Battery-capacitor Hybrid Research Articles

Agar-Activated Carbon Cathode with Optimized Redox Electrolyte for High-Energy and Stable Aqueous Zinc Hybrid Battery–Capacitor

Agar-Activated Carbon Cathode with Optimized Redox Electrolyte for High-Energy and Stable Aqueous Zinc Hybrid Battery–Capacitor

Zinc-iodine battery-capacitor hybrid device with excellent electrochemical performance enabled by a robust iodine host

Zinc-iodine battery-capacitor hybrid device with excellent electrochemical performance enabled by a robust iodine host

Hybridization of battery and ultracapacitor for electric vehicle application with dynamic energy management and non-linear state feedback controller

• Proposed a dynamic energy management system for hybrid sources in an electric vehicle. • Buck-boost H-bridge converters are introduced for bidirectional power flow control. • System non-linearities are addressed using a nonlinear state feedback controller. • The proposed system accurately delivers instantaneous vehicle speed and torque. This paper describes a methodology to control a multi-source battery-capacitor hybrid EV incorporating a dynamic power splitting strategy. Considering the requirement for precise speed control characteristics of the EV and the non-linear behavior of traction motor with system disturbances, a non-linear state feedback controller (NLSFC) with a disturbance observer is suggested as the speed control technique for the EV traction motor. To interface a parallel configured multi-source system, a non-inverted buck-boost H-bridge is proposed as the source side converter for effective recovery of the braking energy. Detailed control design for traction motor and converter is also presented for efficient control of EV. Besides, an adaptive energy management strategy considering power profile and dynamic source characteristics is incorporated into the overall control system. The simulation results from various case studies indicate that the proposed system can follow the required vehicle speed and torque despite the sudden change in EV load torque. Furthermore, the comparative analysis between NLSFC and PI controller shows improvement with steady-state error reduction from 0.43 to 0.0014 and peak overshoot drop from 12.07% to 3.51% during acceleration of the system when proposed NLSFC is adopted. The proposed solutions will be implemented in a prototype EV system in the future.

Coordination of thermal/wind energies in power-to-gas process for cost/pollution abatement considering wind energy recovery

ABSTRACT This paper utilizes the thermal and wind energies in power to gas (P2G) process. The purpose of the proposed P2G system is to reduce the operating costs and environmental pollutions. The wind energy is used to produce Hydrogen (H2) via water electrolyzer. The Carbon dioxide (CO2) of thermal energies is also captured by Carbon Capture and Storage (CCS). The achieved H2 and CO2 are combined to make Methane (CH4) through Methanation reaction. The unit commitment denotes the optimal operation schedule of thermal generating units at each hour. The proposed model also determines the optimal size of wind energy. In the case of any event or outage, the wind energy recovery is studied by application of hybrid battery-capacitor storage system. The achieved CH4 from wind energy is sold to make profit. The wind speed volatility is included in the model and handled by stochastic programming. The proposed P2G achieves several purposes including optimal wind turbine sizing, uncertainty management, CO2 decrease and operating cost reduction. It is demonstrated that the Carbon tax can reduce the CO2 pollutions up to 8%. The high-cost and high-polluting generating systems like oil fired steam turbines are only used at on-peak hours like 17–21. These units produce about 6% of total energy but releases 11% of total CO2. The optimal capacity of wind generating system is obtained equal to 107 MW and the profit of process is estimated about 2.383 million $ in year.

Towards Rechargeable Aluminum-Ionic Liquid Batteries for Low-Temperature Space Applications

