Enhancing Charge Storage in Ti3c2tx Mxene Through Manganese Ion Implantation: Towards High-Energy-Density Supercapacitors

Abstract

Ti3C2Tx MXene has attracted considerable attention as a negative electrode material for supercapacitors due to its high metallic conductivity, multiple surface terminations and suitable potential range. However, the susceptibility to interlayer restacking and the attachment of inactive -F terminations limit their practical application of Ti3C2Tx in high-performance supercapacitors. Herein, a Mn2+ ions implantation strategy was employed to regulate the interlayer environment and modify surface chemistry of Ti3C2Tx. By integrating alkali pretreatment, Mn2+ ions exchange, and annealing treatment, the resultant annealed Mn-implanted Ti3C2Tx (a-Ti3C2Tx-Mn) film exhibits a remarkable specific capacitance of 401 F g-1 at 1 A g-1, surpassing pristine Ti3C2Tx by 1.5 times, while retaining 82.3% capacitance retention at 20 A g-1. The assembled asymmetric supercapacitor (a-Ti3C2Tx-Mn//RuO2/SWCNT) delivers a high energy density of 23.1 Wh kg-1 and power density of 12.6 kW kg-1. This work provides a scalable approach to engineer MXene-based negative electrodes for high-energy-density supercapacitors.

Keywords: Supercapacitors, Negative electrode, Ti3C2Tx nanosheets, Mn2+ ions implantation