Vertically aligned ZnCo2O4 nanoplates on Ti3C2 for high-efficiency hybrid supercapacitors

Electrode materials exhibiting higher structural stability and electrochemical activity remain a priority in improving the electrochemical performance of supercapacitors (SCs). Herein, we report the design and synthesis of a novel nanoplate-on-nanosheet architecture with vertically aligned ZnCo2O4 (ZCO) porous nanoplates anchored on ultrathin delaminated-Ti3C2 (d-TC) nanosheets as a high-performance electrode for electrochemical SCs. The unique robust nanoplate-on-nanosheet adhesion promises fast electron and ion transport, large electroactive surface area, and excellent structural stability. Importantly, benefiting from the features of such a configuration, the ZCO/d-TC-350 composite electrode displays a high specific capacity of 195.8 C g(-1) at a current density of 1 A g(-1). Moreover, the constructed hybrid supercapacitor (HSC) consisting of ZCO/d-TC-350||active carbon (AC) achieves a high energy density of 15.6 W h kg(-1) at a power density of 551.1 W kg(-1) and superior long-term stability with 89.5% capacitance retention after 4000 cycles. This work provides a promising strategy for the preparation of advanced MXene-based electrodes for electrochemical capacitors.