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Although high-temperature solid-phase methods have become the dominant route for manufacturing layered oxide cathode materials in industry, severe Li+/Ni2+ cation mixing problems caused by high-temperature processes still prevent the realization of high-performance lithium-ion batteries. Herein, a wet chemical lithiation method by stepwise lithium intercalation to reduce and shorten the sintering temperature and time of the post-treatment process is proposed. Li 0.6 H x Ni 0.52 Co 0.19 Mn 0.29 O 2 stepwise products with lithiation efficiencies exceeding 60% were obtained at reaction temperatures below 200 °C. The as-prepared LiNi 0.52 Co 0.19 Mn 0.29 O 2 (HT-52-S) exhibits low Li+/Ni2+ cation mixing and good comprehensive electrochemical performance after subsequent heat treatment to complete all lithiation. Compared with LiNi 0.52 Co 0.19 Mn 0.29 O 2 (SS-52) prepared by the conventional high-temperature solid-phase method, the Li+/Ni2+ cation mixing of HT-52-S was relatively reduced by 57.9%, and the capacity retention after 100 cycles at 1 C was relatively improved by 22.1%. We believe that this work can serve as a useful reference to develop manufacturing processes for high-performance layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

Aiming for increased nickel and lower cobalt content in layered transition metal oxide cathodes (NCM) is a feasible strategy for achieving increased energy density and cost competitiveness in commercial lithium‐ion batteries. However, the practical long‐term cycling of NCM cathodes suffers from severe capacity degradation due to irreversible interface phase transformation and unavoidable crack formation. Herein, an in situ modification strategy is used to form a uniform and conformal Li1.8Sc0.8Ti1.2(PO4)3 (LSTP) protective layer by interconnecting the single‐crystal‐layered LiNi0.6Co0.1Mn0.3O2 (SC‐NCM) particles. LSTP surface modification helps to construct a robust cathode‐electrolyte interphase thin film between the cathode and the electrolyte, which can prevent SC‐NCM corrosion by electrolyte, and the stability of the mechanics can improve the intergranular cracks caused by long cycles under harsh conditions. Moreover, the LSTP conductive modification layer facilitates the lithium‐ion transport among cathode particles, effectively enhancing the rate capability. Impressively, the LSTP modified SC‐NCM exhibits a high reversible capacity of 144.3 mAh g−1 at the high discharge rate of 5 C and maintains a capacity retention of 90.27% even at the ultrahigh charge voltage of 4.6 V operation after 500 cycles. Moreover, in a pouch‐type full battery, the graphite/LSTP modified SC‐NCM maintains a capacity retention of 89.6% after 1700 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] This study aims to prepare an organic-inorganic reticular polymer electrolyte. Isocyanate acts as a bridge that connects fumed silica and PEO molecular chains. The PEO-TDI-SiO 2 solid polymer electrolytes developed can significantly have improved ionic conductivity of 0.12 mS cm−1 at ambient temperature. This is because the TDI-SiO 2 nanoparticles inhibits polymer crystallization which provides more continuous Li-ion transport pathways. Tests at 60 °C indicate that the cross-linked structure of covalent TSI bonded to PEO effectively enlarges the electrochemical window of the polymer electrolyte to 5.6 V. Also, the PTSI electrolyte membrane has a higher Li+ transference number of 0.33 compared to the PEO-LiTFSI electrolytes. It is worth noting that the assembled LiFePO 4 |PTSI8%|Li cells deliver outstanding rate performance and stable cycling performance. All these considerable merits of PTSI membrane demonstrate that PTSI is a promising candidate that can be used as solid polymer electrolytes for the next-generation Li-ion batteries. [ABSTRACT FROM AUTHOR]

Summary: A cross‐linked MnO2 coated ZnFe2O4 hollow nanosphere composite is synthesized and controlled via a facial and handy route. The connected MnO2 nanoplates form a cross‐linked network, which is conducive to the rapid transfer of Li ions. The composite with unique architecture can not only release the strain and stress caused by the insertion and desertion of lithium ions but also greatly improve the electrical conductivity and lithium ion diffusivity. Consequently, when used as a lithium‐ion battery anode material, the electrode shows an excellent initial reversible capacity of 933.5 mAh/g with an initial coulombic efficiency of 62.5%. After 100 cycles, the reversible capacity stabilized at 605.6 mAh/g with a high capacity retention of 91% from the 20th cycle to the 100th cycle. At a high current density of 3 A/g, an excellent capacity of 390.6 mAh/g can be retained. In this case, the electrode shows broad application prospects for novel power storage systems. [ABSTRACT FROM AUTHOR]

High-performance lithium-ion batteries (LIBs) and sodium-ion battery (SIBs) anode materials Co 3 S 4 –ZnS/NC are prepared by carbonization and subsequent sulfidation using Co, Zn-based zeolitic imidazolate frameworks (ZIF) as a precursor. ZnS and Co 3 S 4 in-situ doping on polyhedral carbon framework, which enhances the conductivity and can buffer the volume expansion during the cycle and improve the kinetics. When Co 3 S 4 –ZnS/NC use as an anode material for LIBs, which can deliver reversible capacity 750 mA h g−1 after 200 cycles at current density of 1 A g−1. It also exhibits excellent sodium storage, with capacities remaining 316.5 mA h g−1, after 1000 cycles at current density of 1 A g−1. Compared with pure ZnS/NC and Co 3 S 4 /NC electrode, the Co 3 S 4 –ZnS/NC electrode also exhibits enhanced rate performance in both Li/Na storage. This excellent performance may be due to the following factors. (a) The polyhedral carbon skeleton makes the composites has superior conductivity and excellent structural stability. (b) The large specific surface area and porous structure can make the electrolyte fully infiltrate the electrode. (c) The high capacitance contribution gives the composite excellent Li/Na storage performance, especially at high current density. These results reveal the potential application prospects of Co 3 S 4 –ZnS/NC in high performance LIBs and SIBs. Schematic illustration of detailed synthesis of three composites material. Firstly, the ZIF polyhedral precursor was prepared by simple liquid phase diffusion method. Then the precursor was carbonized at 600 °C for 2 h under the protection of argon gas. Finally, the subsequent sulfidation process was completed under hydrothermal conditions with TAA, and finally three composites material was obtained. Image 1 [ABSTRACT FROM AUTHOR]

