Showing papers on "Supercapacitor published in 2018"
TL;DR: A novel "localized high-concentration electrolyte" (HCE) is reported that enables dendrite-free cycling of lithium-metal anodes with high Coulombic efficiency (99.5%) and excellent capacity retention (80% after 700 cycles) of Li||LiNi 1/3 Mn1/3 Co1/ 3 O2 batteries.
Abstract: Rechargeable lithium-metal batteries (LMBs) are regarded as the "holy grail" of energy-storage systems, but the electrolytes that are highly stable with both a lithium-metal anode and high-voltage cathodes still remain a great challenge. Here a novel "localized high-concentration electrolyte" (HCE; 1.2 m lithium bis(fluorosulfonyl)imide in a mixture of dimethyl carbonate/bis(2,2,2-trifluoroethyl) ether (1:2 by mol)) is reported that enables dendrite-free cycling of lithium-metal anodes with high Coulombic efficiency (99.5%) and excellent capacity retention (>80% after 700 cycles) of Li||LiNi1/3 Mn1/3 Co1/3 O2 batteries. Unlike the HCEs reported before, the electrolyte reported in this work exhibits low concentration, low cost, low viscosity, improved conductivity, and good wettability that make LMBs closer to practical applications. The fundamental concept of "localized HCEs" developed in this work can also be applied to other battery systems, sensors, supercapacitors, and other electrochemical systems.
702 citations
TL;DR: In this article, a pseudocapacitive negative MXene (Ti3C2Tx) positive electrode was used to design an asymmetric device with a ruthenium oxide (RuO2)-positive electrode.
Abstract: 2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, in particular in electrochemical energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high-rate pseudocapacitive energy storage in MXene electrodes. However, symmetric MXene supercapacitors have a limited voltage window of around 0.6 V due to possible oxidation at high anodic potentials. In this study, the fact that titanium carbide MXene (Ti3C2Tx) can operate at negative potentials in acidic electrolyte is exploited, to design an all-pseudocapacitive asymmetric device by combining it with a ruthenium oxide (RuO2) positive electrode. This asymmetric device operates at a voltage window of 1.5 V, which is about two times wider than the operating voltage window of symmetric MXene supercapacitors, and is the widest voltage window reported to date for MXene-based supercapacitors. The complementary working potential windows of MXene and RuO2, along with proton-induced pseudocapacitance, significantly enhance the device performance. As a result, the asymmetric devices can deliver an energy density of 37 µW h cm−2 at a power density of 40 mW cm−2, with 86% capacitance retention after 20 000 charge–discharge cycles. These results show that pseudocapacitive negative MXene electrodes can potentially replace carbon-based materials in asymmetric electrochemical capacitors, leading to an increased energy density.
664 citations
TL;DR: This review encompasses the approaches and the wide range of methodologies that have been employed over the last five years in the preparation and functionalisation of nanoporous carbon materials via incorporation of metals, non-metal heteroatoms, multiple heteroatOMs, and various surface functional groups that mostly dictate their place in a widerange of practical applications.
Abstract: Functionalized nanoporous carbon materials have attracted the colossal interest of the materials science fraternity owing to their intriguing physical and chemical properties including a well-ordered porous structure, exemplary high specific surface areas, electronic and ionic conductivity, excellent accessibility to active sites, and enhanced mass transport and diffusion. These properties make them a special and unique choice for various applications in divergent fields such as energy storage batteries, supercapacitors, energy conversion fuel cells, adsorption/separation of bulky molecules, heterogeneous catalysts, catalyst supports, photocatalysis, carbon capture, gas storage, biomolecule detection, vapour sensing and drug delivery. Because of the anisotropic and synergistic effects arising from the heteroatom doping at the nanoscale, these novel materials show high potential especially in electrochemical applications such as batteries, supercapacitors and electrocatalysts for fuel cell applications and water electrolysis. In order to gain the optimal benefit, it is necessary to implement tailor made functionalities in the porous carbon surfaces as well as in the carbon skeleton through the comprehensive experimentation. These most appealing nanoporous carbon materials can be synthesized through the carbonization of high carbon containing molecular precursors by using soft or hard templating or non-templating pathways. This review encompasses the approaches and the wide range of methodologies that have been employed over the last five years in the preparation and functionalisation of nanoporous carbon materials via incorporation of metals, non-metal heteroatoms, multiple heteroatoms, and various surface functional groups that mostly dictate their place in a wide range of practical applications.
