Poly(o-phenylenediamine)-Decorated V4C3Tx MXene/Poly(o-phenylenediamine) Blends as Electrode Materials to Boost Storage Capacity for Supercapacitors and Lithium-Ion Batteries

Two-dimensional transition-metal carbides/nitrides (MXenes), as pseudocapacitor materials, have attracted extensive attention in the field of energy storage in recent years. However, the MXene surface is prone to oxidation and their layered structure is easy to stack, which limit their practical application. Here, we propose a facile and cost-effective strategy to fabricate a blend of poly(o-phenylenediamine) (PoPD)-decorated vanadium carbide MXene (N–V4C3Tx) and PoPD as electrode materials to boost the storage capacity for supercapacitors and lithium-ion batteries. N–V4C3Tx nanosheets and PoPD nanoparticles were prepared by in situ oxidant-free polymerization and redox methods, respectively. The electrochemical performance of the blend shows that the introduction of PoPD nanoparticles can effectively improve the specific capacitance of N–V4C3Tx. The N–V4C3Tx/PoPD electrode exhibits excellent specific capacitance of up to 676.5 F g–1 at 1 A g–1 for supercapacitor application. Compared with the V4C3Tx-based device (276.3 F g–1), the capacitance reaches up to 2.48 times enhancement. In addition, the N–V4C3Tx/PoPD electrode also presents satisfactory cyclic stability, and the retention rate can remain unchanged after 10,000 cycles. As the electrode material for lithium-ion batteries, it also shows a high capacity of 561.2 mA h g–1 at 0.1 A g–1, excellent rate performance, and cyclic stability. Our work broadens the application of MXenes and conductive polymers as electrode materials in the field of energy storage and offers a simple and effective strategy to improve the capacity and stability of the pristine MXene.