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Zempachi Ogumi - One of the best experts on this subject based on the ideXlab platform.
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lithium ion Transfer on a lixcoo2 thin film electrode prepared by pulsed laser deposition effect of orientation
Journal of Power Sources, 2007Co-Authors: Izumi Yamada, Yasutoshi Iriyama, Zempachi OgumiAbstract:Abstract LiCoO2 thin films with different orientations were fabricated by pulsed laser deposition, and Li-ion Transfer at the interface between the electrolyte and a LiCoO2 thin film electrode was investigated. This study particularly focused on the effect of orientation on Li-ion Transfer. The thin films were shown to be highly crystallized by X-ray diffraction. Charge Transfer Resistance ascribed to Li-ion Transfer at the interface was observed by ac impedance spectroscopy. While Charge Transfer Resistance was strongly influenced by the preferred orientation of LiCoO2 thin film, the activation energy evaluated from the temperature-dependence of Li-ion Transfer Resistance appeared to be independent of the orientation.
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Lithium-ion Transfer on a LixCoO2 thin film electrode prepared by pulsed laser deposition—Effect of orientation-
Journal of Power Sources, 2007Co-Authors: Izumi Yamada, Yasutoshi Iriyama, Takeshi Abe, Zempachi OgumiAbstract:Abstract LiCoO2 thin films with different orientations were fabricated by pulsed laser deposition, and Li-ion Transfer at the interface between the electrolyte and a LiCoO2 thin film electrode was investigated. This study particularly focused on the effect of orientation on Li-ion Transfer. The thin films were shown to be highly crystallized by X-ray diffraction. Charge Transfer Resistance ascribed to Li-ion Transfer at the interface was observed by ac impedance spectroscopy. While Charge Transfer Resistance was strongly influenced by the preferred orientation of LiCoO2 thin film, the activation energy evaluated from the temperature-dependence of Li-ion Transfer Resistance appeared to be independent of the orientation.
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reduction of Charge Transfer Resistance at the lithium phosphorus oxynitride lithium cobalt oxide interface by thermal treatment
Journal of Power Sources, 2005Co-Authors: Yasutoshi Iriyama, Tomonori Kako, Chihiro Yada, Takeshi Abe, Zempachi OgumiAbstract:Abstract An all-solid-state thin-film battery consisting of a c -axis-oriented LiCoO 2 thin-film and a lithium phosphorus oxynitride (LiPON) glass electrolyte was fabricated. Thermal treatment at 473 K after fabrication of the LiPON/LiCoO 2 interface decreased the Charge Transfer Resistance at the interface, and the Resistance was further reduced by prolonging the thermal treatment time. The Charge Transfer Resistance per unit electrode area (interfacial resistivity) of a film battery thermal-treated for 60 min decreased down to 125 Ω cm 2 , which is ca. five times larger than that in the case of an organic electrolyte (1 mol dm −3 LiClO 4 dissolved in propylene carbonate)/LiCoO 2 interface (25 Ω cm 2 ). Due to the reduction of the Charge Transfer Resistance at the LiPON/LiCoO 2 interface, the reaction current of the film battery was greatly increased by the thermal treatment. Also, thermally treated film batteries showed stable electrochemical lithium insertion/extraction properties compared with the batteries using conventional organic electrolytes. Both the voltammograms and the impedance spectra of the film battery maintained their initial shape for over 100 cycles, and the capacity retention ratio per cycle was calculated to be 99.9%.
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Reduction of Charge Transfer Resistance at the lithium phosphorus oxynitride/lithium cobalt oxide interface by thermal treatment
Journal of Power Sources, 2005Co-Authors: Yasutoshi Iriyama, Tomonori Kako, Chihiro Yada, Takeshi Abe, Zempachi OgumiAbstract:Abstract An all-solid-state thin-film battery consisting of a c -axis-oriented LiCoO 2 thin-film and a lithium phosphorus oxynitride (LiPON) glass electrolyte was fabricated. Thermal treatment at 473 K after fabrication of the LiPON/LiCoO 2 interface decreased the Charge Transfer Resistance at the interface, and the Resistance was further reduced by prolonging the thermal treatment time. The Charge Transfer Resistance per unit electrode area (interfacial resistivity) of a film battery thermal-treated for 60 min decreased down to 125 Ω cm 2 , which is ca. five times larger than that in the case of an organic electrolyte (1 mol dm −3 LiClO 4 dissolved in propylene carbonate)/LiCoO 2 interface (25 Ω cm 2 ). Due to the reduction of the Charge Transfer Resistance at the LiPON/LiCoO 2 interface, the reaction current of the film battery was greatly increased by the thermal treatment. Also, thermally treated film batteries showed stable electrochemical lithium insertion/extraction properties compared with the batteries using conventional organic electrolytes. Both the voltammograms and the impedance spectra of the film battery maintained their initial shape for over 100 cycles, and the capacity retention ratio per cycle was calculated to be 99.9%.