Abstract In this study, a core-shell nanostructure Fe 2 O 3 coated grass-like Mn 3 O 4 supported on graphene has been designed and fabricated via a facile and convenient hydrothermal method and thermal treatment routes. The Fe 2 O 3 coated Mn 3 O 4 nanorods with diameter of 35–40 nm are convolved by flexible graphene, which form a three-dimensional conductive network. As an anode for lithium-ion batteries, the as-prepared composite delivers an initial discharge/charge capacity of 1939.2/1393.5 mAh g−1 with a promising coulombic efficiency of 71.9% and a reversible specific capacity of 795.4 mA g−1 after 400 cycles at a high current density, which exhibits an upward trend in the capacity after long-term cycling as well. Both of the cross-linked structure and the synergistic effect are contributed to the enhance lithium-storage performance and dynamic characteristic, which reveals that the electrode holds a great potential as an anode material for rechargeable Li-ion batteries. Graphical abstract Image 1 Highlights • An insight of fabrication for controlled Mn 3 O 4 @Fe 2 O 3 /graphene hollow core-shell structure and 3D conductive network. • The cross-linked graphene and nanorods accelerate the transportation of ions and electrons. • The optimized anodes exhibit excellent capability at high current density after long-life cycles. • This work can open up an avenue for the rational design anode materials by controlling the structure and conductivity. [ABSTRACT FROM AUTHOR]

Highlights • The NiCo 2 O 4 and NiCo 2 O 4 @MnO 2 composites synthesized by a hydrothermal method. • NiCo 2 O 4 @MnO 2 maintained reversible capacities of 1000 mA h g−1 after 100 cycles. • NiCo 2 O 4 @MnO 2 electrodes demonstrated an enhanced rate performance. Abstract 3D flower-like NiCo 2 O 4 and NiCo 2 O 4 @MnO 2 were successfully synthesized via a hydrothermal method. Scanning electron microscopy results illustrated that NiCo 2 O 4 is formed by stacking nanosheets, and after reaction in KMnO 4 solution, MnO 2 were evenly coated on the surface of NiCo 2 O 4 formed flower-like structure. The as-synthesized materials were evaluated as an anode materials for lithium-ion batteries, NiCo 2 O 4 and NiCo 2 O 4 @MnO 2 exhibited high specific capacities of 841.9 and 1 000 mA h g−1 after 100 cycles respectively. Moreover, NiCo 2 O 4 @MnO 2 composites demonstrate good rate performance. These enhanced electrochemical properties could be attributed to the distinctive 3D flower-like structure, which increases the contact area between the electrolyte and electrode material to provide more active sites, and reduced volume effects during repeated insertion/extraction of lithium ions. The results suggest that the NiCo 2 O 4 @MnO 2 composites could be promising LIBs anode materials. [ABSTRACT FROM AUTHOR]

Abstract Flexible electrodes with light weight, favorable mechanical strength and high energy/power density have attracted tremendous interest for next-generation lithium-ion batteries. Here we develop a novel architecture for preparing a freestanding binder-free flexible electrode (Hierarchical SnS 2 Nanoplates Decorated on the Graphene Supported by Carbon Cloth), which possesses superhigh mass-loading and large specific surface area. The electrode provides the high-rate transportation of electrolyte ions and electrons throughout the electrode matrix and buffers the volumetric expansion effect generated from Li+ insertion/desertion. The uniform size and homogeneous SnS 2 nanoplates on the graphene nanosheets reduced electrode polarization, leading to excellent electrochemical performance. The flexible electrode exhibits an extraordinary initial capacity of 1987.4 mAh g−1, a specific capacity up to 638.1 mAhg−1 after 150 cycles, which integrates that the design strategies to enhance the mass loading of active materials can be responsible for the superior lithium storage performance. Highlights • An insight into design for binder-free SnS 2 /graphene/carbon cloth flexible electrodes. • The electrodes possess larger specific surface area and higher mass loading. • The hierarchical SnS 2 and cross-linking graphene accelerate the transportation of ions and electrons. • The optimized anodes exhibit high specific capacity and stable cycling performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The complete hollow ZnFe 2 O 4 nanospheres were synthesized just by a simple solvothermal process. • The nanospheres show huge and complete inner space with a diameter of 180 nm. • The ZnFe 2 O 4 electrode delivers a capacity more than 1100 mAh·g−1 at 200 mA·g−1 after 120 cycles. • The electrochemical properties of the ZnFe 2 O 4 nanospheres are even superior than many reported composites. Abstract Complete hollow ZnFe 2 O 4 nanospheres with well crystallization and uniform dispersion were successfully synthesized via a facile solvothermal method. The obtained ZnFe 2 O 4 material displays a complete hollow sphere structure with a huge interspace diameter of 180 nm. When used as anodes for lithium ion battery, the as-prepared sample exhibits high initial discharge/charge capacities of 1321.4/976.8 mA h·g−1 at 100 mA·g−1, with an initial Coulombic efficiency reaching as high as 73.9%. Surprisingly, the specific capacity of ZnFe 2 O 4 electrodes experiences a process of decrease in initial 20 cycles and stable increase in subsequent 100 cycles, with a considerable discharge capacity of 1101.3 mA h·g−1 at 200 mA·g−1 after 120 cycles. Even at a high rate of 1600 mA·g−1, the capability for electrodes still maintains at 703.6 mA h·g−1, much larger than traditional commercialized graphite anode (372 mA h·g−1). Such remarkable electrochemical properties of the only ZnFe 2 O 4 material are even superior than those complex and expensive ZnFe 2 O 4 -based composites reported previously. It is believed that zinc ferrite nanosphere material with high reversible capacity, favorable cycling stability and good rate capability holds promise for becoming an alternative anode of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Abstract Binding-free NiCo 2 O 4 @NiO@C/cc electrode was prepared by hydrothermal method, annealing method and physical vapor deposition. In this composite, NiCo 2 O 4 @NiO was strongly grown on carbon cloth and formed a core-shell heterostructure, which can facilitate the transport of ions. What's more, the conductivity was dramatically improved after coating NiO nanofalkes. Additionally, carbon coating can inhibit volume expansion, improve material conductivity and structural stability. The free-standing electrode material showed an initial capacity of 1885 mAh g−1 at a current density of 100 mA g−1, after 100 cycles, the reversible capacity stabilized around 1051 mAh g−1 with Coulomb efficiency of 99.9%. At a high rate of 1600 mA g−1, the capacity exhibited about 721 mAh g−1, indicating that the NiCo 2 O 4 @NiO@C/cc composite is an outstanding material as the anode electrode material for flexible lithium-ion batteries with broad application prospect. [ABSTRACT FROM AUTHOR]

