Spontaneous exfoliation and tailoring derived oxygen-riched porous carbon nanosheets for superior Li+ storage performance

Abstract

2D carbon nanosheets are promising electrode materials for high-efficiency lithium ion batteries (LIBs). However, the bottleneck in this field is how to obtain high quality carbon nanosheets via a scalable and facile procedure while well-maintaining superior Li+ storage performance. Herein, an efficient airflow annealing method to prepare porous carbon nanosheets (PCNs). The structure characteristics and electrochemical properties of PCNs have been fully investigated. The airflow annealing induces ultrathin porous nanosheets with rich oxygen-containing functional groups, which not only provide facile channels for the migration of Li+ ions and charge electron but also greatly improve the surface wettability and active sites. As a result, the PCNs anode exhibits a superior Li+ storage performance, including outstanding reversible capacity (782 mA h g−1), high Li+ diffusion coefficient (5.1 × 10−13 cm2 s−1), excellent rate (294.3 mA h g−1 at 2 A g−1) and cycle performance (742.8 mAh g−1 at 0.1 A g−1 after 100 cycles), outperforming previously reported biomass-carbon anodes. Considering the facile fabrication procedure and excellent electrochemical performance, this work throws light on a new avenue for the development of carbon materials for high-performance energy storage devices.