With the fast-growing energy demand in consumer electronic devices and electric vehicles, there has been great interest worldwide in the development of advanced electrode materials for high-performance energy storage devices. An emerging new concept is to grow electroactive nanostructures on conductive substrates to be directly used as integrated electrodes for supercapacitors.

Now, in a new publication, Professor X. W. Lou and co-workers report a simple template-free solution method combined with a post annealing treatment to grow interconnected mesoporous NiCo₂O₄ nanosheets on various conductive substrates with robust adhesion as a binder and conductive agent-free electrode for supercapacitors. Such integrated electrodes exhibit ultrahigh specific capacitance and excellent cycling stability even at a high charge/discharge current density.