653 citations
TL;DR: This Review seeks to provide a rational and in-depth understanding of the relation between the electrochemical performance and the nanostructural/chemical composition of Ti3 C2 Tx, which will promote the further development of 2D MXenes in energy-storage applications.
Abstract: Ti3 C2 Tx , a typical representative among the emerging family of 2D layered transition metal carbides and/or nitrides referred to as MXenes, has exhibited multiple advantages including metallic conductivity, a plastic layer structure, small band gaps, and the hydrophilic nature of its functionalized surface. As a result, this 2D material is intensively investigated for application in the energy storage field. The composition, morphology and texture, surface chemistry, and structural configuration of Ti3 C2 Tx directly influence its electrochemical performance, e.g., the use of a well-designed 2D Ti3 C2 Tx as a rechargeable battery anode has significantly enhanced battery performance by providing more chemically active interfaces, shortened ion-diffusion lengths, and improved in-plane carrier/charge-transport kinetics. Some recent progresses of Ti3 C2 Tx MXene are achieved in energy storage. This Review summarizes recent advances in the synthesis and electrochemical energy storage applications of Ti3 C2 Tx MXene including supercapacitors, lithium-ion batteries, sodium-ion batteries, and lithium-sulfur batteries. The current opportunities and future challenges of Ti3 C2 Tx MXene are addressed for energy-storage devices. This Review seeks to provide a rational and in-depth understanding of the relation between the electrochemical performance and the nanostructural/chemical composition of Ti3 C2 Tx , which will promote the further development of 2D MXenes in energy-storage applications.
643 citations
TL;DR: Mixed metal sulfides (MMS) have attracted increased attention as promising electrode materials for electrochemical energy storage and conversion systems including lithium-ion batteries (LIBs), SIBs, hybrid supercapacitors (HSCs), metal-air batteries (MABs), and water splitting as discussed by the authors.
Abstract: Mixed metal sulfides (MMSs) have attracted increased attention as promising electrode materials for electrochemical energy storage and conversion systems including lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), hybrid supercapacitors (HSCs), metal–air batteries (MABs), and water splitting. Compared with monometal sulfides, MMSs exhibit greatly enhanced electrochemical performance, which is largely originated from their higher electronic conductivity and richer redox reactions. In this review, recent progresses in the rational design and synthesis of diverse MMS-based micro/nanostructures with controlled morphologies, sizes, and compositions for LIBs, SIBs, HSCs, MABs, and water splitting are summarized. In particular, nanostructuring, synthesis of nanocomposites with carbonaceous materials and fabrication of 3D MMS-based electrodes are demonstrated to be three effective approaches for improving the electrochemical performance of MMS-based electrode materials. Furthermore, some potential challenges as well as prospects are discussed to further advance the development of MMS-based electrode materials for next-generation electrochemical energy storage and conversion systems.
640 citations
631 citations
TL;DR: In this article, a review of 2D supercapacitor electrode materials including transition metal dichalcogenides, transition metal oxides and hydroxides, MXenes, and phosphorene is presented.
Abstract: Supercapacitors represent a major technology to store energy for many applications including electronics, automobiles, military, and space. Despite their high power density, the energy density in supercapacitors is presently inferior to that of the state-of-the-art Li-ion batteries owing to the limited electrochemical performance exhibited by the conventional electrode materials. The advent of two-dimensional (2D) nanomaterials has spurred enormous research interest as supercapacitor electrode materials due to their fascinating electrochemical and mechanical properties. This Review discusses cutting-edge research on some of the key 2D supercapacitor electrode materials including transition metal dichalcogenides, transition metal oxides and hydroxides, MXenes, and phosphorene. Various synthetic approaches, novel electrode designs, and microstructure tuning of these 2D materials for achieving high energy and power densities are discussed.
