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The pressing concerns of environmental sustainability and growing needs of clean energy have raised the demands of carbon and organic based energy storage materials to a higher level. Redox-active organic-carbon composites electrodes are emerging to be enablers for high-performance, high power and long-lasting energy storage solutions, especially for electrochemical capacitors (EC). This review discusses the electrochemical redox active organic compounds and their composites with various carbonaceous materials focusing on capacitive performance. Starting with the most common conducting polymers, we expand the scope to other emerging redox active molecules, compounds and polymers as well as common carbonaceous substrates in composite electrodes, including graphene, carbon nanotube and activated carbon. We then discuss the first-principles computational studies pertaining to the interactions between the components in the composites. The fabrication methodologies for the composites with thin organic coatings are presented with their merits and shortcomings. The capacitive performances and features of the redox active organic-carbon composite electrodes are then summarized. Finally, we offer some perspectives and future directions to achieve a fundamental understanding and to better design organic-carbon composite electrodes for ECs.
Jeanne N’Diaye; Raunaq Bagchi; Jane Howe; Keryn Lian. Redox Active Organic-Carbon Composites for Capacitive Electrodes: A Review. Sustainable Chemistry 2021, 2, 407 -440.
AMA StyleJeanne N’Diaye, Raunaq Bagchi, Jane Howe, Keryn Lian. Redox Active Organic-Carbon Composites for Capacitive Electrodes: A Review. Sustainable Chemistry. 2021; 2 (3):407-440.
Chicago/Turabian StyleJeanne N’Diaye; Raunaq Bagchi; Jane Howe; Keryn Lian. 2021. "Redox Active Organic-Carbon Composites for Capacitive Electrodes: A Review." Sustainable Chemistry 2, no. 3: 407-440.
A tetraphenylporphyrin sulfonate-carbon nanotube (TPPS-CNT) composite was developed and characterized for capacitive charge storage. Density functional theory (DFT) simulations suggested that the adsorption of TPPS on CNT was energetically favored with a strong contribution of the sulfonate groups. The composite electrodes, with a < 2 nm TPPS layer, had up to 80 % increase in volumetric capacitance and faster kinetics over the bare CNT electrodes. The adsorption of TPPS on CNT also led to a 9 % reduction in HOMO-LUMO gap of TPPS, which could be the origin of the synergy for improved performance. The highly capacitive TPPS-CNT composite electrode also had high cycling stability after 10,000 cycles. In a two-electrode symmetrical device, the TPPS-CNT maintained a higher capacitance than that of the CNT device. The device based on the composite materials also had lower charge transfer resistance and faster rate response, very promising for high-rate electrochemical charge storage.
Jeanne N'Diaye; Mohamed Elshazly; Keryn Lian. Capacitive charge storage of tetraphenylporphyrin sulfonate-CNT composite electrodes. Electrochimica Acta 2021, 389, 138593 .
AMA StyleJeanne N'Diaye, Mohamed Elshazly, Keryn Lian. Capacitive charge storage of tetraphenylporphyrin sulfonate-CNT composite electrodes. Electrochimica Acta. 2021; 389 ():138593.
Chicago/Turabian StyleJeanne N'Diaye; Mohamed Elshazly; Keryn Lian. 2021. "Capacitive charge storage of tetraphenylporphyrin sulfonate-CNT composite electrodes." Electrochimica Acta 389, no. : 138593.
Kevin Ton; Asia Vighi; Keryn Lian; Ta-Ya Chu; Ye Tao. Communication—Phosphoric Acid Based Proton Conducting Polymer Electrolytes for Organic Field Effect Transistor Gate Dielectrics. ECS Journal of Solid State Science and Technology 2021, 10, 055003 .
AMA StyleKevin Ton, Asia Vighi, Keryn Lian, Ta-Ya Chu, Ye Tao. Communication—Phosphoric Acid Based Proton Conducting Polymer Electrolytes for Organic Field Effect Transistor Gate Dielectrics. ECS Journal of Solid State Science and Technology. 2021; 10 (5):055003.