Yasutoshi Iriyama - One of the best experts on this subject based on the ideXlab platform.
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reduction of Charge Transfer Resistance at the solid electrolyte electrode interface by pulsed laser deposition of films from a crystalline li2po2n source
Journal of Power Sources, 2016Co-Authors: William C. West, Zachary D. Hood, Shiba P. Adhikari, Chengdu Liang, Abdou Lachgar, Munekazu Motoyama, Yasutoshi IriyamaAbstract:Abstract Amorphous films deposited by pulsed laser deposition from a crystalline Li 2 PO 2 N target in a N 2 ambient atmosphere (LiPON-PLD) have been examined as an approach to reduce the Charge-Transfer Resistance at the electrode-solid electrolyte interface. Despite the relatively low ionic conductivity of ca. 1.5 × 10 −8 S cm −1 at 25 °C, the amorphous LiPON-PLD films deposited between a LiMn 1.485 Ni 0.45 Cr 0.05 O 4 (LNM) cathode and LiPON electrolyte resulted in sharply improved electrochemical performance in terms of Charge-Transfer Resistance and CV profiles. Cells without a LiPON-PLD film had a Charge-Transfer Resistance of 4470 Ω-cm 2 compared to 760 and 960 Ω-cm 2 for the sample with 17 nm and 31 nm thick LiPON-PLD films, respectively. The LiPON-PLD amorphous films show no evidence of the continuous planar P N P N- backbone characteristic of the crystalline target material, but compared with LiPON prepared from radio frequency magnetron sputtering with Li 3 PO 4 in a N 2 atmosphere, the LiPON-PLD films were composed of a higher amount of triply coordinated P − N P P with relatively lower contributions of P N P.
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Reduction of Charge-Transfer Resistance at the solid electrolyte – electrode interface by pulsed laser deposition of films from a crystalline Li2PO2N source
Journal of Power Sources, 2016Co-Authors: William C. West, Zachary D. Hood, Shiba P. Adhikari, Chengdu Liang, Abdou Lachgar, Munekazu Motoyama, Yasutoshi IriyamaAbstract:Abstract Amorphous films deposited by pulsed laser deposition from a crystalline Li 2 PO 2 N target in a N 2 ambient atmosphere (LiPON-PLD) have been examined as an approach to reduce the Charge-Transfer Resistance at the electrode-solid electrolyte interface. Despite the relatively low ionic conductivity of ca. 1.5 × 10 −8 S cm −1 at 25 °C, the amorphous LiPON-PLD films deposited between a LiMn 1.485 Ni 0.45 Cr 0.05 O 4 (LNM) cathode and LiPON electrolyte resulted in sharply improved electrochemical performance in terms of Charge-Transfer Resistance and CV profiles. Cells without a LiPON-PLD film had a Charge-Transfer Resistance of 4470 Ω-cm 2 compared to 760 and 960 Ω-cm 2 for the sample with 17 nm and 31 nm thick LiPON-PLD films, respectively. The LiPON-PLD amorphous films show no evidence of the continuous planar P N P N- backbone characteristic of the crystalline target material, but compared with LiPON prepared from radio frequency magnetron sputtering with Li 3 PO 4 in a N 2 atmosphere, the LiPON-PLD films were composed of a higher amount of triply coordinated P − N P P with relatively lower contributions of P N P.
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lithium ion Transfer on a lixcoo2 thin film electrode prepared by pulsed laser deposition effect of orientation
Journal of Power Sources, 2007Co-Authors: Izumi Yamada, Yasutoshi Iriyama, Zempachi OgumiAbstract:Abstract LiCoO2 thin films with different orientations were fabricated by pulsed laser deposition, and Li-ion Transfer at the interface between the electrolyte and a LiCoO2 thin film electrode was investigated. This study particularly focused on the effect of orientation on Li-ion Transfer. The thin films were shown to be highly crystallized by X-ray diffraction. Charge Transfer Resistance ascribed to Li-ion Transfer at the interface was observed by ac impedance spectroscopy. While Charge Transfer Resistance was strongly influenced by the preferred orientation of LiCoO2 thin film, the activation energy evaluated from the temperature-dependence of Li-ion Transfer Resistance appeared to be independent of the orientation.