561 citations
TL;DR: In this article, a novel energy storage system of zinc-ion hybrid supercapacitors (ZHSs) was proposed, in which activated carbon materials, Zn metal and ZnSO4 aqueous solution serve as cathode, anode and electrolyte, respectively.
501 citations
TL;DR: In this paper, a hierarchical porous carbons (HPC) was constructed from ant powder and a 3D framework comprised of interconnected macro-, meso-and micropores with suitable pore size distribution, together with an appropriate heteroatom doping of O, N and S.
495 citations
TL;DR: In this paper, the authors review the recent works devoted to the application of various battery/supercapacitor hybrid systems in EVs and present a review of these works from an electrical engineering point of view.
440 citations
TL;DR: Supercapacitors represent the alternative to common electrochemical batteries, mainly to widely spread lithium-ion batteries as discussed by the authors, and their properties are between batteries and capacitors, where they are able to quickly accommodate large amounts of energy (smaller than in the case of batteries).
Abstract: Energy accumulation and storage is one of the most important topics in our times. This paper presents the topic of supercapacitors (SC) as energy storage devices. Supercapacitors represent the alternative to common electrochemical batteries, mainly to widely spread lithium-ion batteries. By physical mechanism and operation principle, supercapacitors are closer to batteries than to capacitors. Their properties are somewhere between batteries and capacitors. They are able to quickly accommodate large amounts of energy (smaller than in the case of batteries – lower energy density from weight and volume point of view) and their charging response is slower than in the case of ceramic capacitors. The most common type of supercapacitors is electrical double layer capacitor (EDLC). Other types of supercapacitors are lithium-ion hybrid supercapacitors and pseudo-supercapacitors. The EDLC type is using a dielectric layer on the electrode − electrolyte interphase to storage of the energy. It uses an electrostatic mechanism of energy storage. The other two types of supercapacitors operate with electrochemical redox reactions and the energy is stored in chemical bonds of chemical materials. This paper provides a brief introduction to the supercapacitor field of knowledge.
TL;DR: In this paper, a mini review of the development of metal organic framework (MOF)-derived 1D porous or hollow carbon nanofibers using the electrospinning method and their application in energy storage (e.g., supercapacitors and rechargeable batteries) and conversion devices (e., fuel cells) is presented.
Abstract: Metal organic framework (MOF)-derived nanoporous carbons (NPCs) have been proposed as promising electrode materials for energy storage and conversion devices. However, MOF-derived NPCs typically suffer from poor electrical conductivity due to the lack of connectivity between these particles and a micropore-dominated storage mechanism, which hinder mass and electron transfer, thereby leading to poor electrochemical performance. In recent years, one-dimensional (1D) MOF-derived carbon nanostructures obtained using an electrospinning method have emerged as promising materials for both electrochemical energy storage (EES) and energy conversion applications. In this mini review, the recent progress in the development of MOF-derived 1D porous or hollow carbon nanofibers using the electrospinning method and their application in energy storage (e.g., supercapacitors and rechargeable batteries) and conversion devices (e.g., fuel cells) is presented. The synthetic method, formation mechanism and the structure–activity relationship of such porous or hollow carbon nanofibers are also discussed in detail. Finally, future perspectives on the development of electrospun MOF-derived carbon nanomaterials for energy storage and conversion applications are provided. This review will provide some guidance for future derivations of 1D hollow carbon nanomaterials from MOFs using electrospinning technology.
TL;DR: A morphology and phase-controlled electrodeposition of MnO2 with ultrahigh mass loading of 10 mg cm-2 on a carbon cloth substrate is performed to achieve high overall capacitance without sacrificing the electrochemical performance.