Chicago/Turabian StyleKevin Ton; Asia Vighi; Keryn Lian; Ta-Ya Chu; Ye Tao. 2021. "Communication—Phosphoric Acid Based Proton Conducting Polymer Electrolytes for Organic Field Effect Transistor Gate Dielectrics." ECS Journal of Solid State Science and Technology 10, no. 5: 055003.
The development of neutral pH polymer electrolytes has enabled high-performance solid-state, thin, and flexible electrochemical capacitors (ECs) to provide power for future consumer electronics and Internet-of-Thing devices. Notwithstanding their promising prospect, there is still some lack of understandings or disconnections from fundamental science to practical applications of these electrolytes. In this review, we provide an overview of state-of-the-art studies on ECs with neutral pH electrolytes in both liquid and solid configurations. Starting from the fundamental studies on the voltage window and ion conduction of salt species in liquid solution to polymer electrolytes, key considerations in developing neutral pH polymer electrolytes are discussed. The performance of the polymer electrolytes along with their enabled solid symmetric and asymmetric EC devices, as well as some enhanced functionalities are presented. The future directions for research on neutral pH polymer electrolytes are proposed, expected to provide reference for further enriching the fundamental knowledge and improving the device performances.
Alvin Virya; Keryn Lian. A review of neutral pH polymer electrolytes for electrochemical capacitors: Transitioning from liquid to solid devices. Materials Reports: Energy 2020, 1, 100005 .
AMA StyleAlvin Virya, Keryn Lian. A review of neutral pH polymer electrolytes for electrochemical capacitors: Transitioning from liquid to solid devices. Materials Reports: Energy. 2020; 1 (1):100005.
Chicago/Turabian StyleAlvin Virya; Keryn Lian. 2020. "A review of neutral pH polymer electrolytes for electrochemical capacitors: Transitioning from liquid to solid devices." Materials Reports: Energy 1, no. 1: 100005.
Synergy between a redox active polymer and a polyoxometalate leading to an extended voltage window and capacitive charge storage.
Jeanne N'Diaye; Shaheer Siddiqui; Kin Long (Thomas) Pak; Keryn Lian. Layer-by-layer assembly of inorganic–organic molybdovanadogermanic (GeMoV)-polyluminol composite electrodes for capacitive charge storage. Journal of Materials Chemistry A 2020, 8, 23463 -23472.
AMA StyleJeanne N'Diaye, Shaheer Siddiqui, Kin Long (Thomas) Pak, Keryn Lian. Layer-by-layer assembly of inorganic–organic molybdovanadogermanic (GeMoV)-polyluminol composite electrodes for capacitive charge storage. Journal of Materials Chemistry A. 2020; 8 (44):23463-23472.
Chicago/Turabian StyleJeanne N'Diaye; Shaheer Siddiqui; Kin Long (Thomas) Pak; Keryn Lian. 2020. "Layer-by-layer assembly of inorganic–organic molybdovanadogermanic (GeMoV)-polyluminol composite electrodes for capacitive charge storage." Journal of Materials Chemistry A 8, no. 44: 23463-23472.
The ion-conducting properties of two neutral pH polymer electrolytes using polyacrylamide (PAM) with Li2SO4 or Na2SO4 ion conductors were studied and compared at various temperatures. Their electrochemical performance over temperatures was correlated to the respective thermal characteristics. Ion hopping was considered as the likely mechanism for both electrolytes at and above ambient temperatures, determined by their low activation energies for conduction. At elevated temperatures where both electrolytes contained fully solvated ions, the ionic conductivity was highly dependent on the mobility of its hydrated ions. While Na2SO4-PAM showed higher ionic conductivity than Li2SO4-PAM at elevated temperatures, the trend was reversed at sub-zero conditions. Cells with Li2SO4-PAM electrolyte maintained good capacitive behavior at -30 ˚C, whereas the cells with Na2SO4-PAM had a catastrophic loss of capacitance at low temperatures. The low temperature phenomenon was correlated to the formation of crystal hydrate with different amount of crystallized water, which affected the hopping sites for ion conduction differently. This understanding will provide insights for materials and operating condition selections in the next generations of aqueous-based polymer electrolytes.
Alvin Virya; Gary Liu; Keryn Lian. A Comparative Study of Sulfate-Based Neutral pH Polymer Electrolytes: Effects of Temperature on Ionic Conductivity. Journal of The Electrochemical Society 2020, 167, 1 .