Abstract Flexible lithium-ion batteries are being given great attention as up-and-coming power source for the development of flexible and wearable electronic devices. In this work, a carbon and silicon coated 3D α-Fe 2 O 3 nanorod arrays on carbon cloth composite was firstly designed by facile hydrothermal method and physical vapor deposition process. The as-prepared composite can be directly applied as flexible anode for Li-ion batteries without adding any binder and conducting materials. The electrochemical results show that the composite exhibits outstanding electrochemical lithium storage properties with high initial Coulombic Efficiency of 76% at 100 mA g−1 current density and a superior cycling performance that could maintain about 910 mAh·g−1 after 500 cycles at a 500 mA g−1 current density, which is two to three times of commercial graphite anodes. This study offers a promising route to greatly enhance the electrochemical properties of metal oxides and provides suggestive insights for developing high-performance electrode materials for flexible energy storage devices. Highlights • Binder-free α-Fe 2 O 3 @Si@C/carbon cloth flexible electrode was prepared via a facile route. • α-Fe 2 O 3 @Si@C/carbon cloth electrode is composed of carbon cloth, α-Fe 2 O 3 nanorods, silicon and carbon coating layer. • α-Fe 2 O 3 @Si@C/carbon cloth anode exhibits high specific capacity and stable cycling performance. • α-Fe 2 O 3 @Si@C/carbon cloth anode displays good rate-capability and flexibility. [ABSTRACT FROM AUTHOR]

A novel type of cobalt nanofibers coated with layered nickel silicate (Co nanofibers @ voids @ Ni 3 Si 2 O 5 (OH) 4 ) coaxial core-shell composites were successfully prepared via a well-known Stöber process and two hydrothermal methods. In the composites, the international nanosheet structure of the nickel silicate provided interlayer spaces for lithium ions in the process of insertion and extraction. The cobalt nanofibers served as a mechanical support for the nickel silicate nanosheets, which increased the electrical conductivity of the whole electrode. In addition, one-dimensional coaxial structure was stable to buffer the volume change and avoid the destruction of the structure. Moreover, the voids provided effective channels for the transportation of lithium ions. The Co nanofibers @ voids @ Ni 3 Si 2 O 5 (OH) 4 ) coaxial core-shell composites presented superior electrochemical properties compared with the published Ni 3 Si 2 O 5 (OH) 4 -related materials. With the advantages of exceptional performances and facile preparation, the composites show prospective application potential as advanced anode materials in lithium ion batteries. [ABSTRACT FROM AUTHOR]

Controlled Mn 3 O 4 hollow polyhedron with average size of 1 μm was successfully synthetized via one-step hydrothermal method, followed by coated with carbon layer on the surface of the polyhedron using dopamine as carbon source to form the hollow core–shell structured Mn 3 O 4 @C composites. The unique morphology and strong structure effectively enhanced the cycling stability of electrode materials. The electrochemical results show that the as-prepared Mn 3 O 4 @C composite exhibits outstanding electrochemical lithium storage properties with high initial discharge capacity of 2057.1 mAhg −1 and a superior cycling performance that could maintain about 885.5 mAhg −1 after 200 cycles at a 100 mAg −1 current density. These promising results demonstrate that the Mn 3 O 4 @C composite could be promising LIBs anode materials. [ABSTRACT FROM AUTHOR]

A novel type of porous TiO 2 nanobelts anchored with Sn 3 O 4 nanosheets (TiO 2 nanobelts @Sn 3 O 4 nanosheets) core-shell composites were developed via two-step hydrothermal methods. The structure, morphology, formation mechanism and electrochemical performance of the porous TiO 2 nanobelts coated with mixed transition-metal oxides Sn 3 O 4 nanosheets core-shell composites were researched. The results illustrated that the Sn 3 O 4 nanosheets were uniformly anchored on the surface of the porous TiO 2 nanobelts, which were almost perpendicular to the porous TiO 2 nanobelts. The composites as anode materials exhibited more remarkable electrochemical performances than the Sn 3 O 4 nanosheet and the porous TiO 2 nanobelts, in terms of the cycling performance and rate capability. The initial discharge capacity was 1513.7 mAh/g and the reversible capacity was 659 mAh/g after 50 cycles. This study perhaps inspired the designing of other transition metal oxide-based anode materials with desirable electrochemical performance for applications of lithium ion batteries. [ABSTRACT FROM AUTHOR]

Carbonaceous polypyrrole nanotubes coated with SnS 2 nanosheets (CPN@SnS 2 ) were successfully synthesized via a simple polymerization process and further a hydrothermal method. Used as anode materials, the CPN@SnS 2 electrode exhibited a high specific reversible capacity, significant rate capability as well as enhanced cycling stability. It was found that the initial discharge capacity was 1422 mAh/g and the reversible capacity was 699.2 mAh/g after 100 cycles. The unique structure and synergetic effect of the CPN@SnS 2 composite were contributed to the enhanced electrochemical performance, in which the 2D ultrathin nanostructure facilitated lithium ions insertion and the CPN greatly improved the electronic conductivity for fast electron supply. In addition, acting as a mechanical support, the conductive CPN could buffer the strain resulting from the volume change in the process insertion/extration of lithium ions. This study inspired a better design of other transition metal oxide-based anode materials with desirable electrochemical performance for lithium ion battery applications. [ABSTRACT FROM AUTHOR]

With the advent of flexible electronics, flexible secondary rechargeable batteries have attracted considerable attentions as a promising power source in the new generation of flexible electronics such as roll-up displays, smart electronics, and implantable medical devices. In this work, we report the fabrication of 3D NiCo 2 O 4 arrays on carbon cloth as a binder-free anode for sodium/lithium ion storage. Amorphous carbon layer is used to modify the surface of NiCo 2 O 4 arrays by physical vapor deposition (PVD). The electrochemical performance measurements demonstrate that the amorphous carbon layer can improve the electrochemical stability of NiCo 2 O 4 . The NiCo 2 O 4 @ C/carbon cloth electrode exhibits a high reversible capacity of 749.9 mAh g −1 , stable cycling with more than 535.47 mAh g −1 at 500 mA g −1 over 100 cycles and impressive rate capability (318 mAh g −1 at 5 A g −1 over 700 cycles) for SIBs and excellent electrochemical performance for LIBs (reversible capacity of 807.63 mAh g −1 were observed for 100 cycles). [ABSTRACT FROM AUTHOR]

