Graphene nanopetal wire supercapacitors with high energy density and thermal durability

Xiong, Guoping; He, Pingge; Huang, Baoyu; Chen, Tengfei; Bo, Zheng; Fisher, Timothy S.

doi:10.1016/j.nanoen.2017.05.050

Cited by 61 publications

(19 citation statements)

References 54 publications

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“…As shown in Figure a, as the operating temperature increases, the area of the CV curve loop significantly increases, indicating an enhancement in capacitance. This phenomenon should be attributed to the improved ionic conductivity of electrolyte, enhanced electron mobility and charge transfer between the electrodes and electrolyte caused by an elevated operating temperature . Meanwhile, Figure b shows GCD profiles of the symmetric SC at 0.5 A g −1 and different operating temperatures, which are in accordance with the CV results.…”

Section: Resultssupporting

confidence: 75%

“…The charge/discharge curves of the SCs become more asymmetric with the increase of the operating temperature. The highly asymmetric shapes of the charge/discharge curves at higher operating temperature indicate the occurrence of more side reactions during the charge/discharge process, which can be explained by the fact that high operating temperature facilitates ion mobility and charge transfer, making impurities in electrode materials more reactive with electrolyte and leading to imbalanced kinetics during charge/discharge process and low coulombic efficiency (48%). However, if the SC is put back at room temperature for 12 h, coulombic efficiency of the SC can rise again to be close to that of 20 °C.…”

Section: Resultsmentioning

confidence: 99%

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Achieving of Flexible, Free‐Standing, Ultracompact Delaminated Titanium Carbide Films for High Volumetric Performance and Heat‐Resistant Symmetric Supercapacitors

Yang

Tang

Tian

et al. 2018

Adv Funct Materials

116

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The volumetric performance of supercapacitors (SCs), besides the gravimetric performance, is attracting an increasing attention due to the fast development of electric vehicles and smart devices. Here, a unique design of symmetric supercapacitor material is reported with a tight face-to-face architecture by applying a high pressure to the delaminated Ti 3 C 2 (d-Ti 3 C 2 ) films. The high pressure makes the d-Ti 3 C 2 films achieve an increased density, high electron conductivity, good wettability, and abundant interconnected mesopore channels to promote ion transport efficiently, that is, more cations can intercalate/deintercalate in the charging-discharging process. As a result, with the increase of the applying pressure, the d-Ti 3 C 2 film pressured at 40 MPa in 1 m Li 2 SO 4 exhibits an ultrahigh capacitance of over 633 F cm −3 , outstanding energy density, and cyclic stability. Especially, the corresponding SC in 1 m 1-ethyl-3-methylimidazolium tetrafluoroborate/acetonitrile organic electrolyte shows a high volumetric energy density of 41 Wh L −1 , which is the highest value reported for the SCs based on MXene materials in organic electrolytes. The outstanding volumetric electrochemical performance and thermal stability of the SCs based on the ultracompact d-Ti 3 C 2 film demonstrate their promising potential as forceful power sources for small electronic devices.

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Section: Resultssupporting

confidence: 75%

Section: Resultsmentioning

confidence: 99%

Achieving of Flexible, Free‐Standing, Ultracompact Delaminated Titanium Carbide Films for High Volumetric Performance and Heat‐Resistant Symmetric Supercapacitors

Yang

Tang

Tian

et al. 2018

Adv Funct Materials

116

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“…Remarkably, Fe 2 O 3 nanoparticles exhibit abundant and suitable mesoporous channels, which ensures the high ionic diffusion kinetics of the IL ions during the repeated charging‐discharging processes, thereby providing the P−Fe 2 O 3 /G electrode with outstanding capacitance behavior and cycling performance in IL electrolyte. Moreover, conductive graphene allows for rapidly efficient charge transfer, endowing the P−Fe 2 O 3 /G electrode with acceptable rate capability. As a result, a kind of asymmetric SCs (ASCs) was successfully fabricated by using P−Fe 2 O 3 /G as negative electrode, carbon dodecahedrons/graphene (CDs/G) as positive electrode and EMIMBF 4 IL as electrolyte.…”

Section: Introductionmentioning

confidence: 99%

Sustainable Energy System Utilizing High‐Voltage‐Stable and Energy‐dense Supercapacitors Based on Porous Fe₂O₃@Graphene Electrode in Ionic Liquid Electrolyte