AMA StyleAlvin Virya, Gary Liu, Keryn Lian. A Comparative Study of Sulfate-Based Neutral pH Polymer Electrolytes: Effects of Temperature on Ionic Conductivity. Journal of The Electrochemical Society. 2020; 167 (12):1.
Chicago/Turabian StyleAlvin Virya; Gary Liu; Keryn Lian. 2020. "A Comparative Study of Sulfate-Based Neutral pH Polymer Electrolytes: Effects of Temperature on Ionic Conductivity." Journal of The Electrochemical Society 167, no. 12: 1.
Jeanne N'diaye; Shaheer Siddiqui; Keryn Lian. Surface Engineering of Carbon Nanotubes with Inorganic-Organic Materials for Electrochemical Capacitors. ECS Meeting Abstracts 2020, MA2020-01, 2830 -2830.
AMA StyleJeanne N'diaye, Shaheer Siddiqui, Keryn Lian. Surface Engineering of Carbon Nanotubes with Inorganic-Organic Materials for Electrochemical Capacitors. ECS Meeting Abstracts. 2020; MA2020-01 (51):2830-2830.
Chicago/Turabian StyleJeanne N'diaye; Shaheer Siddiqui; Keryn Lian. 2020. "Surface Engineering of Carbon Nanotubes with Inorganic-Organic Materials for Electrochemical Capacitors." ECS Meeting Abstracts MA2020-01, no. 51: 2830-2830.
Polymer electrolytes are key enablers for solid-state electrical double layer capacitors (EDLCs) that have thin and flexible form factors. Aqueous-based polymer electrolytes with neutral pH are interesting for their non-corrosiveness, intrinsically safe, and wider voltage window from high overpotential on water decomposition [1-3]. Previously, two neutral pH polymer electrolytes based on polyacrylamide (PAM) host and Li2SO4 [4] or Na2SO4 [5] as ion conductor were developed. These two systems demonstrated good chemical stability (shelf-life >30 days) and wide voltage window (1.9 V with activated carbon). Na2SO4-PAM showed higher ionic conductivity than Li2SO4-PAM under ambient conditions. Nonetheless, the effects of temperature and change in structure (e.g. freezing) to the electrochemical performance are still unclear. In this study, the performances of Li2SO4-PAM and Na2SO4-PAM at different temperatures were compared. The objectives were to (i) understand the ion conduction mechanisms within the polymeric structure, (ii) investigate the working temperature range of these electrolytes, and (iii) correlate the ion-conducting behaviour to their respective thermal properties, especially at the temperature below 0 °C. Metallic cells were constructed to study the electrochemical characteristics of the polymer electrolytes, while differential scanning calorimetry (DSC) was employed to characterize the thermal properties. From the activation energy of conduction above ambient temperatures, ion hopping was considered as the primary mechanism for ion movement in both electrolytes. Interestingly, although Li2SO4-PAM was able to maintain capacitive behaviour <0 ˚C, Na2SO4-PAM underwent severe loss in capacitive behaviour and significant loss in ionic conductivity. By comparing the DSC curves against the respective ionic conductivity at low temperatures (Fig. 1), the amount of crystallized water involved during freezing/melting was deduced as the source of this behaviour. This study elucidated the structure-performance relationship of polymer electrolytes at the low temperature conditions. References: [1] K. Fic, G. Lota, M. Meller, and E. Frackowiak, "Novel insight into neutral medium as electrolyte for high-voltage supercapacitors," Energy & Env. Sci., 2, 2012 [2] C. Zhong, et al., "A review of electrolyte materials and compositions for electrochemical supercapacitors," Chem. Soc. Rev., 44, 2015 [3] H.Y. Jin, Z.H. Peng, W.M. Tang, and H.L.W. Chan, "Controllable functionalized carbon fabric for high-performance all-carbon-based supercapacitors", RSC Advances, 4, 2014 [4] A. Virya and K. Lian, "Li2SO4-polyacrylamide polymer electrolytes for 2.0 V solid symmetric supercapacitors," Electrochem. Comm., 81, 2017 [5] A. Virya, J. Abella, A. Grindal, and K. Lian, "Na2SO4‐polyacrylamide electrolytes and enabled solid‐state electrochemical capacitors," Batteries & Supercaps, 2019 Figure 1: Ionic conductivities at various low temperature overlaid with DSC curve for (a) Li2SO4-PAM and (b) Na2SO4-PAM Figure 1
Alvin Virya; Gary Liu; Keryn Lian. A Comparative Study of Sulfate-Based Neutral pH Polymer Electrolytes for Low Temperature Applications. ECS Meeting Abstracts 2020, MA2020-01, 1602 -1602.
