Field‐Free Spin‐Polarized Charge Transport in Chiral Co ₃ O ₄ Boosts Supercapacitor Kinetics

ABSTRACT

Supercapacitors offer ultrahigh power density but remain fundamentally constrained by limited interfacial charge‐transfer kinetics at high rates. Although magnetic‐field‐assisted spin control has recently emerged as a promising strategy to regulate electrochemical kinetics, its reliance on external fields and magnetic components limits practical device integration. Here we establish chirality as an intrinsic, field‐free handle to regulate electron spin transport in supercapacitors by leveraging the chiral‐induced spin selectivity (CISS) effect. Enantiopure threonine is employed to template cobalt hydroxide nanoflakes, and subsequent calcination removes all organic species while imprinting robust chirality into purely inorganic Co ₃ O ₄ films. Magnetic conductive‐probe AFM reveals pronounced spin‐selective transport with spin polarization up to ∼48% at room temperature. Compared with racemic and non‐templated controls, chiral Co ₃ O ₄ electrodes exhibit markedly enhanced specific capacitance, superior rate capability, and improved cycling stability under zero magnetic field. Electrochemical impedance spectroscopy and distribution of relaxation times analysis reveal a 6.4‐fold reduction in charge‐transfer resistance and accelerated pseudocapacitive kinetics, consistent with CISS‐induced spin‐polarized currents that suppress spin‐flip scattering and facilitate interfacial electron transfer. This work establishes chirality as a new design dimension for electrochemical energy storage and opens a general pathway toward spin‐aware engineering of high‐performance supercapacitors without external magnetic fields.