The
rational design and construction of composite electrodes are
crucial for overcoming the issues of poor working stability and slow
ionic electron mobility of a single component. Nevertheless, it is
a big challenge to construct core–shell heterostructures with
crystalline/amorphous/crystalline heterointerfaces in straightforward
and efficient methods. Here, we have successfully converted a portion
of crystalline CoGa2O4 into the amorphous phase
by employing a facile sulfidation process (denoted as CoGa2O4–S), followed by anchoring crystalline NiCo-layered
double hydroxide (denoted as NiCo-LDH) nanoarrays onto hexagonal plates
and nucleation points of CoGa2O4–S, synthesizing
dual-type hexagonal and flower-like 3D CoGa2O4–S@NiCo-LDH core–shell heterostructures with crystalline/amorphous/crystalline
heterointerfaces on carbon cloth. Furthermore, we further adjust the
Ni/Co ratio in LDH, achieving precise and controllable core–shell
heterostructures. Benefiting from the abundant crystalline/amorphous/crystalline
heterointerfaces and synergistic effect among various components,
the CoGa2O4–S@Ni2Co1-LDH electrode exhibits a specific capacity of 247.8 mAh·g–1 at 1 A·g–1 and good rate performance.
A CoGa2O4–S@Ni2Co1-LDH//AC flexible asymmetric supercapacitor provides an energy density
of 58.2 Wh·kg–1 at a power density of 850 W·kg–1 and exhibits an impressive capacitance retention
of 105.7% after 10,000 cycles at 10 A·g–1.
Our research provides profound insights into the design of other similar
core–shell heterostructures.