Surface Spatial Confinement Effect on Mn–Co LDH@Carbon Dots for High-Performance Supercapacitors

Abstract

The charge transport between layers of layered double hydroxide (LDH) with structural stability is generally considered as a key factor in restricting electrochemical performances. Herein, we report the surface spatial confinement effect on Mn–Co LDH@carbon dots (CDs) to enhance charge transfer and the stable structure for high-performance supercapacitors. The surface confined effect should be characterized as the charge transfer and interaction between Mn–Co LDH and CDs using density functional theory calculations. CDs can improve the density of states near the Fermi level to achieve an enhanced conductivity. The geometric structure can remain stable at room temperature within 200 fs by using ab initio molecular dynamics simulations. The two-electrode device gained the energy density of 79 W h kg–1 and a power density of 666 W kg–1 at 1 A g–1. This design concept will help to design, prepare, and assemble the high-efficiency and long-lifetime electrochemical energy storage devices based on various layered materials.