The demand of microelectronic devices postulated high energetic flexible energy storage devices. Flexible solid state supercapacitor is flawless possible candidate to fulfill the requirement of microelectronic devices...The demand of microelectronic devices postulated high energetic flexible energy storage devices. Flexible solid state supercapacitor is flawless possible candidate to fulfill the requirement of microelectronic devices. This investigation provides practical evidence of the use of flexible solid state supercapacitors based on MnOelectrodes with polyvinylpyrrolidone(PVP)-Li ClOgel electrolyte. Initially, different acid mediated growths of MnOhave been carried. Later, the electrochemical performances of MnOelectrodes have been carried out. Impressively, the fabricated symmetric flexible solid state supercapacitor(FSS-SC) device demonstrates the highest operating potential window of 1.6 V with extended cycling stability. Moreover, the cell exhibits high energy density of 23 Wh/kg at power density of 1.9 k W/kg. It is interesting to note that the device shows excellent flexibility upon bending at angle of 180° for number of times. These results clearly evidenced those symmetric FSS-SC devices based on MnOelectrodes are promising energy storage devices for microelectronic applications.展开更多
Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple...Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCoS@Mn S/CC electrode shows high capacitance of 1908.3 F gat a current density of 0.5 A gwhich is higher than those of NiCoSand Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor（ASC） is constructed by using NiCoS@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly（vinyl alcohol）(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kgat 1 A g, a maximum power density of about7.5 kw kgat 10 A gand remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCoS@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCoS@Mn S/CC electrode shows a promising potential for energy storage applications in the future.展开更多
Supercapacitors have attracted much attention in the field of electrochemical energy storage.However,material preparation,stability,performance as well as power density limit their applications in many fields.Herein,a...Supercapacitors have attracted much attention in the field of electrochemical energy storage.However,material preparation,stability,performance as well as power density limit their applications in many fields.Herein,a sponge-like red phosphorus@graphene(rP@rGO)negative electrode and a Ni2P positive electrode were prepared using a simple one-step method.Both electrodes showed excellent performances(294 F g^−1 and 1526.6 F g^−1 for rP@rGO and Ni2P,respectively),which seem to be the highest among all rP@rGO-and Ni2P-based electrodes reported so far.The asymmetric solid-state supercapacitor was assembled by sandwiching a gel electrolyte-soaked cellulose paper between rP@rGO and Ni2P as the negative and positive electrodes.Compared to other asymmetric devices,the device,which attained a high operating window of up to 1.6 V,showed high energy and power density values of 41.66 and 1200 W kg−1,respectively.It also has an excellent cyclic stability up to 88%after various consecutive charge/discharge tests.Additionally,the device could power commercial light emitting diodes and fans for 30 s.So,the ease of the synthesis method and excellent performance of the prepared electrode materials mat have significant potential for energy storage applications.展开更多
Ionic liquid gel polymers have widely been used as the electrolytes in all-solid-state supercapacitors, but they suffer from low ionic conductivity and poor electrochemical performance. Arc discharge is a fast, low-co...Ionic liquid gel polymers have widely been used as the electrolytes in all-solid-state supercapacitors, but they suffer from low ionic conductivity and poor electrochemical performance. Arc discharge is a fast, low-cost and scalable method to prepare multi-layered graphene nanosheets, and as-made graphene nanosheets （denoted as ad-GNSs） with few defects, high electrical conductivity and high thermal stability should be favorable conductive additive materials. Here, a novel ionic liquid gel polymer electrolyte based on an ionic liquid （EM1MNTF2） and an copolymer （P（VDF-HFP）） was modified by the addition of ad-GNSs as an ionic conducting promoter. This modified gel electrolyte shows excellent thermal stability up to 400 ℃ and a wide electrochemical window of 3 V. An all-solid-state supercapacitor based on commercial activated carbon was fabricated using this modified ionic liquid gel polymer electrolyte, which shows obviously improved electrochemical behaviors compared with those of the corresponding all-solid-state supercapacitor using pure ionic liquid gel polymer electrolyte. Specially, smaller internal resistance, higher specific capacitance, better rate performance and cycling stability are achieved. These results indicate that the ionic liquid gel polymers modified by ad-GNSs would be promising and suitable gel electrolytes for high performance all-solid-state electrochemical devices.展开更多
Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature ph...Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb205 nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb2O5 nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g^-1. Additionally, non-aqueous asymmetric supercapacitors （ASCs） were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF6-based organic electrolyte achieved an energy density of 45.1 Wh·kg^-1 at 715.2 W·kg^-1. The working potential could be further enhanced to 4 V when a polymer ionogel separator （PVDF-HFP/LiTFSI/EMIMBF4） and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60℃ and delivered a maximum energy density of 70 Wh·kg^-1 at 1 kW·kg^-1.展开更多
All-solid-state micro-supercapacitors are acknowledged as a very promising class of microscale energy storage devices for directly integrating portable and wearable electronics. However, the improvement of electrochem...All-solid-state micro-supercapacitors are acknowledged as a very promising class of microscale energy storage devices for directly integrating portable and wearable electronics. However, the improvement of electrochemical performance from materials to devices still remains tremendous challenges. Here, we demonstrate a novel and universal mask-assisted filtration technology for the simplified fabrication of all-solid-state planar micro-supercapacitors（MSCs） based on interdigital patterns of 2D pseudocapacitive MnO2 nanosheets and electrochemically exfoliated graphene film as both electrode and current collector, and polyvinyl alcohol/Li Cl gel as electrolyte. Remarkably, the resulting MSCs exhibit outstanding areal capacitance of ～355 m F/cm^2, which is among the highest values reported in the state-of-the-art MSCs. Meanwhile, MSCs possess exceptionally mechanical flexibility as high as ～92% of initial capacitance even at a highly bending angle of 180°, excellent cyclability with a capacitance retention of 95% after 3000 cycles, and impressive serial or parallel integration for modulating the voltage or capacitance. Therefore, our proposed strategy of simplified construction of MSCs will pave the ways for utilizing graphene and analogous pseudocapactive nanosheets in high-performance MSCs.展开更多
We report a simple method for fabricating all-solid-state micro-supercapacitors, utilizing laser writing technology. Porous graphene films with three-dimensional networks induced by laser from commercial polymer was a...We report a simple method for fabricating all-solid-state micro-supercapacitors, utilizing laser writing technology. Porous graphene films with three-dimensional networks induced by laser from commercial polymer was acted as scaffold for loading MnO2, a typical pseudocapacitive materials. Using gel electrolyte, all-solid-state pseudocapacitive micro-supercapacitors were fabricated. Compare to traditional printing and lithography techniques produced micro-supercapacitors, the as-fabricated devices demonstrate high volumetric capacitances, good stability and low leakage current, indicating a scalable and facile approach for future energy storage devices in portable microelectronics.展开更多
The nano-MnO2 as active electrode material for supercapacitor was synt hesized by solid-state reaction between KMnO4 and manganese acetate at room temp erature. The products annealed at 100 ℃ and 200 ℃ were characte...The nano-MnO2 as active electrode material for supercapacitor was synt hesized by solid-state reaction between KMnO4 and manganese acetate at room temp erature. The products annealed at 100 ℃ and 200 ℃ were characterized by XRD an d TEM. The results showed the sample annealed at 100 ℃ was poorly crystallized phase with an average grain size of <20 nm. Electrochemical performances of mang anese oxide electrode were investigated by cyclic voltammetry and constant curre nt charge/discharge. The manganese oxide electrode annealed at 100 ℃ in 1 mol· L-1 Na2SO4 aqueous electrolyte exhibited excellent capacitive behavior between - 0.2 and +0.8 V (vs SCE). By 5 mA and 10 mA constant current charge/discharge, th e nano-MnO2 annealed at 100 ℃ can provide a specific capacitance of 158.5 F·g- 1 and 151.2 F·g-1, respectively.展开更多
基金DAE-BRNS, BARC Mumbai, India for financial support through research Project no.2012/34/67/BRNS/2911 dtd. 07/03/2013
文摘The demand of microelectronic devices postulated high energetic flexible energy storage devices. Flexible solid state supercapacitor is flawless possible candidate to fulfill the requirement of microelectronic devices. This investigation provides practical evidence of the use of flexible solid state supercapacitors based on MnOelectrodes with polyvinylpyrrolidone(PVP)-Li ClOgel electrolyte. Initially, different acid mediated growths of MnOhave been carried. Later, the electrochemical performances of MnOelectrodes have been carried out. Impressively, the fabricated symmetric flexible solid state supercapacitor(FSS-SC) device demonstrates the highest operating potential window of 1.6 V with extended cycling stability. Moreover, the cell exhibits high energy density of 23 Wh/kg at power density of 1.9 k W/kg. It is interesting to note that the device shows excellent flexibility upon bending at angle of 180° for number of times. These results clearly evidenced those symmetric FSS-SC devices based on MnOelectrodes are promising energy storage devices for microelectronic applications.