Well-designed hierarchical nanostructured composites consisting of one dimensional cobalt fibers and thin tin disulfide nanosheets were successfully synthesized for the first time through a hydrothermal method. The SnS 2 nanosheets were uniformly grown onto the Co fibers and were almost perpendicular to the Co fibers. The composites as one kind anode materials exhibited more remarkable lithium ion storage properties than SnS 2 nanosheets. The composites exhibited a capacity of 500.5 mA h/g after 100 cycles even at 1000 mA/g. The improved electrochemical performance could be assigned to the Co fiber substrate support, which could provide short lithium ion and electron pathways, alleviate large volume expansion, contribute to the capacity, and offer mechanical stability for the anode electrode. This special designing perhaps could lay a foundation for the preparation of high performance lithium ion battery anode materials. [ABSTRACT FROM AUTHOR]

Hybrid hollow urchin-like cobalt and copper silicate constructed by nanotubes encapsulated in graphene nanosheets composites were successfully prepared using graphene oxide as carrier and silica spheres as template, which were done through a well-known Stȍber process and a hydrothermal method. In fact, the synthesis of hybrid urchin-like silicate constructed by nanotubes through onestep hydrothermal reaction has rarely been reported.The electrochemical performances of the composites as lithium-ion battery anode materials were studiedfor the first time. As novel anode materials of Li-ion batteries, the special hollow urchin-like structure not only could facilitate the Li + diffusion and electron transport but alsocouldaccommodate the volume variation during the conversion reactions. In addition, the introduction of graphene can make the electrical conductivity better. Graphene wrapped hollow urchin-like silicate compositespossesses superior electrochemical cycling properties. The first discharge capacity is1955.2mAh/g with a current density of 300 mA/g. The unique well-designed configuration presents a beneficial method to synthesize efficient and high performance electrode materials for advanced power applications. [ABSTRACT FROM AUTHOR]

A free-standing Si@Co 9 S 8 CF electrode with excellent rate capability and cycling performance was obtained by electrospinning, vulcanization, and carbonization processes as high-performance anode for Li-ion batteries. [Display omitted] • Si@Co 9 S 8 CF films are explored by electrospinning, vulcanization and carbonization. • The yolk-shelled Si@Co 9 S 8 can remarkably alleviate the volume expansion. • The introduction of CFs can improve the electrical conductivity of the electrodes. • The free-standing anode avoids the conventional process of electrode preparation. Silicon-based (Si-based) materials have aroused extensive attention owing to their ultra-high theoretical specific capacity, while the huge volume expansion and inferior electronic conductivity have impeded their practical application in lithium-ion batteries (LIBs). Rational structural design has been regarded as a fascinating strategy, especially for yolk-shell structures. Herein, Si nanoparticles (Si NPs) were encapsulated in ZIF-67 metal–organic frameworks to obtain Si@ZIF-67 particles, which were wrapped in one-dimensional carbon fibers (CFs) by simple processes of electrospinning, vulcanization and carbonization to obtain a free-standing Si@Co 9 S 8 CF electrode. The yolk-shelled Si@Co 9 S 8 particles could remarkably ameliorate the volume variation of Si materials during the lithiation/de-lithiation cycling and the introduction of CFs endowed an efficient one-dimensional electronic pathway accurately to improve the conductivity of composite materials. In addition, it was not negligible that the as-obtained Si@Co 9 S 8 CF films could be as a self-supporting electrode, which avoided the traditional cumbersome procedure of the electrode preparation. The resulting composite electrodes possess an excellent rate performance and an ultra-stable cycling lifespan. We hope this work can provide some novel insights for the development of the self-supporting Si-based electrode materials. [ABSTRACT FROM AUTHOR]

Although sodium-ion batteries (SIBs) are considered as alternatives to lithium-ion batteries (LIBs), the electrochemical performances, in particular the energy density, are much lower than LIBs. A metal-organic compound, cuprous 7,7,8,8-tetracyanoquinodimethane (CuTCNQ), is presented as a new kind of cathode material for SIBs. It consists of both cationic (CuII↔CuI) and anionic (TCNQ0↔TCNQ−↔ TCNQ2−) reversible redox reactions, delivering a discharge capacity as high as 255 mAh g−1 at a current density of 20 mA g−1. The synergistic effect of both redox-active metal cations and organic anions brings an electrochemical transfer of multiple electrons. The transformation of cupric ions to cuprous ions occurs at near 3.80 V vs. Na+/Na, while the full reduction of TCNQ0 to TCNQ− happens at 3.00-3.30 V. The remarkably high voltage is attributed to the strong inductive effect of the four cyano groups. [ABSTRACT FROM AUTHOR]

Although sodium-ion batteries (SIBs) are considered as alternatives to lithium-ion batteries (LIBs), the electrochemical performances, in particular the energy density, are much lower than LIBs. A metal-organic compound, cuprous 7,7,8,8-tetracyanoquinodimethane (CuTCNQ), is presented as a new kind of cathode material for SIBs. It consists of both cationic (CuII↔CuI) and anionic (TCNQ0↔TCNQ−↔ TCNQ2−) reversible redox reactions, delivering a discharge capacity as high as 255 mAh g−1 at a current density of 20 mA g−1. The synergistic effect of both redox-active metal cations and organic anions brings an electrochemical transfer of multiple electrons. The transformation of cupric ions to cuprous ions occurs at near 3.80 V vs. Na+/Na, while the full reduction of TCNQ0 to TCNQ− happens at 3.00-3.30 V. The remarkably high voltage is attributed to the strong inductive effect of the four cyano groups. [ABSTRACT FROM AUTHOR]