Abstract: Metal oxides have attracted renewed interest as promising electrode materials for high energy density supercapacitors. However, the electrochemical performance of metal oxide materials deteriorates significantly with the increase of mass loading due to their moderate electronic and ionic conductivities. This limits their practical energy. Herein, we perform a morphology and phase-controlled electrodeposition of MnO2 with ultrahigh mass loading of 10 mg cm–2 on a carbon cloth substrate to achieve high overall capacitance without sacrificing the electrochemical performance. Under optimum conditions, a hierarchical nanostructured architecture was constructed by interconnection of primary two-dimensional e-MnO2 nanosheets and secondary one-dimensional α-MnO2 nanorod arrays. The specific hetero-nanostructures ensure facile ionic and electric transport in the entire electrode and maintain the structure stability during cycling. The hierarchically structured MnO2 electrode with high mass loading yields an outsta...
TL;DR: The first synthesis of 2D hierarchical porous carbon nanosheets (2D-HPCs) with rich nitrogen dopants is reported, which is prepared with high scalability through a rapid polymerization of a nitrogen-containing thermoset and a subsequent one-step pyrolysis and activation into 2D porous nanOSheets.
Abstract: 2D carbon nanomaterials such as graphene and its derivatives, have gained tremendous research interests in energy storage because of their high capacitance and chemical stability. However, scalable synthesis of ultrathin carbon nanosheets with well-defined pore architectures remains a great challenge. Herein, the first synthesis of 2D hierarchical porous carbon nanosheets (2D-HPCs) with rich nitrogen dopants is reported, which is prepared with high scalability through a rapid polymerization of a nitrogen-containing thermoset and a subsequent one-step pyrolysis and activation into 2D porous nanosheets. 2D-HPCs, which are typically 1.5 nm thick and 1-3 µm wide, show a high surface area (2406 m2 g-1 ) and with hierarchical micro-, meso-, and macropores. This 2D and hierarchical porous structure leads to robust flexibility and good energy-storage capability, being 139 Wh kg-1 for a symmetric supercapacitor. Flexible supercapacitor devices fabricated by these 2D-HPCs also present an ultrahigh volumetric energy density of 8.4 mWh cm-3 at a power density of 24.9 mW cm-3 , which is retained at 80% even when the power density is increased by 20-fold. The devices show very high electrochemical life (96% retention after 10000 charge/discharge cycles) and excellent mechanical flexibility.
TL;DR: A novel/universal one‐step laser irradiation method is developed that overcomes all challenges and obtains the oxygen‐vacancy abundant ultrafine Co3O4 nanoparticles/ graphene (UCNG) composites with high SCs performance and is demonstrated to be universal for other metal oxide/graphene Composites with tuned electrical conductivity and electrochemical activity.
Abstract: The metal oxides/graphene composites are one of the most promising supercapacitors (SCs) electrode materials. However, rational synthesis of such electrode materials with controllable conductivity and electrochemical activity is the topical challenge for high-performance SCs. Here, the Co_3O_4/graphene composite is taken as a typical example and develops a novel/universal one-step laser irradiation method that overcomes all these challenges and obtains the oxygen-vacancy abundant ultrafine Co_3O_4 nanoparticles/graphene (UCNG) composites with high SCs performance. First-principles calculations show that the surface oxygen vacancies can facilitate the electrochemical charge transfer by creating midgap electronic states. The specific capacitance of the UCNG electrode reaches 978.1 F g^(−1) (135.8 mA h g^(−1)) at the current densities of 1 A g^(−1) and retains a high capacitance retention of 916.5 F g^(−1) (127.3 mA h g^(−1)) even at current density up to 10 A g^(−1), showing remarkable rate capability (more than 93.7% capacitance retention). Additionally, 99.3% of the initial capacitance is maintained after consecutive 20 000 cycles, demonstrating enhanced cycling stability. Moreover, this proposed laser-assisted growth strategy is demonstrated to be universal for other metal oxide/graphene composites with tuned electrical conductivity and electrochemical activity.
TL;DR: In this paper, a Zn-ion based hybrid supercapacitor (Zn-HSC) was proposed to achieve high energy density with low cost by using Zn foil as both anode and current collector and bio-carbon derived porous material as the cathode.