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Lithium-ion Transfer on a LixCoO2 thin film electrode prepared by pulsed laser deposition—Effect of orientation-
Journal of Power Sources, 2007Co-Authors: Izumi Yamada, Yasutoshi Iriyama, Takeshi Abe, Zempachi OgumiAbstract:Abstract LiCoO2 thin films with different orientations were fabricated by pulsed laser deposition, and Li-ion Transfer at the interface between the electrolyte and a LiCoO2 thin film electrode was investigated. This study particularly focused on the effect of orientation on Li-ion Transfer. The thin films were shown to be highly crystallized by X-ray diffraction. Charge Transfer Resistance ascribed to Li-ion Transfer at the interface was observed by ac impedance spectroscopy. While Charge Transfer Resistance was strongly influenced by the preferred orientation of LiCoO2 thin film, the activation energy evaluated from the temperature-dependence of Li-ion Transfer Resistance appeared to be independent of the orientation.
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reduction of Charge Transfer Resistance at the lithium phosphorus oxynitride lithium cobalt oxide interface by thermal treatment
Journal of Power Sources, 2005Co-Authors: Yasutoshi Iriyama, Tomonori Kako, Chihiro Yada, Takeshi Abe, Zempachi OgumiAbstract:Abstract An all-solid-state thin-film battery consisting of a c -axis-oriented LiCoO 2 thin-film and a lithium phosphorus oxynitride (LiPON) glass electrolyte was fabricated. Thermal treatment at 473 K after fabrication of the LiPON/LiCoO 2 interface decreased the Charge Transfer Resistance at the interface, and the Resistance was further reduced by prolonging the thermal treatment time. The Charge Transfer Resistance per unit electrode area (interfacial resistivity) of a film battery thermal-treated for 60 min decreased down to 125 Ω cm 2 , which is ca. five times larger than that in the case of an organic electrolyte (1 mol dm −3 LiClO 4 dissolved in propylene carbonate)/LiCoO 2 interface (25 Ω cm 2 ). Due to the reduction of the Charge Transfer Resistance at the LiPON/LiCoO 2 interface, the reaction current of the film battery was greatly increased by the thermal treatment. Also, thermally treated film batteries showed stable electrochemical lithium insertion/extraction properties compared with the batteries using conventional organic electrolytes. Both the voltammograms and the impedance spectra of the film battery maintained their initial shape for over 100 cycles, and the capacity retention ratio per cycle was calculated to be 99.9%.
Xuehui Tian - One of the best experts on this subject based on the ideXlab platform.
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A high surface area N-doped holey graphene aerogel with low Charge Transfer Resistance as high performance electrode of non-flammable thermostable supercapacitors
Carbon, 2019Co-Authors: Qiuming Gao, Hang Zhang, Hong Xiao, Xiao Liang, Tengfei Zhang, Xuehui Tian, Chenhao LiuAbstract:Abstract The high quality carbonaceous material with high surface area and low Charge Transfer Resistance is vital for assembling the advanced supercapacitor. Herein, a novel kind of N-doped holey graphene aerogel (NHGA) is prepared. The NHGA has high specific BET surface area of 446 m2 g−1 and low Charge Transfer Resistance of 0.4 Ω. A large specific capacity of 318.3 F g−1 is obtained at 0.5 A g−1 in a three-electrode configuration in 6 M KOH electrolyte, indicating the high capacity characteristic. As to the NHGA based symmetrical supercapacitor, the specific capacity of 96.0 F g−1 can be achieved at 200 A g−1, presenting its robust rate property. After 10,000 cycles at 2 A g−1, the specific capacity is 262.5 F g−1 with the capacity retention of 98.4%, showing its excellent cyclic stability. Notably, the energy density of 60.3 Wh kg−1 superior to that of the related typical reported supercapacitors, is obtained at the power density of 0.9 kW kg−1 in a non-flammable ionic liquid EMIMTFSI-80 electrolyte, which is effective from 20 to 100 °C. Thus, the advanced electrochemical property of NHGA is distinctly valuable for the supercapacitor utilization especially in the extremely conditions such as fire safety and/or high temperature.