Batteries operating reliably at low temperatures are required to power robotic spacecraft, particularly those that embark on planetary science missions1. For example, Mars surface missions have typical temperature targets of -40 to -60 °C, while surface mission concepts to the outer planets or Ocean Worlds, such as Europa, have targets down to -180 °C. At low temperatures, state-of-the-art lithium-ion batteries suffer from lithium plating and dendritic growth on the graphite anodes, severe capacity loss associated with sluggish ion diffusion in crystalline transition metal cathodes, and kinetic limitations2. While organic electrolyte mixtures have been developed that enable moderate low-temperature performance, new battery concepts, including those using ionic liquid electrolytes, are needed to enable new paradigms in low or ultra-low temperature space missions. Recently, rechargeable aluminum batteries have been developed that use chloroaluminate-containing ionic liquid electrolytes, which may be suitable alternatives to lithium-based batteries when used under extreme temperatures. Aluminum metal is also distinguished by its high energy density, safety, low cost, and sustainability, which are also key properties for space applications.Herein we present, for the first time, results towards rechargeable Al-batteries designed specifically for low-temperature space missions that demonstrate high capacity retention, long-term cyclability, and favorable electrochemical kinetics at low temperatures down to -40 °C. We focus on the development of ionic liquid electrolytes with mixed anion-cation compositions to impart disorder and disrupt crystallization, while pairing them with functionalized graphite and conducting polymer cathodes.3 , 4 The resulting aluminum batteries were characterized by variable-temperature and rate cyclic voltammetry (CV), galvanostatic cycling, electrochemical impedance spectroscopy (EIS), and solid-state nuclear magnetic resonance (NMR) spectroscopy to understand their reaction mechanisms and factors limiting their rate performance. The ionic liquid electrolyte mixtures were also characterized by a combination of differential scanning calorimetry (DSC) and electrochemical methods to understand their freezing points and electrochemical stability. The results provide fundamental insights into the design of positive electrode materials and ionic liquid electrolyte mixtures in novel batteries for low-temperature space applications.References Bugga, R. V.; Brandon, E. J., Energy Storage for the Next Generation of Robotic Space Exploration. Electrochemical Society Interface 2020, 29 (1), 59-63.Jones, J.-P.; Smart, M. C.; Krause, F. C.; Bugga, R. V., The Effect of Electrolyte Additives upon Lithium Plating during Low Temperature Charging of Graphite-LiNiCoAlO2 Lithium-Ion Three Electrode Cells. Journal of The Electrochemical Society 2020, 167 (2), 020536.Schoetz, T.; Kurniawan, M.; Stich, M.; Peipmann, R.; Efimov, I.; Ispas, A.; Bund, A.; Ponce de Leon, C.; Ueda, M., Understanding the charge storage mechanism of conductive polymers as hybrid battery-capacitor materials in ionic liquids by in situ atomic force microscopy and electrochemical quartz crystal microbalance studies. Journal of Materials Chemistry A 2018, 6 (36), 17787-17799.Xu, J. H.; Turney, D. E.; Jadhav, A. L.; Messinger, R. J., Effects of Graphite Structure and Ion Transport on the Electrochemical Properties of Rechargeable Aluminum–Graphite Batteries. ACS Applied Energy Materials 2019, 2 (11), 7799-7810.

Introducing oxygen vacancies for improving the electrochemical performance of Co9S8@NiCo-LDH nanotube arrays in flexible all-solid battery-capacitor hybrid supercapacitors

In this work, rich oxygen vacancies are obtained in Co9S8@NiCo-LDH core-shell nanotube arrays (NTAs), which boost its electrochemical energy storage performance. The flexible carbon cloth (CC) supported Co9S8@NiCo-LDH NTAs are synthesized by situ growth and electrodeposition method. After reacting with NaBH4, the rich oxygen vacancies are generated in NiCo-LDH nanosheets to obtain Co9S8@oxygen vacancies-NiCo-LDH NTAs (Co9S8@OV-NiCo-LDH NTAs). These oxygen vacancies increase the charge transfer rate in the multi-level redox processes and make the electrochemical performance improve sharply. At a current density of 0.5 A g−1, the mass specific capacity of Co9S8@OV-NiCo-LDH NTAs is up to 1335 C g−1, which is more than four times higher than that of the untreated Co9S8@NiCo-LDH NTAs. In addition, with the prepared Co9S8@OV-NiCo-LDH core-shell NTAs as a positive electrode, along with the negative electrode of activated carbon (AC), a high-performance flexible all-solid battery-capacitor hybrid supercapacitors (HSC) device is assembled. The maximum energy density is up to 101.1 Wh kg−1 when the power density is 800 W kg−1.

