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.