Interface metallization enabled an ultra-stable Fe2O3 hierarchical anode for pseudocapacitors

Abstract

Despite significant advances in cathode materials, developing high-performance anodes remains a key challenge for future pseudocapacitors. Fe₂O₃ has been considered as a promising anode candidate due to its high theoretical capacitance, environmental benignity, and earth-abundant characteristics. However, the low electronic conductivity and poor cyclability of Fe₂O₃ significantly limit its practical application. In this work, a 3D nickel-metalized carbon nanofiber network was developed to deposit an Fe₂O₃ nanosheet anode. The nickel layer not only improved the electronic conductivity and the wettability of the 3D carbon substrate but also benefit the stability of the Fe₂O₃/carbon interfaces and the stress-release upon cycling. As a result, the newly designed Fe₂O₃ anode composite exhibited a high areal capacitance of 1.80 F cm⁻² at a high mass loading of 4.2 mg cm⁻¹ and ultra-high capacitance retention of 85.1% after successive 100 000 cycles, outperformed most of the reported Fe₂O₃-based anode materials. Extended the interface metallization method to a MnO₂ cathode, excellent capacitance retention of 108.2% was reached after 26 000 cycles, suggesting a potentially broad application of such an interface-management method in elevating the stability of metal oxide materials in various pseudocapacitive energy storage devices.