Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Erciyes Üniversitesi, Fen Fakültesi, Kimya, Türkiye
Tezin Onay Tarihi: 2018
Tezin Dili: İngilizce
Öğrenci: MUSTAFA RAQEEB MOHAMMED
Danışman: Şaban Patat
Özet:
In this work, nickel-manganese oxides/hydroxide/carbonate@activated carbon (AC),
NiMn layered double hydroxide@activated carbon and cobalt-manganese
oxide/hydroxide/carbonate@activated carbon composite electrode materials for
supercapacitor have been synthesized by a hydrothermal method from the solution of
metals salts and urea after the thermal hydrolysis of urea. Physical properties,
morphology, and specific surface area of the composites were characterized by X-Ray
powder diffraction (XRD), scanning electron microscopy (SEM) equipped with energydispersive
spectroscopy (EDX), DC conductivity and nitrogen absorption/desorption
measurements. SEM images confirmed the NiMn layered double hydroxide, Mn3O4,
MnCO3, NiCO3, Ni(OH)2, Co3O4, Co(OH)2 and CoCO3 dispersed on the external
surface of activated carbon particles.
The electrochemical performance of the composites was investigated by cyclic
voltammetry and galvanostatic charge/discharge measurements. The electrochemical
investigation shows that AC//AC@NiMn(1:1) and AC//AC@CoMn(1:1) asymmetric
supercapacitors (ASC) exhibit high energy and power densities, good rate capability and
excellent cycling stability, which can be attributed to the synergetic effects between the
conductivity of the activated carbon and the redox properties of the metal
oxide/hydroxide/carbonate. The AC//AC@NiMn(1:1) ASC operating at 1.2 V delivers a
high energy density of 5.5 Wh/kg-1 at a power density of 1000 W/kg-1 and excellent
cycling stability with 96% retention of initial capacitance after 5000 cycles. The
AC//AC@CoMn(1:1) ASC operating at 1.2 V delivers a high energy density of 4.9 Wh
/kg-1 at a power density of 1000 W/kg-1 and excellent cycling stability with 97%
retention of initial capacitance after 5000 cycles.
This work shows that nickel-manganese oxides/hydroxide/carbonate@activated carbon,
NiMn layered double hydroxide@activated carbon and cobalt-manganese
oxide/hydroxide/carbonate@activated carbon composite electrode materials were found
to be promising electrode materials for the supercapacitor working at high current
density.