Emerging trends in anion storage materials for the capacitive and hybrid energy storage and beyond.

Electrochemical capacitors charge and discharge more rapidly than batteries over longer cycles, but their practical applications remain limited due to their significantly lower energy densities. Pseudocapacitors and hybrid capacitors have been developed to extend Ragone plots to higher energy density values, but they are also limited by the insufficient breadth of options for electrode materials, which require materials that store alkali metal cations such as Li+ and Na+. Herein, we report a comprehensive and systematic review of emerging anion storage materials for performance- and functionality-oriented applications in electrochemical and battery-capacitor hybrid devices. The operating principles and types of dual-ion and whole-anion storage in electrochemical and hybrid capacitors are addressed along with the classification, thermodynamic and kinetic aspects, and associated interfaces of anion storage materials in various aqueous and non-aqueous electrolytes. The charge storage mechanism, structure-property correlation, and electrochemical features of anion storage materials are comprehensively discussed. The recent progress in emerging anion storage materials is also discussed, focusing on high-performance applications, such as dual-ion- and whole-anion-storing electrochemical capacitors in a symmetric or hybrid manner, and functional applications including micro- and flexible capacitors, desalination, and salinity cells. Finally, we present our perspective on the current impediments and future directions in this field.

Achieving a Zn-ion battery-capacitor hybrid energy storage device with a cycle life of more than 12,000 cycles

Prussian blue is considered as a promising zinc ion battery material because of its advantages such as stable structure, large lattice gap and simple preparation process. However, the poor conductivity seriously hinders the application of Prussian blue electrode materials. Herein we report a simple and interesting strategy to grow Prussian blue nanoparticle on expanded graphite electrode through a facile electrochemical method. Thanks to the synergy between Prussian blue analogue nanoparticles and self-supporting graphite flakes, the composite electrode with unique architectural structure possess both battery and capacitor characteristics. What's even more interesting is that the defects of Prussian blue crystals are gradually reduced during the extraction and insertion of zinc ions, and then the increasingly perfect crystal structure result in excellent cycling performance (120% capacitance retention after 12,000 cycles).

Fast Charging Hybrid Battery-Capacitor Based on Electrochemically-Intercalated Ni-Graphite

The electrochemical intercalation of Ni(II) as a redox-spacer between graphite sheets is demonstrated as an efficient way to produce a fast-charging aqueous hybrid battery-capacitor (Scheme). The approach is based on the electrochemical exfoliation of free-standing graphite sheets and the intercalation of Ni(II) by a single step. This is accomplished by applying a negative potential to graphite in an isopropyl alcohol solution consisting of Ni(II), leading to an increase of the electrode’s active area and prevents the restacking of the graphene sheets. The fabricated hybrid electrodes demonstrate a specific capacity of 84 mAh g−1 at high charge-discharge rates of 30-300 mA (7.5-75 C rates) in aqueous solution. The performance of an asymmetric full cell, consisting of the hybrid electrode and an activated carbon electrode, delivers a specific energy of 96 Wh kg-1 and exceptionally high specific power of 6.2 kW kg-1 at 300 mA (45 C) charge-discharge rate. The hybrid electrode and the full cell were cycled over 10,000 times under very fast very fast cycling conditions with minimal decrease in performance. The intercalation of Ni(II) into the layers is confirmed by cross-section electron microscopy and electrochemistry.The outstanding storage performance of this system is attributed to the redox reaction of the intercalated Ni(II) inside the graphite layers, which have an additional capacitive contribution, combining the advantages of battery and capacitor in one material. Furthermore, the very efficient charge transfer stems from the proximity of the redox to the highly conductive graphite. Figure 1

Redox-Active Vertically Aligned Mesoporous Silica Thin Films as Transparent Surfaces for Energy Storage Applications.

