Interlayer‐Tailored MXene@MWCNT Heterostructures Enabling Superior Charge Storage in Aqueous Electrolytes

The intentional design of hybrid nanoarchitectures is crucial for achieving enhanced electrochemical performance in next‐generation energy storage systems. These designs must facilitate rapid ion transport, provide numerous active surface sites, and maintain effective electron‐transfer pathways. In this study, an MXene@MWCNT heterostructure was rationally engineered via a solvothermal strategy to integrate the redox‐active surface chemistry of MXene with the high electrical conductivity and mechanical robustness of multiwalled carbon nanotubes (MWCNT). The structural stability and compositional integrity of the heterostructure were rigorously confirmed by XRD, FESEM, EDS, FTIR, BET, and Raman spectroscopy, which collectively verified effective interfacial coupling without observable phase degradation. Raman spectroscopy revealed an optimized defect–graphitic balance, with an I _D /I _G ratio of 0.99 and a high  I _2D /I _G ratio of 0.97, indicative of abundant electrochemically active sites and well‐preserved conductive domains. Owing to the synergistic contributions of electric double‐layer capacitance and pseudocapacitive charge‐storage mechanisms, the MXene@MWCNT electrode exhibits a high specific capacitance of 232 F g ⁻¹ at 10 mV s ⁻¹ , along with excellent rate performance and cycling stability. These results underscore the effectiveness of interfacial nanoengineering in MXene‐based hybrids and highlight a viable pathway toward high‐performance, sustainable aqueous energy storage systems.