Cluster-Bridging-Coordinated Bimetallic Metal-Organic Framework as High-Performance Anode Material for Lithium-Ion Storage

Metal-organic frameworks (MOFs) are potential electrode materials for energy storage owing to abundance of active sites, structural versatility, and well-organized porous framework. Herein, a cluster-bridging-coordinated bimetallic Co-4(mu(4)-O)[Ir(ppy-COO)(3)](2) MOF (Co-4-Ir MOF) with high conductivity and desirable porosity is proposed as promising anode materials for Li+ storage. The Co-4-Ir MOF consists of Co-4(mu(4)-O) clusters bridge-coordinated by Ir(ppy-COOH)(3), leading to electrical conductivity four orders of magnitude higher than that of conventional insulating MOFs and Li+ diffusion coefficient two orders of magnitude higher than that of graphite, thus boosting rate capability. The laminated stacking structure and ordered porous framework of Co-4-Ir MOF ensure rapid Li+ transport and storage without large volume variation. As a result, Co-4-Ir MOF anodes deliver high capacity of 1202 mAh g(-1), outstanding rate performance (515 mAh g(-1) at 3000 mA g(-1)), and good cycling stability (average capacity decay of 0.041% per cycle for 1000 cycles). Soft-packed full batteries assembled with Co-4-Ir MOF anodes and LiNi0.5Co0.2Mn0.3O2 cathodes exhibit good stability and flexibility. Moreover, Co-4-Ir MOF anode with fast kinetics is applied in hybrid lithium-ion capacitor, demonstrating good compatibility with capacitor-type cathode. This work suggests great potential to rationally design MOF materials with intriguing structures and performances for sustainable energy storage applications.

Automated summary

A bimetallic Co-4-Ir MOF with high conductivity and desirable porosity is proposed as a promising anode material for Li+ storage, showing significantly improved rate capability and cycling stability. This research demonstrates the potential to design MOF materials with intriguing structures and performances for sustainable energy storage applications.