Facile synthesis of porous tubular NiO with considerable pseudocapacitance as high capacity and long life anode for lithium-ion batteries

Porous NiO microtubules have been fabricated by a very facile impregnation method, followed heating treatment using absorbent cotton fibers as template. The obtained porous NiO microtubules are composed of primary nanocrystallines with the average size of similar to 62.4 nm. Due to the unique hierarchical micro/nano architecture, the porous NiO microtubules exhibit excellent high-rate and long-life performances to serve as the anode materials for lithium-ion batteries. A high reversible capacity up to 926 mA h g(-1) is retained after 500 cycles at 1000 mA g(-1). Even at a high current density of 3 A g(-1), the NiO electrode still delivers a stable discharge capacity of 574 mA h g(-1) after 1100 cycles. Electrochemical kinetic analysis reveals that pseudocapacitive behavior contributes a great portion of the total stored charge, which greatly boosts the electrochemical performance of the porous NiO microtubules. The results reported in this work could offer clues for the structural design and performance optimization of electrode materials with both high energy density and power density for next-generation lithium-ion batteries.