In this paper, we report the original synthesis of hollow Si-Ni 3 Sn 2 @ graphene composite and its high reversible capacity as lithium-ion battery anodes. To build the new architecture, three strategies of hollow architectures, porous surface and specific composition of graphene are attempted to develop lithium storage with far greater energy density and outstand rate performance. The results show that as-designed hollow Si-Ni 3 Sn 2 @graphene composites exhibit outstanding reversible capacity of 855.7 mAh g −1 during the first cycle, and 576.6 mAh g −1 can be maintained during a cycling test of 50 cycles at 300 mA g −1 . The rate capability is also enhanced, delivering reversible capacity of 449.8, 420.4, 392.7 and 377.1 mAh g −1 at current densities of 600, 800, 1200 and 1800 mA h g −1 , thus exhibiting great potential as an anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Nitrogen and sulfur co-doped graphene supported hollow ZnFe 2 O 4 nanosphere composites have been successfully synthesized via a facile, two-step hydrothermal method. The obtained ZnFe 2 O 4 /NSG samples show interconnected hollow sphere nanostructure with a size of ∼250 nm. The product demonstrated a high initial discharge capacity of 2478.6 mAhg −1 at a rate of 300 mAg −1 . After 100 cycles, it delivered a high reversible capacity of 729.06 mAhg −1 and coulombic efficiency of 99.36%, while at high rate capability of 1800 mAg −1 , the rate capacity stabilize at 650.1 mAhg −1 . It is believed that the composite with good rate capability and stability can be a competitive anode for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Novel a - MoO 3 nanorods coated with SnS 2 nanosheets core-shell nanorod composite has been synthesized via two hydrothermal routes. More importantly, as the anode materials for lithium ion batteries, the MoO 3 @SnS 2 core-shell nanorod composite has not been investigated in detail. The one-dimensional core-shell nanorod composite has high surface area, which could offer larger contact area for material and electrolyte. In addition, there are large enough inner spaces between the SnS 2 nanosheets, which provides an efficient transport of electrons and ions. In addition, the core-shell nanostructure could accommodate the volume changes caused by the charge/discharge reaction and could avoid the agglomerations and pulverization of anode materials.As anode materials for LIBs, the as-prepared MoO 3 @SnS 2 core-shell nanorod composite displayed 1663.2mAh/g discharge capacity in the first cycle at the current of 60mA/g. After 100 cycles, the remained capacity is 568.2mAh/g, which is both higher than that of a-MoO 3 and SnS 2 . Considering the excellent electrochemical performance with high capacity and good cycling stability, the as-prepared the MoO 3 @SnS 2 core-shell nanorod composite has the potential to be the next generation anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Porous SnO 2 /NiO/graphene ternary composites had been synthesized. Used as anode materials for lithium ion batteries, graphene supported porous SnO 2 /NiO ternary composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 1280.4 mAh/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 410.74 mAh/g and the coulomb efficiency reaches at 99.4%. [ABSTRACT FROM AUTHOR]

Flower-like ZnO–NiO mesoporous architectures were synthesized through annealing the zinc hydroxide carbonate–nickel hydroxide carbonate composite precursor, which was prepared via a one-pot hydrothermal route. More importantly, we successfully prepared flower-like porous ZnO–NiO/graphene composites by introducing flexible graphene into the flower-like porous ZnO–NiO. In addition, we explore the application of the 3D flower-like ZnO–NiO composite mesoporous architectures and flower-like porous ZnO–NiO/graphene composites as anode materials for lithium ion battery. Electrochemical study presented that the as-prepared flower-like porous ZnO–NiO/graphene composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 1205.7 mA h/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 452.7 mA h/g at a current density of 300 mA/g and the coulomb efficiency reaches at 99%.The improved electrochemical performances are mainly attributed to its morphological characteristics of mesoporous, nanosheet self-assembling architectures, as well as the addition of graphene. These results suggest that such 3D flower-like porous ZnO–NiO/graphene composites are promising materials for lithium ion battery. [ABSTRACT FROM AUTHOR]

Flower-like ZnO/CuO microstructures have been fabricated on Cu substrate via a simple hydrothermal method. The as-prepared ZnO/CuO flowers/graphene (GNS) composites had distributed the ZnO/CuO flowers on the graphene sheets. As anode materials for lithium ion batteries (LIBs), the ZnO/CuO flowers/GNS composites showed substantially higher reversible capacity and better cycling stability compared to ZnO/CuO flowers, which has been attributed to the improvement of structure stability and electrical contact by GNS. The method may be readily extended to synthesize other classes of hybrids based on graphene sheets for technological applications. [ABSTRACT FROM AUTHOR]

Graphene supported porous Si@C ternary composites had been synthesized by various routes and their structural, morphological and electrochemical properties were investigated. Porous Si spheres coated with carbon layer and supported by graphene have been designed to form a 3D carbon conductive network. Used as anode materials for lithium ion batteries, graphene supported porous Si@C ternary composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 2184.7 mA h/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 652.4 mA h/g at a current density of 300 mA/g and the coulomb efficiency reaches at 98.7%. Due to their excellent electrochemical properties, graphene supported porous Si@C ternary composites can be a kind of promising anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Silver particles were dispersed on the hollow ZnSnO 3 cubes by a thermal decomposition method. With good cycling performance for lithium-ion batteries anode materials, the impacts of the Ag content on the electrochemical properties of the electrodes were compared. The results showed that the silver-modified hollow ZnSnO 3 boxes composites exhibit higher specific capacity and better cycling performance than hollow ZnSnO 3 boxes. When Ag content reaches at about 5 wt%, the retain capacity is 464.5 mAh/g after 45 cycles at a current density of 300 mA/g, which is higher than that of hollow ZnSnO 3 boxes. [ABSTRACT FROM AUTHOR]

Hydriodic acid and self-assembly approach are used to fabricate graphene wrapped sulfur composite. The self-assembly process of the relative “large” graphene sheet and “small” sulfur is quite controllable, and the sulfur particles are completely enfolded by RGO sheets with a unique stacked structure .The RGO/S composite with 80 wt.% sulfur shows an initial discharge capacity of 865.1 mAh g −1 at 0.5 mA/cm 2 . A high specific capacity of 720 mAh g −1 with a coulombic efficiency of 95% is achieved after 50 cycles of charge/discharge. The material also delivered a capacity of more than 580 mAh g −1 at 2 mA/cm 2 and can be recovered to 736 mAh g −1 when the rate is returned to 0.2 mA/cm 2 , representing a promising cathode material for high current discharge lithium-sulfur batteries. [ABSTRACT FROM AUTHOR]

