•Cyanogel-derived thermal-oxidation route to nanoporous Sn–Fe–Ni ternary oxide network.•Synergistic effects between SnO2, Fe2O3 and NiO together with nanoporous structure.•The ternary oxide network manifests high capacities and excellent capacity retention.A novel type of ternary oxide nanohybrids, i.e., nanoporous Sn–Fe–Ni ternary oxide network, has been designed and constructed through facile thermal-oxidation route using a cyano-bridged Sn(IV)–Fe(II)–Ni(II) ternary metallic coordination polymer hydrogel (Sn–Fe–Ni cyanogel) as a precursor. The nanoporous ternary oxide network is assembled by numerous interconnected SnO2, Fe2O3, and NiO nanocrystal building blocks, and these oxide components are homogeneously distributed within the nanoporous network. The unique structural and compositional features are beneficial for enhanced lithium storage performances, and thus the nanoporous Sn–Fe–Ni ternary oxide network manifests much higher reversible capacities and markedly improved capacity retention in comparison with bare SnO2 nanocyrstals.

•Facile solid-state coordination and pyrolysis route for constructing Ni@C network.•Unique structural and compositional superiorities toward lithium storage.•Desirable Li-storage performances in terms of capacity, cycle life, and so forth.Micro/nano-architectured transition-metal@C hybrids possess unique structural and compositional features toward lithium storage, and are thus expected to manifest ideal anodic performances in advanced lithium-ion batteries (LIBs). Herein, we propose a facile and scalable solid-state coordination and subsequent pyrolysis route for the formation of a novel type of micro/nano-architectured transition-metal@C hybrid (i.e., Ni@C nanosheet-assembled hierarchical network, Ni@C network). Moreover, this coordination-pyrolysis route has also been applied for the construction of bare carbon network using zinc salts instead of nickel salts as precursors. When applied as potential anodic materials in LIBs, the Ni@C network exhibits Ni-content-dependent electrochemical performances, and the partially-etched Ni@C network manifests markedly enhanced Li-storage performances in terms of specific capacities, cycle life, and rate capability than the pristine Ni@C network and carbon network. The proposed solid-state coordination and pyrolysis strategy would open up new opportunities for constructing micro/nano-architectured transition-metal@C hybrids as advanced anode materials for LIBs.Download high-res image (342KB)Download full-size image

Nanoporous networks of tin-based alloys immobilized within carbon matrices possess unique structural and compositional superiorities toward lithium-storage, and are expected to manifest improved strain-accommodation and charge-transport capabilities and thus desirable anodic performance for advanced lithium-ion batteries (LIBs). Herein, a facile and scalable hybrid aerogel-derived thermal-autoreduction route has been developed for the construction of nanoporous network of SnNi alloy immobilized within carbon/graphene dual matrices (SnNi@C/G network). When applied as an anode material for LIBs, the SnNi@C/G network manifests desirable lithium-storage performances in terms of specific capacities, cycle life, and rate capability. The facile aerogel-derived route and desirable Li-storage performance of the SnNi@C/G network facilitate its practical application as a high-capacity, long-life, and high-rate anode material for advanced LIBs.Download high-res image (102KB)Download full-size image

Metal oxide nanohybrids with uniform dimensions and controlled architectures possess unique compositional and structural superiorities, and thus harbor promising potential for a series of applications in energy, catalysis, and sensing systems. Herein, we propose a facile, general, and scalable cyano-bridged coordination polymer hydrogel-derived thermal-oxidation route for the construction of main-group metal and transition-metal heterometallic oxide nanohybrids with controlled constituents and architectures. The formation of Sn–Fe binary oxide nanohybrids has been demonstrated as an example by using cyano-bridged Sn(IV)–Fe(II) bimetallic coordination polymer hydrogels (i.e., SnCl4–K4Fe(CN)6 cyanogels, Sn–Fe cyanogels) as precursors. The physicochemical properties of Sn–Fe cyanogels with different Sn/Fe ratios have been systematically examined, and it is found that perfect Sn–Fe cyanogels without unbridged Sn(IV) or Fe(II) can be formed with Sn/Fe ratios from 2:1 to 1:2. More importantly, the simple adjustment of Sn/Fe ratios in the Sn–Fe cyanogel precursors can realize flexible dimensional control of the Sn–Fe binary oxide nanohybrids, and 2D/1D SnO2–Fe2O3 hierarchitectures, 2D SnO2–Fe2O3 nanosheets, and 3D SnO2–Fe2O3 networks have been synthesized using the Sn–Fe 1:2, Sn–Fe 1:1, and Sn–Fe 2:1 cyanogels as precursors, respectively. To demonstrate their compositional/structural superiorities and potential applications, the lithium-storage utilization of the Sn–Fe binary oxide nanohybrids has been selected as an objective application, and the nanohybrids exhibit Sn/Fe ratio-dependent lithium-storage performance. As a representative example, the 2D/1D SnO2–Fe2O3 hierarchitectures manifest markedly enhanced Li-storage performance in terms of reversible capacities and cycling stability in comparison with their constituent units, i.e., bare SnO2 nanosheets and Fe2O3 nanorods. The proposed cyanogel-derived thermal-oxidation strategy could open up new opportunities for constructing heterometallic oxide nanohybrids, and the rationally designed metal oxide nanohybrids may find broad applications in energy, catalysis, and sensing fields by virtue of their structural and compositional features.