AMA StyleAlvin Virya, Gary Liu, Keryn Lian. A Comparative Study of Sulfate-Based Neutral pH Polymer Electrolytes for Low Temperature Applications. ECS Meeting Abstracts. 2020; MA2020-01 (38):1602-1602.
Chicago/Turabian StyleAlvin Virya; Gary Liu; Keryn Lian. 2020. "A Comparative Study of Sulfate-Based Neutral pH Polymer Electrolytes for Low Temperature Applications." ECS Meeting Abstracts MA2020-01, no. 38: 1602-1602.
A free-standing electrode with hierarchical pores and graphite surface is derived from wood pellet via a catalytic graphitization. The aligned microchannels of natural wood and the high conductivity of graphite has enabled fast ionic and electronic transport. The high porosity leads to a large surface area for the deposition of redox active materials. After an electrodeposition of Ni(OH)2 and Co(OH)2 on the graphitized wood, the electrode exhibits a high areal capacity without significant degradation in the electrochemical performance. An asymmetric supercapacitor, with a graphitized wood as the negative electrode and a Ni(OH)2/Co(OH)2 deposited wood as the positive electrode, shows a high areal capacitance of 2 409 m F/cm2, a high energy density of 0.75 mWh/cm2 at a power density of 0.750 mW/cm2. This high performance, free-standing and biodegradable wood-derived asymmetric supercapacitor demonstrates promising applications as energy storage devices.
Zhen Liu; Haoran Wu; Yao Li; Jiawang Song; Wang Zhang; Hao Yuan; Muhammad Imtiaz; Shenmin Zhu; Keryn Lian. Redox active coating on graphite surface of hierarchically porous wood electrodes for supercapacitor application. Materials Today Communications 2020, 24, 101045 .
AMA StyleZhen Liu, Haoran Wu, Yao Li, Jiawang Song, Wang Zhang, Hao Yuan, Muhammad Imtiaz, Shenmin Zhu, Keryn Lian. Redox active coating on graphite surface of hierarchically porous wood electrodes for supercapacitor application. Materials Today Communications. 2020; 24 ():101045.
Chicago/Turabian StyleZhen Liu; Haoran Wu; Yao Li; Jiawang Song; Wang Zhang; Hao Yuan; Muhammad Imtiaz; Shenmin Zhu; Keryn Lian. 2020. "Redox active coating on graphite surface of hierarchically porous wood electrodes for supercapacitor application." Materials Today Communications 24, no. : 101045.
A novel rechargeable PbO2-Zn battery system using Zn as negative and PbO2 as positive electrodes in a KOH-H2SO4 dual-electrolyte is developed. Using a bi-polar ion exchange membrane that effectively prevents the H+ and OH− from neutralization, the positive and negative electrodes operate in the respective electrolytes with different pH. The Zn electrode provides a low potential of −1.3 V in KOH solution and the PbO2 has a high potential of +1.5 V in H2SO4 solution. This resulted in a cell operating voltage of 2.8 V in an aqueous electrolyte. The system also demonstrated a high rate performance and good rechargeability. This simple, low-cost system not only overcomes the thermodynamic limit of water decomposition and achieves a high voltage aqueous based battery, but also provides a new approach in design of future electrochemical devices.
Haoran Wu; Szu-Jia Liu; Keryn Lian. Aqueous based dual-electrolyte rechargeable Pb–Zn battery with a 2.8 V operating voltage. Journal of Energy Storage 2020, 29, 101305 .
