Lead-carbon Hybrid Ultracapacitors Research Articles

Bio-Waste Derived Honeycomb Structured Activated Carbons as Anode Materials for Lead-Carbon Hybrid Ultracapacitors

Lead-carbon hybrid ultracapacitors (Pb-C HUC) are the solution to the sulfation issue of lead-acid batteries. The Pb-C HUCs are of much interest due to the aqueous system with longer cycle life and higher power density. Here, honeycomb structured porous activated carbons with 1790 m2 g−1 of surface area were synthesized from Carica papaya biowaste by chemical treatment followed by carbonization at 800 °C (PAC-800). PAC-800 composite electrode delivers a specific capacitance of 250 F g−1 at 1 Ag−1 and has 10000 stable cycle life in 4.5 M H2SO4. Further, a kinetic study of the PAC-800 electrode illustrates that at 2 mV s−1, they show 61% of capacitive and 39% of pseudocapacitive charge storage. Pb-C HUCs fabricated using in situ activated PbO2 sheet as cathode and PAC-800 composite electrode as anode delivers 390 F g−1 at 1 A g−1 and have 93% capacitance retention over 15000 cycles at 5 A g−1. Further, the current Pb-C HUC results are compared with commercially available high surface area (2484 m2 g−1) carbons based Pb-C HUCs. This work illustrates an easy, scalable synthesis root for biowaste carbons and their electrochemical performance in Pb-C HUCs, which is on par with commercial high surface area carbons.

Electrochemically Exfoliated Layered Carbons as Sustainable Anode Materials for Lead Carbon Hybrid Ultracapacitor

AbstractLead‐carbon hybrid ultracapacitors (Pb−C HUC) have become apparent as a way out of the sulfation issue of lead‐acid batteries, simultaneously enhancing the system‘s power density and cycle life. In this work, exfoliated graphene oxides (EGO) were synthesized by the electrochemical exfoliation method followed by chemical activation and carbonization at 600 °C (AEGO‐600). The composite electrode delivered 800 F g−1 capacitance at 1 A g−1. The Pb−C HUC fabricated using AEGO‐600 anode and PbO2 cathode can achieve capacitance of 325 F g−1 at 10 A g−1 and retain 71 % capacitance after 15000 charge‐discharge cycles in the voltage range of 2.3–0.8 V. The highly stable capacitance was due to the formation of layered carbons in AEGO‐600 that enhanced the favorable electrolyte ion assessment to maximum active sites. Owing to the facile, cost‐effective synthesis approach and better charge storage behavior, the activated‐exfoliated graphene oxides thus produced could be suitable candidates for future hybrid ultracapacitor systems.

Lead–carbon hybrid ultracapacitors fabricated by using sulfur, nitrogen-doped reduced graphene oxide as anode material derived from spent lithium-ion batteries

Lead–carbon hybrid ultracapacitors fabricated by using sulfur, nitrogen-doped reduced graphene oxide as anode material derived from spent lithium-ion batteries

Bio‐waste derived carbon nano‐onions as an efficient electrode material for symmetric and lead‐carbon hybrid ultracapacitors

Carbon and metal oxide nanocomposites have been extensively studied as electrode materials to develop energy and power-dense supercapacitors in recent years. Nevertheless, nano carbons with improved porosity and functional moieties are the most eco-friendly and cost-effective supercapacitor materials. In this work, carbon nano-onions (CNOs) synthesized by a single-step flame soot collection method, subsequently calcined at 600°C in an inert environment (CNO-600), are used as electrode material for the supercapacitors. CNO-600 s have a layer-by-layer nano onion structure with a ~25 nm particle size and a Brunauer–Emmett–Teller surface area of 147 m2 g−1. CNO-600 delivers 266 and 186 F g−1 of capacitance at 0.5 A g−1 for half cells and symmetric ultracapacitors, respectively. Ultracapacitors show capacitance retention of 91% with 20 000 GCD cycles in 1 M H2SO4 electrolyte. The stable capacitance of CNO-600 is due to easy intercalation/de-intercalation of electrolyte ions and electrons in the layer-by-layer structure of CNOs, contributing to pseudocapacitive charge storage with electric double layer capacitor behavior. The lead-carbon hybrid ultracapacitor fabricated using CNO-600 as anode material and PbO2 as cathode delivers a specific capacitance of 515 F g−1 at 1 A g−1 in 4.5 M H2SO4 electrolyte in the voltage range of 2.3 and 0.6 V. The substantial improvement of charge storage in CNO-based symmetric and lead-carbon hybrid system, demonstrate an excellent opportunity for the development of high-performance supercapacitors.

