Tailoring polyacrylonitrile sulfuration chemistry with curtailed dimensions: Toward rapid synthesis of practical all-sulfur-rich cathodes for fast lithium storage usage

Commercial bulky sulfurized polyacrylonitrile (SPAN) cathodes struggle to sustain high sulfur (S) contents, rapid production rates and expedite charge-storage capabilities owing to their sluggish sulfuration chemistry and overlong ionic commute distances. To overcome these constraints, we propose to simplify the monomer polymerization route with smart azobisisobutyronitrile initiators and tailor the intrinsic PAN sulfuration chemistry by curtailed diffusion dimensions, enabling the rapid synthesis (<4 h) of uniform “all-S-rich” SPAN nanoparticles (∼150 nm) and quick lithium (Li) migration (τ: 2.56 × 10^-4 s) for steady/fast charge-storage utilizations. The time-of-flight secondary ion mass spectrometry unveils their distinct ample S^-/S₂^- distribution tendencies in SPAN solids. Systematic electrochemical tests coupled with in-situ probing/simulation results verify their superior Li⁺ diffusion and thionic redox reaction kinetics/reversibility, including impressive rate capabilities (∼520 mAh g^-1 at 10 A g^-1 with seldom voltage plateaus decline), salient long-cyclic endurance (capacity retention: ∼95.6%) and eminent gas-forming-free properties. Packed pouch cells with thick SPAN electrodes ( Max. areal mass loading: ∼14.2 mg cm^-2) and lean ester electrolyte conditions (≤ 1.5 μL mg_span^-1) achieve remarkable volumetric energy and power densities (∼803 Wh L^-1/9406 W L^-1), showing great promise for pragmatic reliable high-power supplies in manifold scenarios.