Nitrogen-rich two-dimensional π-conjugated porous covalent quinazoline polymer for lithium storage

The feasibility of assorted characteristics of fast charge-transport, abundance active sites, and controlled molecular designing of the π-conjugated porous two-dimensional covalent organic polymer offers exclusive alternative electrode materials for lithium storage. However, the functioning of an organic polymer electrode in terms of specific capacity, cycle life, and rate performance is still lacking. In this work, we report the theoretical design and corresponding practical development of a nitrogen-rich two-dimensional π-conjugated porous covalent quinazoline polymer (HAT-CQP). The results show that HAT-CQP as anode for lithium-ion batteries can produce an excellent electrochemical performance.The discharge-specific capacity reaches 478 mAh g−1 even after 510 cycles, and a 82.3% of capacity retention rate is acquired at 800 mAg−1. The X-ray photoelectron spectroscopy results along with theoretical calculations reveal that the designed structure of HAT-CQP can store 7 Li+ located on a pyrazine-like C=N and conjugated heterocycles.