Cavity-Enabled Supramolecular Regulation of Capacitive-Redox Bromine Electrochemistry in Zinc-Bromine Batteries.

The intrinsic trade-offs between high-rate capacitive processes and high-capacity redox reactions fundamentally limit advanced electrochemical energy storage. Here, we transcend this paradigm by introducing cavity-enabled supramolecular microreactors as a versatile platform for synergistic bromine capacitive-redox electrochemistry. These microreactors exhibit voltage-responsive dual functions, operating as a high-capacity ion-sequestration matrix at low voltages governed by their tailored electrostatic cavity landscape, and dynamically switching to an anchoring and conversion-promoting center at high voltages via spatially confined noncovalent interactions distinct from conventional bonding. Deployed in an aqueous zinc-bromine battery, this strategy delivers a specific capacity of 481.8 mAh g-1 at 0.83 A g-1 and retains 89.4% of its capacity after 1500 cycles at a specific current of 8.3 A g-1. Our work transcends the conventional material design philosophy, establishing a general approach for breaking the intrinsic limits of electrode materials through molecular-scale ion regulation.