Electrochemical Energy Storage Performance Research Articles

A Rechargeable Al/Graphite Battery Based on AlCl3/1‐butyl‐3‐methylimidazolium Chloride Ionic Liquid Electrolyte

AbstractAs a new and efficient power storage device, Al‐ion batteries present good prospects due to its many advantages, such as excellent performance and rich resources. In this work, a rechargeable Al‐ion battery system has been fabricated in pouch cell based on a room temperature ionic liquid (RTIL) containing AlCl3/1‐butyl‐3‐methylimidazolium chloride (BMIC) as electrolyte. The capacity of the battery is 86.4 mAh g−1 at the 100th cycle at a current density of 50 mA g−1, and it remains above 78.0 mAh g−1 after 300 cycles. A high discharge voltage platform about 2.15 V vs. Al3+/Al is obtained. In addition, in situ X‐Ray Diffraction (XRD) measurements were conducted to confirm the intercalation/de‐intercalation mechanism in the graphite layers. All of these suggest that the Al/graphite battery based on AlCl3/BMIC electrolyte, which exhibits an excellent electrochemical performance for energy storage, may be a promising Al‐ion battery system.

Phosphorus-doped graphene-improved Na3V2(PO4)3@C nanocomposite possessing high-rate performance for electrochemical energy storage

Abstract NASICON-type Na3V2(PO4)3 is a promising cathode for sodium-ion batteries owing to its low cost and great thermal stability as well as high energy density, which has attracted ever growing attention. Nevertheless, the pure Na3V2(PO4)3 possesses a bad electrical conductivity, which hinders its Na+-storage performance for energy storage. Designing and fabrication of the phosphorus-doped graphene-decorated Na3V2(PO4)3@C nanocomposite is performed in this research by a simple and rapid method. The constructed network by phosphorus-doped graphene sheet and carbon layer can greatly strengthen the electron and ionic conductivities of Na3V2(PO4)3, leading to outstanding rate capacity together with cyclic property. The as-fabricated electrode shows a specific capacity of 110.6 mAh g−1 at 0.5 C and a high capacity retention of 91.2% over 500 cycles at 20 C. Therefore, this designed nanocomposite is thought as a prospective cathode for batteries that utilize sodium ion as the charge carrier.

Hierarchical CoNi2S4 nanosheet/nanotube array structure on carbon fiber cloth for high-performance hybrid supercapacitors

Well-defined nanostructures are attractive due to their excellent advantages in enhancing the performance of electrochemical energy storage. In this work, a kind of hybrid structure of hierarchical CoNi2S4 nanosheet/nanotube array directly assembled on carbon fiber cloth has been designed and developed for high-performance supercapacitors. CoNi2S4 nanosheet/nanotube arrays are fabricated through orderly electrodeposition of ZnO nanorod arrays and CoNi2S4 nanosheets, followed by removing ZnO nanorods template. Benefiting from the unique hollow nanostructure with abundant electrochemical active sites, the specific capacitance of this electrode can reach up to 995.8 C g−1 at a current density of 2 A g−1, along with excellent rate capability (740 C g−1 at 50 A g−1). Moreover, the hybrid supercapacitors are prepared by using hierarchical CoNi2S4 nanosheet/nanotube arrays as positive electrode and reduced graphene oxide-carbon nanotubes as negative electrode for energy storage application, which demonstrate a high energy density of 35 Wh kg−1 at a power density of 3 kW kg−1 and excellent cycle stability with 96.9% capacitance retention after 10000 cycles. This work provides a feasible and a practical approach to fabricate CoNi2S4 hollow nanostructures and its huge potential in energy storage.

