Doping Ti3C2Tx with Sn to enhance the stability of electrode for supercapacitor

Abstract

The chemical instability and self-restacking have become major hurdle to the practical application of Ti3C2Tx although it is considered to be the promising candidates for energy storage. Herein, one-step process is developed to increase the stability and inhibit the self-agglomeration of Ti3C2Tx by using SnCl2 in ethanol to intercalate Ti3C2Tx. Characterization results demonstrate that Sn has doped into Ti3C2Tx (termed Ti3C2Tx-Sn). The obtained Ti3C2Tx-Sn shows an enlarged interlayer spacing to facilitate the rapid diffusion of electrolyte ions, and improve the stability by reducing its oxidation rate. In 1.0 M H2SO4 solution, the optimal Ti3C2Tx-Sn sample (labelled as Ti3C2Tx-Sn-2) can retain 93.5 % of its initial capacitance after 10,000 cycles, but Ti3C2Tx electrode only 51.2 %. Especially, after storage for 120 days in a refrigerator at −18 °C, the Ti3C2Tx-Sn-2 sample still exhibits excellent cycle stability (84.6 % capacitive retention after 10,000 cycles) while Ti3C2Tx sample remains negligible capacitance retention (only 2.7 % of its initial capacitance). It is believed that this work provides a simple and mild strategy to prepare high-stability Ti3C2Tx-based electrodes for energy storage.