Integrated SnO2 nanorod array with polypyrrole coverage for high-rate and long-life lithium batteries

Progress in Iron Oxides Based Nanostructures for Applications in Energy Storage

The demand for green and efficient energy storage devices in daily life is constantly rising, which is caused by the global environment and energy problems. Lithium-ion batteries (LIBs), an important kind of energy storage devices, are attracting much attention. Graphite is used as LIBs anode, however, its theoretical capacity is low, so it is necessary to develop LIBs anode with higher capacity. Application strategies and research progresses of novel iron oxides and their composites as LIBs anode in recent years are summarized in this review. Herein we enumerate several typical synthesis methods to obtain a variety of iron oxides based nanostructures, such as gas phase deposition, co-precipitation, electrochemical method, etc. For characterization of the iron oxides based nanostructures, especially the in-situ X-ray diffraction and ⁵⁷Fe Mössbauer spectroscopy are elaborated. Furthermore, the electrochemical applications of iron oxides based nanostructures and their composites are discussed and summarized.

Graphic Abstract

Electrodeposition Technologies for Li-Based Batteries: New Frontiers of Energy Storage

Electrodeposition induces material syntheses on conductive surfaces, distinguishing it from the widely used solid-state technologies in Li-based batteries. Electrodeposition drives uphill reactions by applying electric energy instead of heating. These features may enable electrodeposition to meet some needs for battery fabrication that conventional technologies can rarely achieve. The latest progress of electrodeposition technologies in Li-based batteries is summarized. Each component of Li-based batteries can be electrodeposited or synthesized with multiple methods. The advantages of electrodeposition are the main focus, and they are discussed in comparison with traditional technologies with the expectation to inspire innovations to build better Li-based batteries. Electrodeposition coats conformal films on surfaces and can control the film thickness, providing an effective approach to enhancing battery performance. Engineering interfaces by electrodeposition can stabilize the solid electrolyte interphase (SEI) and strengthen the adhesion of active materials to substrates, thereby prolonging the battery longevity. Lastly, a perspective of future studies on electrodepositing batteries is provided. The significant merits of electrodeposition should greatly advance the development of Li-based batteries.

SnO2 Quantum Dots@Graphene Framework as a High-Performance Flexible Anode Electrode for Lithium-Ion Batteries

Three-dimensional (3D) layered tin oxide quantum dots/graphene framework (SnO₂ QDs@GF) were designed through anchoring SnO₂ QD on the graphene surface under the hydrothermal reaction. SnO₂ QDs@GF have a 3D skeleton with a large number of mesopores and ultrasmall SnO₂ QDs with a large surface area. The unique design of this structure improves the specific area and promotes ion transport. The mechanically strong SnO₂ QDs@GF can directly be used as the anode of lithium-ion batteries (LIBs); it displays a high reversible capacity (1300 mA h g^-1 at 100 mA g^-1), excellent rate performance (642 mA h g^-1 at 2000 mA g^-1), and superior cyclic stability (when the current density is 10 A g^-1, the capacity loss is less than 2% after 5000 cycles). This novel synthetic method can further be expanded for the production of other quantum dots/graphene composites with a 3D structure as high-performance electrodes for LIBs.

Sb₂S₃@PPy Coaxial Nanorods: A Versatile and Robust Host Material for Reversible Storage of Alkali Metal Ions

Chalcogenides have attracted great attention as functional materials in optics, electronics, and energy-related applications due to their typical semiconductor properties. Among those chalcogenides, Sb₂S₃ holds great promise in energy storage field, especially as an anode material for alkali metal (Li, Na, and K) batteries. In this work, a one-dimensional coaxial Sb₂S₃@PPy is investigated as a versatile and robust anode in three kinds of alkali metal batteries for the first time, and the energy storage mechanism of these batteries is systematically discussed. As an anode material for sodium ion batteries (SIBs) and potassium ion batteries (KIBs), Sb₂S₃@PPy exhibits high reversible capacity and impressive cycle lifespan. Sb₂S₃@PPy anode demonstrates an adsorption behavior that has a significant influence on its sodium storage behavior, providing a universal model for studying the application of chalcogenide compounds.

