Template-free synthesis of hollow carbon-based nanostructures from MOFs for rechargeable battery applications

Hollow carbon-based nanostructures (HCNs) have found broad applications in various fields, particularly rechargeable batteries. However, the syntheses of HCNs usually rely on template methods, which are time-consuming, low-yield, and environmentally detrimental. Metal-organic frameworks (MOFs), constructed by organic ligands and inorganic metal nodes, have been identified as effect platforms for preparing HCNs without adding extra templates. This review summarized the recent progress in template-free synthesis of HCNs enabled by MOFs and their applications in rechargeable batteries. Different template-free strategies were introduced first with mechanistic insights into the hollowing mechanism. Then the electrochemical performances of the HCNs were discussed with highlight on the structure-function correlation. It is found that the built-in cavities and nonporous for HCNs is of critical importance to increase the storage sites for high capacity, to enhance charge and mass transport kinetics for high-rate capability, and to ensure the resilient electrode structure for stable cycling. Finally, the challenges and opportunities regarding MOFs-derived HCNs and their applications in rechargeable batteries were discussed.