Organic-inorganic hybrid membranes, made of a high density of redox active moieties covalently bonded to the internal surfaces of vertically aligned mesoporous silica thin films, are relevant for applications in transparent energy storage devices. This is demonstrated here on the basis of functionalized transparent mesoporous silica thin films prepared on the indium-tin oxide electrode from the combination of an electrochemically induced self-assembly method (to generate azide-functionalized silica) and a copper-catalyzed azide-alkyne click reaction (to derivatize the material with electroactive groups). The very small thickness (105 nm) and the uniformly distributed vertical mesochannels with ultranarrow diameter (2 nm) make the hybrid film a promising substrate that not only achieves a transparency of 82% but also provides large surface area to accommodate a high density of redox active species such as ferrocene. In such rigid and insulating porous membranes, the charge transfer reactions take place through a pure electron-hopping mechanism between adjacent redox sites, which are favored by the ordered and oriented mesostructure containing large amounts of uniformly distributed ferrocene functions in the mesochannels. Their performance results from both high charge transfer rates (electron hopping) and easy mass transport (fast diffusion of counter ions). The most effective system is the ferrocene-functionalized silica film prepared from 40% organosilane, which is able to deliver a capacity of 105 C cm-3 (1.10 mC cm-2) at a current density of 0.4 A cm-3 (with up to 48% capacity retention achieved at a charging time as short as 2.8 s). Such an electrode can be associated to an electrodeposited graphene anode in a solid-state battery-capacitor hybrid device, which can deliver 0.74 mC cm-2 at a potential scan rate of 20 mV s-1. The azide-functionalized mesoporous silica film is actually a versatile platform that can be functionalized with different redox molecules, as shown here for cobaltocenium moieties, which may broaden its application field.

Hierarchical porous biomass activated carbon for hybrid battery capacitors derived from persimmon branches

Activated carbon materials are used in hybrid battery capacitors. They reduce energy density of devices, and can greatly improve the cycle life and power density. Herein, we used fast-growing persimmon branches in Shaanxi as a biomass carbon source. The persimmon branch activated carbon (PB-AC850) material was found to exhibit abundant graded pore structure similar to graphite structure after KOH activation. The macro/mesoporous structure in PB-AC850 facilitated the ions (solvated PF-6 ) transport, resulting in much better rate capability as compared to commercial activated carbon. It was moreover found from preparation of the hybrid battery capacitor that the addition of activated carbon reduced resistance and polarization of the device. LFP+PB-AC850 exhibited excellent cycle stability with high to 93.4% capacity reservation after 500 cycles at 5C.

High Power Na3V2(PO4)3@C/AC Bi-material Cathodes for Hybrid Battery-Capacitor Energy Storage Devices

We have reported the synthesis and electrochemical characteristics of carbon-coated sodium vanadium phosphate/activated carbon (NVP@C/AC) bi-material electrodes. We have reported that bi-material type NVP@C/AC cathodes offer superior rate performance as compared to either NVP@C or AC electrodes. Through a detailed impedance spectroscopy analyses, we demonstrated that the synergic effect observed in the bi-material electrodes correlates well with the lowering of their charge transfer resistances (RCT) and the increase of Li+ diffusion coefficient (DLi+) with the increase of activated carbon content from 0 to 0.60 weight fraction. Through a detailed cyclic voltammogram analyses we have delineated the faradaic and capacitive contribution towards the overall capacities of the bi-material electrodes at various rate conditions. For both these bi-materials, irrespective of the AC content and rate, capacitive contribution dominates the overall capacity. NVP@C/AC40 yields discharge capacities of 67 and 40 mAh g−1 with capacity retention of more than 93% and 67% after 500 cycles measured at 50 and 1000 mA g−1, respectively. These bi-materials are demonstrated to be excellent material candidates for high power density lithium titanium oxide (LTO)//NVP@C/AC hybrid battery-capacitor (bat-cap) energy storage devices.