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a large sized reduced graphene oxide with low Charge Transfer Resistance as a high performance electrode for a nonflammable high temperature stable ionic liquid based supercapacitor
Chemsuschem, 2018Co-Authors: Qiuming Gao, Hang Zhang, Hong Xiao, Qiang Zhang, Weiqian Tian, Xuehui TianAbstract:Large-sized reduced graphene oxide prepared was prepared by combined microwave intermittent heating and an extraction process (e.g., 900 W for 10 min (MRG-900-10)) with a lateral size of several micrometers and a thickness of 4-6 monosheets . The MRG-900-10 has a high C/O molar ratio (5.89) and a sp2 C content of 69.0 %, which leads to a fast electronic transmission in the sample. In addition, MRG-900-10 possesses a large specific surface area of 568.2 m2 g-1 , which increases the contact surface area between the active material and the electrolyte, thus enhancing the electron and ion transport in the interfaces when used as the electrode material in supercapacitors. MRG-900-10 possesses a low Charge-Transfer Resistance (≈0.36 Ω). Used as the electrode material for a supercapacitor in 6 m KOH aqueous electrolyte, MRG-900-10 produces a high specific capacity of 327.6 F g-1 at the current density of 0.5 A g-1 . A specific capacity of 248.3 F g-1 was obtained at a high current density of 100 A g-1 , which indicated its high-rate ability. The initial capacity of 92 % can be maintained after 40 000 cycles at 5 A g-1 , which indicated its high cycling stability. As for the MRG-900-10 symmetric supercapacitors, the energy densities of 11.0 and 36.2 Wh kg-1 were obtained in 6 m KOH aqueous and 1 m tetraethylammonium tetrafluoroborate ([TEA]BF4 )/acetonitrile (ACN) electrolytes, respectively. Importantly, a high energy density of 68.6 Wh kg-1 was achieved in the nonflammable ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane)sulfonimide ([EMIM][TFSI])/ACN (80 vol % [EMIM][TFSI]), and the supercapacitor was effective from room temperature to 100 °C.
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A Large‐Sized Reduced Graphene Oxide with Low Charge‐Transfer Resistance as a High‐Performance Electrode for a Nonflammable High‐Temperature Stable Ionic‐Liquid‐Based Supercapacitor
ChemSusChem, 2018Co-Authors: Qiuming Gao, Hang Zhang, Hong Xiao, Qiang Zhang, Weiqian Tian, Xuehui TianAbstract:Large-sized reduced graphene oxide prepared was prepared by combined microwave intermittent heating and an extraction process (e.g., 900 W for 10 min (MRG-900-10)) with a lateral size of several micrometers and a thickness of 4-6 monosheets . The MRG-900-10 has a high C/O molar ratio (5.89) and a sp2 C content of 69.0 %, which leads to a fast electronic transmission in the sample. In addition, MRG-900-10 possesses a large specific surface area of 568.2 m2 g-1 , which increases the contact surface area between the active material and the electrolyte, thus enhancing the electron and ion transport in the interfaces when used as the electrode material in supercapacitors. MRG-900-10 possesses a low Charge-Transfer Resistance (≈0.36 Ω). Used as the electrode material for a supercapacitor in 6 m KOH aqueous electrolyte, MRG-900-10 produces a high specific capacity of 327.6 F g-1 at the current density of 0.5 A g-1 . A specific capacity of 248.3 F g-1 was obtained at a high current density of 100 A g-1 , which indicated its high-rate ability. The initial capacity of 92 % can be maintained after 40 000 cycles at 5 A g-1 , which indicated its high cycling stability. As for the MRG-900-10 symmetric supercapacitors, the energy densities of 11.0 and 36.2 Wh kg-1 were obtained in 6 m KOH aqueous and 1 m tetraethylammonium tetrafluoroborate ([TEA]BF4 )/acetonitrile (ACN) electrolytes, respectively. Importantly, a high energy density of 68.6 Wh kg-1 was achieved in the nonflammable ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane)sulfonimide ([EMIM][TFSI])/ACN (80 vol % [EMIM][TFSI]), and the supercapacitor was effective from room temperature to 100 °C.
Qiuming Gao - One of the best experts on this subject based on the ideXlab platform.