et al. 2018

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Energy‐dense supercapacitors (SCs) based on metal oxides@graphene electrode and ionic liquid (IL) electrolyte hold great promise in sustainable energy system. However, these types of SCs suffer from poor cycling stability, especially at high working voltage. Herein, a porous ferric oxide/graphene (P−Fe2O3/G) electrode has been developed, in which Fe2O3 nanoparticles exhibit abundant and suitable mesoporous channels. This structure ensures the high ionic diffusion kinetics of the IL ions during the repeated charging‐discharging processes, thereby providing the P−Fe2O3/G electrode with outastanding capacitance behavior and cycling performance in IL electrolyte. As a result, an ingenious asymmetric electrode concept has been put forward to fabricate energy‐dense SCs based on this P−Fe2O3/G as negative electrode, carbon dodecahedrons/graphene (CDs/G) as positive electrode and IL electrolyte. Remarkably, the fabricated devices exhibit superior high‐voltage cycling stability with 95 % retention after 20 000 cycles, which are much better than that of most previously reported SCs based on metal oxides/graphene electrode and IL electrolyte. On this basis, a sustainable energy system combining wind harvesting with asymmetric SCs has been established, wherein the asymmetric SCs can be effectively recharged by harvesting sustainable wind power and repeatedly supply power without decline of electrochemical performance. Therefore, this work can provide a promising porous electrode for high performance SCs in sustainable energy system.

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“…The activation energy slightly increases from 2.38 to 3.15 kJ mol À 1 as the current density increases from 1 to 20 A g À 1 . The activation energies are much lower than that of the asymmetric supercapacitor based on MnO 2 materials (32.8 kJ mol À 1 ), [59] and comparable to those of the EDLCs based on porous carbon (0.92~2.80 kJ mol À 1 ) [16] and graphene (3.01~7.87 kJ mol À 1 ). [14] Such low activation energies reveal the fast charge storage process in the GN/ VGNS/MnO 2 electrodes, which is slightly dependent on the operating temperature.…”

Section: Temperature Stability Of the Gn/vgns/mno 2 Pseudocapacitormentioning

confidence: 70%

Well‐Aligned Hierarchical Graphene‐Based Electrodes for Pseudocapacitors with Outstanding Low‐Temperature Stability

Kong

Xiong

et al. 2019

ChemElectroChem

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The relatively poor performance stability of pseudocapacitors over a wide temperature window (i. e. temperature stability), particularly at low temperatures, hinders their practical applications. Here, well‐aligned hierarchical pseudocapacitive electrodes are fabricated, featuring run‐through channels in a graphene network (GN) as ion‐buffering reservoirs, open inter‐sheet channels between vertical graphene nanosheets (VGNSs) for fast ion transport and MnO2 nanopetals on VGNSs for efficient interfacial pseudocapacitive reactions. With reduced ion diffusion length and charge‐transfer resistance as well as improved ion‐transport rate, the capacitance of pseudocapacitive electrodes decreases from 541 to 490 F g−1 at 1 A g−1 as the temperature drops from 25 to 0 °C, revealing a high capacitance retention of 90.7 %. Furthermore, the specific capacitance of a symmetric device based on the hierarchical electrodes at −30 °C maintains 80.8 % of the room‐temperature capacitance. Such outstanding temperature stability is comparable to the state‐of‐the‐art electric double‐layer capacitors. Importantly, 86.0 % of capacitance is retained after repeated heating and cooling at temperatures ranging from −30 to 60 °C for 5000 cycles. Asymmetric supercapacitors with the hierarchical architecture in the positive electrode exhibit stable performance over a wide temperature range. These results demonstrate the rationality of the electrode design for practical energy storage applications in harsh temperature environments.

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Graphene nanopetal wire supercapacitors with high energy density and thermal durability

Cited by 61 publications

References 54 publications

Achieving of Flexible, Free‐Standing, Ultracompact Delaminated Titanium Carbide Films for High Volumetric Performance and Heat‐Resistant Symmetric Supercapacitors

Achieving of Flexible, Free‐Standing, Ultracompact Delaminated Titanium Carbide Films for High Volumetric Performance and Heat‐Resistant Symmetric Supercapacitors

Sustainable Energy System Utilizing High‐Voltage‐Stable and Energy‐dense Supercapacitors Based on Porous Fe₂O₃@Graphene Electrode in Ionic Liquid Electrolyte

Well‐Aligned Hierarchical Graphene‐Based Electrodes for Pseudocapacitors with Outstanding Low‐Temperature Stability

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Graphene nanopetal wire supercapacitors with high energy density and thermal durability

Cited by 61 publications

References 54 publications

Achieving of Flexible, Free‐Standing, Ultracompact Delaminated Titanium Carbide Films for High Volumetric Performance and Heat‐Resistant Symmetric Supercapacitors

Achieving of Flexible, Free‐Standing, Ultracompact Delaminated Titanium Carbide Films for High Volumetric Performance and Heat‐Resistant Symmetric Supercapacitors

Sustainable Energy System Utilizing High‐Voltage‐Stable and Energy‐dense Supercapacitors Based on Porous Fe2O3@Graphene Electrode in Ionic Liquid Electrolyte

Well‐Aligned Hierarchical Graphene‐Based Electrodes for Pseudocapacitors with Outstanding Low‐Temperature Stability

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Sustainable Energy System Utilizing High‐Voltage‐Stable and Energy‐dense Supercapacitors Based on Porous Fe₂O₃@Graphene Electrode in Ionic Liquid Electrolyte