Hollow Zn 2 SnO 4 boxes@C/graphene ternary composites with a three-dimensional triple buffering structure are prepared by two hydrothermal processes followed by a calcined process. The structure, morphology and electrochemical properties of the ternary composites were investigated by means of XRD, FTIR, Raman, BET, BJH, SEM, TEM, and electrochemical measurements. The hollow Zn 2 SnO 4 boxes are coated with carbon layer and then supported by graphene sheets to form a 3D carbon conductive network. Compared with the hollow Zn 2 SnO 4 boxes@graphene binary composites, the hollow Zn 2 SnO 4 boxes@C binary composites, the hollow Zn 2 SnO 4 boxes and the solid Zn 2 SnO 4 cubes, the hollow Zn 2 SnO 4 boxes@C/graphene ternary composites show an enhanced electrochemical performance (726.9 mAh g −1 at a current density of 300 mA g −1 after 50 cycles) and high rate capability. With the unique structure design, this kind of composites with excellent electrochemical properties can be a promising anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

• Bacterial cellulose membrane as support for high mechanical strength. • The BPP60% exhibits an ion conductivity of 2.08 × 10−4 S·cm−1 at 30 °C. • The BPP60% shows excellent stability allowing Li stripping and plating at 0.05 mA·cm−2 for more than 2500 h. • The LiFePO 4 ||Li cell exhibits stable charge–discharge cycle with the initial specific capacities of 147.5 mAh·g−1 at 0.1C. A sandwich-like polyethylene oxide (PEO)-based polymer electrolyte membrane with a thickness of only 60 μm is fabricated. The electrolyte is composed of a porous bacterial cellulose (BC) membrane, polymer matrix and lithium salt, fabricated by only one-step approach. The BC membrane provides strong mechanical property and physically prevents the lithium dendrite from unrestricted growth. Meanwhile, the presence of polar small molecule organics can not only increase the flexibility of polymer chain segments to enhance ion transport capacity, but also obtain a "soft contact" between the electrolyte–electrode. The BPP60% electrolyte shows enhanced electrochemical performance and LiFePO 4 /Li cell processes reliable charge–discharge cycle performance. [ABSTRACT FROM AUTHOR]

LiFePO4 is considered one of the most attractive cathodes for Li ion batteries. However, the electrochemical properties of LiFePO4 are seriously restrained by the intrinsic low electronic conductivity and poor Li ion diffusion. In this work, the problems will be solved by controlling the crystal orientation of LiFePO4 crystals and being compounded with reduced graphene oxide (rGO). A series of experimental results demonstrate that the rGO-modified LiFePO4 nanosheets are synthesized using sodium bis(2-ethylhexyl) sulfosuccinate (AOT) surfactant. The structural characteristics reveal that LiFePO4 nanosheets exhibit thickness with from 50 to 80 nm. TEM results suggest that the exposed facet of the nanosheets is (010) facet. The electrochemical tests show the specific capacity retention of LiFePO4 nanosheets and LiFePO4 nanosheets/rGO is over 95% for after 100 cycles. LiFePO4 nanosheets/rGO exhibits a higher initial discharge specific capacity and more excellent rate capability than LiFePO4 nanosheets. The excellent electrochemical properties of LiFePO4 nanosheets/rGO can be attributed to nanosheet structure with short Li ion diffusion distance and rGO modification with high electrical conductivity. [ABSTRACT FROM AUTHOR]

Abstract: Flower-like Zn2SnO4 composites had been prepared through a green hydrothermal synthesis. The structural, morphological and electrochemical properties were investigated by means of XRD, BET, SEM, TEM, and electrochemical measurement. The results show that the as-prepared sample is in high purity phase and of good crystallinity; meanwhile it has a particular 3-D structure and large surface area. Electrochemical measurement suggests that flower-like Zn2SnO4 composites exhibit better cycling properties and lower initial irreversible capacities than the solid Zn2SnO4 cubes. The first discharge and charge capacities of the material are 1750mAhg−1 and 880mAhg−1 respectively. A higher reversible capacity of 501mAhg−1 was obtained after 50 cycles at a current density of 300mAg−1. The higher reversible capacity and good stability can be related to the special nanostructural features of the material. Such Zn2SnO4 structures synthesized by the simple and cheap method are expected to have potential application in energy storage. [Copyright &y& Elsevier]

Abstract: The graphene wrapped hollow Zn2SnO4 boxes are fabricated via the electrostatic interaction. The flexible graphene wrapping layers, as a physical buffering matrix to reinforce the hollow structure, prevent interparticle agglomeration and improve the electronic conductivity of the hollow Zn2SnO4 boxes. Compared with our previous studies, graphene wrapping Zn2SnO4 boxes show an enhanced electrochemical performance (678.2 mAhg−1 after 45 cycles) and high rate capability. With rational and delicate design, this kind of composites may be the potential anode materials for lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: Polypyrrole-coated hollow Zn2SnO4 boxes (hollow Zn2SnO4@PPY nanocomposites) had been prepared by a microemulsion polymerization. The structural, morphological and electrochemical properties were methodically investigated by means of XRD, TGA, BJH (pore size distribution analysis), SEM, TEM, and electrochemical measurements. Results show that the hollow Zn2SnO4 boxes with the uniform and cube like structure are coated by PPY. Electrochemical measurement suggests that hollow Zn2SnO4@PPY composites exhibit better cycling properties and lower initial irreversible capacities as anode materials for lithium-ion batteries. At a current density of 60mA/g in the voltage about 0.01–3.0V, the first discharge–charge capacities of hollow Zn2SnO4@PPY composites are 1105.2mAh/g and 556mAh/g. After 50 cycles, a specific charge capacity of 478.4mAh/g remained and the coulombic efficiency reaches 98.2%, revealing better capacity retention compared with hollow Zn2SnO4 boxes. [Copyright &y& Elsevier]

Abstract: Hollow Zn2SnO4@N–C composites were synthesized after the calcined process of precursor. The N-doped carbon coating layers, as a physical buffering matrix to reinforce the hollow structure, prevent interparticle agglomeration and improve the electronic conductivity of the electrodes. Compared with our previous studies, Zn2SnO4@N–C composites show an enhanced electrochemical performance (616mAhg−1 after 45 cycles) and high rate capability. With rational and delicate design, this kind of composites may be the potential anode materials for lithium-ion batteries. [Copyright &y& Elsevier]

