Study On Preparation And Performance Of Zeolitic Imidazolate Frameworks-derived Anode Materials For Lithium-ion Batteries

Zeolitic imidazolate frameworks(ZIFs)represent a new class of porous materials with intrinsic pore,controllable structure as well as large specific area.Recently,ZIFs have been applied as precursors for porous carbon-based materials and transitional metal oxide used in lithium ion battery.In this paper,we present the synthesis of different carbon based materials with unique structures derived from different zeolitic imidazolate frameworks,and study their structural characteristics and electrochemical performance.The contents mainly include the following two aspects:1.We take ZIF-8 derived nitrogen-doped porous carbon(NPC)as matrix for Ag nanoparticles,which were encapsulated in NPC via a facile hydrothermal method,to fabricate novel Ag@NPC composite.With structure characterization and electrochemical performance test,we study the mechanism of improvement in electrochemical performance by Ag NPs.Research shows that the synergistic effect between Ag NPs and NPC promotes electrochemical performance.Initial discharge capacity for Ag@NPC is 1374.64 mAh/g at a current of 100mA/g,with a high initial coulombic efficiency of 64.33%.After 200 cycles,its reversible capacity still remains at 852mAh/g.2.We successfully fabricate three kind of ZIF-67 with different structures.Then taking them as precursors to prepare different Co3O4/NPC porous nanoparticles(M-Co3O4/NPC,H-Co3O4/NPC and T-Co3O4/NPC).With structure characterization and electrochemical performance test,we study structural difference between these three composites,and the influence of structure on electrochemical performance.Research shows that M-Co3O4/NPC presented highest reversible capacity and best cycling performance due to its high specific surface area,high volume ratio as well as good structural stability.Its initial discharge capacity is 1428.33mAh/g at a current of 100mA/g,with initial coulombic efficiency of 81.9%.After 200 cycles,reversible capacity still remains at 1156.35mAh/g.