Phase segregation and self-nano-crystallization induced high performance Li-storage in metal-organic framework bulks for advanced lithium ion batteries

摘要

Recently, metal organic framework (MOF) materials in nano-scale have gained enormous interest in Li-ion batteries (LIBs), while those in bulks usually exhibit poor Li-ion storage performance. Herein, we report how to obtain impressive Li-ion storage performance by using MOF bulks firstly. Through suitable design, incorporating small inorganic nano-domains with various dimensions into the MOF bulks, the forming metal inorganic organic hybrid composites (M-IOHCs) could store Li-ions twice more than that of the metal based MOF (M-MOF) bulks. Except for the good Li-ion storage performance, exemplified M-IOHCs also exhibit enhancing cyclibility of more than 400 cycles with tripled capacity and 100% capacity retention. The enhanced Li-ion storage capability and cyclibility is attributed not only to local phase segregation in MOF bulks induced by ultra small inorganic nano-domains and the self-nano-crystallization of MOF bulks and the later forming inorganic nanocrystals themselves, but also to the stabilized frameworks comprised of metal oxide inorganic nanocrystals and enwrapped C-N organic species which brought up no aggregation or grow-up of the inorganic active materials common in new generation electrode materials. Application of the M-IOHCs in full cells was exemplified by Ni-IOHCs anode and commercial LiFePO4 cathode, which delivers excellent energy and power performance.