Hierarchical Fe2O3@C@MnO2@C Multishell Nanocomposites for High Performance Lithium Ion Batteries and Catalysts

The Fe₂O₃@C@MnO₂@C (FCMC) nanocomposites containing spindle-like Fe₂O₃ as a core and MnO₂ nanoflakes as a sandwiched shell and double carbon layers have been successfully prepared by a facile method. As anode materials of lithium ion batteries (LIBs), the cycling stability, rate performance, and conductivity of the prepared FCMC nanocomposites are far beyond those of the carbon-free Fe₂O₃@MnO₂ (FM) nanocomposites. The hierarchical structure with double layers of carbon effectively enhances the ion conductivity and electrochemical performance of transitional metal oxides, indicating that carbon in FCMC played an important role during lithium ion storage. The initial discharge/charge capacity of the FCMC electrode reaches as high as 1240.2/1215.9 mAh g^-1, and the discharge capacity is over 1000 mAh g^-1 at 500 mA g^-1 after 50 cycles. Additionally, the unique hierarchical structural characteristic with double layers of green carbon with a high degree of graphitization makes FCMC an excellent catalyst in removing methylene blue (MB) dye from solution with H₂O₂ under a slight heating with the degradation time as short as 10 min. Our work presents a new perspective on carbon modified multilayer core-shell oxide structure, which can be applied to many fields such as energy storage and catalyst.

In situ synthesized SnO2 nanorod/reduced graphene oxide low-dimensional structure for enhanced lithium storage

A unique SnO₂ nanorod (NR)/reduced graphene oxide (RGO) composite morphology has been synthesized using the in situ hydrothermal method, for use as an anode material in lithium-ion batteries. The SnO₂ NR adhering to the RGO exhibits a length of 250-400 nm and a diameter of 60-80 nm without any obvious aggregation. The initial discharge/charge capacities of the SnO₂ NR/RGO composite are 1761.3 mAh g^-1 and 1233.1 mAh g^-1, with a coulombic efficiency (CE) of 70% under a current density of 200 mA g^-1, and a final capacity of 1101 mAh g^-1 after 50 cycles. The rate capability of the SnO₂ NR/RGO is also improved compared to that of bare SnO₂ NR. The superior electrochemical performance is ascribed to the special morphology of the SnO₂ NRs-which plays a role in shorting the transmission path-and the sheet-like 2D graphene, which prevents the agglomeration of SnO₂ and enhances conductivity during the electrochemical reaction of SnO₂ NR/RGO.

Using a novel rigid-fluoride polymer to control the interfacial thickness of graphene and tailor the dielectric behavior of poly(vinylidene fluoride–trifluoroethylene–chlorotrifluoroethylene) nanocomposites

A rigid liquid crystalline fluoride-polymer has been chosen to tailor the shell thickness of rGO to investigate the effect of interfacial thickness on the dielectric behavior of polymer conductive nanocomposites.

Porous One-Dimensional Nanomaterials: Design, Fabrication and Applications in Electrochemical Energy Storage

Electrochemical energy storage technology is of critical importance for portable electronics, transportation and large-scale energy storage systems. There is a growing demand for energy storage devices with high energy and high power densities, long-term stability, safety and low cost. To achieve these requirements, novel design structures and high performance electrode materials are needed. Porous 1D nanomaterials which combine the advantages of 1D nanoarchitectures and porous structures have had a significant impact in the field of electrochemical energy storage. This review presents an overview of porous 1D nanostructure research, from the synthesis by bottom-up and top-down approaches with rational and controllable structures, to several important electrochemical energy storage applications including lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, lithium-oxygen batteries and supercapacitors. Highlights of porous 1D nanostructures are described throughout the review and directions for future research in the field are discussed at the end.

Phosphorus Enhanced Intermolecular Interactions of SnO2 and Graphene as an Ultrastable Lithium Battery Anode

SnO₂ suffers from fast capacity fading in lithium-ion batteries due to large volume expansion as well as unstable solid electrolyte interphase. Herein, the design and synthesis of phosphorus bridging SnO₂ and graphene through covalent bonding are demonstrated to achieve a robust structure. In this unique structure, the phosphorus is able to covalently "bridge" graphene and tin oxide nanocrystal through PC and SnOP bonding, respectively, and act as a buffer layer to keep the structure stable during charging-discharging. As a result, when applied as a lithium battery anode, SnO₂ @P@GO shows very stable performance and retains 95% of 2nd capacity onward after 700 cycles. Such unique structural design opens up new avenues for the rational design of other high-capacity materials for lithium battery, and as a proof-of-concept, creates new opportunities in the synthesis of advanced functional materials for high-performance energy storage devices.

