Field-Free Spin-Polarized Charge Transport in Chiral Co₃O₄ Boosts Supercapacitor Kinetics

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 Co₃O₄ 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 Co₃O₄ 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.