Polypyrrole-MoS2 Nanopetals as Efficient Anode Material for Lead-Based Hybrid Ultracapacitors

Lead-carbon hybrid ultracapacitors are being a solution to the lead-acid battery to solve issues of sulfation and improve cycle life. In this work, we present polypyrrole-MoS2–based composite anode material coupled with PbO2 cathode for the lead-carbon hybrid ultracapacitors. Ultracapacitor behavior of polypyrrole-MoS2 based composite shows significant improvement in capacitance and power-density due to the synergetic effect of the high conducting polymer network and redox behavior of MoS2. The nanopetal shaped composite materials have been synthesized by a simple hydrothermal method at 160 oC by using polypyrrole. The composite Polypyrrole-MoS2 electrode delivers a specific capacitance of 782 Fg−1 at 1 A g−1 current density with low areal specificresistance (1.15 Ohm cm2) in an aqueous H2SO4 electrolyte. Besides, the PbO2/Polypyrrole-MoS2 hybrid ultracapacitors deliver capacitance of 285 F g−1 at 5 A g−1 and stable over 10,000 cycles. The improved capacitive behavior of the Polypyrrole-MoS2 composite electrode is due to the redox behavior, effective intercalation of H+ ions into the composite frameworks by transporting the electrons as well as have easy doping/de-doping of sulfate ions to the polypyrrole network.

Nitrogen phosphorous derived carbons from Peltophorum pterocarpum leaves as anodes for lead–carbon hybrid ultracapacitors

Abstract Lead–carbon hybrid ultra-capacitors are emerging as an alternative to a lead-acid battery, owing to the absence of sulfation, thereby enhancing cycle life and C rate performances. In this work, Nitrogen and Phosphorous derived carbons are synthesized from the Peltophorum pterocarpum leaves by treating with phosphoric acid followed by carbonization at 550 °C for 3 hrs. These carbons contain about 3.76% of Nitrogen and 1.26% of Phosphorous and have a BET surface area of 443 m2 g−1. Specific capacitances of 1032 F g−1 and 640 F g−1 at current densities of 1 A g−1 and 10 A g−1, respectively in 4.5 M. sulfuric acid are achieved for these carbon-based electrodes. The hybrid ultra-capacitor fabricated by using PbO2 positive electrode and Nitrogen and Phosphorous derived carbons coated on to graphite sheet as a negative electrode shows cycling stability with capacitance retention of >95% for about 15,000 cycles at an applied current density of 5 A g−1. The pseudocapacitive nature of as-synthesized carbon exhibits significant improvement in electrochemical performance in lead–carbon ultra-capacitors.

Boron, Nitrogen-Doped Porous Carbon Derived from Biowaste Orange Peel as Negative Electrode Material for Lead-Carbon Hybrid Ultracapacitors

Lead-Carbon hybrid ultracapacitors have attracted attention in recent times due to high power density and remarkably long cycling stability. Herein, we report bio-waste orange peel derived B, N doped porous carbons as negative electrode active material for Pb-C hybrid ultracapacitors. B, N doped porous carbons are obtained from orange peel using boric acid by carbonization at 800 °C. B, N doped porous carbons contain about 1.22% of boron, 2.89% of nitrogen. These porous carbons exhibit 866 F g−1 capacitance at 1 A g−1 current density in potential range between the −0.4 V to 0.2 V. Pb-C hybrid ultracapacitors assembled with these carbons as the negative electrode and in situ formed PbO2 as a positive electrode can deliver capacitance of 192 F g−1 at 10 A g−1 and stable over 10,000 cycles. The superior electrochemical performance of lead-carbon ultracapacitor is due to the boron and nitrogen doping into the carbon, which increases the hole density and electron carrier, respectively and subsequently enhances the charge storage property. The significant improvement in capacitance of the ultracapacitor electrode of Pb-C hybrid ultracapacitors presented here opens up a new realm of possibilities for the lead-carbon ultracapacitor development and will contribute directly towards improving the energy and power density of the system.

