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In this work, N-doped graphene and carbon co-modified Li 3 V 2 (PO 4 ) 3 composites (LVP/NGC) are successfully fabricated through a xerogel method for the first time. The obtained architecture combines two types of electronic contact with Li 3 V 2 (PO 4 ) 3 particles: the point-to-face contact of N-doped graphene and the face-to-face contact of N-doped carbon coating layers. Profiting from the favorable complex structure, graphene and carbon coating layers offer an extraordinary network for electron transfer and hence an excellent long-term and high-rate performance. Even tested at the rate of 40 C, the reversible capacity still maintains 86.9 mAh g −1 after 800 cycles without any fading. This work provides a promising route to improve the long-term and high-rate performance of cathodes for LIBs and enlightens us on exploring preferable strategies to develop advanced electrode materials for other energy storage devices. [ABSTRACT FROM AUTHOR]

Ultra-small Fe 3 O 4 nanocrystals (NCs)/garphene nanosheets (GNSs) composites have been synthesized through a facile gel-like film (GF) assisted method in this work. Fe 3 O 4 NCs with particle size ∼10 nm homogeneously dispersed on 2D GNSs. Profiting from the ultra-small Fe 3 O 4 NCs and GNSs, the composites demonstrate superior long-term and high-rate performance as anode materials for lithium ion batteries. Even at the current density of 5 A g −1 , the reversible capacity still maintains 323.4 mAh g −1 after 700 cycles. This work might enlighten us on exploring preferable strategies to develop advanced metal oxides NCs/GNSs composites anode materials for lithium ion batteries or other energy storage devices. [ABSTRACT FROM AUTHOR]

Li 3 V 2 (PO 4 ) 3 (LVP) nanoparticles were first prepared via a simple sol-gel route, then deposited on graphene oxide nanosheets, and finally a composite of LVP/reduced graphene oxide (LVP/G) was obtained after heat treatment. Scanning electron microscope and transmission electron microscope images demonstrate that LVP nanoparticles are homogenously enwrapped into graphene nanosheets or anchored onto the surface of graphene nanosheets. Compared with pure LVP, LVP/G nanocomposites exhibited better electrochemical performance (118.4 mAhg −1 at 1C, and 112.1 mAhg −1 at 2C after 100 cycles) and higher cycling stability (97% capacity retention after 100 cycles at 1C, and 89.5% after 500 cycles at 20C) as cathode materials for Li ion batteries. The enhanced performance can be attributed to the presence of graphene nanosheets among LVP nanoparticles. Electrochemical impedance spectroscopy indicates that graphene nanosheets significantly improve the electrical conductivity of LVP. The as-prepared LVP/G nanocomposites with superior cycling performance at high-rate have potential applications as cathode materials in Li ion batteries. [ABSTRACT FROM AUTHOR]

In this work, a composite of cobalt metal nanoparticles/three-dimensional carbon/reduced graphene oxide (Co-3DC-rGO) was synthesized using corn husk, ZIF-67, and graphene oxide as precursors. The Co-3DC-rGO was used to modify commercial PP to prepare the Co-3DC-rGO/PP separator. The performance of Co-3DC-rGO/PP separator was evaluated in lithium-sulfur batteries (LSBs). SEM images exhibited that a three-dimensional carbon (3DC) skeleton was obtained by corn husk transformation, and the ZIF-67-derived cobalt-decorated carbon dodecahedrons were homogeneously filled into the hierarchical pores of the 3DC structure. TEM images displayed that Co metal nanoparticles can escape from ZIF-67 and scatter on the rGO nano-sheets and 3DC skeleton. Benefitting from the synergy effects of the 3D carbon skeleton, rGO, and Co metal nanoparticles, the electrochemical performance of LSBs with Co-3DC-rGO/PP separator is better than LSBs with commercial PP separator. When tested at 1C, the LSB with Co-3DC-rGO/PP separator presents a high stable reversible capacity of 516.3 mA h g−1 after 500 cycles. This research provides new ideas for the preparation of LSBs separator. [Display omitted] • Co/3D carbon/rGO decorated PP separator was prepared and used in Li-S batteries. • Co/3D carbon/rGO can inhibit the shuttle of lithium polysulfides to the Li anode. • Co/3D carbon/rGO accelerate the conversion of lithium polysulfides to Li2S. • The Li-S battery with Co/3DC/rGO/PP separator delivers excellent electrochemical performance. [ABSTRACT FROM AUTHOR]