AMA StyleHaoran Wu, Szu-Jia Liu, Keryn Lian. Aqueous based dual-electrolyte rechargeable Pb–Zn battery with a 2.8 V operating voltage. Journal of Energy Storage. 2020; 29 ():101305.
Chicago/Turabian StyleHaoran Wu; Szu-Jia Liu; Keryn Lian. 2020. "Aqueous based dual-electrolyte rechargeable Pb–Zn battery with a 2.8 V operating voltage." Journal of Energy Storage 29, no. : 101305.
An increasing number of focus has been paid to the study of supercapacitors in the context of the increasing demand for energy storage. As an important component of supercapacitors, the electrolyte has become a focus of research. In this work, an inexpensive and readily approach for synthesizing the polymer electrolytes was established by introducing multi‐walled carbon nanotubes (MWCNTs) as the filler on the basis of cross‐linked chitosan (CS) and poly‐(diallyldimethylammonium chloride) (PDDA), followed by a facile ion‐exchange in the KOH solution. The resultant MWCNTs‐CP‐OH− membrane manifests superb chemical stability, high hydroxide conductivity (0.033 S cm−1), and enhanced mechanical/chemical properties. Consequently, the fabricated all‐solid‐state supercapacitors using MWCNTs‐CP‐OH− composite membrane as a polymer electrolyte displayed prominent cyclic stability over 4000 cycles with 75.3% retention of the capacitance. Aforementioned merits make the MWCNTs‐CP‐OH− membrane highly promising candidate electrolyte material in all‐solid‐state supercapacitors.
Xiaojing Guo; Min Wang; Jak Li; Yanan Wei; Keryn Lian; Jinli Qiao. Multi‐walled carbon nanotubes incorporation into cross‐linked novel alkaline ion‐exchange membrane for high efficiency all‐solid‐state supercapacitors. International Journal of Energy Research 2020, 44, 4038 -4047.
AMA StyleXiaojing Guo, Min Wang, Jak Li, Yanan Wei, Keryn Lian, Jinli Qiao. Multi‐walled carbon nanotubes incorporation into cross‐linked novel alkaline ion‐exchange membrane for high efficiency all‐solid‐state supercapacitors. International Journal of Energy Research. 2020; 44 (5):4038-4047.
Chicago/Turabian StyleXiaojing Guo; Min Wang; Jak Li; Yanan Wei; Keryn Lian; Jinli Qiao. 2020. "Multi‐walled carbon nanotubes incorporation into cross‐linked novel alkaline ion‐exchange membrane for high efficiency all‐solid‐state supercapacitors." International Journal of Energy Research 44, no. 5: 4038-4047.
A facile and one-pot hydrothermal methodology for producing phosphate functionalized reduced graphene oxide with enhanced volumetric capacitance is reported.
Nicolas Roland Tanguy; Jeanne N’Diaye; Mohammad Arjmand; Keryn Lian; Ning Yan. Facile one-pot synthesis of water-dispersible phosphate functionalized reduced graphene oxide toward high-performance energy storage devices. Chemical Communications 2019, 56, 1373 -1376.
AMA StyleNicolas Roland Tanguy, Jeanne N’Diaye, Mohammad Arjmand, Keryn Lian, Ning Yan. Facile one-pot synthesis of water-dispersible phosphate functionalized reduced graphene oxide toward high-performance energy storage devices. Chemical Communications. 2019; 56 (9):1373-1376.
Chicago/Turabian StyleNicolas Roland Tanguy; Jeanne N’Diaye; Mohammad Arjmand; Keryn Lian; Ning Yan. 2019. "Facile one-pot synthesis of water-dispersible phosphate functionalized reduced graphene oxide toward high-performance energy storage devices." Chemical Communications 56, no. 9: 1373-1376.
