Post-synthetic Fully π-Conjugated Three-Dimensional Covalent Organic Frameworks for High-Performance Lithium Storage.

A fully π-conjugated nitrogen-rich three-dimensional covalent organic framework ( PYTRI-COF-2 ) containing both pyrazine and triazine units was prepared through a post-synthetic strategy. The imine linkages in the pre-prepared PYTRI-COF-1 were converted into heterocyclic quinoline by the Povarov reaction. The obtained PYTRI-COF-2 displayed high Li-ion storage capacity and excellent cycling stability when it was used as the lithium (Li)-ion battery electrode.