Fast-Charging Hard Carbon Electrolyte

Boosted kinetics, longer life

Solvent polarity modulation via intermolecular interactions reduces the Na+ de-solvation barrier, enabling fast sodium storage and notably extended cycling life on hard carbon anodes.

Ji, Xiangyu · Fu, Zhiqiang · Wang, Jiali · Yixin, Zhu · Xiao, Yang · Gao, Chongwei · Wen, Bohua · Feng, Guang · Kang, Feiyu · Zhai, Dengyun

Advanced Materials 2026

Specifications

Capacity retention

{'zh': '90.4', 'en': '90.4'} %

Reversible capacity

{'zh': '110.5', 'en': '110.5'} mAh g^-1

Advantages

Faster de-solvation

The introduced co-solvent with electron-withdrawing effect reduces the electron density of the carbonyl in cyclic carbonates, attenuating the coordination ability of high-polarity solvents and facilitating PF₆^- entering the solvation shell, thus lowering the Na⁺ de-solvation energy barrier.

Stable cycling

The decreased polarity mitigates the continuous reduction of solvents triggered by Lewis acid catalyzation, enabling 90.4% capacity retention after 400 cycles.

Practical high-voltage full cell

A practical high voltage HC||Na₃V₂(PO₄)₂O₂F cell with N/P ratio of 1.05 achieves a reversible capacity of 110.5 mAh g^-1, showing the electrolyte's practical viability.

Applications

• Sodium-ion batteries：Directly usable in SIBs with hard carbon anodes to boost rate and cycle life.
• Hard carbon anodes：Overcomes sluggish kinetics of hard carbon without extra surface treatment.
• Fast-charging batteries：Lowers de-solvation barrier, enabling stable Na storage under fast charging.