TABLE 1.

Potential window, equivalent circuit charge transfer, and series resistance (Rct and Rs, respectively) of supercapacitors applying the eight shortlisted ILs at different temperatures were obtained.

T/K	Parameters	[Pyr 1, 3] [TFSI]	[Pyr 1, 5] [TFSI]	[Pyr 1, 3] [FSI]	[Pyr 1, 102] [TFSI]	[Pip 1, 3] [TFSI]	[Pip 1, 3] [FSI]	[N 111, 3] [TFSI]	[N 111, 6] [TFSI]
298.15	Potential Window	4 V	5.2 V	4.8 V	5.2 V	5.4 V	5 V	5.1 V	5.2 V
	Rct/Rs—Before CV	13 Ω/3 Ω	17 Ω/6 Ω	8 Ω/3 Ω	9.5 Ω/3 Ω	17 Ω/8 Ω	6.3 Ω/3.4 Ω	22.1 Ω/4.4 Ω	22.6 Ω/9.8 Ω
	Rct/Rs—After CV	22 Ω/3 Ω	29 Ω/6.5 Ω	18.1 Ω/2.9 Ω	10.8 Ω/4 Ω	23 Ω/9 Ω	13 Ω/3.8 Ω	64 Ω/4.2 Ω	27.5 Ω/11.5 Ω
313.15	Potential Window	4 V	5.2 V	4.8 V	5.2 V	5.4 V	5 V	5.1 V	5.2 V
	Rct/Rs—Before CV	9 Ω/2 Ω	48 Ω/3.5 Ω	17.7 Ω/2 Ω	5.2 Ω/2.3 Ω	11 Ω/1 Ω	11.5 Ω/2 Ω	53.2 Ω/2.1 Ω	22.3 Ω/5 Ω
	Rct/Rs—After CV	16 Ω/1.5 Ω	55.5 Ω/6.5 Ω	19.7 Ω/2 Ω	10.1 Ω/2.6 Ω	20 Ω/2 Ω	14.5 Ω/2.6 Ω	71.2 Ω/2.4 Ω	17.5 Ω/7 Ω
333.15	Potential Window	4 V	5.2 V	4.8 V	5.2 V	5.4 V	5 V	5.1 V	5.2 V
	Rct/Rs—Before CV	12.1 Ω/2 Ω	4.8 Ω/2.5 Ω	20.5 Ω/1.6 Ω	9.8 Ω/2 Ω	7 Ω/5 Ω	14.6 Ω/1.2 Ω	57.5 Ω/1.3 Ω	11.5 Ω/7.5 Ω
	Rct/Rs—After CV	12.9 Ω/1.5 Ω	25.2 Ω/2.3 Ω	30.2 Ω/1.5 Ω	6.5 Ω/2.4 Ω	16 Ω/3 Ω	22 Ω/2.3 Ω	69 Ω/1.4 Ω	19.8 Ω/2.6 Ω
353.15	Potential Window	4 V	5.2 V	4.8 V	5.2 V	5.4 V	5 V	5.1 V	5.2 V
	Rct/Rs—Before CV	16.5 Ω/1 Ω	6.1 Ω/2.2 Ω	27 Ω/1.1 Ω	14.8 Ω/1.6 Ω	4 Ω/3 Ω	21.5 Ω/1.1 Ω	64.5 Ω/1 Ω	19.5 Ω/2.3 Ω
	Rct/Rs—After CV	22.4 Ω/1 Ω	28 Ω/2 Ω	79.5 Ω/1.4 Ω	20.5 Ω/1.7 Ω	7 Ω/4 Ω	27.2 Ω/2.3 Ω	122.5 Ω/1 Ω	27.5 Ω/2.5 Ω