High-yield bottom-up synthesis of 2D metal–organic frameworks via a solvent-free magnetic milling method as high performance anodes for lithium ion batteries

Abstract

Metal–organic frameworks (MOFs) are highly promising for lithium-ion batteries (LIBs) due to their unique structural tunability and fuctional versatility. Mechanochemical synthesis has emerged as a promising bottom-up strategy for fabricating MOFs, yet conventional ball milling faces limitations in efficiency and scalability. In this study, we introduce a novel solvent-free magnetic milling technique using 1,4-dicarboxybenzene (H₂BDC) as the organic ligand for the rapid and scalable synthesis of ultrathin 2D MOF nanosheets (Co-, Ni-, Fe-, and Mn-based). Compared to conventional ball milling, magnetic milling offers significantly higher efficiency, shorter processing time, and enhanced environmental sustainability. As-synthesized Co-BDC exhibited a two-dimensional nanosheet morphology with an ultrathin thickness of 2.8 nm. Electrochemical tests reveal that the magnetic-milled Co-BDC delivers superior performance compared to the ball-milled Co-BDC, achieving a reversible capacity of 524.3 mAh g⁻¹ at 0.2 A g⁻¹ with minimal initial Coulombic efficiency loss. Furthermore, the electrode retains 479 mAh g⁻¹ at 0.5 A g⁻¹ for 140 cycles before gradual capacity fading, stabilizing at 303.5 mAh g⁻¹ after 320 cycles. This work not only advances the mechanochemical synthesis of nanomaterials but also paves the way for the industrial-scale production of high-performance MOFs for energy storage applications.