New Ionic Liquids Eliminate Fluorine Dependency in Supercapacitors
Researchers have developed fluorine-free ionic liquids that deliver high electrochemical performance in supercapacitors, operating reliably at elevated temperatures. The breakthrough addresses supply-chain vulnerabilities tied to fluorine sourcing while enabling more sustainable energy storage solutions for industrial and automotive applications.
Originaltitel: Fluorine-free dialkylphosphate-based ionic liquids as supercapacitor electrolytes
<p>Synthesis, physicochemical, and electrochemical properties are presented for a number of fluorine-free ionic liquids (ILs) comprising dialkylphosphate anions coupled to several N-heterocyclic cations such as pyrrolidinium (Pyrr), piperidinium (Pip) and pyridinium (Py). All the ILs are synthesized in a single-step by reacting trialkyl phosphate with pyrrolidine, piperidine or pyridine. The ILs exhibit thermal decomposition temperatures in the range from 183 to 259 oC, ionic conductivities from 0.07 to 0.57 mS cm−1 at 20 oC and reaches 3.25 mS cm−1 at 60 oC, and electrochemical stability window (ESW) up to 6.8 V on glassy carbon (GC) electrode. The symmetric supercapacitors (SCs) based on multiwalled carbon nanotubes (MWCNTs) using [EMPyrr][DEP] and [BMPyrr][DBP] electrolytes are investigated. The SC based on [EMPyrr][DEP] reveals higher capacity retention, a power density of 1050 W kg−1 and an energy density of 68 Wh kg−1 using 0.5 A g−1 at 60 °C. This paves the way for developing fluorine-free and high-performant electrolytes for supercapacitors operating at elevated temperatures.</p>