A new strategy for the construction of 3D TiO<sub>2</sub> nanowires/reduced graphene oxide for high-performance lithium/sodium batteries

Lee

Intl J of Energy Research

et al. 2021

Summary This study introduces a simple and eco‐friendly synthetic strategy for yolk‐shell nanospheres that consist of manganese selenide yolks and carbon shells (MnSe@C) by reacting manganese salt impregnated in the porous hollow carbon nanospheres (HCNS) with H2O vapor. First, manganese salt dissolved in ethanol was impregnated into the spacious pores of the HCNS by capillary force. Then, heat treatment of the powder in the presence of H2O triggered the nucleation and crystal growth of manganese hydroxide, resulting in the formation of HCNS whose central voids are filled with multiple nanoparticles. Subsequent selenization yielded yolk‐shell nanospheres with MnSe@void@carbon configuration. MnSe@C was applied as the anode for sodium‐ion batteries (SIBs), and the following electrochemical reaction was confirmed from various analytical techniques: MnSe +2Na+ + 2e− ↔ Mn + Na2Se. MnSe@C nanospheres exhibited stable cycle performance up to 1000 cycles at 0.5 A g−1, wherein a reversible capacity of 222 mA h g−1 was delivered in the 1000th cycle. Furthermore, MnSe@C nanospheres exhibited a fair rate performance (209 mA h g−1 at 2.0 A g−1).

Section: Introductionmentioning

confidence: 99%

Synthesis of MnSe @C yolk‐shell nanospheres via a water vapor‐assisted strategy for use as anode in sodium‐ion batteries

Lee

Intl J of Energy Research

et al. 2021

“…GO contains reactive oxygen functional groups (hydroxyl, carboxyl, epoxy groups) attached to an sp 2 /sp 3 hybridized carbon network that provides hydrophilic character and chemical reactivity [24][25][26]. It is a fact that GO has an important impact on many applications nowadays, such as batteries [27], nanofiltration [28], electrodialysis [29], imaging [30], etc. GO-MnO 2 nanocomposites are easier to separate from water, and their high conductivity can accelerate electron transfer [31,32], which is beneficial for the oxidation of organic molecules.…”

Section: Introductionmentioning

confidence: 99%

Effective Dye Degradation by Graphene Oxide Supported Manganese Oxide

Saroyan¹,

Kyzas

Deliyanni

2019

Processes

Graphene oxide (GO) was used as a support for manganese oxide (MnO2) for the preparation of a nanocomposite catalyst for the degradation of an azo dye, Reactive Black 5 (RB5). The nanocomposite was characterized for the structure by XRD, for the morphology with SEM, and for the surface chemistry with FTIR and potentiometric titration measurements. The GO-MnO2 nanocomposite presented a high catalytic activity for the degradation/oxidation of RB5 at ambient conditions, which was higher than that of the pure MnO2 and could be attributed to the beneficial contribution of the manganese oxide and the graphene oxide.

“…For NC@ZSO-2, the intensity ratio of D peak to G peak is 1.02. This indicates that there are lots of vacancies and graphitized carbon between the layers of carbon in this material (Yu et al, 2018). The surface elemental compositions and electronic states of ZSO@NC-2 were characterized by XPS measurement.…”

Section: Resultsmentioning

confidence: 99%

“…Finally, a relatively stable discharge capacity of 967 mA h g −1 was achieved after 300 cycles with the CE approaching 100%. The gradual increase in the capacity may have mainly resulted from the formation of a gel-like polymeric layer and possibly interfacial lithium storage as well as electrochemical activation process of the composite during the repeated Li insertion/extraction ( Yu et al, 2018 ; Hu et al, 2013 ; Liang et al, 2018 ). To highlight the advantage of bimetallic oxide, ZnO-SnO 2 @NC is obtained at 800°C for 2 h at a heating rate of 5°C/min under a protective atmosphere.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 5D reveals the Nyquist plots of ZSO@NC-(1,2,3) and pure ZnSnO 3 . In general, the electrolyte resistance (R s ) corresponds to the first intercept of semicircle on the Z′ axis, the charge transfer resistance (R ct ) is determined by the diameter of the semicircle, and the resistance of Li ion diffusion (Z w ) is related to the linear slope ( Yu et al, 2018 ). The R s and R ct values of ZSO@NC-2 are 11.1 and 143.4 Ω, respectively.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Nitrogen-Doped Carbon Encapsulated Partial Zinc Stannate Nanocomposite for High-Performance Energy Storage Materials

Liu

Zhang

et al. 2021

Front. Chem.

Self Cite

As a bimetal oxide, partial zinc stannate (ZnSnO3) is one of the most promising next-generation lithium anode materials, which has the advantages of low operating voltage, large theoretical capacity (1,317 mA h g−1), and low cost. However, the shortcomings of large volume expansion and poor electrical conductivity hinder its practical application. The core-shell ZnSnO3@ nitrogen-doped carbon (ZSO@NC) nanocomposite was successfully obtained by coating ZnSnO3 with polypyrrole (PPy) through in situ polymerization under ice-bath conditions. Benefiting from this unique compact structure, the shell formed by PPy cannot only effectively alleviate the volume expansion effect of ZnSnO3 but also enhance the electrical conductivity, thus, greatly improving the lithium storage performance. ZSO@NC can deliver a reversible capacity of 967 mA h g−1 at 0.1 A g−1 after 300 cycles and 365 mA h g−1 at 2 A g−1 after 1,000 cycles. This work may provide a new avenue for the synthesis of bimetal oxide with a core–shell structure for high-performance energy storage materials.