CeO2-NiO/N,O-rich porous carbon derived from covalent-organic framework for enhanced Li-storage

Abstract

Heteroatom-doped porous carbon is crucial to improve energy storage performance of transition metal oxide (TMO)/carbon nanocomposites. However, their traditional template synthesis, and chemical or thermal activation methods are cumbersome and inefficient. Crystalline covalent-organic framework (COF) has customizable structure and abundant heteroatoms. Its abundant heteroatoms and ordered network structure make it to be promising precursors to prepare TMO/carbon nanocomposites. Herein, a new N,O-rich COFDHNDA-BTH with ribbon morphology was synthesized by amine-aldehyde condensation reaction. Using COFDHNDA-BTH as precursors, CeO2-doped NiO heterostructures/N,O-rich porous carbon (CeO2-NiO/NC) nanocomposites were synthesized and successfully applied for enhanced Li-storage. The N,O-rich COFDHNDA-BTH as precursors can not only avoid the cumbersome procedures and low efficiency of traditional template method but also provide more uniformly distributed active sites to anchor CeO2-NiO and hierarchical pores. Thanks to larger lattice space provided by doping of large radius cerium for Li+ insertion/de-insertion and uniformly distributed small CeO2-NiO nanoparticles with a diameter of 18 nm, the obtained 1/5CeO2-NiO/NC exhibits excellent Li-storage performance with a capacity of 852 mAh g−1 after 500 cycles at 1000 mA g−1. The simple yet efficient strategy provides a new guide to prepare CeO2-doped TMO heterostructures/NC nanocomposites for enhanced Li-storage.