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Lithium metal has always been considered as a “Holy Grail” of anode materials for high-energy-density batteries owing to its extremely high theoretical gravimetric capacity of 3860 mAh g −1 and the lowest electrochemical potential of −3.04 V. Unfortunately, huge challenges including unlimited dendrite growth and complex interfacial reaction accompanied with relatively low Coulombic efficiency have extremely restricted its practical applications for decades. In this review, we discuss recently exciting achievements in modifying Li metal anodes, particularly regarding porous structure design, surface modification, heterogeneous seed strategy, potential substitutes including Li powder, and pre-lithiated composite. Although each improvement method has its own advantage, we believe appropriate combination of them will yield more promising results. Finally, we discuss core issues and potential opportunities of Li metal anode, expecting to shed new light on future research in this field. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cookies-shaped LiV3O8 material was synthesized by a facile sol–gel method. [•] The compound shows high capacity retentions at different current densities. [•] The good performance is due to high crystallinity and little dissolution of vanadium. [ABSTRACT FROM AUTHOR]

Abstract: Porous Fe3O4/C core/shell nanorods have been prepared by a facile hydrothermal method using porous Fe2O3 nanorods as the precursor and glucose as the carbon source. The Fe3O4/C nanorods possess a uniform size with 50–80nm in diameter and 300–500nm in length, and are homogenously coated by amorphous carbon layer. The porous nanorods greatly increase the electrical contact, thus facilitating the Li-ion and electron transportation, and enhancing the reactivity of the electrode. Also, the carbon layer can effectively limit the volume expansion and detachment of Fe3O4, and thus increase its structure stability during cycling. In the context of lithium storage behavior, the Fe3O4/C nanorod electrode shows high capacity and good cycle stability, as well as enhanced rate performance. After 50 cycles, the reversible capacity of the porous Fe3O4/C nanorods is 762.1mAhg−1 at 0.1C and 597.2mAhg−1 at 0.5C, much higher than that of α-Fe2O3 nanorods (276.4mAhg−1) and Fe3O4 nanoparticles (307.9mAhg−1). At a high rate of 1C, the specific capacity of Fe3O4/C nanorods is still as high as 630.1mAhg−1. [Copyright &y& Elsevier]

Abstract: Li3V2(PO4)3/C cathode material was synthesized by using a freeze-drying method followed by carbon-thermal reduction. This as-prepared material has a uniform particle size distribution and a well carbon coating on the surface of Li3V2(PO4)3 particles. The Li3V2(PO4)3/C exhibits good electrochemical performance and cycling stability. Between 3.0 and 4.3V, the composite delivered a reversible capacity of 125.2mAhg−1 at a charge–discharge rate of 1.48C (1C=133mAg−1) and without obviously capacity fading after 100 cycles. Even at 14.8C and 29.6C rates, it can still deliver discharge capacities of 105.6mAhg−1 and 93.3mAhg−1, and the discharge capacities of 84.5 and 60.5mAhg−1 are sustained after 500 cycles, respectively. [Copyright &y& Elsevier]

Abstract: The multi-walled carbon nanotubes (MWCNTs) modified Li3V2(PO4)3/C composite is synthesized by polyvinyl alcohol (PVA) based carbon-thermal reduction method using MWCNTs as a highly conductive agent. PVA mainly supplies a reductive atmosphere to reduce V5+ and provides a network of carbon to inhibit the aggregation of Li3V2(PO4)3 particles. The amorphous carbon coating and MWCNTs co-modified composite shows excellent high-rate lithium intercalation/deintercalation property and cycling performance between 3.0 and 4.3V. The discharge capacities of 131.7 and 122.9mAhg−1 are obtained at rates of 1C and 10C, respectively, for the Li3V2(PO4)3/(C+MWCNTs). These improvements are attributed to the valid conducting networks of C+MWCNTs and the reduced Li3V2(PO4)3 particle size by the network carbon from the pyrolysis of PVA. [Copyright &y& Elsevier]

Abstract: NiO film with sandwich-like morphology is fabricated on nickel foam by a simple ammonia-evaporation process. Ammonia plays a major role in controlling the final geometry during this template- and surfactant-free synthesis. The obtained NiO film is constructed by regular triangular prisms with side length of 500nm. Each triangular prism is self-assembled by single crystalline platelets. As an anode for lithium ion battery, this NiO film electrode exhibits high discharge capacity and excellent cycling performance. The reversible capacity of the sandwich-like NiO film sustains 400mAhg−1 even after 50 cycles at 2C, much higher than that of the dense NiO film prepared by eletrodeposition (198mAhg−1). The high rate capability and reversibility of this NiO film can be attributed to its unique sandwich-like architecture. [Copyright &y& Elsevier]