Nanoarchitectonics of multilayered NiO submicron flakes for ultrafast and stable lithium storage

Nickel oxide (NiO) holds great promise as a high-capacity anode material for rechargeable lithium-ion batteries. However, the major concern is the tremendous stresses and volume changes associated with repeated lithium insertion/extraction processes, leading to poor capacity retention and rate capability. To circumvent this problem, we demonstrate a rational design for the fabrication of multilayered NiO submicron flakes using a selective chemical etching strategy followed by a calcination treatment. When serving as lithium storage anodes, the multilayered NiO submicron flakes exhibit excellent cycling stability and rate capability, with a high reversible lithium extraction specific capacity of 532 mAh g −1 at a current rate of 0.6 C (1 C = 718 mA g −1 ) and a Coulombic efficiency close to 100% after 630 deep cycles. Even at an extremely high current rate of 120 C ( i.e. , 86,160 mA g −1 ), a suitable capacity of 61 mAh g −1 is still attained. Moreover, the electrodes also show superiority in function at high temperature (55 °C), delivering stable reversible capacities of 646 and 581 mAh g −1 at 0.2 and 0.4 C, respectively, after 50 cycles. Moreover, the post morphologies and compositions after long cycles are finally determined to demonstrate the efficient lamellar structure of the multilayers. This strategy provides a new avenue for designing various multilayered metal oxides and/or hybrid materials for use in energy storage and other related applications.