Sodiumation of Biomass‐Derived Quinones Enables High‐Rate and Long‐Life Cathodes for Sodium‐Ion Batteries

ABSTRACT Biomass‐derived quinones are promising green and sustainable cathode materials for sodium‐ion batteries (SIBs), yet their practical application is hindered by poor cycling stability due to dissolution in conventional electrolytes. Herein, we demonstrate that sodiumation is an effective strategy to enhance both rate capability and cycling stability of the natural anthraquinone derivative, 2‐hydroxyanthraquinone (2‐HAQ). Density functional theory (DFT) calculations and molecular dynamic (MD) simulations reveal that the sodiumated form, Na(2‐HAQ), maintains the redox activity and theoretical capacity of 2‐HAQ while exhibiting increased molecular polarity, which improves compatibility with ether‐based electrolytes. After identifying 1,2‐dimethoxyethane (DME) as a suitable electrolyte, we demonstrate the good electrochemical performance of Na(2‐HAQ) as a cathode by experimental measurements, which is further improved by compositing with calcined multi‐walled carbon nanotubes (MWCNTs) to form Na(2‐HAQ)@calcined MWCNTs. Using 1 M NaPF 6 in DME as the electrolyte, the composite delivers a reversible specific capacity of 156 mAh g −1 , a high energy density of 284 Wh kg −1, and outstanding cycling stability over 5000 cycles at 2C. This exceptional performance, surpassing that of many state‐of‐the‐art inorganic and organic cathode materials under high‐rate conditions, is attributed to a capacitive‐controlled Na + storage mechanism that enables rapid ion kinetics. The combination of high performance, cost‐effectiveness, and environmental sustainability positions Na(2‐HAQ)@calcined MWCNTs as a compelling cathode candidate for next‐generation high‐rate SIBs.