A highly ionic‐conductive and high‐performance neutral pH polymer electrolyte comprises of Na2SO4 and polyacrylamide (PAM) was developed for solid electrochemical double‐layer capacitors (EDLCs). Na2SO4 was compared with Li2SO4 baseline in liquid electrolyte and exhibited higher ionic conductivity and identical stability window. Na2SO4‐PAM electrolytes were optimized by varying their salt‐to‐polymer ratio. While all compositions show excellent stability for over 30‐day tracking period, an ionic conductivity of ca. 30 mS cm‐1 was attained at 10,000:1 molar ratio of Na2SO4:PAM, among the highest reported for neutral pH polymer electrolytes. Raman spectroscopy verified that the electrolyte maintained well‐hydrated ions throughout the 30 days monitoring period. Solid EDLCs were constructed using activated carbon electrodes and Na2SO4‐PAM electrolyte. They exhibited a wide 1.9 V operating window at 50 mV s‐1 CV scan rate, with comparable capacitance to its liquid baseline. The solid EDLCs outperformed many symmetric devices in terms of energy and power densities. They also displayed good rate capability (up to 500 mV s‐1 ) and excellent cycle life (>8,000 cycles).
Alvin Vimala Virya; Justin Abella; Andrew Grindal; Keryn Lian. Na 2 SO 4 ‐Polyacrylamide Electrolytes and Enabled Solid‐State Electrochemical Capacitors. Batteries & Supercaps 2019, 3, 194 -200.
AMA StyleAlvin Vimala Virya, Justin Abella, Andrew Grindal, Keryn Lian. Na 2 SO 4 ‐Polyacrylamide Electrolytes and Enabled Solid‐State Electrochemical Capacitors. Batteries & Supercaps. 2019; 3 (2):194-200.
Chicago/Turabian StyleAlvin Vimala Virya; Justin Abella; Andrew Grindal; Keryn Lian. 2019. "Na 2 SO 4 ‐Polyacrylamide Electrolytes and Enabled Solid‐State Electrochemical Capacitors." Batteries & Supercaps 3, no. 2: 194-200.
Since the beginning of this century, considerable research efforts have focused on solid supercapacitors that leverage hydroxide (OH−) ion conducting polymer electrolytes as a high performance, safe energy storage technology, capable of lightweight and flexible architectures. Here, we present an overview of the state-of-the-art solid supercapacitors enabled by OH− ion conducting polymer electrolytes. We found that progress regarding OH− ion conducting polymer electrolytes is slow compared with others such as proton conducting electrolytes. Furthermore, their role in the capacitance, rate capability, and long-term reliability of solid supercapacitors is unclear. This has resulted in many demonstrations of materials that are excellent in OH− media, but there is no clear road map moving forward due to the limited availability of viable polymer electrolyte chemistry. In this review, we briefly introduce the fundamentals of supercapacitors, and the mechanisms for OH− ion conduction in a polymer matrix while identifying several important relationships between the properties of the polymer electrolyte and the performance of the solid supercapacitor. We categorized OH− ion conducting polymer electrolytes into two types: anion exchange membranes and alkaline polymer electrolytes based on composition and synthesis. The performance and shortcomings of solid supercapacitors enabled by these classes of electrolytes are discussed. Some perspectives are offered to address the areas of improvement. Finally, we propose key research directions to facilitate robust contributions for advanced solid supercapacitors based on OH− ion conducting polymer electrolytes.
Jak Li; Jinli Qiao; Keryn Lian. Hydroxide ion conducting polymer electrolytes and their applications in solid supercapacitors: A review. Energy Storage Materials 2019, 24, 6 -21.
AMA StyleJak Li, Jinli Qiao, Keryn Lian. Hydroxide ion conducting polymer electrolytes and their applications in solid supercapacitors: A review. Energy Storage Materials. 2019; 24 ():6-21.
Chicago/Turabian StyleJak Li; Jinli Qiao; Keryn Lian. 2019. "Hydroxide ion conducting polymer electrolytes and their applications in solid supercapacitors: A review." Energy Storage Materials 24, no. : 6-21.
Yao Li; Fufei An; Haoran Wu; Shenmin Zhu; Chenyangzi Lin; Mengdan Xia; Kun Xue; Di Zhang; Keryn Lian. A NiCo2S4 /hierarchical porous carbon for high performance asymmetrical supercapacitor. Journal of Power Sources 2019, 427, 138 -144.
AMA StyleYao Li, Fufei An, Haoran Wu, Shenmin Zhu, Chenyangzi Lin, Mengdan Xia, Kun Xue, Di Zhang, Keryn Lian. A NiCo2S4 /hierarchical porous carbon for high performance asymmetrical supercapacitor. Journal of Power Sources. 2019; 427 ():138-144.
