Synthesis and Electrochemical Properties of CoAl, NiAl, CoFe and NiFe Layered Double Hydroxide Films

Abstract

For electric energy storage device electrodes with nanosheet architectures can offer the possibility to achieve enhanced energy storage performance. Layered double hydroxide (LDH) is one of the candidate of electrode materials for electrochemical capacitor. Herein, we have successfully synthesized CoAl, NiAl and NiFe LDH nano-films grown on Ni substrate by hydrothermal methods. For CoFe, LDH nano-film cannot be obtained using same experiment conditions. SEM micrographs show that the thickness of LDH layered nanosheet are ~100, ~ 40 and ~85 nm for CoAl, NiAl and NiFe samples. The LDHs nanosheet film were grown perpendicularly on the substrate as electrode materials. The electrochemical performance of LDHs were tested by cyclic voltammetry. The measured cyclic voltammograms indicated that CoAl LDH has the best reversibility and the highest capacitance (554 F/g) among the three types of LDHs. A good cycling stability was also observed for the CoAl LDH nanosheet with the specific capacitance remained at 425 F/g and retained 77.3% of the high value after 6000 cycles at current density 10A/g.

Layered Double Hydroxide-Modified Electrodes for Gaseous Acetaldehyde Degradation at the Solid-Gas Interphase

“…The size of the leaf paddle of each LDH was 300, 300, and 100 nm for NiAl, CoAl, and NiCo respectively, which more closely align with those mentioned in the existing publication. 32 Further, the size difference could be from the role of each metal ion as the preparation conditions were the same for all LDHs.…”

“…The NiAl, CoAl, and NiCo LDHs were synthesized using a procedure described previously. 32 Briefly, 0.8 mmol Co(NO 3 ) 2 6H 2 O (0.233 g), 0.4 mmol Al(NO 3 ) 3 9H 2 O (0.15 g), 4 mmol NH 4 F (0.15 g), and 28 mmol urea (1.7 g) were added to a 100 ml beaker and mixed with 40 ml deionized water. The solution was continuously stirred for approximately 30 min, and then transferred to a 50 ml Teflon-lined stainless-steel autoclave (4 cm 2 NiCrFeAl 3D foam piece or without the 3D foam piece).…”