01888nas a2200265 4500008004100000022001400041245008700055210006900142260007100211300001600282490000600298520096500304653003001269653002301299653002001322653001701342653002001359653001701379100002001396700002101416700002601437700001801463700002501481856011601506 2014 eng d a1944-824400aHollow Co0.85Se nanowire array on carbon fiber paper for high rate pseudocapacitor0 aHollow Co085Se nanowire array on carbon fiber paper for high rat a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a18844-188520 v63 a

A supercapacitor electrode is fabricated with Co0.85Se hollow nanowires (HNW) array, which is synthesized by wet chemical hydrothermal selenization of initially grown cobalt hydroxyl carbonate nanowires on conductive CFP. The dense self-organized morphology of Co0.85Se HNWs is revealed by scanning/transmission electron microscopy. The as-synthesized Co0.85Se HNWs possess high pseudocapacitive property with high capacitance retention and high durability. The areal capacitance value is seen to vary from 929.5 to 600 mF cm(-2) (60% retention) as the current density is increased from 1 to 15 mA cm(-2), an increase of a factor of 15. Based on mass loading, this corresponds to a very high gravimetric capacitance of 674 (for 2 mA cm(-2) or 1.48 Ag-1) and 444 Fg(1-) (for 15 mA cm(-2) or 11 A g(-1)) in a full-cell configuration with the Co0.85Se HNWs as cathode and activated carbon as anode (asymmetric configuration) promising results are obtained.

10aasymmetric supercapacitor10acarbon fiber paper10acobalt selenide10ahydrothermal10apseudocapacitor10aselenization1 aBanerjee, Abhik1 aBhatnagar, Sumit1 aUpadhyay, Kush, Kumar1 aYadav, Prasad1 aOgale, Satishchandra uhttps://library.ncl.res.in/content/hollow-co085se-nanowire-array-carbon-fiber-paper-high-rate-pseudocapacitor-002153nas a2200253 4500008004100000022001400041245013200055210006900187260000800256300001500264490000600279520124500285653003001530653002101560653002601581653003201607653003001639100001701669700002201686700001401708700002401722700002301746856013001769 2022 eng d a2365-654900aSingle-step synthesis of exfoliated Ti3C2Tx MXene through NaBF4/HCl etching as electrode material for asymmetric supercapacitor0 aSinglestep synthesis of exfoliated Ti3C2Tx MXene through NaBF4HC cMAY ae2022011660 v73 a

Two-dimensional Ti3C2Tx MXene, derived from the parent Ti3AlC2 phase, is considered a promising electrode material for electrochemical energy storage applications. Ti3C2Tx MXene synthesis methods often employ concentrated hydrofluoric acid (HF), which is harsh, corrosive, and hazardous to the environment. Herein, we report the preparation of Ti3C2Tx MXene following a new synthetic route under a mild reaction condition comprising an aqueous solution of NaBF4 and HCl. This etching environment at a moderate temperature of 130 degrees C effectively removes the Al layer of the Ti3AlC2 precursor, assisted by the in situ formed HF in the reaction medium. Electron microscopy images of the as-prepared Ti3C2Tx (MX-130) reveal a partially exfoliated nanosheet-like morphology. The material displays a specific capacitance of 262 F g(-1) (three-electrode assembly, 1 A g(-1), -0.85 to -0.25 V vs. Hg/Hg2SO4) in 1 M H2SO4 electrolyte. The achieved specific capacitance is superior to that of Ti3C2Tx prepared via the common HF-treatment (25 F g(-1)). Additionally, the potential application of the optimized MXene as a negative electrode material is demonstrated in a quasi-solid-state RuO2|MX-130 asymmetric supercapacitor device.

10aasymmetric supercapacitor10aElectrochemistry10aFluoride salt etchant10aLayered electrode materials10aTransition metal carbides1 aGhosh, Meena1 aSzunerits, Sabine1 aCao, Ning1 aKurungot, Sreekumar1 aBoukherroub, Rabah uhttps://library.ncl.res.in/content/single-step-synthesis-exfoliated-ti3c2tx-mxene-through-nabf4hcl-etching-electrode-material02510nas a2200301 4500008004100000022001400041245014300055210006900198260000800267300001200275490000800287520147800295653003001773653002401803653001801827653003101845653002001876100002401896700001801920700002201938700001901960700002201979700001902001700002302020700001902043700002502062856012102087 2023 eng d a0008-622300aUltra-fast electro-reduction and activation of graphene for high energy density wearable supercapacitor asymmetrically designed with MXene0 aUltrafast electroreduction and activation of graphene for high e cJAN a191-2010 v2033 a

Controlled perforation of graphene is vital to surpass the performance of supercapacitors that rely on their pristine form. However, their practical utilization has been halted by energy-inefficient and lengthy processing. Here, we are reporting a pulse Joule heating strategy for on-site reduction and activation to realize a multimodal porous framework made of perforated graphene using millisecond current pulses. The multimodal porosity and surface functionalities of graphene were regulated at an ultrafast rate by passing a transient current. Asdeveloped ready-to-use electrode composed of nano-to-macro multimodal porosity displays high areal capacitance of 380.2 mF cm-2 in symmetric two-electrode configuration, which is nearly 1.6 times higher than the nonelectro activated counterpart. Furthermore, a high-performance wearable asymmetric supercapacitor with an areal energy density of 107.8 mu Wh cm-2 was realized using this multimodal porous graphene in combination with suitable negative electrodes made of MXene. High energy density, together with stable and repeatable performance of the wearable device for 10000 cycles of charge-discharge and 5000 cycles of bending, signifies the importance of the as-developed device for practical wearable applications. Direct, simple processing of electrodes and orders of magnitude lower cost-and-processing-time can make the process appealing for practical wearable and other energy storage applications.

10aasymmetric supercapacitor10aGraphene activation10aJoule heating10aSolid-state supercapacitor10aWearable device1 aKarim, Golam, Masud1 aDutta, Pronoy1 aMajumdar, Abhisek1 aPatra, Amalika1 aDeb, Sujit, Kumar1 aDas, Snehasish1 aDambhare, Neha, V.1 aRath, Arup, K.1 aMaiti, Uday, Narayan uhttps://library.ncl.res.in/content/ultra-fast-electro-reduction-and-activation-graphene-high-energy-density-wearable