(Invited) Lithium-Ion Battery-Capacitor Hybrid Energy Storage Devices

As a new generation of supercapacitor, the Li-ion capacitor (LIC) is an advanced energy storage device which consists of an electric double-layer capacitor (EDLC) cathode and a pre-lithiated anode [1,2], between which the ions shuttle during charge and discharge processes. Because of using pre-lithiated and low surface anode materials, the LIC can be charged to a maximum voltage as high as 4.0 V, which is much higher than of EDLCs and comparable to Li-ion batteries (LIBs); therefore, it allows the LIC and LIB to be assembled in one package as a LIB/LIC hybrid energy storage cell. We have demonstrated a new hybrid energy storage cell that combines the advantages of both the LIB and the LIC [3], thereby avoiding their inherent defects, while bridging the gap between the high energy densities offered by batteries and the high power densities seen in EDLCs. The energy density and power density of the hybrid cell can be designed to meet the requirements by a reasonable distribution of the ratio between LIB and LIC electrode materials in the internal hybrid cell. For example, we show a hybrid LIC consisting of a Li nickel cobalt manganese oxide (NMC)/activated carbon (AC) composite cathode in combination with an ultra-thin Li film (u-Li) pre-loaded hard carbon anode. Additionally, we show that by utilizing three design approaches: dry composite electrode fabrication method, cathode to anode capacity ratio design, and pre-lithiation method using u-Li, we can demonstrate an energy storage device with excellent cycle life, and that can be tailored by composite ratios within the cathode to fit different applications. Shown here is an in-depth look at various composite material ratios, pre-lithiation calculations and hybrid Li-ion battery-capacitor energy storage device creation based on targeting essential energy-power performance characteristics.

Dual-ion hybrid supercapacitor: Integration of Li-ion hybrid supercapacitor and dual-ion battery realized by porous graphitic carbon

Abstract Lithium-ion hybrid supercapacitors (Li-HSCs) and dual-ion batteries (DIBs) are two types of energy storage devices that have attracted extensive research interest in recent years. Li-HSCs and DIBs have similarities in device structure, tendency for ion migration, and energy storage mechanisms at the negative electrode. However, these devices have differences in energy storage mechanisms and working potentials at the positive electrode. Here, we first realize the integration of a Li-HSC and a DIB to form a dual-ion hybrid supercapacitor (DIHSC), by employing mesocarbon microbead (MCMB)-based porous graphitic carbon (PGC) with a partially graphitized structure and porous structure as a positive electrode material. The MCMB-PGC-based DIHSC exhibits a novel dual-ion battery-capacitor hybrid mechanism: it exhibits excellent electronic double-layer capacitor (EDLC) behavior like a Li-HSC in the low-middle wide potential range and anion intercalation/de-intercalation behavior like a DIB in the high-potential range. Two types of mechanisms are observed in the electrochemical characterization process, and the energy density of the new DIHSC is significantly increased.

Preparation and Optimization of New High-Power Nanoscale Li₄Ti5O12 Full-Cell System.

Lithium ion batteries with graphite negative electrodes have been developed to date due to their low power density, which limits their application in many cases, however. Nanoscale Li4Ti5O12 has higher power density than conventional graphite anode materials. In order to ensure that the full-cell system has high power and high energy, cathode materials are very important. In this paper, three different cathode materials, LiNi0.8Co0.15Al0.05O2 (NCA), LiNi0.6Co0.2Mn0.2O2 (NCM622), and LiCoO2 (LCO), were used to conduct a comprehensive study, and optimal NCA-Li4Ti5O12(LTO) full battery system was selected under high power conditions. On the basis, in order to further increase battery power density, and in combination with the mechanism of the supercapacitor non-Faradic energy storage, polyaniline activated carbon material (PANI-AC) with excellent capacitance characteristics was prepared. In the end, we proposed a new type of hybrid battery capacitor system with high power and high energy.