SnO2@PANI Core-Shell Nanorod Arrays on 3D Graphite Foam: A High-Performance Integrated Electrode for Lithium-Ion Batteries

The rational design and controllable fabrication of electrode materials with tailored structures and superior performance is highly desirable for the next-generation lithium ion batteries (LIBs). In this work, a novel three-dimensional (3D) graphite foam (GF)@SnO₂ nanorod arrays (NRAs)@polyaniline (PANI) hybrid architecture was constructed via solvothermal growth followed by electrochemical deposition. Aligned SnO₂ NRAs were uniformly grown on the surface of GF, and a PANI shell with a thickness of ∼40 nm was coated on individual SnO₂ nanorods, forming a SnO₂@PANI core-shell structure. Benefiting from the synergetic effect of 3D GF with large surface area and high conductivity, SnO₂ NRAs offering direct pathways for electrons and lithium ions, and the conductive PANI shell that accommodates the large volume variation of SnO₂, the binder-free, integrated GF@SnO₂ NRAs@PANI electrode for LIBs exhibited high capacity, excellent rate capability, and good electrochemical stability. A high discharge capacity of 540 mAh g^-1 (calculated by the total mass of the electrode) was achieved after 50 cycles at a current density of 500 mA g^-1. Moreover, the electrode demonstrated superior rate performance with a discharge capacity of 414 mAh g^-1 at a high rate of 3 A g^-1.

Assembly of flexible CoMoO4@NiMoO4·xH2O and Fe2O3 electrodes for solid-state asymmetric supercapacitors

In this work, CoMoO₄@NiMoO₄·xH₂O core-shell heterostructure electrode is directly grown on carbon fabric (CF) via a feasible hydrothermal procedure with CoMoO₄ nanowires (NWs) as the core and NiMoO₄ nanosheets (NSs) as the shell. This core-shell heterostructure could provide fast ion and electron transfer, a large number of active sites, and good strain accommodation. As a result, the CoMoO₄@NiMoO₄·xH₂O electrode yields high-capacitance performance with a high specific capacitance of 1582 F g^-1, good cycling stability with the capacitance retention of 97.1% after 3000 cycles and good rate capability. The electrode also shows excellent mechanical flexibility. Also, a flexible Fe₂O₃ nanorods/CF electrode with enhanced electrochemical performance was prepared. A solid-state asymmetric supercapacitor device is successfully fabricated by using flexible CoMoO₄@NiMoO₄·xH₂O as the positive electrode and Fe₂O₃ as the negative electrode. The asymmetric supercapacitor with a maximum voltage of 1.6 V demonstrates high specific energy (41.8 Wh kg^-1 at 700 W kg^-1), high power density (12000 W kg^-1 at 26.7 Wh kg^-1), and excellent cycle ability with the capacitance retention of 89.3% after 5000 cycles (at the current density of 3A g^-1).

Pd–ZnO nanowire arrays as recyclable catalysts for 4-nitrophenol reduction and Suzuki coupling reactions

Hybrid Pd–ZnO nanowire arrays for catalysis: Pd–ZnO@Zn nanowire arrays have been found to be applicable as recyclable catalysts for 4-nitrophenol reduction and Suzuki coupling reactions.

Rapid preparation of SnO2/C nanospheres by using organotin as building blocks and their application in lithium-ion batteries

SnO₂/C nanospheres (∼500 nm) with ultrasmall SnO₂ particles of 4 nm are prepared by using triphenyltin chloride as building blocks. The SnO₂/C nanospheres show high lithium storage capacity and superior cycling stability.

Recent Progress in Self-Supported Metal Oxide Nanoarray Electrodes for Advanced Lithium-Ion Batteries

The rational design and fabrication of electrode materials with desirable architectures and optimized properties has been demonstrated to be an effective approach towards high-performance lithium-ion batteries (LIBs). Although nanostructured metal oxide electrodes with high specific capacity have been regarded as the most promising alternatives for replacing commercial electrodes in LIBs, their further developments are still faced with several challenges such as poor cycling stability and unsatisfying rate performance. As a new class of binder-free electrodes for LIBs, self-supported metal oxide nanoarray electrodes have many advantageous features in terms of high specific surface area, fast electron transport, improved charge transfer efficiency, and free space for alleviating volume expansion and preventing severe aggregation, holding great potential to solve the mentioned problems. This review highlights the recent progress in the utilization of self-supported metal oxide nanoarrays grown on 2D planar and 3D porous substrates, such as 1D and 2D nanostructure arrays, hierarchical nanostructure arrays, and heterostructured nanoarrays, as anodes and cathodes for advanced LIBs. Furthermore, the potential applications of these binder-free nanoarray electrodes for practical LIBs in full-cell configuration are outlined. Finally, the future prospects of these self-supported nanoarray electrodes are discussed.

