Crystalline, porous, covalent polyoxometalate-organic frameworks for lithium-ion batteries

The development of covalent organic frameworks (COFs) with new building units is of critical importance for enriching the structural diversity and expanding their functions. However, the construction of COFs has been thus far limited primarily to traditional organic linkers. Herein, we report three-dimensional porous crystalline covalent polyoxometalate-organic frameworks (CPOFs) constructed from both inorganic and organic building blocks with reversible covalent bonds. These highly crystalline CPOFs exhibited 3-fold interpenetrated diamondoid topology, permanent porosity and high stability. Furthermore, these CPOFs could be directly applied as anode materials for lithium-ion batteries (LIBs) and displayed high reversible capacity (as high as 550 mA h g−1), rate performance, and cycling stability (up to 500 cycles).