基金supported by the Grant-in-Aid for Scientific Research (KAKENHI) program, Japan (C, Grant Number 15K05597)Takahashi Industrial and Economic Research Foundation (Takahashi Grant Number 06-003-154)
文摘Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCoS@Mn S/CC electrode shows high capacitance of 1908.3 F gat a current density of 0.5 A gwhich is higher than those of NiCoSand Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor（ASC） is constructed by using NiCoS@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly（vinyl alcohol）(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kgat 1 A g, a maximum power density of about7.5 kw kgat 10 A gand remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCoS@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCoS@Mn S/CC electrode shows a promising potential for energy storage applications in the future.
基金supported by Basic Sci-ence Research Program through National Research Foundation of Korea(NRF)founded by the ministry of Education(NRF-2017R1D1A1B03030456)
文摘Supercapacitors have attracted much attention in the field of electrochemical energy storage.However,material preparation,stability,performance as well as power density limit their applications in many fields.Herein,a sponge-like red phosphorus@graphene(rP@rGO)negative electrode and a Ni2P positive electrode were prepared using a simple one-step method.Both electrodes showed excellent performances(294 F g^−1 and 1526.6 F g^−1 for rP@rGO and Ni2P,respectively),which seem to be the highest among all rP@rGO-and Ni2P-based electrodes reported so far.The asymmetric solid-state supercapacitor was assembled by sandwiching a gel electrolyte-soaked cellulose paper between rP@rGO and Ni2P as the negative and positive electrodes.Compared to other asymmetric devices,the device,which attained a high operating window of up to 1.6 V,showed high energy and power density values of 41.66 and 1200 W kg−1,respectively.It also has an excellent cyclic stability up to 88%after various consecutive charge/discharge tests.Additionally,the device could power commercial light emitting diodes and fans for 30 s.So,the ease of the synthesis method and excellent performance of the prepared electrode materials mat have significant potential for energy storage applications.
基金the support from the Top Hundred Talents Program of Chinese Academy of Sciencesthe National Natural Science Foundation of China(Nos.21203223 and 21303234)
文摘Ionic liquid gel polymers have widely been used as the electrolytes in all-solid-state supercapacitors, but they suffer from low ionic conductivity and poor electrochemical performance. Arc discharge is a fast, low-cost and scalable method to prepare multi-layered graphene nanosheets, and as-made graphene nanosheets （denoted as ad-GNSs） with few defects, high electrical conductivity and high thermal stability should be favorable conductive additive materials. Here, a novel ionic liquid gel polymer electrolyte based on an ionic liquid （EM1MNTF2） and an copolymer （P（VDF-HFP）） was modified by the addition of ad-GNSs as an ionic conducting promoter. This modified gel electrolyte shows excellent thermal stability up to 400 ℃ and a wide electrochemical window of 3 V. An all-solid-state supercapacitor based on commercial activated carbon was fabricated using this modified ionic liquid gel polymer electrolyte, which shows obviously improved electrochemical behaviors compared with those of the corresponding all-solid-state supercapacitor using pure ionic liquid gel polymer electrolyte. Specially, smaller internal resistance, higher specific capacitance, better rate performance and cycling stability are achieved. These results indicate that the ionic liquid gel polymers modified by ad-GNSs would be promising and suitable gel electrolytes for high performance all-solid-state electrochemical devices.