Tuning the Electrochemical Property of the Ultrafine Metal‐oxide Nanoclusters by Iron Phthalocyanine as Efficient Catalysts for Energy Storage and Conversion

Nanoclusters (NCs) have been demonstrated of outstanding performance in electrochemical energy storage and conversion technologies due to their strong quantum confinement effects and strong interaction with supports. Here, we developed a class of ultrafine metal‐oxide (MOx, M = Fe, Co and Ni) NCs incorporated with iron phthalocyanine (FePc), MOx/FePc‐G, supported on graphene as high‐performance catalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and carbon dioxide reduction (CO2RR). The high activities for ORR and OER are attributed to the electron donation and accepting ability of the highly redox active of FePc‐G that could tune the properties of MOx. The FeOx/FePc‐G exhibits an extremely positive half‐wave potential (E1/2) of 0.888 and 0.610 V for ORR in alkaline and neutral conditions, respectively, which is around 60 mV more positive than that of Pt/C. And NiOx/FePc‐G shows similar OER activity with the state‐of‐the‐art catalysts, Ir/C, and better performance than NiFeO NCs supported on graphene. Remarkably, the CoOx/FePc‐G and NiOx/FePc‐G show high activity and selectivity to reduce CO2 into CO with a low onset potential of −0.22 V (overpotential is 0.11 V).

FeNb11O29 nanotubes: Superior electrochemical energy storage performance and operating mechanism

Due to high capacity from multiple redox couples, niobium-based oxides are promising anode materials for lithium-ion batteries (LIBs). However, their poor electronic conductivity restricts their electrochemical performance. Here, we report the FeNb11O29 nanotubes as an advanced anode material. FeNb11O29 nanotubes exhibit an impressive charge capacity of 272.64 mAh g−1 with high initial cycle Coulombic efficiency of 90.13% at 0.1 C and outstanding cyclic stability (only 0.0123% of capacity decay per cycle during 2000 cycles). Furthermore, according to the in-situ XRD, the behavior of lithium atoms distribution in the FeNb11O29 framework during the insertion and extraction is studied in detail. In addition, full cells are assembled with commercially available cathodes. Coupled with LiFePO4, which is used as cathode, the full cell displays good electrochemical performance. In summary, FeNb11O29 nanotubes can be used as an ideal anode material due to the excellent electrochemical performance.

Comparative studies on electrochemical energy storage of NiFe-S nanoflake and NiFe-OH towards aqueous supercapacitor

In this study, electrochemical energy storage performances of an efficient Ni–Fe sulfide and hydroxide supported on porous nickel foam are compared. X-ray diffraction (XRD), X-rayphotoelectron spectroscopy (XPS) and energy-dispersive X-ray spectrometer (EDS) results confirmed the formation of Ni–Fe–S and Ni–Fe–OH electrodes. In addition, Brunauer–Emmett Teller (BET) was used to determine the specific surface area of the prepared materials. Moreover, the morphologies were observed by scanning electron microscopy (SEM). The brilliant characteristics of Ni–Fe–S could be attributed to transport acceleration in electrolyte ions and electrons, occurrence of redox reactions as well as the higher conductivity of the sample. From stand point of comparison, the capacitance of Ni–Fe–S is more than that of Ni–Fe–OH. Therefore, the exchange of O2− with S2− in Ni–Fe–OH lattice obviously improves the electrochemical performance. The as-fabricated Ni–Fe sulfide electrode exhibits a tremendous specific capacitance of 884.9 F g−1 at 1 A g−1. Furthermore, an assembled asymmetric supercapacitor device using the activated carbon as negative electrode and this smart configuration (Ni–Fe–S) as positive electrode also provided a maximum specific power and specific energy of 8000 W kg−1, 37.9 Wh kg−1, respectively. Also, it shows cycling stability with 88.8% capacitance retention after 1700 cycles in aqueous electrolyte, demonstrating its potential application in the next-generation high-performance supercapacitors used for energy storage.

Unique oblate-like ZnWO4 nanostructures for electrochemical energy storage performances

Unique ZnWO4 oblate nanospheres (ZWO-ONSs) deposited on Nickel foam (Ni foam) are successfully prepared via facile hydrothermal route. The ZWO-ONSs show high specific surface area of 89.47 m2 g−1. The as-prepared nanostructures tested in 3 M KOH aqueous solution, perform excellent electrochemical performances showing specific capacity of 1198 F g−1 at 1 A g−1, and high retention rate cyclic stability 96.56% after 1000 cycles at 10 A g−1. Distinctive binary metal oxide nanoarchitectures are dynamic material for energy storage systems.