Bamboo charcoal/LiSnO composites for lithium-ion batteries were synthesized by a sol-gel route. The structure, morphology, and electrochemical properties of the composites were detected by means of X-ray diffraction, scanning electron microscope, Raman spectroscopy, thermal gravimetric analysis, and electrochemical measurements. The results showed that LiSnO particles were loaded on the surface of bamboo charcoal and some of them entered into the hole. The bamboo charcoal/LiSnO composites exhibited good electrochemical performance with high capacity and good cycling stability (616.5 mAh g after 50 cycles). The composites showed a better electrochemical property than LiSnO and bamboo charcoal. [ABSTRACT FROM AUTHOR]

Abstract: The GNS/Li2SnO3/PPY ternary composites were synthesized by a deoxidation technique. The soft polymer matrix and flexible graphene provide a dual buffering structure for Li2SnO3 which synergistic leads to improved stability, enhanced electric conductivity and better electrochemical performance. The GNS/Li2SnO3/PPY composites tested as anode materials for lithium ion batteries exhibit a high reversible capacity of 699.4mAh/g over 30 cycles, which is much better than that of pure Li2SnO3, PPY/Li2SnO3 and GNS/Li2SnO3 composites. [Copyright &y& Elsevier]

Tin-based oxide Li2SnO3 has been synthesized by a hydrothermal route as negative material for lithium-ion batteries. The microstructure and electrochemical properties of the as-synthesized materials were investigated by some characterizations means and electrochemical measurements. The as-synthesized Li2SnO3 is a porous rod, which is composed of many uniform and regular nano-flakes with a size of 50-60 nm. Li2SnO3 also displays an electrochemical performance with high capacity and good cycling stability (510.2 mAh g−1 after 50 cycles at a current density of 60 mA g−1 between 0.0 V and 2.0 V verusus Li/Li+). Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A graphene-supported Ce- SnS2 ( Ce- SnS2/graphene) nanocomposite has been synthesized via a hydrothermal route. Structure, morphology, and electrochemical properties of the composites were studied by means of XRD, SEM, TEM, Raman, XPS, TGA, and electrochemical measurements. The Ce- SnS2 crystal particles with a flower-like structure were distributed on the graphene sheets ( GNS). The particle sizes of each petal are in the range 50-100 nm with clear lattice fringes. The atomic ratio of Sn, S, Ce, C, and O is estimated to be 1:2:0.05:3.11:0.64 and the content of Ce- SnS2 composite is 80 wt.% in the as-synthesized sample. The Ce- SnS2/graphene composite exhibits high initial discharge capacity (1638.3 mAh/g at 0.5 C), high capacity retention (707 mAh/g at 0.5 C after 50 cycles), and good rate capability due to the synergy effect between Ce- SnS2 nanoparticles and graphene nanosheets. The superior performance is ascribed to the presence of graphene keeping the structure stable. [ABSTRACT FROM AUTHOR]

Abstract: The carbon-doped Li2SnO3/graphene composites for lithium-ion batteries were synthesized by the hydrothermal route. The structure, morphology and electrochemical properties of the composites were detected by means of XRD, SEM, TEM, Raman, TGA and electrochemical measurements. The Li2SnO3 nanoparticles are surrounded by graphene sheets (GNS) and amorphous carbon layers. The carbon-doped Li2SnO3/graphene materials exhibit good electrochemical performance with high capacity and good cycling stability (736.3mAh/g after 50 cycles at 60mA/g).The presence of graphene sheets and carbon layer can alleviate the effects of volume changes, keep the structure stable and increase the conductivity. Conclusively, The C/Li2SnO3/GNS composites exhibit better electrochemical properties than GNS/Li2SnO3 and Li2SnO3. [Copyright &y& Elsevier]

Abstract: The nanocomposites Li2SnO3/polyaniline (Li2SnO3/PANI) have been synthesized by a micro emulsion polymerization method. The structure, morphology and electrochemical properties of the as-prepared materials are characterized by XRD, FTIR, Raman, XPS, TGA, TEM and electrochemical measurements. Results show that Li2SnO3/PANI nanocomposites are composed of uniform and blocky nano-sized particles (40–50nm) with clear lattice fringes. Electrochemical measurement suggests that Li2SnO3/PANI exhibits better cycling properties and lower initial irreversible capacities than Li2SnO3 as negative electrodes materials for lithium-ion batteries. At a current density of 60mAg−1 in the voltage about 0.05–2.0V, the initial irreversible capacity of Li2SnO3/PANI is 563mAhg−1 while it is 687.5mAhg−1 to Li2SnO3. The capacity retained of Li2SnO3/PANI (569.2mAhg−1) is higher than that of Li2SnO3 (510.2mAhg−1) after 50 cycles. The PANI in the Li2SnO3/PANI nanocomposites can buffer the released stress caused by the drastic volume variation during the alloying/de-alloying process of Li–Sn. [Copyright &y& Elsevier]

Abstract: Composite Li2SnO3/C with good cycle performance for lithium-ion batteries was synthesized by a hydrothermal route. The structure, morphology and electrochemical properties of the as-prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA) and electrochemical measurements. Results show that the length of the Li2SnO3 nanorods are in the range of 40–60nm while the average diameter is approximately 30nm. Amorphous carbons are distributed among the Li2SnO3 nanoparticles. The first discharge–charge capacities of Li2SnO3/C are 2045.8mAhg−1 and 1756.6mAhg−1. After the 50th cycles, the capacity retained is 598.3mAhg−1 at a constant current density of 60mAg−1 in the voltage range of 0.05–2.0V. The composite Li2SnO3/C exhibits a better electrochemical property than Li2SnO3. [Copyright &y& Elsevier]

Abstract: Tin-based oxides Li2SnO3 precursor and carbon-doped Li2SnO3 (Li2SnO3/C) nanocomposite with good cycle performance for lithium-ion batteries have been synthesized by sol–gel preparation and carbothermic reduction process. Results show that Li2SnO3/C is composed of regular rod nanoparticles (20–30nm) with clear lattice fringes, which exhibit better electrochemical properties than Li2SnO3. At a current density of 60mAg−1 in the voltage about 0.05–2.0V, the first discharge–charge capacities of the composite Li2SnO3/C are 1671.1mAhg−1 and 1558.6mAhg−1 while they are 1909.4mAhg−1 and 1745.8mAhg−1 to Li2SnO3. The retain capacity (576.9mAhg−1) of Li2SnO3/C is higher than that of Li2SnO3 after 50 cycles. [Copyright &y& Elsevier]

