<p>The recycling of lithium from spent batteries is crucial for mitigating resource shortages, yet achieving high Li⁺ selectivity over competing multivalent ions remains a major challenge. Here, we report a porphyrin-functionalized amorphous covalent-organic framework (COF) membrane that enables highly selective and efficient Li+ separation <i>via</i> self-inhibited multivalent ion transport. The membrane features sub-0.3 nm pores that sterically hinder hydrated multivalent ions, while porphyrin moieties strongly bind multivalent ions, increasing positive surface charge and electrostatically repelling subsequent multivalent ions. This self-inhibition mechanism, combined with distinct weakly interacting pathways for Li⁺, amplifies the Li⁺ selectivity by an order of magnitude, reaching 650 or even higher, depending on the multivalent ion type. Applied to cathode leachates, the membrane achieves Li⁺ purity up to 98.75% for LiFePO₄ and 99.97% for nickel manganese cobalt (NMC) systems <i>via</i> only a single-step separation. This work should guide the development of selective ion recovery methods, highlighting the potential of decoupled ion transport pathways in membrane design.</p>