•Facile template-engaged synthesis of Pt–Pd HPNSs via layer-by-layer assembly.•Unique compositional and structural features of hollow porous Pt–Pd catalyst.•Markedly enhanced electrocatalytic performances toward methanol oxidation reaction.Hollow porous structures of Pt–Pd bimetallic alloy possess unique compositional and structural superiorities for catalytic and electrocatalytic applications, and are thus anticipated to manifest novel properties and/or enhanced performance compared with their monometallic counterparts. Herein, a general electrostatic-attraction-directed layer-by-layer assembly approach has been developed for the construction of a novel type of hollow porous Pt–Pd alloy nanospheres (Pt–Pd HPNSs) using SiO2 nanospheres as templates. Moreover, the Pt–Pd HPNSs with controllable shell thickness are prepared and their comparative electrocatalytic performances toward methanol oxidation reaction (MOR) are investigated. It's found that optimized Pt–Pd HPNSs manifests markedly enhanced catalytic activity and durability in comparison with both commercial Pt black and Pd black catalysts.

Herein, we rationally design and construct a novel type of sparsely studded noble-metal nanocrystals inside graphene hollow sphere network (abbreviated as noble-metal@G HSN) through an electrostatic-attraction-directed self-assembly approach. The formation of Pt@G and Pd@G hollow sphere networks have been illustrated as examples using SiO2 spheres as templates. Moreover, the electrocatalytic performance of the Pt@G HSN for methanol oxidation reaction has been examined as a proof-of-concept demonstration of the compositional and structural superiorities of noble-metal@G HSN toward electrocatalyst utilization. The as-prepared Pt@G HSN manifests higher catalytic activity and markedly enhanced long-term durability in comparison with commercial Pt/C catalyst.Keywords: electrocatalyst utilization; graphene; hollow sphere network; noble-metal nanocrystals; self-assembly route

A novel type of nanoporous In2O3–Co3O4 hybrid network has been synthesized using a cyano-bridged coordination polymer gel as a precursor. When applied as an anode in lithium-ion batteries, the In2O3–Co3O4 network manifests remarkable capacity retention and high reversible capacities by virtue of its unique compositional and structural features.

A novel type of NiO-based anodes, i.e., NiO@polypyrrole hollow spheres (NiO@PPy HSs), has been constructed by using SiO2 spheres as templates. The PPy component serves as an ideal supporting matrix for NiO anodes owing to its high structural stability and electrical conductivity. Thus, the NiO@PPy HSs demonstrate markedly enhanced lithium storage capabilities in terms of cycling stability compared with bare NiO spheres. For example, a high reversible capacity of 520.0 mA h g−1 can be delivered after 200 cycles in NiO@PPy anode at a current density of 100 mA g−1. The superior cycling stability of NiO@PPy HSs makes it an ideal anodic candidate for long-life lithium-ion batteries.

A novel type of 3D porous Si–G micro/nanostructure (i.e., 3D interconnected network of graphene-wrapped porous silicon spheres, Si@G network) was constructed through layer-by-layer assembly and subsequent in situ magnesiothermic-reduction methodology. Compared with bare Si spheres, the as-synthesized Si@G network exhibits markedly enhanced anodic performance in terms of specific capacity, cycling stability, and rate capability, making it an ideal anode candidate for high-energy, long-life, and high-power lithium-ion batteries.Keywords: anodes; graphene; interconnected network; lithium-ion batteries; magnesiothermic reduction; silicon;

•Self-made mesoporous carbon (MC) as a novel supporting matrix for SnO2 anode.•High and uniform loading of SnO2 on MC matrix via a facile chemical solution route.•Markedly improved lithium storage capability by virtue of its structure superiority.This paper reports the synthesis of highly loaded SnO2/mesoporous carbon (MC) nanohybrid through a facile chemical solution process and subsequent annealing methodology, by using a novel three-dimensional (3D) MC as a buffering and conducting matrix. Owing to its unique structural characteristics, the MC–SnO2 nanohybrid anode exhibits markedly improved cycling stability and rate capability compared to pure SnO2 nanoparticles, facilitating its application in advanced Li-ion batteries (LIBs) with long cycle life and high power density.

