Hierarchical porous NiCo2O4 nanosheet arrays directly grown on carbon cloth with superior lithium storage performance

Binary metal oxides have been explored as advanced candidates in lithium-ion battery (LIB) anodes due to their high specific capacity. Herein, the hierarchical structures of porous NiCo₂O₄ nanosheets directly grown on a conductive carbon cloth substrate (3D NCO-PSA/CC) were obtained by a facile in situ synthetic strategy. When applied as a binder-free LIB anode, it exhibited satisfactory performance with a high discharge capacity (a first discharge capacity of 2090.8 mA h g^-1 and a stable capacity of 1687.6 mA h g^-1 at 500 mA g^-1), superior rate capacity (discharge capacity of 375.5 mA h g^-1 at 6000 mA g^-1) and excellent reversibility (coulombic efficiency of approximately 100%). The outstanding performances should be attributed to the 3D porous structures, nanosheets and good conductivity of NCO-PSA/CC that could not only ensure the rapid transport of Li⁺ ions and electrons but also remit the huge volume change during lithiation/delithiation processes. Undoubtedly, the present facile and effective strategy can be extended to other binary metal-oxide materials for use as high-performance energy storage and conversion devices.

Novel Ag@Nitrogen-doped Porous Carbon Composite with High Electrochemical Performance as Anode Materials for Lithium-ion Batteries

A novel Ag@nitrogen-doped porous carbon (Ag-NPC) composite was synthesized via a facile hydrothermal method and applied as an anode material in lithium-ion batteries (LIBs). Using this method, Ag nanoparticles (Ag NPs) were embedded in NPC through thermal decomposition of AgNO₃ in the pores of NPC. The reversible capacity of Ag-NPC remained at 852 mAh g^-1 after 200 cycles at a current density of 0.1 A g^-1, showing its remarkable cycling stability. The enhancement of the electrochemical properties such as cycling performance, reversible capacity and rate performance of Ag-NPC compared to the NPC contributed to the synergistic effects between Ag NPs and NPC.