Effect of intercalated alkali ions in layered manganese oxide nanosheets as neutral electrochemical capacitors

Abstract

New insight into the influence of Li+, Na+, and K+ cations between adjacent layers of birnessite-type manganese oxides (MnOx) towards the intercalation/deintercalation charge storage mechanism as a neutral electrochemical capacitor (1 M Na2SO4) is demonstrated.

Engineering Co3O4/MnO2 nanocomposite materials for oxygen reduction electrocatalysis

“…where, hν α, 5), ( 6), ( 7), (8), ( 9), ( 10), ( 11), ( 12), ( 13), (14), and (15). The two classic oxygen catalysts are metal oxides and metals, and the ORR mechanism by these catalysts has been intensively investigated.…”

“…From them, manganese dioxide (MnO 2 ) has become the potential and most attractive material with best electrochemical characteristics due to its excellent specific capacity, high abundance, high specific surface area, eco-friendly, low cost, and boost catalytic activity [11,12]. However, poor electronic conductivity is one of the opposing outcomes observed when MnO 2 is applied as an electrocatalyst owing to its limited cycle performance [13,14]. The principal approach for enhancing the performance of MnO 2 is to blend it with conducting materials like oxides, metals, and carbon-derived materials [15,16].…”

Tuning electronic structure of δ-MnO2 by the alkali-ion (K, Na, Li) associated manganese vacancies for high-rate supercapacitors

“…Two-dimensional d-MnO 2 generally displays higher capacitance and good rate capability compared to other crystal phases (a, b, c, k types), due to the interlayer tunnels of MnO 2 nanosheet can offer high-speed pathways for diffusion of alkali-ions or protons during the charge/discharge process. For example, Nattapol Ma et al investigated the effect of K + , Na + and Li + cations between adjacent layers of d-MnO 2 towards the intercalation/deintercalation charge storage mechanism, which not only played a significant role in electron transfer during the faradaic redox reaction, but also in accessibility of the compensating electrolyte ions [30]. In this work, alkali-ion (K, Na and Li) associated manganese (Mn) vacancies d-MnO 2 is fabricated by simple hydrothermal reaction.…”

Recent Development of Flexible and Stretchable Supercapacitors Using Transition Metal Compounds as Electrode Materials

“…It is well‐known that the crystalline structure of MnO 2 (α‐, β‐, γ‐, δ‐, and λ‐phase) affects its electrochemical performance due to their physicochemical properties. [ 310 ] For example, the δ‐MnO 2 is more suitable for the storage of alkali cations or protons because its interlayer spacing (0.7 nm) is wider than that of the tunnel size of α‐MnO 2 (0.46 nm), δ‐MnO 2 is more suitable for the storage of alkali cations or protons. However, synthesizing materials with multiple crystalline phases may result in synergistic effects at their grain boundaries and further enhance electrochemical performance.…”