Core-shell porous carbon hosts with spatially regulated lithium affinity for inward lithium deposition

Lithium metal anodes are promising for high-energy-density batteries, but their reversibility is limited by nonuniform lithium (Li) deposition and continuous interfacial degradation during repeated plating and stripping. Three-dimensional conductive hosts can reduce local current density and buffer volume changes, yet internal pore volume alone does not ensure effective Li storage. Preferential Li nucleation at the electrolyte-facing outer region blocks Li⁺ access to internal pores, leading to surface-biased growth and poor pore utilization. Here, we report a metal-organic framework (MOF)-derived core-shell porous carbon framework, denoted ZC-PCF, designed to coordinate Li⁺ accessibility and outer-region Li nucleation behavior. The host is prepared from a ZIF-8-derived core and a Zn/Co mixed-metal MOF shell, enabling selective outer-region modification. During carbonization, Co-containing species promote local carbon restructuring and mesopore-enriched pore evolution, increasing the total pore volume from 0.15 to 0.29 cm³ g^-1 while reducing the micropore contribution from 28.7 to 15.0%. The optimized ZC-PCF-12 enables improved LiFePO₄ full-cell cycling, retaining 93.4% of its initial capacity after 100 cycles at 1.0 mA cm^-2. This work suggests the importance of coordinating pore accessibility and Li nucleation behavior for reversible Li metal storage.