In Situ Synthesis of MnO₂/Porous Graphitic Carbon Composites as High-Capacity Anode Materials for Lithium-Ion Batteries

Abstract

Unique high-capacity MnO2/porous graphitic carbon (MnO2/PGC) composites were fabricated by a mild and efficient in situ precipitation approach using PGC derived from coal tar pitch as the carbonaceous precursor and KMnO4 as the manganese source. MnO2/PGC composites with reasonable surface areas (190–229 m2 g–1) retain the superior structure of interconnected nanopores and graphitic crystallite from PGC and contain evenly distributed MnO2 modified on the surface of the carbon skeleton in PGC, which can not only provide sufficient active sites for lithium-ion storage but also enhance electron transport capability and efficient lithium-ion diffusion capability. As a result of the synergistic effect of PGC and MnO2, MnO2/PGC composites as anode materials in lithium-ion batteries (LIBs) exhibit excellent reversible capacity, rate performance, and cycling stability. In particular, the MnO2/PGC-36 composite possesses a high initial reversible capacity of 1516 mAh g–1 at a current density of 0.05 A g–1 and an average reversible capacity of 399 mAh g–1 at a high rate of 5.00 A g–1. Moreover, such a MnO2/PGC-36 composite also exhibits a superior long-term cycling stability, with over 90.0% capacity retention after 400 cycles. These outstanding electrochemical performances demonstrate that the MnO2/PGC composite can be a promising anode material in LIBs for further practical application.

Direct Z-scheme α-MnO2@MnIn2S4 hierarchical photocatalysts with atomically defined junctions for improved photocatalytic activities

“…Importantly, the photogenerated electrons generated by semiconductors with a deeper conduction band top have extremely strong reducibility and have attracted the attention of researchers. 3 , and metal-Mn LDH) are widely used in photocatalytic environmental remediation, supercapacitors, lithium-sulfur batteries, and guided cancer treatments due to their low-cost and easy availability, environmental friendliness, high theoretical capacitance, and narrow band gap [23][24][25][26][27] . Among them, the visible light absorption capability of manganese oxide is high due to its narrow band gap which makes it a promising candidate for photocatalysis.…”

Facile and Efficient Fabrication of Bandgap Tunable Carbon Quantum Dots Derived From Anthracite and Their Photoluminescence Properties

“…The chemical structures at the surface of the as-prepared CQDs were further investigated by X-ray photoelectron spectroscopy (XPS) analyses. The XPS survey spectra of CQDs (Figure 5A) show that the as-prepared CQDs primarily consist of carbon and oxygen (Zhang Q. et al, 2017(Zhang Q. et al, , 2019Zeng et al, 2020). It can be seen that the oxygen content gradually increases from 34.4 to 42.6% with the increasing of the H 2 O 2 concentration in Table 1, indicating the higher the concentration of H 2 O 2 , the stronger the oxidation ability, due to the increase of the number of·OH radical.…”

Recent advances in graphite carbon nitride-based nanocomposites: structure, antibacterial properties and synergies

“…[200][201][202][203][204] MnO 2 is an inexpensive, abundant, biocompatible semiconductor that has a similar bandgap to g-C 3 N 4 . [205][206][207][208][209][210][211] Wu et al…”