MOF Glass Confined Black Phosphorus via Co─P Anchoring for Advanced Lithium-Ion Battery Anodes

Although lithium-ion batteries (LIBs) dominate the commercial energy storage market, the prevailing graphite anode is approaching its theoretical capacity limit. Alloy-type anode materials like black phosphorus (BP) offer high theoretical capacity and intrinsic conductivity, but suffer from severe volume expansion and resultant structural instability. Here, an in situ vitrification strategy is reported to construct a composite anode material by integrating BP, Ketjenblack, and single wall carbon nanotube into a zeolitic imidazolate framework (ZIF) glass matrix. The established 3D network provides rapid electron and Li⁺ transport pathways, while BP nanoparticles are strongly anchored to Co nodes within the disordered ZIF glass via Co─P bonding. This architecture facilitates the pre-activation of deeply embedded Li⁺ storage sites of ZIF glass and effectively buffers volume changes of BP, limiting structural expansion to less than 10%, as evidenced by in situ TEM. As a result, the as-fabricated composite anode delivers a high reversible capacity of 652.3 mAh g^-1 with ≈98% capacity retention over 1000 cycles at 1 A g^-1. This work demonstrates the potential of metal-organic framework (MOF) glass as a robust matrix to stabilize alloy-type anode materials, offering a promising avenue for the development of next-generation LIB anode materials.