Directly scalable preparation of sandwiched MoS2/graphene nanocomposites via ball-milling with excellent electrochemical energy storage performance

The few-layered transitional sulphide/oxide nanosheets and graphene composites attract increasingly interest as electrode materials although facing the significant preparation challenge such as low quantities and uncontrollable homogeneity. Using MoS2 and graphene oxide (GO) bulk materials as the raw materials, we demonstrate a novel solvent-free and one-step ball-milling approach to prepare massive sandwiched MoS2/reduced graphene oxide (rGO) nanocomposites. The reduction of GO to rGO, the exfoliation of bulk layered materials and assembly of the obtained MoS2 and rGO nanosheets are achieved all together in the ball-milling process. The orderly assembled MoS2/rGO composite as electrode material used in supercapacitor delivers a high specific capacitance of 306 F g−1 at a current density of 0.5 A g−1 and approximately two times higher than that of the pure MoS2. Besides, it exhibits nearly no discharge capacity decay used both in lithium-ion batteries (0.2 A g−1 after 100 cycles) and supercapacitor (4 A g−1 after 5000 cycles). This work has developed an encouraging approach for preparation of this series of graphene-based hybrid electrode materials with ideal performance for potential application in energy storage devices.

Hierarchical nickel/phosphorus/nitrogen/carbon composites templated by one metal–organic framework as highly efficient supercapacitor electrode materials

Novel carbon materials containing Ni, P, N and O were fabricated from the sacrificial MOF template, which exhibits high performance in electrochemical energy storage.

Design of High-Performance Wearable Energy and Sensor Electronics from Fiber Materials.

A fiber material is composed of a group of flexible fibers that are assembled in a certain dimensionality. With its good flexibility, high porosity, and large surface area, it demonstrates a great potential in the development of flexible and wearable electronics. In this work, a kind of nickel/active material-coated flexible fiber (NMF) electrodes, such as Ni/MnO2/reduced graphene oxide (rGO) NMF electrodes, Ni/carbon nanotube (CNT) NMF electrodes, and Ni/G NMF electrodes, is developed by a new general method. In contrast with previous approaches, it is for the first time that porous and rich hydrophilic structures of fiber materials have been used as the substrate to fully absorb active materials from their suspension or slurry and then to deposit a Ni layer on active material-coated fiber materials. The proposed processes of active material dip-coating and then Ni electroless plating not only greatly enhance the electrical conductivity and functional performance of fiber materials but also can be applied to an extensive diversity of fiber materials, such as fabrics, yarns, papers, and so on, with outstanding flexibility, lightweight, high stability, and conductivity for making kinds of energy and sensor devices. As demonstration, a two-dimensional (2D) Ni/MnO2/rGO NMF electrode is obtained for supercapacitors, showing excellent electrochemical performance for energy storage. Then, Ni/CNT NMF electrodes with different dimensionalities, including one-dimensional fiber-shaped, 2D plane, and three-dimensional spatial, are fabricated as various tensile and compressive strain sensors for observation of human's movements and health. Finally, a 2D Ni/graphene NMF electrode is developed for assembling triboelectric nanogenerators for mechanical energy harvesting. Benefiting from wearable property of the textile substrates, the obtained NMF electrodes are expected to be designed into kinds of wearable devices for the future practical applications. The NMF electrode designed in this work provides a simple, stable, and effective approach for designing and fabricating wearable energy and sensor electronics from fiber materials.

Understanding the Thermal Treatment Effect of Two-Dimensional Siloxene Sheets and the Origin of Superior Electrochemical Energy Storage Performances.

Two-dimensional siloxene sheets are an emerging class of materials with an eclectic range of potential applications including electrochemical energy conversion and storage sectors. Here, we demonstrated the dehydrogenation/dehydroxylation of siloxene sheets by thermal annealing at high temperature (HT) and investigated their supercapacitive performances using ionic liquid electrolyte. The X-ray diffraction analysis, spectroscopic (Fourier transform infrared, laser Raman, and X-ray photoelectron spectroscopy) studies, and morphological analysis of HT-siloxene revealed the removal of functional groups at the edges/basal planes of siloxene, and preservation of oxygen-interconnected Si6 rings with sheet-like structures. The HT-siloxene symmetric supercapacitor (SSC) operates over a wide potential window (0-3.0 V), delivers a high specific capacitance (3.45 mF cm-2), high energy density of about 15.53 mJ cm-2 (almost 2-fold higher than that of the as-prepared siloxene SSC), and low equivalent series resistance (compared to reported silicon-based SSCs) with excellent rate capability and long cycle life over 10 000 cycles.