A novel Si/Sn composite with entangled ribbon structure as anode materials for lithium ion battery

A novel Si/Sn composite anode material with unique ribbon structure was synthesized by Mechanical Milling (MM) and the structural transformation was studied in the present work. The microstructure characterization shows that Si/Sn composite with idealized entangled ribbon structured can be obtained by milling the mixture of the starting materials, Si and Sn for 20 h. According to the calculated results based on the XRD data, the as-milled 20 h sample has the smallest avergae crystalline size. It is supposed that the flexible ribbon structure allows for accommodation of intrinsic damage, which significantly improves the fracture toughness of the composite. The charge and discharge tests of the as-milled 20 h sample have been performed with reference to Li⁺/Li at a current density of 400 mA g⁻¹ in the voltage from 1.5 to 0.03 V (vs Li/Li⁺) and the result shows that the initial capacity is ∼1400 mA h g⁻¹, with a retention of ∼1100 mA h g⁻¹ reversible capacity after 50 cycles, which is possible serving as the promising anode material for the lithium ion battery application.

Core-Shell Sn-Ni-Cu-Alloy@Carbon Nanorods to Array as Three-Dimensional Anode by Nanoelectrodeposition for High-Performance Lithium Ion Batteries

We report the synthesis of a novel three-dimensional anode based on the core-shell Sn-Ni-Cu-alloy@carbon nanorods which was fabricated by pulse nanoelectrodeposition. Li ion batteries equipped with the three-dimensional anode demonstrated almost 100% capacity retention over 400 cycles at 450 mA g(-1) and excellent rate performance even up to 9000 mA g(-1) for advanced Li-ion battery. Insight of the high performance can be attributed to three key factors, Li-Sn alloys for Li-ion storage, Ni-Cu matrix for the electronic conductive and nanorods structure, and the carbon shell for the electronic/Li-ion conductive and holding stable solid electrolyte interphase (SEI), because these shells always kept stable volumes after extension of initial charge-discharge cycles.

Applying Nanoscale Kirkendall Diffusion for Template-Free, Kilogram-Scale Production of SnO2 Hollow Nanospheres via Spray Drying System

A commercially applicable and simple process for the preparation of aggregation-free metal oxide hollow nanospheres is developed by applying nanoscale Kirkendall diffusion to a large-scale spray drying process. The precursor powders prepared by spray drying are transformed into homogeneous metal oxide hollow nanospheres through a simple post-treatment process. Aggregation-free SnO2 hollow nanospheres are selected as the first target material for lithium ion storage applications. Amorphous carbon microspheres with uniformly dispersed Sn metal nanopowder are prepared in the first step of the post-treatment process under a reducing atmosphere. The post-treatment of the Sn-C composite powder at 500 °C under an air atmosphere produces carbon- and aggregation-free SnO2 hollow nanospheres through nanoscale Kirkendall diffusion. The hollow and filled SnO2 nanopowders exhibit different cycling performances, with their discharge capacities after 300 cycles being 643 and 280 mA h g(-1), respectively, at a current density of 2 A g(-1). The SnO2 hollow nanospheres with high structural stability exhibit superior cycling and rate performances for lithium ion storage compared to the filled ones.

Acetylene Black Induced Heterogeneous Growth of Macroporous CoV2O6 Nanosheet for High-Rate Pseudocapacitive Lithium-Ion Battery Anode

Metal vanadates suffer from fast capacity fading in lithium-ion batteries especially at a high rate. Pseudocapacitance, which is associated with surface or near-surface redox reactions, can provide fast charge/discharge capacity free from diffusion-controlled intercalation processes and is able to address the above issue. In this work, we report the synthesis of macroporous CoV2O6 nanosheets through a facile one-pot method via acetylene black induced heterogeneous growth. When applied as lithium-ion battery anode, the macroporous CoV2O6 nanosheets show typical features of pseudocapacitive behavior: (1) currents that are mostly linearly dependent on sweep rate and (2) redox peaks whose potentials do not shift significantly with sweep rate. The macroporous CoV2O6 nanosheets display a high reversible capacity of 702 mAh g(-1) at 200 mA g(-1), excellent cyclability with a capacity retention of 89% (against the second cycle) after 500 cycles at 500 mA g(-1), and high rate capability of 453 mAh g(-1) at 5000 mA g(-1). We believe that the introduction of pseudocapacitive properties in lithium battery is a promising direction for developing electrode materials with high-rate capability.

