A Flexible Nanocomposite Film of Electrochemically Exfoliated Graphene @ Ti₃CNT_x for Supercapacitors with high Volumetric Capacitance

Abstract

Interest in developing electrodes for flexible supercapacitors for wearable and portable electronic devices is rising. 2D interfacial heterostructures have garnered significant attention due to their robust structural integrity and excellent electrochemical compatibility. This work demonstrates an innovative and novel electrode combining Ti3CNTx and Nitrogen-doped electrochemically exfoliated graphene (N-EEG) for flexible supercapacitors, effectively mitigating self-restacking and enabling enhanced diffusion of electrolyte ions to electroactive sites. The maximum volumetric capacitance of 331 F cm–3 (at a current density of 1 mA cm–2) was achieved with an optimized ratio of N-EEG to Ti3CNTx, surpassing some reported graphene- or MXene-based supercapacitors. This hybrid electrode retained 93% capacitance after 10 000 charge–discharge cycles, highlighting its durability. A symmetric supercapacitor exhibited a volumetric capacitance of 155 F cm–3 and good stability with ∼100% retention after 10 000 cycles. Such a remarkable performance underscores the potential of the N-EEG@Ti3CNTx nanocomposite for the development of supercapacitors.