Outstanding Compatibility of Hard‐Carbon Anodes for Sodium‐Ion Batteries in Ionic Liquid Electrolytes

• DOI: 10.1002/cssc.202300840
• Publication Date: 2023-07-26T11:20:56Z
• Authors: Giovanna Maresca; Angelica Petrongari; Sergio Brutti; Giovanni Battista...
• Keywords: sodium-ion batteries * ionic liquids * hard carbon * electrolytes; 7. Clean energy; 3. Good health

Hard carbons (HC) from natural biowaste have been investigated as anodes for sodium-ion batteries in electrolytes based on 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ([EMI][FSI]) and N-trimethyl-N-butylammonium ([N1114][FSI]) ionic liquids. The Na+ intercalation process has analyzed by cyclic voltammetry tests, performed at different scan rates hundreds of cycles, combination with impedance spectroscopy measurements to decouple bulk interfacial resistances the cells. diffusion coefficient HC host also evaluated via Randles-Sevcik equation. Battery performance liquid galvanostatic charge/discharge cycles room temperature. evolution SEI (solid electrochemical interface) layer grown surface carried out Raman spectroscopy. Overall sodiation is highly reversible reproducible. In particular, a capacity retention exceeding 98 % initial value recorded in[N1114][FSI] after more than 1500 coulombic efficiency above 99 %, largely beyond standard carbonate-based electrolytes. Raman, transport properties confirms that ILs disclose formation layers superior ability support possible minor contributions EMI+cation.