Enhanced Rate Capability of Ion-Accessible Ti3C2Tx-NbN Hybrid Electrodes

Although 2D Ti(3)C(2)T(x)is a good candidate for supercapacitors, the restacking of nanosheets hinders the ion transport significantly at high scan rates, especially under practical mass loading (>10 mg cm(-2)) and thickness (tens of microns). Here, Ti3C2Tx-NbN hybrid film is designed by self-assembling Ti(3)C(2)T(x)with 2D arrays of NbN nanocrystals. Working as an interlayer spacer of Ti3C2Tx, NbN facilitates the ion penetration through its 2D porous structure; even at extremely high scan rates. The hybrid film shows a thickness-independent rate performance (almost the same rate capabilities from 2 to 20 000 mV s(-1)) for 3 and 50 mu m thick electrodes. Even a 109 mu m thick Ti3C2Tx-NbN electrode shows a better rate performance than 25 mu m thick pure Ti(3)C(2)T(x)electrodes. This method may pave a way to controlling ion transport in electrodes composed of 2D conductive materials, which have potential applications in high-rate energy storage and beyond.