Non-Fluorinated Dual-Solvent Electrolyte for High-Performance Zinc-Based Energy Storage

High Resolution Image Download MS PowerPoint Slide Here, we report novel electrolytes based on fluorine-free (F-free) salt zinc methanesulfonate (ZMS) in N,N -dimethylpropyleneurea (DMPU) and triethyl phosphate (TEP). While the single-solvent DMPU-based electrolyte exhibited suboptimal performance at 0.5 mA cm –2, the addition of TEP as a dual solvent significantly enhanced the electrochemical performance for over 1000 h at 1 mA cm –2 and up to 2.5 mAh cm –2 . TEP modulated the solvation structure of the electrolyte, which facilitated Zn 2+ desolvation and promoted uniform zinc plating/stripping, while its partial reduction during initial cycling formed a robust solid electrolyte interphase (SEI) composed of zinc phosphate and organic phosphate species, effectively suppressing the dendrite growth and minimizing side reactions. The dual-solvent electrolyte demonstrated an excellent cycling stability and a high Coulombic efficiency, while the polyaniline (PANI)-based full cell achieved 88% capacity retention at 0.1 A g –1, and ∼80% retention at 1 A g –1 over 500 cycles. Besides, the full cell based on activated carbon (AC) also maintained 76% retention at 0.1 A g –1 . This study manifests the potential of the F-free dual-solvent electrolyte for applications in both zinc-ion supercapacitors (ZICs) and zinc-ion batteries (ZIBs).