Characteristics of pyrolyzed phenol-formaldehyde resin as an anode for lithium-ion batteries

Three kinds of carbon resources, poly(vinyl alcohol), phenol-formaldehyde resin and epoxy resin, were used to prepare the LiFePO4/C composite (LFPC-1, LFPC-2, LFPC-3). XRD patterns show that the LFPC composites possess the typical olivine structure. The particle size and the reunited degree of LFPC-1 are smaller than those of LFPC-2 and LFPC-3. The discharge capacities of LFPC-1 at different C-rates are also much higher than those of the other two samples. Its discharge capacities at 0.1 C and 1 C are 158.8 mAh g-1and 136.20 mAh g-1. Its discharge curve can maintain the stable potential platform of 3.3 V at the rate of 1 C. LFPC-1 possesses the highest electrical conductivity of 5.76×10-2S•cm-1. This is because the ID/IG value of 1.20 in Raman spectra is much lower than that of LFPC-2 and LFPC-3. The selected area electron diffraction in the TEM of LFPC-1 shows directly that the graphitized carbon is formed on the cover surface of LFPC-1 composite.

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Scalable Synthesis of Dual-Carbon Enhanced Silicon-Suboxide/Silicon Composite as Anode for Lithium Ion Batteries

NANO ◽

10.1142/s1793292017500849 ◽

2017 ◽

Vol 12 (07) ◽

pp. 1750084 ◽

Cited By ~ 2

Author(s):

Xuejiao Feng ◽

Hongmin Cui ◽

Zhenming Li ◽

Rongrong Miao ◽

Nanfu Yan

Keyword(s):

Carbon Nanotubes ◽

Spray Drying ◽

Phenol Formaldehyde ◽

Lithium Ion ◽

Reversible Capacity ◽

High Energy ◽

Phenol Formaldehyde Resin ◽

Formaldehyde Resin ◽

Capacity Retention ◽

Initial Capacity

The SiOx/Si composite enhanced by dual-carbon (i.e., multiwall carbon nanotubes and carbon) was fabricated from the micro silicon monoxide (SiO) by the combination of high-energy mechanical milling, spray drying and pyrolysis. The obtained SiOx/Si particles were composed of Si-suboxide and embedded nano-sized Si crystallites. As one of dual-carbons, the multi-walled carbon nanotubes were directly scaffolded of anchoring the SiOx/Si composite particles through spray drying. Another carbon source was directly deposited on the surface of the SiOx/Si by means of the carbonization of phenol–formaldehyde resin. Nano-sized silicon embedded in the Si-suboxide matrix and dual-carbon provided a compromise between the reversible capacity and cycle stability related to the volume change. The obtained SiOx/Si/MWCNT/PC-1 electrode delivered an initial capacity of 936.5[Formula: see text]mAh g[Formula: see text] and the reversible capacity was maintained at 825.9[Formula: see text]mAh g[Formula: see text] with excellent capacity retention of 87.5% on the 200th cycle versus the 6th one (compared with the same current rate). In contrast, although the SiOx/Si presented the higher initial capacity of 1271.4[Formula: see text]mAh g[Formula: see text], its capacity dropped quickly after several cycles and capacity retention was only 25.6% versus the 6th cycle after 100 cycles.

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Purification of water contaminated with heavy metals by example of lead as promising material based on graphene nanostructures

Perspektivnye Materialy ◽

10.30791/1028-978x-2020-9-34-43 ◽

2020 ◽

pp. 34-43

Author(s):

N. R. Memetov ◽

◽

A. V. Gerasimova ◽

A. E. Kucherova ◽

◽

...

Keyword(s):

Adsorption Process ◽

Phenol Formaldehyde ◽

Phenol Formaldehyde Resin ◽

Formaldehyde Resin ◽

Parameter Estimates ◽

Maximum Adsorption Capacity ◽

Ecological Situation ◽

Characteristic Parameters ◽

Purification Of Water ◽

Graphene Nanostructures

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.

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