Enhanced ionic diffusion interface in hierarchical metal-organic framework@layered double hydroxide for high-performance hybrid supercapacitors

Layered double hydroxides (LDHs) with abundant accessible active sites are promising electrode materials for hybrid supercapacitor (HSC) due to their ultrahigh theoretical capacitances. However, the structural agglomeration of LDH leads poor rate capability and durability. Herein, we construct a diffusion-controlled interface in hierarchical architecture metal-organic framework (MOF) HKUST-1@cobalt-nickel (denoted as HKUST-1@CoNiLDH) through an situ etching/electro-deposition strategy. The rapid charge transfer ionic diffusion HKUST-1@CoNiLDH deliver remarkable specific capacity 297.23 mAh·g−1 at 1 A·g−1, superior mostly reported LDH-based electrodes. More importantly, as-prepared HKUST-1 @CoNiLDH//activated carbon HSC exhibit high energy density 39.8 Wh·kg−1 power 799.9 W·kg−1 outstanding capacitance retention 90% after 5,000 charge—discharge cycles. in-depth understanding among MOF/LDH interfaces will greatly promote further development designing synthesizing performance conversion storage devices.