Hierarchical MnS2-MoS2 nanotubes with efficient electrochemical performance for energy storage

Novel hierarchical nanosheet-based MnS2-MoS2 nanotubes are facile fabricated through a one-step hydrothermal method using the MnO2 nanorods as growth template. The (NH4)2MoS4 provides not only sulfur source to react with MnO2 but also the MoS2 precursor. The interconnected MoS2 nanosheets grow upright on the nanosheet-built MnS2 nanotube, leading to the hybrid MnS2-MoS2 hierarchical nanotubes. Moreover, this architecture affords numerous pores with large surface area, high conductivity and excellent structure stability, enabling the superior electrochemical energy storage performance. Even at high current density of 20 A g−1, the hierarchical MnS2-MoS2 nanotubes exhibit specific capacitance of 167.9 F g−1. After 6000 charge-discharge cycles at 16 A g−1, the capacitance can be as high as 87.7% of the initial capacitance, validating the superior cycling durability.

Synthesis of nitrogen doped graphene aerogels using solid supported strategy for supercapacitor

Abstract The development of 3D nitrogen doped graphene aerogels (N-GAs) have attracted great attention due to the excellent performance in electrochemical applications and energy storage. Herein, we present a solid supported method for synthesis of rich porous N-GAs with high specific surface area using urea and KOH as supporting followed by drying at ambient pressure and temperature. The urea and KOH are introduced into the gap of graphene aerogels (GAs) through simple impregnating to effectively prevent the GAs from agglomerating. Consequently, the urea and KOH endow the 3D N-GAs with porous characteristic, high nitrogen content, large specific surface area and good monolith macromorphology. The N-GAs are tested as a binder free electrode for supercapacitor. A specific capacitance as high as 175 F g−1 at 0.5 A g−1 is obtained and an acceptable stability with 87% of initial capacity is retained after 5000 cyclic tests.

Highly mesoporous carbon flakes derived from a tubular biomass for high power electrochemical energy storage in organic electrolyte

Abstract Carbon flakes with a specific surface area of 3010 m2 g−1, a pore volume of 2.756 cm3 g−1 and an ultrahigh mesoporous volumetric ratio of 97.6% were prepared from tubular kapok fibers through a simple low-temperature pre-carbonization and KOH activation process. The low-temperature pre-carbonization in air was effectively dewaxed the biomass and the thus obtained thin precursor was adequately wetted and etched by KOH, both of which might have resulted in the much improved textural properties. When used as electrode materials of symmetric supercapacitors in organic electrolyte, the carbon flakes displayed high energy density at high power density, e.g. 24 Wh kg−1 at 24,029 W kg−1, which was among the best values reported so far on biomass-derived porous carbon electrodes. The results reported in this work indicated that both the selection of bio-resources and pre-carbonization treatment were important for preparation of carbonaceous electrode materials with tailored texture properties and enhanced electrochemical energy storage performance.

Synthesis of Ni4Yb(OH)10NO3 ⋅ 3H2O Nanosheets for Electrode Materials in Electrochemical Energy Storage

AbstractTransition metal hydroxides have attracted considerable attention as promising electrode materials in electrochemical energy storage. In this work, we first used a facile and green approach to synthesize Ni4Yb(OH)10NO3 ⋅ 3H2O nanosheets, which are thin‐layer hexagonal structures. Additionally, this method can be developed to synthesize other lanthanide‐doped Ni(OH)2 materials. When used as electrode materials, these nanosheets exhibited excellent electrochemical energy storage performance and good cycling stability. For example, the Ni4Yb(OH)10NO3 ⋅ 3H2O nanosheet electrode showed a specific capacitance of 1482.1 F g−1 at 1 A g−1, while maintaining great cycling stability (a capacity retention of 71.8 % after 2000 cycles at a current density of 1 A g−1).