Synthesis of SnO2 pillared carbon using long chain alkylamine grafted graphene oxide: an efficient anode material for lithium ion batteries

With the objective of developing new advanced composite materials that can be used as anodes for lithium ion batteries (LIBs), herein we describe the synthesis of SnO2 pillared carbon using various alkylamine (hexylamine; dodecylamine and octadecylamine) grafted graphene oxides and butyl trichlorotin precursors followed by its calcination at 500 °C for 2 h. While the grafted alkylamine induces crystalline growth of SnO2 pillars, thermal annealing of alkylamine grafted graphene oxide results in the formation of amorphous carbon coated graphene. Field emission scanning electron microscopy (FE-SEM) results reveal the successful formation of SnO2 pillared carbon on the graphene surface. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy characterization corroborates the formation of rutile SnO2 crystals on the graphene surface. A significant rise in the BET surface area is observed for SnO2 pillared carbon, when compared to pristine GO. Electrochemical characterization studies of SnO2 pillared carbon based anode materials showed an enhanced lithium storage capacity and fine cyclic performance in comparison with pristine GO. The initial specific capacities of SnO2 pillared carbon are observed to be 1379 mA h g(-1), 1255 mA h g(-1) and 1360 mA h g(-1) that decrease to 750 mA h g(-1), 643 mA h g(-1) and 560 mA h g(-1) depending upon the chain length of grafted alkylamine on the graphene surface respectively. Electrochemical impedance spectral analysis reveals that the exchange current density of SnO2 pillared carbon based electrodes is higher, corroborating its enhanced electrochemical activity in comparison with GO based electrodes.

Flexible additive free H2V3O8nanowire membrane as cathode for sodium ion batteries

A flexible additive free H₂V₃O₈nanowire membrane is presented as a promising sodium-ion battery cathode.

Graphene Oxide Wrapped Amorphous Copper Vanadium Oxide with Enhanced Capacitive Behavior for High-Rate and Long-Life Lithium-Ion Battery Anodes

Graphene oxide-wrapped amorphous copper vanadium oxide is fabricated through a template-engaged redox reaction followed by vacuum dehydration. This material exhibits high reversible capacity, excellent rate capability, and out standing high-rate cyclability. The outstanding performance is attributed to the fast capacitive charge storage and the in situ formed copper with enhanced electrical conductivity.

Conductive polymer-mediated 2D and 3D arrays of Mn3O4 nanoblocks and mesoporous conductive polymers as their replicas

Orientation-controlled 2D and 3D microarrays of Mn3O4 nanocuboids that were mediated by a conductive polymer were fabricated by evaporation-induced self-assembly of the oxide nanoblocks and subsequent polymerization of pyrrole in the interparticle spaces. Free-standing mesoporous polypyrroles (PPy) having chain- and square-grid-like nanovoid arrays were obtained as replicas of the composite assemblies by dissolving the oxide nanoblocks. The PPy-mediated manganese oxide arrays exhibited stable electrochemical performance as an ultrathin anode of a lithium-ion secondary battery.

Synthesis of NiO Nanofibers Composed of Hollow Nanospheres with Controlled Sizes by the Nanoscale Kirkendall Diffusion Process and Their Electrochemical Properties

NiO nanofibers composed of hollow NiO nanospheres with different sizes were prepared by electrospinning method. The mean size of the hollow NiO nanospheres was determined by the mean size of the Ni nanocrystals of the Ni-C composite nanofibers formed as an intermediate product. Porous-structured NiO nanofibers were also prepared as a comparison sample by direct oxidation of the electrospun nanofibers. The discharge capacities of the nanofibers composed of hollow nanospheres reduced at 300, 500, and 700 °C for the 250th cycle were 707, 655, and 261 mA h g(-1), respectively. However, the discharge capacity of the porous-structured NiO nanofibers for the 250th cycle was low as 206 mA h g(-1). The nanofibers composed of hollow nanospheres had good structural stability during cycling.