Chicago/Turabian StyleYao Li; Fufei An; Haoran Wu; Shenmin Zhu; Chenyangzi Lin; Mengdan Xia; Kun Xue; Di Zhang; Keryn Lian. 2019. "A NiCo2S4 /hierarchical porous carbon for high performance asymmetrical supercapacitor." Journal of Power Sources 427, no. : 138-144.
A systematic study on the key factors affecting the performance of electrochemical capacitor electrodes in solid electrolytes and their liquid electrolyte baselines was conducted. The study combined a test matrix of two types of activate carbons (AC) with different specific surface area, pore size and structures at various loadings in three solid and liquid electrolyte pairs. Working curves on loading vs. capacitance of these ACs in solid and corresponding liquid electrolytes revealed the correlation and interconnection of these material properties. A cross-sectional microscopic elemental analysis was used to identify and visualize the influence of these factors. When transition from liquid to solid polymer electrolytes, the infiltration of the electrolyte into the porous carbon plays a critical role in the performance of AC electrode especially at a high loading. When the precursor solution of polymer electrolyte was relatively less viscous, AC with an open structure and mesopores had similar capacitance as their liquid counterparts. A highly viscous precursor solution blocked some access of the polymer electrolytes into the bulk electrode, making infiltration less effective at high loading. This work shows an approach to project the performance of carbon electrodes in solid electrolytes and can provide directions for developing solid-state electrochemical capacitors.
Haoran Wu; Matthew Genovese; Kevin Ton; Keryn Lian. A Comparative Study of Activated Carbons from Liquid to Solid Polymer Electrolytes for Electrochemical Capacitors. Journal of The Electrochemical Society 2019, 166, A821 -A828.
AMA StyleHaoran Wu, Matthew Genovese, Kevin Ton, Keryn Lian. A Comparative Study of Activated Carbons from Liquid to Solid Polymer Electrolytes for Electrochemical Capacitors. Journal of The Electrochemical Society. 2019; 166 (6):A821-A828.
Chicago/Turabian StyleHaoran Wu; Matthew Genovese; Kevin Ton; Keryn Lian. 2019. "A Comparative Study of Activated Carbons from Liquid to Solid Polymer Electrolytes for Electrochemical Capacitors." Journal of The Electrochemical Society 166, no. 6: A821-A828.
Electrochemically active polyluminol was synthesized using an oxidative chemical polymerization reaction. The chemically polymerized luminol (CpLum) exhibited reversible oxidation and reduction reactions with fast kinetics. From Fourier transform infrared spectroscopy analyses, the polymerization occurred by the conversion of primary amine groups into secondary amine groups. The polymer contained benzoid and quinoid segments which were confirmed by UV–visible spectroscopy and X-ray photoelectron spectroscopy. Thermal analysis revealed the semi-crystalline nature of CpLum, with two thermal events at 99 °C and 152 °C corresponding to a glass transition and a melting temperature. The interesting features and electrochemical activities may lead to applications in energy storage.
Jeanne N'Diaye; Keryn Lian. Investigation of the chemical structure and electrochemical activity of a chemically polymerized luminol. Journal of Electroanalytical Chemistry 2019, 839, 90 -95.
AMA StyleJeanne N'Diaye, Keryn Lian. Investigation of the chemical structure and electrochemical activity of a chemically polymerized luminol. Journal of Electroanalytical Chemistry. 2019; 839 ():90-95.
Chicago/Turabian StyleJeanne N'Diaye; Keryn Lian. 2019. "Investigation of the chemical structure and electrochemical activity of a chemically polymerized luminol." Journal of Electroanalytical Chemistry 839, no. : 90-95.
An ultra-high rate solid-state electrochemical capacitor (EC) is studied for 60 Hz AC line-filtering applications. The combination of vertically-oriented graphene nanosheet electrodes and a hydroxide ion-conducting tetraethylammonium hydroxide-polyacrylamide polymer electrolyte enabled an interdigitated planar EC with capacitive behaviour at rates up to 1000 V s−1 and a response time of less than 1 ms. This performance level was maintained for over 3 weeks without capacitor packaging. The EC responded capacitively at 120 Hz at a temperature of 120 °C, demonstrating outstanding high-temperature resiliency. Thermal and chemical characterizations of the polymer electrolyte revealed that electrochemical changes caused by high-temperature are reversible. Two competing factors were identified that govern solid-state capacitor performance at elevated temperatures.