Bioinspired Highly Crumpled Porous Carbons with Multidirectional Porosity for High Rate Performance Electrochemical Supercapacitors

Rational design and facile synthesis of porous carbon materials with optimized porosity are necessary to boost electrochemical performance for energy storage and conversion devices. In this work, we report the fabrication of three-dimensional (3D) highly crumpled porous carbons (HCPCs) inspired by the crumpled structure and functionality of renewable Moringa oleifera leaves by a facile postactivation-free method. The as-resulted HCPCs deliver an interconnected framework, abundant active interfaces, rich heteroatom content, and notably multidirectional porosity for fast ion transport and efficient charge storage. Employed as electrode materials for supercapacitors, the HCPCs exhibit ultrahigh rate capability of capacitance retention over 90% when increasing the current density from 1.0 to 50 A g–1 as well as outstanding cycling stability over 20 000 charge/discharge cycles. Furthermore, the HCPC-based symmetric supercapacitor manifests a high specific energy of 21.6 Wh kg–1, along with excellent structural...

Frozen Spray-Coating Prepared Graphene Aerogel with Enhanced Mechanical, Electrochemical, and Electromagnetic Performance for Energy Storage

As a significant macrostructure of graphene, graphene aerogel (GA) with three-dimensional (3D) porous structure, good mechanical elasticity, and high electrical conductivity, has been an urgent req...

Controllable one-pot synthesis of emerging β-Cu2Se nanowire freely standing on nickel foam for high electrochemical energy storage performance

Transition metal selenide has stimulated much research interest in energy storage and conversion, due to its excellent electrical conductivity. β-Cu2Se with special crystal structure is considered as super-ionic conductor, of which the diffusion coefficient is as large as a liquid. The fast ions and electrons conductor β-Cu2Se with uniformly dense nanowire crossing with each other directly on nickel foam is prepared via simple one-step solvothermal grow method for 4 h, avoiding conductive agent and binder. The feature much benefitting for electrons and ions transfer enable the β-Cu2Se-4h electrode delivers specific capacity as high as 182.4 mA h g−1 at current density of 2 mA cm−2, which is still 105.6 mA h g−1 even at high current density of 50 mA cm−2, and excellent cycling stability of 85% after repetitively charge-discharge 10,000 times. The fabricated asymmetric supercapacitor (β-Cu2Se-4h//AC) achieves maximum energy and power density is 48 Wh kg−1 and 5500 W kg−1.

Titania nanotubes dispersed graphitic carbon nitride nanosheets as efficient electrode materials for supercapacitors

Herein, we report the synthesis of a hybrid nanocomposite containing one dimensional (1D) TiO2 nanotube supported over a two dimensional (2D) network of conducting graphitic carbon nitride (g-C3N4) nanosheets by a facile hydrothermal strategy. Symmetric supercapacitors based on the hybrid composite electrodes were fabricated and their electrochemical energy storage performances were evaluated and the results were compared with individual component based supercapacitors. The symmetric supercapacitor based on the composite with 1:4 weight ratios of TiO2 and g-C3N4 exhibited a remarkable increase in the specific capacitance in comparison with the individual components. The improvement in electrochemical behavior of the composite sample was attributed to the increase in surface area of the composite due to the spacer effect of titania nanotubes in the 2D g-C3N4 nanosheets.

Designing MOFs-Derived FeS2@Carbon Composites for High-Rate Sodium Ion Storage with Capacitive Contributions.

Sodium-ion batteries suffer the disadvantages of poor rate performance and cycling stability due to its sluggish sodiation kinetics. A rational design strategy for both materials compositions and structures has been proposed to meet these challenges. Herein, a triple-component composite derived from metal-organic frameworks, comprising FeS2, nitrogen-sulfur co-doped porous carbon, and reduced graphene oxide (FeS2@NSC/G), has been successfully synthesized. With the capacities contributions from different sodium storage routes (diffusion-controlled processes and surface capacitive processes) at varies rate conditions, it is aiming to make full use of each component in the electrode composite and their unique porous structures. Expected electrode properties have been achieved and related electrochemical behaviors have also been investigated. The strategy would present a promising thought for composites design, which could enhance high-rate electrochemical energy storage performances.