Nitrogen-doped 3D nanocarbon with nanopore defects as high-capacity and stable anode materials for sodium/lithium-ion batteries

Abstract

Carbon materials are among the most important materials used for anodes in rechargeable batteries due to their extensive resources and good cycling stability. However, the electrochemical performance of carbon-based anodes is closely related with their electronic states and morphologies/microstructures. Herein, we present a simple approach to synthesize a nitrogen-doped 3D nanocarbon (N-Carbon) with nanopore defects as high-capacity and stable anodes for sodium/lithium-ion batteries. This carbon material well inherits the unique nanosheet-like morphology of the template, which is composed of twisted-interconnected cuboidal hollow nanocages with a large number of nanopores across the shells. N-Carbon with integration of N heteroatom and 3D porous structure exhibits high reversible capacities of sodium-ion batteries, up to 401.9 and 311.7 mAh g−1 at 0.1 and 0.5 A g−1 after 100 cycles, respectively. This unique carbon material simultaneously exhibits excellent rate capability and cycling stability, with reversible capacities of 199.7 and 97.9 mAh g−1 at large current densities of 1 and 5 A g−1 even after 10,000 cycles, respectively. Moreover, N-Carbon also exhibits high capacity of 709 mAh g−1 for lithium-ion batteries after 2500 cycles at 10 A g−1. The excellent reversibility, rate capability, and cycling stability are attributed to this unique N-Carbon integrating into rich nitrogen-doped induced ion-storage sites and its relative ordered 3D pore structure.