(Battery Division Technology Award) Lead-Carbon Ultracapacitors: How, Why and Where is the Technology

Energy is both enabling and pervasive. Of all forms of the energy, electrical energy is the most convenient and cleanest to use. The excess electricity generated by any power plant needs to be stored to meet the peak-power demand. In recent times, multifunctionality is driving the change in the energy storage land-scape. The parameters required to characterize the energy-storage devices are: their energy density that emphasizes the weight and the size of the device, their power density that is the delivery rate at which the energy needs to be made available, their life for which the energy-storage devices will be used to store and withdraw energy, their response time, their safety, and last but not the least is the all important factor of their cost. The objectives of storage could be many. These could be to level energy supply that would involve large amounts of energy. Technologies suitable for such applications are classified as energy-management technologies. There could be a need for electrical energy of constant voltage and frequency. Another kind of demand is for a large surge of power for a short duration, for example, in the starting of a car. Technologies for these applications are classified as quality-power technologies. Broadly speaking, energy-management technologies are well established and are industrially in use. Quality-power technologies are relatively new and many are still under development. It is noteworthy that a mix of storage devices with different characteristics may prove to be more efficient than a single one. For the purpose of a broad description, the technologies are classified into two categories, namely the conventional and newer technologies. The well-established conventional technologies are compressed-air energy storage, pumped hydroelectric-energy-storage, and fly wheel. These technologies can be thought of as physical storage since energy is stored as potential, kinetic or pressure-volume. These technologies are, by and large, the energy management technologies. These are primarily being practiced in industrially-developed countries. The effectiveness of these technologies is well known to be recounted here. The newer technologies, such as storage batteries, flow batteries, ultracapacitors and superconducting magnetic-energy storage are meant to provide quality power. It is the storage batteries, flow batteries and ultracapacitors among the newer technologies that are chemical in nature and are particularly seminal to renewable energy so much so that the experts regard them as the missing link in the success of renewable energy. In recent years, we have developed and tested substrate-integrated lead-carbon ultracapacitors. The lead-carbon ultracapacitors have attractive features for energy storage and delivery. It is noteworthy that the problems faced with lead-acid batteries in various applications are mostly related to the negative plates as the negative plates in the lead-acid batteries cannot accept high charging-currents and batteries operating at partial-state-of-charge suffer from rapid sulfation of the negative plates. The most logical approach to mitigate the aforesaid problem lies in looking for alternatives to the conventional lead plates or to reduce their contribution to battery operation. We have expended our efforts to develop Lead-Carbon hybrid ultracapacitors with substrate-integrated positive plates and graphitic carbon as negatives so as to mitigate the problems faced with Lead-Acid batteries. These capacitors exhibit long cycle-life and, although the energy density of these ultracacpacitors remains limited to ca. 2 Wh/kg, they exhibit power-density values as high as 2.5 kW/kg at a response time of about 2 s. Various technical features of these lead-carbon ultracapacitors will be highlighted along with some of their applications.

Studies on 12 V substrate-integrated lead-carbon hybrid ultracapacitors

A cost-effective 12 V substrate-integrated lead-carbon hybrid ultracapacitor is developed and performance tested. These hybrid ultracapacitors employ flexible-graphite sheets as negative plate current-collectors that are coated amperometrically with a thin layer of conducting polymer, namely poly-aniline to provide good adhesivity to activated-carbon layer. The positive plate of the hybrid ultracapacitors comprise conventional lead-sheet that is converted electrochemically into a substrate-integrated lead-dioxide electrode. 12 V substrate-integrated lead-carbon hybrid ultracapacitors both in absorbent-glass-mat and polymeric silica-gel electrolyte configurations are fabricated and characterized. It is possible to realize 12 V configurations with capacitance values of ∼200 F and ∼300 F, energy densities of ∼1.9 Wh kg−1 and ∼2.5 Wh kg−1 and power densities of ∼2 kW kg−1 and ∼0.8 kW kg−1, respectively, having faradaic-efficiency values of ∼90 % with cycle-life in excess of 100,000 cycles. The effective cost of the mentioned hybrid ultracapacitors is estimated to be about ∼4 US$/Wh as compared to ∼20 US$/Wh for commercially available ultracapacitors. Low-cost substrate-integrated lead-carbon hybrid ultracapacitor employs flexible exfoliated graphite sheets as negative current-collectors, which are coated with a layer of poly-aniline to provide good adhesivity to activated-carbon-layer as well as good substrate-conductivity. These ultracapacitors are estimated to cost about 4 US$/Wh as compared to ~ 20 US$/Wh for presently available commercial ultracapacitors.

