率密度器件的制造。在此，我们报告了一种基于单向冷冻铸造的简单、高效且可扩展的工艺，用于从 2D Ti3C2TxMXene 薄片制造有序和多孔 3D 气凝胶。所制备的气凝胶表现出优异的机械、电气和电化学性能。我们的研究表明，加工条件显着影响 MXene 气凝胶的性能。制造的气凝胶的电导率和机械性能与其结构特征直接相关。机械测试结果表明，具有有序结构的MXene气凝胶在恢复到原始形状之前可以承受近50%的应变，并在连续压缩循环过程中保持其导电性。作为锂离子电容器的电极材料，所制备的气凝胶具有极高的比容量（0.05 A/g 时~1210 mAh/g）、优异的倍率性能（10 A/g 时~200 mAh/g）和出色的循环性能。我们相信，具有有序结构的 MXene 气凝胶具有广泛的应用前景，包括储能设备和应变传感器。
Assembling two-dimensional (2D) materials into functional three-dimensional (3D) structures can enable their use in a wide variety of applications. For energy storage devices, 3D electrodes with high ionic and electronic transport properties and decent mechanical properties are expected to prompt the fabrication of the next generations of devices with high energy and power densities. Herein, we report a simple, efficient, and scalable process based on unidirectional freeze casting to fabricate ordered and porous 3D aerogels from 2D Ti3C2TxMXene flakes. The fabricated aerogels show excellent mechanical, electrical, and electrochemical properties. Our studies show that the processing conditions significantly affect the properties of MXene aerogels. The electrical conductivity and mechanical properties of fabricated aerogels directly correlate with their structural features. The mechanical test results showed that MXene aerogels with ordered structures could withstand almost 50% of strain before recovering to their original shape and maintain their electrical conductivities during continuous compressive cycling. As electrode materials for lithium-ion capacitors, the fabricated aerogels delivered a significantly high specific capacity (~1210 mAh/g at 0.05 A/g), excellent rate capability (~200 mAh/g at 10 A/g), and outstanding cycling performance. We believe that the MXene aerogels with ordered structures have promising properties for a broad range of applications, including energy storage devices and strain sensors.