Jak Li; Han Gao; John R. Miller; Ronald A. Outlaw; Sue Butler; Keryn Lian. Study of solid alkaline electrolyte under high temperatures and its application in electrochemical capacitors for AC line-filtering. Journal of Power Sources 2019, 417, 145 -149.
AMA StyleJak Li, Han Gao, John R. Miller, Ronald A. Outlaw, Sue Butler, Keryn Lian. Study of solid alkaline electrolyte under high temperatures and its application in electrochemical capacitors for AC line-filtering. Journal of Power Sources. 2019; 417 ():145-149.
Chicago/Turabian StyleJak Li; Han Gao; John R. Miller; Ronald A. Outlaw; Sue Butler; Keryn Lian. 2019. "Study of solid alkaline electrolyte under high temperatures and its application in electrochemical capacitors for AC line-filtering." Journal of Power Sources 417, no. : 145-149.
This study focuses on the performance of solid electrochemical capacitors (ECs) after being subjected to a series of bending tests. A systematic approaching using cyclic voltammetry to track the electrodes and devices reveals the effects of bending parameters include angle, radius and number of cycles. For a single bending cycle, the bending angles from 90° to 180° has little effect on the performance of the solid EC cells. A small bending radius (e.g. < 5mm) increases the cell resistance as a result of delamination at the current collector/electrode interface. For repeated bending cycles, even a relatively small bending angle with a large radius causes soft shorting by the localized deformations at the electrolyte-separator film. Cross-sectional analyses with scanning electron microscopy support these notions and reveal the failure mechanism of these solid-state, thin and flexible ECs after bending. Although the approach is demonstrated on a sandwiched solid EC cell with a commercial activated carbon and a neutral pH polymer electrolyte, it can be extended to other solid-state, flexible, and wearable electrochemical devices.
Haoran Wu; Julian Rosas; Keryn Lian. A Study of Bending Properties of Solid Electrochemical Capacitors. Journal of The Electrochemical Society 2019, 166, A15 -A20.
AMA StyleHaoran Wu, Julian Rosas, Keryn Lian. A Study of Bending Properties of Solid Electrochemical Capacitors. Journal of The Electrochemical Society. 2019; 166 (2):A15-A20.
Chicago/Turabian StyleHaoran Wu; Julian Rosas; Keryn Lian. 2019. "A Study of Bending Properties of Solid Electrochemical Capacitors." Journal of The Electrochemical Society 166, no. 2: A15-A20.
A polymer electrolyte was developed by blending lithium (LiPAA) with non-ionic polyacrylamide (PAM). The LiPAA-PAM showed synergic effect and achieved an ionic conductivity of 13.8 ± 2.4 mS cm−1, higher than previously developed neutral pH polymer electrolytes. Chemical and structural characterizations of the LiPAA-PAM films revealed a stable homogeneous amorphous structure. The performance of double layer capacitors using LiPAA-PAM electrolyte system was demonstrated using YP-50F activated carbon electrodes. These solid cells demonstrated wide voltage window (1.5 V), good cycle life (>10,000 cycles), and excellent rate capability (up to 500 mV s−1 in cyclic voltammetry).
Alvin Virya; Keryn Lian. Lithium polyacrylate-polyacrylamide blend as polymer electrolytes for solid-state electrochemical capacitors. Electrochemistry Communications 2018, 97, 77 -81.
AMA StyleAlvin Virya, Keryn Lian. Lithium polyacrylate-polyacrylamide blend as polymer electrolytes for solid-state electrochemical capacitors. Electrochemistry Communications. 2018; 97 ():77-81.
Chicago/Turabian StyleAlvin Virya; Keryn Lian. 2018. "Lithium polyacrylate-polyacrylamide blend as polymer electrolytes for solid-state electrochemical capacitors." Electrochemistry Communications 97, no. : 77-81.