TL;DR: Graphene aerogels are promising materials for energy systems due to their porous hierarchical structure which affords rapid electron/ion transport, superior chemical and physical stability, and good cycle performance as discussed by the authors.
Abstract: Concerns over air quality reduction resulting from burning fossil fuels have driven the development of clean and renewable energy sources. Supercapacitors, batteries and solar cells serve as eco-friendly energy storage and conversion systems vitally important for the sustainable development of human society. However, many diverse elements influence the performance of energy storage and conversion systems. The overall efficiency of systems depends on the specific structure and properties of incorporated functional materials. Carbon materials, such as graphene, are especially promising for materials development in the energy storage and conversion fields. Graphene, a two-dimensional (2D) carbon material only a single atom thick, has massless Dirac fermions (electron transport is governed by Dirac's equation), displays outstanding electrical conductivity, superior thermal conductivity and excellent mechanical properties. 2D free-standing graphene films and powders have paved the way for promising energy applications. Recently, much effort has been spent trying to improve the number of active sites in electrode materials within 3D network/aerogel structures derived from graphene. This is because graphene aerogels are promising materials for energy systems due to their porous hierarchical structure which affords rapid electron/ion transport, superior chemical and physical stability, and good cycle performance. This review aims to summarize the synthetic methods, mechanistic aspects, and energy storage and conversion applications of novel 3D network graphene, graphene derivatives and graphene-based materials. Areas of application include supercapacitors, Li-batteries, H2 and thermal energy storage, fuel cells and solar cells.
TL;DR: A self-template and recrystallization-self-assembly strategy for the one-step synthesis of core-shell-like cobalt phosphide nanoparticles embedded into nitrogen and phosphorus codoped porous carbon sheets (CoP⊂NPPCS), which manifest outstanding electrochemical performances as anode materials for both lithium- and potassium-ion batteries.
Abstract: Despite the desirable advancement in synthesizing transition-metal phosphides (TMPs)-based hybrid structures, most methods depend on foreign-template-based multistep procedures for tailoring the specific structure. Herein, a self-template and recrystallization-self-assembly strategy for the one-step synthesis of core-shell-like cobalt phosphide (CoP) nanoparticles embedded into nitrogen and phosphorus codoped porous carbon sheets (CoP⊂NPPCS), is first proposed. Relying on the unusual coordination ability of melamine with metal ions and the cooperative hydrogen bonding of melamine and phytic acid to form a 2D network, a self-synthesized single precursor can be attained. Importantly, this approach can be easily expanded to synthesize other TMPs⊂NPPCS. Due to the unique compositional and structural characteristics, these CoP⊂NPPCSs manifest outstanding electrochemical performances as anode materials for both lithium- and potassium-ion batteries. The unusual hybrid architecture, the high specific surface area, and porous features make the CoP⊂NPPCS attractive for other potential applications, such as supercapacitors and electrocatalysis.
TL;DR: This Review summarizes the commonly used routes to build 3D TMD architectures and highlights their applications in electrochemical energy storage and conversion, including batteries, supercapacitors, and electrocatalytic hydrogen evolution.
Abstract: Transition metal dichalcogenides (TMDs) have attracted considerable attention in recent years due to their unique properties and promising applications in electrochemical energy storage and conversion. However, the limited number of active sites and blocked ion and mass transport severely impair the electrochemical performance of TMDs. Construction of three-dimensional (3D) architectures from TMD nanomaterials has been proven an effective strategy to solve the aforementioned problems due to their large specific surface area and short ion and mass transport distance. Here, we summarize the commonly used routes to build 3D TMD architectures and highlight their applications in electrochemical energy storage and conversion, including batteries, supercapacitors, and electrocatalytic hydrogen evolution. Moreover, the challenges and outlooks in this research area are also discussed.
TL;DR: The unique hierarchical Co3 O4 /NHCS core-shell structure with hierarchical structures is a promising electrode material for high-performance supercapacitors.
