Amino-functionalized MOF derived porous Fe₃O₄/N-doped C encapsulated within a graphene network by self-assembling for enhanced Li-ion storage

Abstract

A graphene-wrapped porous Fe3O4/N-doped C composite was synthesized by an electrostatic interaction induced self-assembly process, showing an excellent electrochemical performance.

Selenium-Doped Amorphous Black Phosphorus@TiO2/C Heterostructures for High-Performance Li/Na/K Ion Batteries

“…Conversely, as the scan rate exceeds 2 mV s –1 , a significant capacity decay is observed in region 2, which reflects a rate-dependent diffusion process. The capacitive and diffusion capacities can be further separated by the k 1 – k 2 analysis, as shown in formula , the capacitive capacity is ∼86.4% of the total capacity at 2 mV s –1 (the inset of Figure c), while the remaining capacity is close to the redox peaks, which is attributed to the Li + diffusion in the active materials. At other scan rates, these specific capacities also mainly come from the capacitive contribution (Figure d).…”

“…Conversely, as the scan rate exceeds 2 mV s −1 , a significant capacity decay is observed in region 2, which reflects a rate-dependent diffusion process. The capacitive and diffusion capacities can be further separated by the k 1 −k 2 analysis, as shown in formula 2 11,47…”

“…One central mission for the advancement of such batteries is the exploration of new anode materials with a high specific capacity, long lifespan, and appropriate redox potential . Up to now, numerous materials, such as carbon materials, , titanate, , silicon, , phosphorus, , and transition metal compounds, , have been prosperously developed as anode materials with impressive electrochemical performance. Nevertheless, just as coins have two sides, each of these materials has its merits and demerits that limit their use.…”

Pomegranate Clusters of N-Doped Carbon-Coated CoOx Supported on Graphene as a Flexible Lithium-Ion Battery Anode

“…The reason was that N-doped carbon reduced the signal value of the peak, which further indicated the successful N-doped carbon coating layer formation outside CoO x clusters. , The Raman spectra of the composites of NC@CoO x @GF, CoO x @GF, CoO x , NC@CoO x , and NC@GF are investigated in Figure b and Figure S2b. The intensity of the D and G band of NC@CoO x @GF was 1.53, which is higher than that of PANI@Co-MOF@GO (1.09), showing successful graphene oxide reduction, superior graphitic crystallinity, and enhanced electrical conductivity. , The spectral D and G peaks in the NC@CoO x @GF can be matched as visible I, D, D″, and G bands at ∼1368, ∼1352, ∼1605, and ∼1603 cm –1 , separately, which denoted the existence of conjugated polyene and graphitic lattice disconcertment or sp 2 –sp 3 bonds. , The peak at 686 cm –1 in both CoO x @GF and pure CoO x samples was due to the stretching vibration of Co–O, further indicating that Co-MOF was converted into cobalt oxide after calcination, while it was too weak in NC@CoO x @GF due to N-doped carbon coating outside of the clusters. − …”

“…36,37 The spectral D and G peaks in the NC@CoO x @GF can be matched as visible I, D, D″, and G bands at ∼1368, ∼1352, ∼1605, and ∼1603 cm −1 , separately, which denoted the existence of conjugated polyene and graphitic lattice disconcertment or sp 2 −sp 3 bonds. 38,39 The peak at 686 cm −1 in both CoO x @GF and pure CoO x samples was due to the stretching vibration of Co−O, further indicating that Co-MOF was converted into cobalt oxide after calcination, while it was too weak in NC@CoO x @GF due to N-doped carbon coating outside of the clusters. 39−41 To better comprehend the crystalline structure of composites, the XRD patterns of NC@CoO x @GF, CoO x @ GF, pure CoO x , PANI@Co-MOF@GO, NC@CoO x , and NC@GF are characterized in Figure 3c and Figure S2c.…”