Series-Connected Substrate-Integrated Lead-Carbon Hybrid Ultracapacitors with Voltage-Management Circuit

Cell voltage for a fully-charged substrate-integrated lead-carbon hybrid ultracapacitor is about 2.3 V. Therefore, for applications requiring higher dc voltage, several of these ultracapacitors need to be connected in series. However, voltage distribution across each series-connected ultracapacitor tends to be uneven due to tolerance in capacitance and parasitic parallel-resistance values. Accordingly, voltage-management circuit is required to protect constituent ultracapacitors from exceeding their rated voltage. A design of the 12 V substrate-integrated lead-carbon hybrid ultracapacitor by series-connected six 2 V cells with co-located terminals is presented in Figure 1 (a). The schematic diagram of voltage-management cell-balancing circuit for the ultracapacitor is shown in Figure 1 (b). The ultracapacitor with the voltage-management circuit is tested, and the data are summarized in Figure 2. It is clearly seen that in steady state, the voltage tends to distribute uniformly across the individual ultracapacitor in the series arrangement. Figure 1

Series-connected substrate-integrated lead-carbon hybrid ultracapacitors with voltage-management circuit

Cell voltage for a fully charged-substrate-integrated lead-carbon hybrid ultracapacitor is about 2.3 V. Therefore, for applications requiring higher DC voltage, several of these ultracapacitors need to be connected in series. However, voltage distribution across each series-connected ultracapacitor tends to be uneven due to tolerance in capacitance and parasitic parallel-resistance values. Accordingly, voltage-management circuit is required to protect constituent ultracapacitors from exceeding their rated voltage. In this study, the design and characterization of the substrate-integrated lead-carbon hybrid ultracapacitor with co-located terminals is discussed. Voltage-management circuit for the ultracapacitor is presented, and its effectiveness is validated experimentally.

A photovoltaic stand-alone lighting system with polymeric-silica-gel-electrolyte-based substrate-integrated lead-carbon hybrid ultracapacitors

AbstractHarnessing solar electricity generated through photovoltaic cells with lead-acid batteries remains the most compelling option at present. But lead-acid batteries have encountered problems in photovoltaic installations, mainly due to their premature failure. To circumvent the aforesaid problem, a new technology referred to as substrate-integrated lead-carbon hybrid ultracapacitor with polymeric-silica-gel electrolyte, is developed inhouse and tested for solar-electricity storage for a lighting application. The high-throughput performance tests for the device are conducted at laboratory scale and compatibility of the device for photovoltaic application is evaluated. In doing so, the device is installed with a photovoltaic panel for field test and data are collected from August 2012 through July 2013. The year round field-test data analyzed in the light of the available global-horizontalirradiance data show attractive performance for the device. It is noteworthy that, unlike lead-acid batteries, seasonal variations in solar radiance exhibit little effect on the performance of the device.

A Low-Cost Substrate-Integrated Lead-Carbon Hybrid Ultracapacitor with an Organic Metal

A cost-effective substrate-integrated lead-carbon hybrid ultracapacitor using an organic metal is developed and performance tested. The hybrid ultracapacitor employs flexible exfoliated graphite sheets as negative plate current-collectors that are coated amperometrically with a thin layer of organic metal, namely poly-aniline; the latter providing good adhesivity to activated carbon layer that is pasted on to it for realizing an electrical-double-layer capacitor. The positive plate comprises the conventional lead sheet that is converted electrochemically into a substrate-integrated lead-oxide electrode.1 12V substrate-integrated lead-carbon hybrid ultracapacitor both in absorbent-glass-mat and polymeric silica gel electrolyte configurations are developed and performance tested. It is possible to realize 12V lead-carbon hybrid ultracapacitors both in absorbent-glass-mat and silica gel configurations with capacitance values of ~200 F and ~300 F, respectively, with faradaic efficiency value of ~ 90 % and cycle-life in excess of 100000 cycles. The effective cost of these ultracapacitors is estimated to be about US$ 4-5 Wh-1 as compared to US$20-30 Wh-1 for presently available commercial ultracapacitors. The performance-test data for 12V devices are summarized in Table 1. The galvanostatic discharge data and pulse cycle-life testing data for the substrate-integrated lead-carbon hybrid ultracapacitor are shown in Figures 1 and 2, respectively.2 Reference A. Banerjee, M. K. Ravikumar, A. Jalajakshi, P. S. Kumar, S. A. Gaffoor, and A. K. Shukla, J. Chem. Sci., 124, 747 (2012).A. K. Shukla and A. Banerjee, Indian Patent Application No. 1454/CHE/2014, dated 19/03/2014.