Abstract: Co3 O4 /nitrogen-doped carbon hollow spheres (Co3 O4 /NHCSs) with hierarchical structures are synthesized by virtue of a hydrothermal method and subsequent calcination treatment. NHCSs, as a hard template, can aid the generation of Co3 O4 nanosheets on its surface; while SiO2 spheres, as a sacrificed-template, can be dissolved in the process. The prepared Co3 O4 /NHCS composites are investigated as the electrode active material. This composite exhibits an enhanced performance than Co3 O4 itself. A higher specific capacitance of 581 F g-1 at 1 A g-1 and a higher rate performance of 91.6% retention at 20 A g-1 are achieved, better than Co3 O4 nanorods (318 F g-1 at 1 A g-1 and 67.1% retention at 20 A g-1 ). In addition, the composite is employed as a positive electrode to fabricate an asymmetric supercapacitor. The device can deliver a high energy density of 34.5 Wh kg-1 at the power density of 753 W kg-1 and display a desirable cycling stability. All of these attractive results make the unique hierarchical Co3 O4 /NHCS core-shell structure a promising electrode material for high-performance supercapacitors.
TL;DR: In this article, a two-dimensional Ti3C2Tx MXene is employed as a flexible, conductive, and electrochemically active binder for one-step fabrication of MXene-bonded activated carbon as flexible electrode for supercapacitors in an organic electrolyte.
Abstract: We report a strategy to employ two-dimensional Ti3C2Tx MXene as a flexible, conductive, and electrochemically active binder for one-step fabrication of MXene-bonded activated carbon as a flexible electrode for supercapacitors in an organic electrolyte. In this electrode, the activated carbon particles are encapsulated between the MXene layers, eliminating the need for insulative polymer binders. MXene plays a multifunctional role in the electrode, including as a binder, a flexible backbone, a conductive additive, and an additional active material. The synergetic effect of MXene and activated carbon constructs a three-dimensional conductive network and enlarges the distance between the MXene layers, greatly enhancing the electrode capacitance and rate capability. As a result, the flexible MXene-bonded activated carbon electrode exhibits a high capacitance of 126 F g–1 at 0.1 A g–1 and a retention of 57.9% at 100 A g–1 in an organic electrolyte, which is required for developing high-performance, flexible su...
TL;DR: The working principle of LICs is discussed, and the recent advances in LIC electrode materials, particularly activated carbon and lithium titanate, as well as in electrolyte development are reviewed, providing deep insights into the LIC field for continuing research and development of second-generation energy-storage technologies.
Abstract: Among the various energy-storage systems, lithium-ion capacitors (LICs) are receiving intensive attention due to their high energy density, high power density, long lifetime, and good stability. As a hybrid of lithium-ion batteries and supercapacitors, LICs are composed of a battery-type electrode and a capacitor-type electrode and can potentially combine the advantages of the high energy density of batteries and the large power density of capacitors. Here, the working principle of LICs is discussed, and the recent advances in LIC electrode materials, particularly activated carbon and lithium titanate, as well as in electrolyte development are reviewed. The charge-storage mechanisms for intercalative pseudocapacitive behavior, battery behavior, and conventional pseudocapacitive behavior are classified and compared. Finally, the prospects and challenges associated with LICs are discussed. The overall aim is to provide deep insights into the LIC field for continuing research and development of second-generation energy-storage technologies.
TL;DR: A critical overview of fractional-order techniques for managing lithium-ion batteries, lead-acid batteries, and supercapacitors is provided, and these models offer 15–30% higher accuracy than their integer-order analogues, but have reasonable complexity.
TL;DR: Here, many kinds of carbon materials derived from metal-organic frameworks are introduced with a particular focus on their promising applications in batteries, supercapacitors, electrocatalytic reactions, water treatment, and other possible fields.
