Localized Ligands Assist Ultrafast Multivalent-Cation Intercalation Pseudocapacitance.

Rechargeable batteries based on multivalent cation (Mv , n>1) carriers are considered potentially low-cost alternatives to lithium-ion batteries. However, the high charge-density Mv carriers generally lead to sluggish kinetics and poor structural stability in cathode materials. Herein, we report an Mv storage via intercalation pseudocapacitance mechanism in a 2D bivalve-like organic framework featured with localized ligands. By switching from conventional intercalation to localized ligand-assisted-intercalation pseudocapacitance, the organic cathode exhibits unprecedented fast kinetics with little structural change upon intercalation. It thus enables an excellent power density of 57 kW kg over 20000 cycles for Ca storage and a power density of 14 kW kg with a long cycling life over 45000 cycles for Zn storage. This work may provide a largely unexploited route toward constructing a local dynamic coordination microstructure for ultrafast Mv storage.