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Sn/Nitrogen-doped reduced graphene oxide (Sn@N-G) composites have been successfully synthesized via a facile method for lithium-ion batteries. Compared with the Sn or Sn/graphene anodes, the Sn@N-G anode exhibits a superb rate capability of 535 mAh g−1 at 2C and cycling stability up to 300 cycles at 0.5C. The improved lithium-storage performance of Sn@N-G anode could be ascribed to the effective graphene wrapping, which accommodates the large volume change of Sn during the charge–discharge process, while the nitrogen doping increases the electronic conductivity of graphene, as well as provides a large number of active sites as reservoirs for Li+ storage. [ABSTRACT FROM AUTHOR]

Zero-dimensional quantum dots (QDs) are desired to enhance electrochemical response in energy storage. Here, we successfully synthesize well-dispersed and ultrafine TiO 2 -QDs, which are in situ embedded into the three-dimensional porous graphene-like networks (denoted as TiO 2 -QDs-3D GNs) via a simple low-temperature mixed solvothermal method, aiming at a fast electrochemistry with high-efficient electron and ion transport for lithium ion battery (LIB) anodes. By combining the advantages of the porous 3D GNs and ultrafine TiO 2 -QDs, the as-prepared TiO 2 -QDs-3D GNs hybrid electrode exhibits a high reversible capacity of 219 mA h g −1 after 100 cycles at 0.1 A g −1 , accompanied with an ultrahigh-rate capability of 121 mA h g −1 and a super-long lifespan of 3000 cycles with ∼82.0% capacity retention at 10 A g −1 . Detailed electrochemical analysis reveals that the superior rate capability and cycle performance are the main results of the integrated intercalation-based and interfacial lithium storage as well as the 3D fast electron/ion transfer of materials, which is attributed to the ultra-small size and high surface-to-volume ratio of TiO 2 -QDs as well as the 3D conducting networks of the integrated hybrid electrode. This study demonstrates the distinct advantages of our material design strategy, making it promising for the fast and ultralong-life anodes in LIBs. [ABSTRACT FROM AUTHOR]

Metal oxides are considered as promising anodes for alkali-ion batteries due to their high theoretical capacity and moderate volume expansion. However, they still suffer from the low electrical conductivity and capacity decay, resulting poor rate capability and cyclic stability. In this work, core-shell ZnO polyhedrons coated by Co nanoparticle embedded in N-doped carbon (ZnO@Co/NC) were prepared via a convenient route using zeolitic imidazolate frameworks as precursors. The unique structural design not only synergistically forms a three-dimensional conductive network to promote the transfer and storage of Li+/K+ ions, but also restrains the volume changes of ZnO polyhedron during repeated lithiation/potassiation processes, contributing to enhanced lithium and potassium storage performances. The ZnO@Co/NC anode delivers 458.3 mAh g−1 after 1000 cycles at an ultrahigh current density of 10 A g−1 with a capacity retention of 95% for LIBs, and remains 181.5 mAh g−1 after 1000 cycles at 200 mA g−1 with 84% retention for KIBs. When coupled with commercial LiFePO 4 cathode, the full cell delivers a capacity of 140.6 mAh g−1 after 250 cycles at 1 A g−1. This work not only shows the promising potential ZnO-based materials for long-term and high-rate lithium-ion batteries, but also gives an insight into the design of ZnO-based anodes for potassium storage. [Display omitted] • The Co-containing N-doped carbon layer provides three-dimensional networks to accelerate the transfer of ions and electrons. • The shell restrains the volume expansion of ZnO and modified the interfacial properties between anode and electrolyte. • The optimized anodes exhibit excellent cyclic stability and rate capability both in both lithium and potassium storage. • The potassium storage behaviors of ZnO-based electrode is revealed and analyzed in detail. [ABSTRACT FROM AUTHOR]

Abstract: A novel silicon-based glassy composite anode material with high initial coulombic efficiency and long cycling performance for lithium-ion batteries was synthesized by a wet mechanochemical reduction method. The in situ formed Si particles with size of 5–10nm were uniformly distributed in the glassy matrices formed by B2O3 and P2O5. The as-prepared composite electrode revealed an initial charge and discharge capacity of 432.7 and 514.4mAhg−1, respectively, with an initial coulombic efficiency of 84%. After 100cycles, the reversible capacity retention rate was still up to 97%, meaning a favorable cycling stability. [Copyright &y& Elsevier]