Performance Enhancement of Carbon Nanomaterials for Supercapacitors

Table 2

CNTs, open tips, and functionalized CNTs as electrodes for supercapacitors.

Ref	Material type	Growth process	Collector type	Electrolyte	Specific surface area	Specific capacitance	Energy and power density
[24]	MWCNTs,	LPCVD		1 M H2SO4; 1 V		79 F/g	1.1 Wh/kg; 8.6 MW/kg
[25]	CNTs		Al/Al2O3/Fe:Co	(TEABF4)/AN; 4 V		25.6 F/g	3.56 wh/kg, 2400 kW/kg
			Al/Al2O3/Fe:Mo			61.2 F/g	8.5 wh/kg, 6580 kW/kg
[26]	Thin Al foil with thin Ni film. MWCNTs growth at 600°C	CVD		1 M H2SO4; 1 V	SSA: 120 m^2/g; Pore volume: 0.149 cm^3/g	68 F/g
				Organic electrolyte		79 F/g
[27]	MWCNTs	CVD	Inconel 600	6 M KOH; 1.5 V		18 F/g at	7 kW/kg
[28]	AMWCNTS.	CVD	Inconel (600)	(Et)4NBF4/PC; 2.5 V		83 F/g at	0.55 Ω ESR
[29]	SWCNT + PVDF binder.	arc discharge	Raw CNTs	6 M KOH; 0.8 V	236 m^2/g	30 F/g
			Oxidized in air at 300–550°C		644 m^2/g	140 F/g
[30]	SWCNTs; Transferred Cu.	WACVD; 750°C	Solid state capacitor	ALD coating of Al2O3 and top electrode		23 mF/cm^3 at 20 Hz and 6 mF/cm^3 at 20 kHz.	0.01–0.13 Wh/k
[31]	CNTs on Ni; Foam using binder	TCVD; 610°C		6 M KOH; 0.8 V		25 F/g
	transferred					9–13 F/g
[32]	CNTs,; No collector or binder.	suspension	On double sided tape	1 M H2SO4; 1 V		39 F/g	0.02 Wh/kg; 5.8 W/kg
[16]	Carbon cloth/CNTs.	MPECVD		neutral PH; 0,5 M Na2SO4; 2 V,	724.8 m^2/g	225 F g^−1	28 Wh/kg; 87% after 10 k cycles
[33]	MWCNTs; transferred on Ni foil	CVD		6 N KOH		21 F g^−1	20 kW/kg
[34]	MWCNT.; Separated and purified	TCVD; At 700°C	Transferred Ni foil.	6 N KOH; 1 V		21 F g^−1	30 kW/kg
Open tubes or catalyst removed
[35]	MWCNTs; catalyst removed by HNO3, functionalized by oxygenation	Arc discharge.		H2SO4; 1 V	430 m^2/g	104 F/g	8 KW/kg.; 94 mΩ ESR
	As produced				250 m^2/g
[36]	VADWCNTs on CP.	WACVD		1 M TEABF4/PC.; 2.5 V	SSA is 561 m^2/g	66 F/g Organic electrolyte.
				[EMIm][NTf2]; 3 V		75 F/g,; 28 F/cm^2	27 Wh/kg,; 987 kW/kg
	Electrochemical oxidation in HNO3			1 M TEABF4/PC.; 2.5 V		117 F/g
				[EMIm][NTf2]; 3 V		158 F/g,; 63 F/cm^2	52 Wh/kg,; 563 kW/kg
[5]	VASWCNTs	WACVD.		Et4NBF4/propylene; 3.5 V	1300 m^2/g	73 F/g,	16 wh/kg
	open tips and side wall windows by heating				2240 m^2/g; (inner 1180 m^2/g) (outer 1060 m^2/g)	114 F/g	24.7 Wh/g.
[37]	CNTs.	TCVD		1 M KCl; 0.7 V		42 F/g.
	Tips opened; and N2- doped					146 F/g.
[38]	MWCNT + binder; on stainless-steel			1 M Na2SO4; 0.8 V		61.46 F/g,
	500°C in air and microwave treatment					214.45 F/g
	Oxygen plasma treated					238.23 F/g
[39]	MWCNTs,; Purification and activation + binder	TCVD	Silica	1 M H2SO4	1035 m^2/g	95 F/g
				1.4 M TEABF4/AN; 2 V		65 F/g in
	CNTs; Purification and activation + binder			6 M KOH; 1 V	885 m^2/g	90 F/g
				1 M H2SO4		85 F/g
				1.4 M TEABF4/AN; (2 V)		65 F/g
[40]	VAMWCNTs; transferred.; tip removal; O2 plasma.	TCVD		[EMIM][Tf2N] IL (4 V).	400 m^2/g.	440 F/g	148 Wh/kg; 315 kW/kg