ATP-supported MnO2 nanofibers for high-performance supercapacitors

Manganese dioxide (MnO 2 ), known for its high theoretical specific capacitance, is considered one of the most promising electrode materials for supercapacitors. However, its poor intrinsic conductivity and structural degradation during cycling severely limit its practical application. To address these challenges, an interwoven MnO 2 nanofiber network-based attapulgite (ATP)/MnO 2 composite was constructed by in-situ growth of MnO 2 nanofibers on natural ATP clay scaffolds via a one-step hydrothermal method. The microstructures and morphologies of pure ATP, pure MnO 2 , and the ATP/MnO 2 composite were systematically characterized and compared. Furthermore, the electrochemical performances of pure MnO 2 and the ATP/MnO 2 composite were evaluated. Results indicate that the ATP/MnO 2 composite possesses a more favorable specific surface area and pore structure than pure ATP or MnO 2 , with an approximate 40% increase in specific surface area. Electrochemical measurements demonstrated that the ATP/MnO 2 composite delivered a specific capacitance of 218.8 F g -1 at a current density of 0.5 A g -1 , approximately 50% higher than that of pure MnO 2 . Moreover, the composite exhibited outstanding cycling stability, retaining 89.9% of its initial capacitance after 5000 charge-discharge cycles at 3 A g -1 . This study demonstrates the role of natural ATP in synergistically optimizing the specific surface area and active sites of MnO 2 -based materials. The proposed strategy offers a feasible route for designing high-performance, low-cost, and sustainable MnO 2 -based electrodes, while also providing new insights into the development of long-lasting energy storage materials.