Hierarchical CuCo Carbonate Hydroxide Nanowires@FeCo‐Layered Double Hydroxide Hexagonal Nanosheets of Penetrating Architecture for High‐Performance Asymmetric Supercapacitor

Abstract

Rational construction of heterostructures can compensate for the property shortfalls of a single component, which is a promising and challenging approach to develop high‐performance electrode materials. Herein, CuCo carbonate hydroxide nanowires@FeCo‐layered double hydroxide hexagonal nanosheets (CuCo‐CH@FeCo‐LDH) with a unique nanowire‐penetrated‐nanosheet architecture have been prepared through a facile two‐step hydrothermal method. The nanowires serve as fast channels for charge transfer of FeCo‐LDH and alleviate the blocked electroactive utilization induced by self‐stacking of LDH nanosheets, while the FeCo‐LDH contributes high specific capacitance. The resultant CuCo‐CH@FeCo‐LDH exhibits pseudocapacitive behavior with near‐rectangular CV profiles and overall enhanced electrochemical performance compared to individual CuCo‐CH and FeCo‐LDH. An assembled asymmetric supercapacitor (CuCo‐CH@FeCo‐LDH//N/S co‐doped graphene) delivers high energy density (46.9 Wh kg−1 at 750 W kg−1), high power density (29.0 Wh kg−1 at 7500 W kg−1), and outstanding cycling stability (81.7 % capacitance retention after 5000 cycles).

Conductive Micropatterns Containing Photoinduced In Situ Reduced Graphene Oxide Prepared by Ultraviolet Photolithography

“…A smaller diameter corresponds to a smaller internal resistance. [ 42 ] The line in the low‐frequency region is related to the electrolyte diffusion process. [ 43 ] The corresponding equivalent circuit is presented in the inset.…”

Electron transfer and surface activity of NiCoP-wrapped MXene: cathodic catalysts for the oxygen reduction reaction

“…The product MXene@NiCo-precursor was cleaned repeatedly until the pH reached neutral and vacuum-dried at 60 °C. 17–19 The hydrothermal reaction formulas were as follows: 20 2CO(NH 2 ) 2 + Ni 2+ + Co 2+ + MXene+5H 2 O → MXene@NiCoCO 3 (OH) 2 + 4NH 4 + + CO 2 The obtained MXene@NiCo-precursor was subsequently converted to MXene@NiCoP via a phosphorization procedure using NaH 2 PO 2 as the P source. The phosphorization process may involve the following reaction formulas: 21 2NaH 2 PO 2 ·H 2 O → PH 3 + Na 2 HPO 4 + 2H 2 O3MXene@NiCoCO 3 (OH) 2 + 4PH 3 → 3MXene@NiCoP + 3CO 2 + 9H 2 O + P0.1 g MXene@NiCo-precursor and 1.0 g NaH 2 PO 2 ·H 2 O were placed in two separate porcelain boats for phosphorization.…”

“…The product MXene@NiCo-precursor was cleaned repeatedly until the pH reached neutral and vacuum-dried at 60 °C. [17][18][19] The hydrothermal reaction formulas were as follows: 20…”