文摘Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb205 nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb2O5 nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g^-1. Additionally, non-aqueous asymmetric supercapacitors （ASCs） were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF6-based organic electrolyte achieved an energy density of 45.1 Wh·kg^-1 at 715.2 W·kg^-1. The working potential could be further enhanced to 4 V when a polymer ionogel separator （PVDF-HFP/LiTFSI/EMIMBF4） and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60℃ and delivered a maximum energy density of 70 Wh·kg^-1 at 1 kW·kg^-1.
基金the financial support from the National Natural Science Foundation of China(No.51572259)National Key R&D Program of China(Nos.2016YBF0100100 and2016YFA0200200)+2 种基金Thousand Youth Talents Plan of China,Natural Science Foundation of Liaoning Province(No.201602737)DICP(No.Y5610121T3)China Postdoctoral Science Foundation(Nos.2016M601348 and 2016M601349)
文摘All-solid-state micro-supercapacitors are acknowledged as a very promising class of microscale energy storage devices for directly integrating portable and wearable electronics. However, the improvement of electrochemical performance from materials to devices still remains tremendous challenges. Here, we demonstrate a novel and universal mask-assisted filtration technology for the simplified fabrication of all-solid-state planar micro-supercapacitors（MSCs） based on interdigital patterns of 2D pseudocapacitive MnO2 nanosheets and electrochemically exfoliated graphene film as both electrode and current collector, and polyvinyl alcohol/Li Cl gel as electrolyte. Remarkably, the resulting MSCs exhibit outstanding areal capacitance of ～355 m F/cm^2, which is among the highest values reported in the state-of-the-art MSCs. Meanwhile, MSCs possess exceptionally mechanical flexibility as high as ～92% of initial capacitance even at a highly bending angle of 180°, excellent cyclability with a capacitance retention of 95% after 3000 cycles, and impressive serial or parallel integration for modulating the voltage or capacitance. Therefore, our proposed strategy of simplified construction of MSCs will pave the ways for utilizing graphene and analogous pseudocapactive nanosheets in high-performance MSCs.
基金financially supported by the National Natural Science Foundation of China(Nos.51706016,51506014)the China Postdoctoral Science Foundation(No.2017T100677)
文摘We report a simple method for fabricating all-solid-state micro-supercapacitors, utilizing laser writing technology. Porous graphene films with three-dimensional networks induced by laser from commercial polymer was acted as scaffold for loading MnO2, a typical pseudocapacitive materials. Using gel electrolyte, all-solid-state pseudocapacitive micro-supercapacitors were fabricated. Compare to traditional printing and lithography techniques produced micro-supercapacitors, the as-fabricated devices demonstrate high volumetric capacitances, good stability and low leakage current, indicating a scalable and facile approach for future energy storage devices in portable microelectronics.
文摘The nano-MnO2 as active electrode material for supercapacitor was synt hesized by solid-state reaction between KMnO4 and manganese acetate at room temp erature. The products annealed at 100 ℃ and 200 ℃ were characterized by XRD an d TEM. The results showed the sample annealed at 100 ℃ was poorly crystallized phase with an average grain size of <20 nm. Electrochemical performances of mang anese oxide electrode were investigated by cyclic voltammetry and constant curre nt charge/discharge. The manganese oxide electrode annealed at 100 ℃ in 1 mol· L-1 Na2SO4 aqueous electrolyte exhibited excellent capacitive behavior between - 0.2 and +0.8 V (vs SCE). By 5 mA and 10 mA constant current charge/discharge, th e nano-MnO2 annealed at 100 ℃ can provide a specific capacitance of 158.5 F·g- 1 and 151.2 F·g-1, respectively.