Abstract: Carbon materials derived from metal-organic frameworks (MOFs) have attracted much attention in the field of scientific research in recent years because of their advantages of excellent electron conductivity, high porosity, and diverse applications. Tremendous efforts are devoted to improving their chemical and physical properties, including optimizing the morphology and structure of the carbon materials, compositing them with other materials, and so on. Here, many kinds of carbon materials derived from metal-organic frameworks are introduced with a particular focus on their promising applications in batteries (lithium-ion batteries, lithium-sulfur batteries, and sodium-ion batteries), supercapacitors (metal oxide/carbon and metal sulfide/carbon), electrocatalytic reactions (oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction), water treatment (MOF-derived carbon and other techniques), and other possible fields. To close, some existing problem and corresponding possible solutions are proposed based on academic knowledge from the reported literature, along with a great deal of experimental experience.
TL;DR: In this article, a flexible supercapacitor electrode composed of hierarchical FeCo2O4@NiCo-LDH core/shell heterostructures on carbon cloth is reported by a facile and cost-effective method.
TL;DR: The results suggest that this garlic skin-derived 3D hierarchical porous carbon is a promising electrode material for high-performance supercapacitors.
Abstract: A three-dimensional hierarchical porous carbon is synthesized via a facile chemical activation route with garlic skin as the precursor and KOH as the activating agent. The as-obtained carbon presents a high specific surface area of 2818 m2 g−1 and a hierarchical porous architecture containing macroporous frameworks, mesopores (2–4 nm), and micropores (0.6–1.0 nm). As the electrode material for a supercapacitor, due to its unique interconnected porous structure, this garlic skin-derived carbon exhibits excellent electrochemical performance and cycling stability. At a current density of 0.5 A g−1, the capacitance is up to 427 F g−1 (162 F cm−3). Even at a high current density of 50 A g−1, the capacitance can be maintained to a high value of 315 F g−1 (120 F cm−3). After charging–discharging at a current density of 4.5 A g−1 for 5000 cycles, the capacitance retention is as high as 94%. The results suggest that this garlic skin-derived 3D hierarchical porous carbon is a promising electrode material for high-performance supercapacitors.
TL;DR: A review of the most recent developments in the field of green binders for batteries and supercapacitors can be found in this paper, where the authors discuss how they could decrease cost and environmental impact, and yet improve the performance of electrochemical energy devices.
Abstract: In this review, we discuss the most recent developments in the field of green binders for batteries and supercapacitors and explain how they could decrease cost and environmental impact, and yet improve the performance of electrochemical energy devices. The different classes of green binders reported to date in the literature are firstly classified according to their processability (the solvent required for electrode manufacturing), chemical composition (F-free), and natural availability (synthetic or bio-derived). The benefits originating from their employment are analysed for different devices. The most popular lithium-ion batteries are thoroughly discussed both from the anode and the cathode side. While high capacity Si-based anodes benefit from enhanced cyclability due to the interaction between the active particles’ surface and the functional groups of, e.g., polysaccharides such as carboxymethyl cellulose and alginate, the transition to water-processable cathodes is certainly more challenging. In particular, strategies to suppress the aluminium corrosion affecting most lithiated transition metal oxides are discussed. Despite the much more limited literature available, the role of the binder is increasingly recognized in the emerging field of lithium–sulphur and sodium-ion batteries, and electrochemical double layer capacitors and, therefore, here discussed as well.
TL;DR: In this paper, the growth of oriented, interlayer-expanded MoSe2 nanosheets on graphene with Mo-C bonding via a surfactant-directed hydrothermal reaction was reported.
TL;DR: In this article, a facile one-pot soft-templating and one-step pyrolysis method was used to synthesize carbon spheres with mesoporous structure and nitrogen doping for high-performance supercapacitor applications.
TL;DR: In this article, the influence of KOH dosage on the morphology, structure and electrochemical performance (supercapacitor and oxygen reduction reaction (ORR)) was studied in detail, and the optimized ANPC-3, synthesized under the KOH/carbon mass ratio of 3/1, possesses high specific surface area of 1749m 2 ǫg −1, developed hierarchical micro-mesoporous structures as well as moderate nitrogen content (1.37