Vanadium Nitride Nanowire Supported SnS2 Nanosheets with High Reversible Capacity as Anode Material for Lithium Ion Batteries

The vulnerable restacking problem of tin disulfide (SnS2) usually leads to poor initial reversible capacity and poor cyclic stability, which hinders its practical application as lithium ion battery anode (LIB). In this work, we demonstrated an effective strategy to improve the first reversible capacity and lithium storage properties of SnS2 by growing SnS2 nanosheets on porous flexible vanadium nitride (VN) substrates. When evaluating lithium-storage properties, the three-dimensional (3D) porous VN coated SnS2 nanosheets (denoted as CC-VN@SnS2) yield a high reversible capacity of 75% with high specific capacity of about 819 mAh g(-1) at a current density of 0.65 A g(-1). Remarkable cyclic stability capacity of 791 mAh g(-1) after 100 cycles with excellent capacity retention of 97% was also achieved. Furthermore, discharge capacity as high as 349 mAh g(-1) is still retained after 70 cycles even at a elevated current density of 13 A g(-1). The excellent performance was due to the conductive flexible VN substrate support, which provides short Li-ion and electron pathways, accommodates large volume variation, contributes to the capacity, and provides mechanical stability, which allows the electrode to maintain its structural stability.

Hierarchical Graphene-Encapsulated Hollow SnO2@SnS2 Nanostructures with Enhanced Lithium Storage Capability

Complex hierarchical structures have received tremendous attention due to their superior properties over their constitute components. In this study, hierarchical graphene-encapsulated hollow SnO2@SnS2 nanostructures are successfully prepared by in situ sulfuration on the backbones of hollow SnO2 spheres via a simple hydrothermal method followed by a solvothermal surface modification. The as-prepared hierarchical SnO2@SnS2@rGO nanocomposite can be used as anode material in lithium ion batteries, exhibiting excellent cyclability with a capacity of 583 mAh/g after 100 electrochemical cycles at a specific current of 200 mA/g. This material shows a very low capacity fading of only 0.273% per cycle from the second to the 100th cycle, lower than the capacity degradation of bare SnO2 hollow spheres (0.830%) and single SnS2 nanosheets (0.393%). Even after being cycled at a range of specific currents varied from 100 mA/g to 2000 mA/g, hierarchical SnO2@SnS2@rGO nanocomposites maintain a reversible capacity of 664 mAh/g, which is much higher than single SnS2 nanosheets (374 mAh/g) and bare SnO2 hollow spheres (177 mAh/g). Such significantly improved electrochemical performance can be attributed to the unique hierarchical hollow structure, which not only effectively alleviates the stress resulting from the lithiation/delithiation process and maintaining structural stability during cycling but also reduces aggregation and facilitates ion transport. This work thus demonstrates the great potential of hierarchical SnO2@SnS2@rGO nanocomposites for applications as a high-performance anode material in next-generation lithium ion battery technology.

Coaxial CoMoO4 nanowire arrays with chemically integrated conductive coating for high-performance flexible all-solid-state asymmetric supercapacitors

Flexible all-solid-state supercapacitors have offered promising applications as novel energy storage devices based on their merits, such as small size, low cost, light weight and high wearability for high-performance portable electronics. However, one major challenge to make flexible all-solid-state supercapacitors depends on the improvement of electrode materials with higher electrical conductivity properties and longer cycling stability. In this article, we put forward a simple strategy to in situ synthesize 1D CoMoO4 nanowires (NWs), using highly conductive CC and an electrically conductive PPy wrapping layer on CoMoO4 NW arrays for high performance electrode materials. The results show that the CoMoO4/PPy hybrid NW electrode exhibits a high areal specific capacitance of ca. 1.34 F cm(-2) at a current density of 2 mA cm(-2), which is remarkably better than the corresponding values for a pure CoMoO4 NW electrode of 0.7 F cm(-2). An excellent cycling performance of nanocomposites of up to 95.2% (ca. 1.12 F cm(-2)) is achieved after 2000 cycles compared to pristine CoMoO4 NWs. In addition, we fabricate flexible all-solid-state ASC which can be cycled reversibly in the voltage range of 0-1.7 V, and exhibits a maximum energy density of 104.7 W h kg(-1) (3.522 mW h cm(-3)), demonstrating great potential for practical applications in flexible energy storage electronics.

Facile synthesis of SnO2 nanocrystals anchored onto graphene nanosheets as anode materials for lithium-ion batteries

A SnO₂/graphene nanocomposite was prepared via a facile solvothermal process using stannous octoate as a Sn source, which exhibited excellent electrochemical behavior with a high reversible capacity, a long cycle life and a good rate capability when used as an anode material for lithium-ion batteries.

Electrochemical properties of SnO2 nanoparticles immobilized within a metal–organic framework as an anode material for lithium-ion batteries

SnO₂ nanoparticles have been immobilized within MIL-101(Cr) crystals through a post-synthesis method for a lithium-ion battery anode.