Achieving High Pseudocapacitance of 2D Titanium Carbide (MXene) by Cation Intercalation and Surface Modification |
| |
Authors: | Jian Li Xiaotao Yuan Cong Lin Yanquan Yang Le Xu Xin Du Jinglin Xie Jianhua Lin Junliang Sun |
| |
Institution: | 1. College of Chemistry and Molecular Engineering, Peking University, Beijing, China;2. College of Chemistry and Chemical Engineering, Chongqing University, Shapingba District, Chongqing, China |
| |
Abstract: | Supercapacitors attract great interest because of the increasing and urgent demand for environment‐friendly high‐power energy sources. Ti3C2, a member of MXene family, is a promising electrode material for supercapacitors owing to its excellent chemical and physical properties. However, the highest gravimetric capacitance of the MXene‐based electrodes is still relatively low (245 F g?1) and the key challenge to improve this is to exploit more pseudocapacitance by increasing the active site concentration. Here, a method to significantly improve the gravimetric capacitance of Ti3C2Tx MXenes by cation intercalation and surface modification is reported. After K+ intercalation and terminal groups (OH?/F?) removing , the intercalation pseudocapacitance is three times higher than the pristine MXene, and MXene sheets exhibit a significant enhancement (about 211% of the origin) in the gravimetric capacitance (517 F g?1 at a discharge rate of 1 A g?1). Moreover, the as‐prepared electrodes show above 99% retention over 10 000 cycles. This improved electrochemical performance is attributed to the large interlayer voids of Ti3C2 and lowest terminated surface group concentration. This study demonstrates a new strategy applicable to other MXenes (Ti2CTx , Nb2CTx , etc.) in maximizing their potential applications in energy storage. |
| |
Keywords: | energy storage supercapacitors titanium carbide (MXene) |
|
|