General Polyethyleneimine‐Mediated Synthesis of Ultrathin Hexagonal Co₃O₄ Nanosheets with Reactive Facets for Lithium‐Ion Batteries

Abstract

Ultrathin hexagonal Co3O4 nanosheets with exposed reactive facets and porous architectures are synthesized by using a polyethyleneimine (PEI)‐mediated hydrothermal strategy. Characterization of the material indicates typical Co3O4 nanosheets of hexagonal shape that are approximately 100 nm in side length and 15 nm thick. PEI plays crucial roles in the synthesis of hexagonal Co3O4. The effects of the reaction conditions on the precursor morphologies and dimensions are investigated to understand the various roles of PEI. Electrochemical tests reveal the superior performance of ultrathin hexagonal Co3O4 nanosheets, including a remarkable specific capacity (e.g. 1007 mAh g−1 at 100 mA g−1 and 858 mAh g−1 at 500 mA g−1), excellent cyclability (e.g. capacity retention: 96–99 %), and a high rate capability. The improved performance is attributed to the combined effects from the high percentage reactive facets as well as the ultrathin and porous structures. This synthesis strategy can be extended to fabricate other anode materials for lithium‐ion batteries.

Photovoltaically self-charging cells with WO3·H2O/CNTs/PVDF composite

“…With reduced pH values and concentrations of reactants, the size of nanoplates could be decreased; yet, spherical hierarchical structures could form via secondary growth as we reported before [16] . PEI is a popular stabilizer, which can be used to protect nanostructures from agglomeration and inhibit crystallite-size growth of nanomaterials [22,23] . Figure 1 shows WO 3 ·H 2 O nanoplates fabricated with PEI assistance and morphologies of WO 3 ·H 2 O/CNTs/PVDF composite film.…”

Oxygen‐Deficient Three‐Dimensional Porous Co3O4 Nanowires as an Electrode Material for Water Oxidation and Energy Storage

“…However, its application is further limited by poor cyclic stability and electrical conductvity. Different strategies to improve its poor stability and conductivity such as composite formation, nanostructuring,, carbon mixing/coating, mixing with graphene, etc. has all shown great development.…”

Role of a Topotactic Electrochemical Reaction in a Perovskite‐Type Anode for Lithium‐Ion Batteries

“…The expansion and contraction of electrode materials during the lithium insertion/deinsertion or alloying/dealloying will damage the structure integrity and decrease the reversibility of a LIB. The morphology control of the electrode materials involving hierarchical morphology or macro/mesoporous structure has been extensively explored and applied to uphold the capacity retention ,…”