Exploring the Capacity Limit: A Layered Hexacarboxylate-Based Metal-Organic Framework for Advanced Lithium Storage.

Our previous work suggested that more carboxylate groups might lead to higher energy density for metal-organic frameworks. In this study, we synthesized a layered metal-organic framework (MOF) Ni-BHC by use of 1,2,3,4,5,6-benzenehexacarboxylic acid. After evacuation by thermal treatment, this MOF was employed as an anode for lithium storage. For its rich lithiation sites as well as layered fast-kinetics structure, it delivers a superior reversible capacity of 1261.3 mA h g-1 at 100 mA g-1, far exceeding the performance of previously reported MOF-based anode materials. Density functional theory calculation and O soft X-ray absorption spectroscopy suggest that the luxuriant carboxylate-metal units play an important part in the electrochemical process.