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A high surface area N-doped holey graphene aerogel with low Charge Transfer Resistance as high performance electrode of non-flammable thermostable supercapacitors
Carbon, 2019Co-Authors: Qiuming Gao, Hang Zhang, Hong Xiao, Xiao Liang, Tengfei Zhang, Xuehui Tian, Chenhao LiuAbstract:Abstract The high quality carbonaceous material with high surface area and low Charge Transfer Resistance is vital for assembling the advanced supercapacitor. Herein, a novel kind of N-doped holey graphene aerogel (NHGA) is prepared. The NHGA has high specific BET surface area of 446 m2 g−1 and low Charge Transfer Resistance of 0.4 Ω. A large specific capacity of 318.3 F g−1 is obtained at 0.5 A g−1 in a three-electrode configuration in 6 M KOH electrolyte, indicating the high capacity characteristic. As to the NHGA based symmetrical supercapacitor, the specific capacity of 96.0 F g−1 can be achieved at 200 A g−1, presenting its robust rate property. After 10,000 cycles at 2 A g−1, the specific capacity is 262.5 F g−1 with the capacity retention of 98.4%, showing its excellent cyclic stability. Notably, the energy density of 60.3 Wh kg−1 superior to that of the related typical reported supercapacitors, is obtained at the power density of 0.9 kW kg−1 in a non-flammable ionic liquid EMIMTFSI-80 electrolyte, which is effective from 20 to 100 °C. Thus, the advanced electrochemical property of NHGA is distinctly valuable for the supercapacitor utilization especially in the extremely conditions such as fire safety and/or high temperature.
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A C-coated and Sb-doped SnO2 nanocompsite with high surface area and low Charge Transfer Resistance as ultrahigh capacity lithium ion battery anode
Materials Today Energy, 2019Co-Authors: Qiang Zhang, Qiuming Gao, Hang Zhang, Weiwei Qian, Weiqian TianAbstract:Abstract A novel kind of C-coated and Sb-doped SnO2 (ATO/C) nanocomposite is prepared by a facile hydrothermal method following with high-temperature pyrolysis. The ATO/C particles are uniform, irregular, crystalline and small sizes (∼5–8 nm). High specific BET surface area of 192.1 m2 g−1 and low Charge Transfer Resistance of 98.9 Ω are obtained for the ATO/C. When used as the anode of lithium ion battery, the ATO/C shows an ultrahigh lithium storage capacity. It may deliver an initial disCharge specific capacity of 2634.9 mAh g−1 with the Coulombic efficiency of 88.4% at 0.1 C, and the capacity increases to the highest 2847.4 mAh g−1 after 50 cycles. Even after 1000 cycles at the increased current density of 1 C, the disCharge capacity of 1008.5 mAh g−1 can be preserved indicating its high cyclic stability. Besides, it has a capacity of 370.8 mAh g−1 at the higher current density of 10 C, exhibiting the robust rate property.
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a large sized reduced graphene oxide with low Charge Transfer Resistance as a high performance electrode for a nonflammable high temperature stable ionic liquid based supercapacitor
Chemsuschem, 2018Co-Authors: Qiuming Gao, Hang Zhang, Hong Xiao, Qiang Zhang, Weiqian Tian, Xuehui TianAbstract:Large-sized reduced graphene oxide prepared was prepared by combined microwave intermittent heating and an extraction process (e.g., 900 W for 10 min (MRG-900-10)) with a lateral size of several micrometers and a thickness of 4-6 monosheets . The MRG-900-10 has a high C/O molar ratio (5.89) and a sp2 C content of 69.0 %, which leads to a fast electronic transmission in the sample. In addition, MRG-900-10 possesses a large specific surface area of 568.2 m2 g-1 , which increases the contact surface area between the active material and the electrolyte, thus enhancing the electron and ion transport in the interfaces when used as the electrode material in supercapacitors. MRG-900-10 possesses a low Charge-Transfer Resistance (≈0.36 Ω). Used as the electrode material for a supercapacitor in 6 m KOH aqueous electrolyte, MRG-900-10 produces a high specific capacity of 327.6 F g-1 at the current density of 0.5 A g-1 . A specific capacity of 248.3 F g-1 was obtained at a high current density of 100 A g-1 , which indicated its high-rate ability. The initial capacity of 92 % can be maintained after 40 000 cycles at 5 A g-1 , which indicated its high cycling stability. As for the MRG-900-10 symmetric supercapacitors, the energy densities of 11.0 and 36.2 Wh kg-1 were obtained in 6 m KOH aqueous and 1 m tetraethylammonium tetrafluoroborate ([TEA]BF4 )/acetonitrile (ACN) electrolytes, respectively. Importantly, a high energy density of 68.6 Wh kg-1 was achieved in the nonflammable ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane)sulfonimide ([EMIM][TFSI])/ACN (80 vol % [EMIM][TFSI]), and the supercapacitor was effective from room temperature to 100 °C.