This paper reports the synthesis of novel SnO2@C yolk–shell spheres by using Sn spheres as sacrificial templates. When tested as a potential anode for lithium-ion batteries (LIBs), the SnO2@C yolk–shell spheres demonstrate higher capacities, improved cycling stability, and higher rate capability owing to the unique structural characteristics. The enhanced lithium storage capabilities of SnO2@C yolk–shell spheres make it an ideal anode candidate for advanced LIBs with long cycle life, high energy and power densities.

A novel type of one-dimensional (1D) nanohybrid of SnO2 and transition-metal oxides, i.e. CuO nanobelts decorated with SnO2 nanocrystals (CuO@SnO2 nanobelts), has been constructed via a facile hydrothermal approach by using CuO nanobelts as templates. The as-prepared CuO@SnO2 nanobelts have been applied as a potential anode material for lithium-ion batteries (LIBs), and exhibit markedly enhanced lithium-storage capabilities in terms of specific capacity and cycling stability compared with the single CuO and SnO2 counterparts. The synergistic effects between CuO and SnO2 together with the unique 1D belt-like nanostructure could be responsible for the high capacity and remarkable capacity retention. The facile synthetic approach and superior lithium-storage capabilities of CuO@SnO2 nanobelts make them an ideal anodic candidate for advanced LIBs with high energy density and long cycle life.

A novel type of graphene supported tin-based alloy, i.e. graphene supported FeSn2 nanocrystals (G–FeSn2 nanohybrid), has been designed and synthesized through a chemical reduction route in a polyol system. When examined as an anode material for lithium-ion batteries (LIBs), the as-synthesized G–FeSn2 nanohybrid displays markedly enhanced Li-storage capabilities in terms of specific capacities and cycling stability compared with bare FeSn2 nanocrystals.

A novel type of graphene-supported Fe3O4 nanohybrid, i.e. graphene wrapped single-crystalline Fe3O4 nanorods (Fe3O4@G nanorods), has been synthesized through a layer-by-layer assembly and a subsequent annealing approach. The as-synthesized Fe3O4@G nanorods have been used as anode materials for lithium-ion batteries, and manifest superior lithium-storage capabilities in terms of high reversible capacities, excellent capacity retention, and high rate capability.

By using large mesoporous carbon (LMC) as a novel host matrix, LMC–FePO4 nanohybrid has been synthesized through a facile homogeneous precipitation process and subsequent annealing approach. When evaluated as a cathode for lithium-ion batteries (LIBs), the LMC–FePO4 nanohybrid exhibits higher specific capacities, improved rate capability, and better cycling performance by virtue of its unique structural characteristics.Graphical abstractHighlights► Self-made nano-CaCO3 templated LMC as a novel supporting matrix for FePO4 cathode. ► The 3D porous structure of LMC is well retained in LMC–FePO4 nanohybrid. ► Its reaction kinetics of lithium insertion/extraction is significantly improved. ► Markedly higher capacities and rate capability by virtue of its structure superiority.

We propose a facile, scalable, yet versatile methodology for the formation of three-dimensional mesoporous (3DMP) tin-based alloy anodes for lithium-ion batteries (LIBs), using cyanogel coordination polymers as precursors for the first time. The synthesis of a 3DMP Sn–Ni alloy network with a high surface area and uniform mesopores has been demonstrated as an example using SnCl4/K2Ni(CN)4 cyanogel as the precursor. After surface carbon coating, the 3DMP Sn–Ni@C network exhibited enhanced lithium storage capabilities by virtue of its unique structural characteristics, such as its excellent structural stability, high charge transport capability, and improved reaction kinetics of lithium insertion/extraction. The proposed synthetic strategy could open up new opportunities for constructing advanced tin-based alloy anodes for LIBs.

Herein, we have designed and synthesized a novel type of nitrogen-doped carbon-supported CoO nanohybrids, i.e., nitrogen-doped carbon-wrapped porous single-crystalline CoO nanocubes (CoO@N–C nanocubes), by using Co3O4 nanocubes as precursors. Owing to its unique structural features, the as-synthesized CoO@N–C nanocubes demonstrate markedly enhanced anodic performance in terms of reversible capacity, cycling stability, and rate capability, facilitating its application as a high-capacity, long-life, and high-rate anode for advanced lithium-ion batteries.