Electrode material has been cited as one of the most important determining factors in classifying an energy storage system’s charge storage mechanism,i.e.,as battery-type or supercapacitive-type.In this paper,we show...Electrode material has been cited as one of the most important determining factors in classifying an energy storage system’s charge storage mechanism,i.e.,as battery-type or supercapacitive-type.In this paper,we show that along with the electrode material,the electrolyte also plays a role in determining the charge storage behaviour of the system.For the purpose of our research,we chose multi-elemental spinal type CuMn_(2)O_(4) metal oxide nanofibers to prove the hypothesis.The material is synthesized as nanofibers of diameter~120 to 150 nm in large scales by a pilot scale electrospinning set up.It was then tested in three different electrolytes(1 M KOH,1 M Na_(2)SO_(4) and 1 M Li_(2)SO_(4)),two of which are neutral and the third is alkaline(KOH).The cyclic voltammograms and the galvanostatic charge-discharge of the electrode material in a three-electrode sys-tem measurement showed that it exhibit different charge storage mechanism in different electrolyte solutions.For the neutral electrolytes,a capacitive behaviour was observed whereas a battery-type behaviour was seen for the alkaline electrolyte.This leads us to conclude that the charge storage mechanism,along with the active material,also depends on the electrolyte used.展开更多
This article reports that extremely thin nanobelts(thickness~10 nm)exhibit pseudocapacitive(PC)charge storage in the asymmetric supercapacitor(ASC)configuration,while show battery-type charge storage in their single e...This article reports that extremely thin nanobelts(thickness~10 nm)exhibit pseudocapacitive(PC)charge storage in the asymmetric supercapacitor(ASC)configuration,while show battery-type charge storage in their single electrodes.Two types of nanobelts,viz.NiO-Co_(3)O_(4) hybrid and spinal-type NiCo_(2)O_(4),developed by electrospinning technique are used in this work.The charge storage behaviour of the nanobelts is benchmarked against their binary metal oxide nanowires,i.e.,NiO and Co_(3)O_(4),as well as a hybrid of similar chemistry,CuO-Co_(3)O_(4).The nanobelts have thickness of~10 nm and width~200 nm,whereas the nanowires have diameter of~100 nm.Clear differences in charge storage behaviours are observed in NiO-Co_(3)O_(4) hybrid nanobelts based ASCs compared to those fabricated using the other materials-the former showed capacitive behav-iour whereas the others revealed battery-type discharge behaviour.Origin of pseudocapacitance in nanobelts based ASCs is shown to arise from their nanobelts morphology with thickness less than typical electron diffusion lengths(~20 nm).Among all the five type of devices fabricated,the NiO-Co_(3)O_(4) hybrid ASCs exhibited the highest specific energy,specific power and cycling stability.展开更多
基金funded by the Fundamental Research Grant Scheme of the Ministry of Education,Govt.of Malaysia through FRGS/1/2019/STG07/UMP/01/1(http://www.ump.edu.my)Battery Research Centre of Green Energy(BRCGE)of Ming Chi University of Technology,New Taipei,TaiwanTaiwan Experience Education Program(TEEP@AsiaPlus)for their research financial support.
文摘Electrode material has been cited as one of the most important determining factors in classifying an energy storage system’s charge storage mechanism,i.e.,as battery-type or supercapacitive-type.In this paper,we show that along with the electrode material,the electrolyte also plays a role in determining the charge storage behaviour of the system.For the purpose of our research,we chose multi-elemental spinal type CuMn_(2)O_(4) metal oxide nanofibers to prove the hypothesis.The material is synthesized as nanofibers of diameter~120 to 150 nm in large scales by a pilot scale electrospinning set up.It was then tested in three different electrolytes(1 M KOH,1 M Na_(2)SO_(4) and 1 M Li_(2)SO_(4)),two of which are neutral and the third is alkaline(KOH).The cyclic voltammograms and the galvanostatic charge-discharge of the electrode material in a three-electrode sys-tem measurement showed that it exhibit different charge storage mechanism in different electrolyte solutions.For the neutral electrolytes,a capacitive behaviour was observed whereas a battery-type behaviour was seen for the alkaline electrolyte.This leads us to conclude that the charge storage mechanism,along with the active material,also depends on the electrolyte used.
基金This work is supported by the Research and Inno-vation Department of University Malaysia Pahang(http://ump.edu.my)under the Flagship Leap 3 Program(RDU172201).
文摘This article reports that extremely thin nanobelts(thickness~10 nm)exhibit pseudocapacitive(PC)charge storage in the asymmetric supercapacitor(ASC)configuration,while show battery-type charge storage in their single electrodes.Two types of nanobelts,viz.NiO-Co_(3)O_(4) hybrid and spinal-type NiCo_(2)O_(4),developed by electrospinning technique are used in this work.The charge storage behaviour of the nanobelts is benchmarked against their binary metal oxide nanowires,i.e.,NiO and Co_(3)O_(4),as well as a hybrid of similar chemistry,CuO-Co_(3)O_(4).The nanobelts have thickness of~10 nm and width~200 nm,whereas the nanowires have diameter of~100 nm.Clear differences in charge storage behaviours are observed in NiO-Co_(3)O_(4) hybrid nanobelts based ASCs compared to those fabricated using the other materials-the former showed capacitive behav-iour whereas the others revealed battery-type discharge behaviour.Origin of pseudocapacitance in nanobelts based ASCs is shown to arise from their nanobelts morphology with thickness less than typical electron diffusion lengths(~20 nm).Among all the five type of devices fabricated,the NiO-Co_(3)O_(4) hybrid ASCs exhibited the highest specific energy,specific power and cycling stability.