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A Large‐Sized Reduced Graphene Oxide with Low Charge‐Transfer Resistance as a High‐Performance Electrode for a Nonflammable High‐Temperature Stable Ionic‐Liquid‐Based Supercapacitor
ChemSusChem, 2018Co-Authors: Qiuming Gao, Hang Zhang, Hong Xiao, Qiang Zhang, Weiqian Tian, Xuehui TianAbstract:Large-sized reduced graphene oxide prepared was prepared by combined microwave intermittent heating and an extraction process (e.g., 900 W for 10 min (MRG-900-10)) with a lateral size of several micrometers and a thickness of 4-6 monosheets . The MRG-900-10 has a high C/O molar ratio (5.89) and a sp2 C content of 69.0 %, which leads to a fast electronic transmission in the sample. In addition, MRG-900-10 possesses a large specific surface area of 568.2 m2 g-1 , which increases the contact surface area between the active material and the electrolyte, thus enhancing the electron and ion transport in the interfaces when used as the electrode material in supercapacitors. MRG-900-10 possesses a low Charge-Transfer Resistance (≈0.36 Ω). Used as the electrode material for a supercapacitor in 6 m KOH aqueous electrolyte, MRG-900-10 produces a high specific capacity of 327.6 F g-1 at the current density of 0.5 A g-1 . A specific capacity of 248.3 F g-1 was obtained at a high current density of 100 A g-1 , which indicated its high-rate ability. The initial capacity of 92 % can be maintained after 40 000 cycles at 5 A g-1 , which indicated its high cycling stability. As for the MRG-900-10 symmetric supercapacitors, the energy densities of 11.0 and 36.2 Wh kg-1 were obtained in 6 m KOH aqueous and 1 m tetraethylammonium tetrafluoroborate ([TEA]BF4 )/acetonitrile (ACN) electrolytes, respectively. Importantly, a high energy density of 68.6 Wh kg-1 was achieved in the nonflammable ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane)sulfonimide ([EMIM][TFSI])/ACN (80 vol % [EMIM][TFSI]), and the supercapacitor was effective from room temperature to 100 °C.
Jinglei Ping - One of the best experts on this subject based on the ideXlab platform.
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quantifying the intrinsic surface Charge density and Charge Transfer Resistance of the graphene solution interface through bias free low level Charge measurement
Applied Physics Letters, 2016Co-Authors: Jinglei Ping, A Charlie T JohnsonAbstract:Liquid-based bio-applications of graphene require a quantitative understanding of the graphene-liquid interface, with the surface Charge density of adsorbed ions, the interfacial Charge Transfer Resistance, and the interfacial Charge noise being of particular importance. We quantified these properties through measurements of the zero-bias Faradaic Charge-Transfer between graphene electrodes and aqueous solutions of varying ionic strength using a reproducible, low-noise, minimally perturbative Charge measurement technique. The measurements indicated that the adsorbed ions had a negative surface Charge density of approximately −32.8 mC m−2 and that the specific Charge Transfer Resistance was 6.5 ± 0.3 MΩ cm2. The normalized current noise power spectral density for all ionic concentrations tested collapsed onto a 1/fα characteristic with α = 1.1 ± 0.2. All the results are in excellent agreement with predictions of the theory for the graphene-solution interface. This minimally perturbative method for monitori...
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Quantifying the intrinsic surface Charge density and Charge-Transfer Resistance of the graphene-solution interface through bias-free low-level Charge measurement
Applied Physics Letters, 2016Co-Authors: Jinglei Ping, A. T. Charlie JohnsonAbstract:Liquid-based bio-applications of graphene require a quantitative understanding of the graphene-liquid interface, with the surface Charge density of adsorbed ions, the interfacial Charge Transfer Resistance, and the interfacial Charge noise being of particular importance. We quantified these properties through measurements of the zero-bias Faradaic Charge-Transfer between graphene electrodes and aqueous solutions of varying ionic strength using a reproducible, low-noise, minimally perturbative Charge measurement technique. The measurements indicated that adsorbed ions had a negative surface Charge density of approximately -32.8 mC m-2 and that the specific Charge Transfer Resistance was 6.5pm0.3 M${\Omega}$ cm2. The normalized current noise power spectral density for all ionic concentrations tested collapsed onto a 1/f characteristic with ${\alpha}$=1.1pm0.2. All the results are in excellent agreement with predictions of the theory for the graphene-solution interface. This minimally-perturbative method for monitoring Charge-Transfer at the sub-pC scale exhibits low noise and ultra-low power consumption (~ fW), making it well-suited for use in low-level bioelectronics in liquid environments.