• The structure of HCN can be controlled by the carbonization temperature. • HCN-800 shows an ultra-long cycle life and excellent electrochemical performance. • Achieved high areal mass loading through 3D printing technology. • LiCo 2 O 4 ||HCN-800 and Na 3 V 2 (PO 4) 3 ||HCN-800 full cells exhibits a stable cycle. Hollow nanostructures have shown great potential in energy storage and have attracted widespread attention. Here, we report a series of hollow carbon nanocage (HCN) by carbonizing ZIF-8@ZIF-67 core–shell precursor at different temperatures. The study found that when the carbonization temperature is 800 °C, HCN-800 has a good hollow structure, thin shell and large specific surface area, and contains abundant micropores and mesopores. When used as an anode material, even at a current density of 10.0 A g−1, it can still obtain reversible capacities of 236.1 mA h g−1 (5000 cycles, lithium ion batteries LIBs) and 111.7 mA h g−1 (10000 cycles, sodium ion batteries SIBs), showing excellent cycle stability and long cycle lifespan. And this outstanding ability can still be maintained under high areal mass loading. In addition, the lithium/sodium storage behavior was analyzed by CV kinetic analysis, ex-situ XPS and Raman tests. Benefiting from these advantages, HCN-800 can be prepared with higher areal mass loading by 3D printing and exhibit excellent lithium/sodium storage performance, which will bring broad application prospects for the development of high energy density secondary batteries. Finally, by using LiCoO 2 /Na 3 V 2 (PO 4) 3 cathode and HCN-800 anode to assemble a full cell to study the cycle performance. After 100 cycles at 0.1 A g−1 current density, the reversible capacity of 561.5 mA h g−1 (LIBs) and 164.7 mA h g−1 (SIBs) can be provided respectively, indicates that it has the potential of practical application. [ABSTRACT FROM AUTHOR]

Anionic redox activity can trigger structural instability in Li‐rich Mn‐based cathodes. Lattice oxygen activity can be tuned through liquid acid‐induced spinel phases and oxygen vacancies. However, the liquid‐acid‐modified surface is still attacked by the electrolyte. Besides, the underlying mechanism of spinel phase suppression of lattice oxygen activity is controversial. Here, a solid acid strategy for modification is proposed and the underlying mechanism is investigated in detail. Unique solid acid can in situ generate an interface protection layer and remarkably stabilize the structure. Theoretical calculations and experimental characterizations reveal that the spinel phase suppresses the irreversible loss of lattice oxygen by decreasing the O 2p non‐bonding energy level and enriching electrons at the layered/spinel phase interface. The inert layer on the surface prevents highly active On− from being attacked by electrolytes. The obtained material exhibits significantly reduced irreversible lattice oxygen release and improved electrochemical performance. After 300 cycles, a slow capacity fading of 0.177 mAh g−1 per cycle and suppressed voltage fading are achieved. This study reveals the regulation method and mechanism for the anion activity of oxide cathodes in next‐generation Li‐ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] With the development of high energy density battery technology, layered transition metal oxide cathode materials, particularly Ni-rich layered cathodes of Li-ion batteries are urgently required due to its high energy density. However, Li/Ni intermixing inevitably occurs in Ni-rich cathode materials and affects the materials in terms of structure and performance. This review comprehensively summarizes the causes of Li/Ni intermixing and analyzes its inevitability due to ionic radius, Ni migration, magnetic interactions, and thermal stability. In addition, the effect of Li/Ni intermixing on materials is summarized, particularly its benefits, which have not yet been comprehensively examined. Finally, the methods for regulating Li/Ni intermixing that corresponds to its causes are presented in detail. This review can help researchers fully understand Li/Ni intermixing and propose solutions for the current shortcomings of Li/Ni intermixing research and directions for future studies. [ABSTRACT FROM AUTHOR]

A facial and efficient process for the synthesis of porous Zn x Co 3-x O 4 hollow nanoboxes using zeolitic imidazolate frameworks as precursors has been demonstrated in this study, the as-prepared electrodes are applied for both LIBs and SIBs. The porous structure and hollow interspace can not only provide valuable channels and voids for lithium/sodium ion transfer and storage, but also buffer the stress/strain caused by volume changes. Besides, the enhanced electrical conductivity can effectively improve the reaction kinetics by synergistic effect of the binary metal oxides, as studied by density functional theory (DFT) calculations and storage mechanism studies. For lithium-ion batteries, the electrode exhibits an ultrahigh reversible capacity of 1141.7 mAh g−1, with an initial coulombic efficiency of 95.6%, and an ultralong life up to 800 cycles at 500 mA g−1. Even at a high current of 3.0 A g−1, a superior capacity of 484 mAh g−1 can be achieved. When using for sodium-ion battery anode, the reversible capacity is remained at 310 mAh g−1 after 100 cycles at 200 mA g−1, with a capacity retention of 90.4%. The electrode materials show long-term cycle stability and excellent rate capability, which gives a bright prospect for energy storage devices. • The unique structure can accelerate the transportation of ions. • The synergistic effect shows enhanced electrical conductivities and ion diffusions. • The general phenomenon of the capacities rise is discussed in detail. • The electronic structures of Zn/Co oxides were studied by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

In this paper, phosphorus-doped porous carbon was obtained via a simple method with leaves as raw materials, and its broad application prospects in sodium-ion and lithium-ion battery were proved. The effect of different mass ratios on microstructure and properties were investigated. Phosphorus-doped porous carbon has high specific surface area and pore volume, which is favorable for contact with electrolyte and transportation of electron/ion. Meanwhile, doping of phosphorus increases layer spacing of carbon lattice and enhances adsorption of sodium ion, which are more conducive to the storage of sodium ions. Based on above advantages, PC-3 has stable and fast sodium-ion and lithium-ion storage performance with capacity of 310.4 mAh g−1 for sodium-ion battery and 723.4 mAh g−1 for lithium-ion battery after 200 cycles. Furthermore, carbonization temperature of this method is lower than other reports, saving energy and having better practical value. [ABSTRACT FROM AUTHOR]