Performance comparison for 12 V lead-carbon hybrid ultracapacitors with substrate-integrated and conventional pasted positive plates

Lead-carbon hybrid ultracapacitors comprise positive lead dioxide plates of the lead-acid battery and negative plates of carbon-based electrical double-layer capacitors (EDLCs). Accordingly, a lead-carbon hybrid ultracapacitor has the features of both the battery and that of an EDLC. In this study, the development and performance comparison between the two types of lead-carbon hybrid ultracapacitors, namely those with substrate-integrated and conventional pasted positive plates, is presented as such a study is lacking in the literature. The study suggests that the faradaic efficiencies for both types of lead-carbon hybrid ultracapacitors are comparable. However, their capacitance values as well as energy and power densities differ significantly. For substrate-integrated positive plate hybrid ultracapacitor, capacitance and energy density values are lower, but power density values are higher than pasted positive plate lead-carbon hybrid ultracapacitors due to their shorter response time. Accordingly, internal resistance values are also lower for substrate-integrated lead-carbon hybrid ultracapacitors. Both types of lead-carbon hybrid ultracapacitors exhibit good cycle life of 100,000 pulse charge-discharge cycles with only a nominal loss in their capacitance values.

Design of Substrate-Integrated Lead-Carbon Hybrid Ultracapacitor and Experimental Validation

Suitability of substrate-integrated lead-carbon hybrid ultracapacitors for low-power back-up applications is studied. A practical application that provides 30 W power back-up to low-power medical gadgets for use in grid-power-deficient rural areas is presented. An ultracapacitor bank is designed for this application and the sizing calculations are provided. Experimental validation and results are also discussed.

Sizing Calculations for Substrate-Integrated Lead-Carbon Hybrid Ultracapacitors and Their Experimental Validation

not Available.

12 V / Kilo-Farad Range Lead-Carbon Hybrid Ultracapacitors and Their Envisaged Applications

12 V substrate-integrated lead-carbon hybrid ultracapacitors (HUCs) where in the conventional positive plates of lead-acid batteries are replaced with substrate-integrated PbO2 positive plates and the negative plates are replaced with carbon-coated graphitic electrodes, providing totally non-faradaic and corrosion-free electrodes, are developed and performance tested. Constant-current discharge data at varying load-currents, constant-power discharge data at varying power values, and the capacitance data at different temperature for a 12 V / kF range substrate-integrated lead-carbon HUC are described along with its resistance, leakage current, self-discharge and cycle-life characteristics.

Performance Comparison of Lead-Carbon Hybrid Ultracapacitors with Substrate-Integrated and Pasted-Positive Plates

not Available.

Substrate integrated Lead-Carbon hybrid ultracapacitor with flooded, absorbent glass mat and silica-gel electrolyte configurations

Lead-Carbon hybrid ultracapacitors (Pb-C HUCs) with flooded, absorbent-glass-mat (AGM) and silica-gel sulphuric acid electrolyte configurations are developed and performance tested. Pb-C HUCs comprise substrate-integrated PbO2 (SI-PbO2) as positive electrodes and high surface-area carbon with graphite-sheet substrate as negative electrodes. The electrode and silica-gel electrolyte materials are characterized by XRD, XPS, SEM, TEM, Rheometry, BET surface area, and FTIR spectroscopy in conjunction with electrochemistry. Electrochemical performance of SI-PbO2 and carbon electrodes is studied using cyclic voltammetry with constant-current charge and discharge techniques by assembling symmetric electrical-double-layer capacitors and hybrid Pb-C HUCs with a dynamic Pb(porous)/PbSO4 reference electrode. The specific capacitance values for 2 V Pb-C HUCs are found to be 166 F/g, 102 F/g and 152 F/g with a faradaic efficiency of 98%, 92% and 88% for flooded, AGM and gel configurations, respectively.