Optimization of Sodium Bis(oxalato)borate (NaBOB) in Triethyl Phosphate (TEP) by Electrolyte Additives

The electrolyte solution of NaBOB in TEP is a low-cost, fluorine-free and flame-retardant with ionic conductivity 5 mS cm −1 , recently discovered to show promises for sodium-ion batteries. Here, the abilities this effectively form solid interphase (SEI) was augmented five common additives fluoroethylene carbonate (FEC), vinylene (VC), prop-1-ene-1,3-sultone (PES), 1,3,2-dioxathiolane 2,2-dioxide (DTD) tris(trimethylsilyl)phosphite (TTSPi). Full-cells electrodes Prussian white hard carbon industrial mass loadings >10 mg −2 volumes <5 ml g were used. X-ray photoelectron spectroscopy (XPS) pressure analysis also deployed investigate parasitic reactions. Cells using PES, PES+DTD PES+TTSPi (3 wt%) showed significantly increased performance terms capacity retention initial Coulombic efficiency as compared additive-free NaBOB–TEP. best cell retained 80% discharge (89 mAh ) after 450 cycles, which better than reference cells 1 M NaPF 6 EC:DEC electrolyte. This study sheds light on opportunities optimize NaBOB–TEP full-cell batteries order move from low-mass-loading lab-scale high loading aiming commercialization