Lithium ion supercapacitor composed by Si-based anode and hierarchal porous carbon cathode with super long cycle life

A lithium ion supercapacitor full cell is fabricated with a Fluorine-doped carbon encapsulated SiOx as anode and a Nitrogen-doped carbon with hierarchical meso-micro porous structure as cathode. Benefited from the fast kinetic lithium reaction as well as longevity in the newly synthesized Si-base anode and high capacitance on the porous carbon, the hybrid device delivering of high power density, high energy density and super long cycle life is demonstrated. After prelithiation of Si-base anode, this hybrid supercapacitor exhibits a high capacity of 120 mAh g−1 at 0.2 A g−1 after 1600 cycles. A capacity of 42 mAh g−1 can still be obtained even under the current density of 3 A g−1. Furthermore, Super long cycle life (45 mAh g−1 capacity with 1 A g−1 after 10,000 cycles), low leakage current (3.8 μA) and low self-discharge (82% voltage retention after 48 h resting in open-circuit potential) are revealed. This work presents not only a simple route for the synthesis of Si-base anode for energy storage devices on lithium chemistry, but also a new approach to the construction of hybrid battery-capacitor device.

Flexible Anion Microbatteries: Towards Construction of a Hybrid Battery-Capacitor Device.

A proof-of-principle study is presented on the rechargeable anion storage capability of ferrocyanide immobilized in a polysilsesquioxane (PSQ)-modified flexible/rigid film for aqueous battery applications. This electrode material delivers high power density up to 140 μWh cm-2 and energy density of 9.4 μWh cm-2 with a long cycle life of more than 200 cycles in chloride ion medium. The proposed energy storage mechanism of this system is based on insertion and extraction of the anion into the [Fe(CN)6 ]4- -PSQ film during charging and discharging processes, respectively. Moreover, a hybrid battery-capacitor device comprising a graphite rod (capacitor) and the ferrocyanide-immobilized PSQ film as a faradaic electrode shows enhanced electrochemical performance.

Electro-polymerisation of 3,4-ethylenedioxythiophene on reticulated vitreous carbon in imidazolium-based chloroaluminate ionic liquid as energy storage material

This work shows the electro-polymerisation of thin film poly(3,4-ethylenedioxythiophene) on three-dimensional reticulated vitreous carbon substrates by cyclic voltammetry and pulsed polymerisation methods from a Lewis neutral chloroaluminate ionic liquid containing 3,4-ethylenedioxythiophene monomer. The polymer composite is attractive as an energy storage electrode for sustainable and high-performance technologies due to its unique properties of battery and capacitor in one system, i.e., the redox reaction occurring simultaneously with the anion doping/de-doping of the conductive polymer with AlCl4− ionic species contained in the ionic liquid. The structure of the polymer films, their doping/de-doping mechanism and the stability in the ionic liquid were characterised by scanning electron microscopy and cyclic voltammetry and compared with films electro-polymerised on planar vitreous carbon. The typical granular and nano/micro-porous polymer structure observed on planar vitreous carbon was successfully replicated on the macro-porous reticulated vitreous carbon surface. The polymer films show approximately 45% higher capacity than films on planar substrates and similar efficient redox behaviour, proving that the material has hybrid battery-capacitor properties enhanced by the higher area per unit volume of reticulated vitreous carbon.

Shift to Post-Li-Ion Capacitors: Electrochemical Behavior of Activated Carbon Electrodes in Li-, Na- and K-Salt Containing Organic Electrolytes

The interest in exploring intercalation ions-based energy storage systems, which can be alternatives to the well-established Li+ -based systems, is exponentially growing in the scientific community. This shift involves pure battery and hybrid battery-capacitor systems, which contains, at the same time, faradaic-type and double layer-type materials. In order to assess the feasibility of such hybrid system, the single materials have to be firstly analyzed independently. In this work, a commercial activated carbon is taken as an example of double layer-type material and is electrochemically investigated in several organic electrolytes with salts composed of various cations (Li+, Na+ and K+) and anions (PF6−, TFSI− and FSI−). The adsorption of these cations/anions on the activated carbon and their kinetic properties are studied by means of cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. Finally, the effect of the different cations on ageing mechanism of symmetric capacitors is studied. The results reveal that the ageing mechanism induced by the Li-salts is different from those achieved with analogue salts containing Na and K cations.

Understanding the charge storage mechanism of conductive polymers as hybrid battery-capacitor materials in ionic liquids by in situ atomic force microscopy and electrochemical quartz crystal microbalance studies

Morphological changes of a conductive polymer in an ionic liquid during charging and discharging.