Pyrrolidinium, 1,1-dimethyl-, tetrafluoroborate (DMPBF4), also known as 1,1-Dimethylpyrrolidinium tetrafluoroborate, could be used as the conducting salt for electric double-layer capacitors (EDLCs). This compound has a smaller cation size in contrast to TEA+ and SBP+. The smaller cation size leads to the easier diffusion of DMPBF4 into carbon pores [1]. Compared to the standard electrolytes TEABF4 and SBPBF4, the novel DMPBF4 electrolyte exhibits a higher gravimetric capacitance, superior rate capability, and improved cycling stability. The energy and power density of EDLCs using DMPBF4 in the ACN electrolyte reach 40.61?Wh kg?1 and 8.09?kW?kg?1, respectively, at the working voltage of 3.0?V. Moreover, EDLCs with DMPBF4 in ACN (PC) retain 87.9% (87.5%) of their initial capacitance after 1000?h of float testing at 3.0?V.
[1] Hoai Van T. Nguyen , Kyung-Koo Lee, Kyungwon Kwak . “1,1-Dimethylpyrrolidinium tetrafluoroborate as novel salt for high-voltage electric double-layer capacitors.” Electrochimica Acta 299 (2019): Pages 98-106.