Carbon Nanocones as Electrode Material in Lithium Ion Batteries

A carbon powder containing carbon nanocones was used as an anode material in lithium ion batteries. The powder was also treated in different ways, chemically, with microwaves, and with heat. The carbon powder was tape casted onto copper before being assembled into batteries with lithium metal as the counter electrode. The batteries were characterized by measuring the capacity during cycling. X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used to characterize the powders and casts. Fourier transformed infrared spectroscopy (FTIR) was done to both the carbon powder and the used anode material.The solid electrolyte interface (SEI) was characterized and found to contain components like ce{(CH2OCO2Li)2}, ce{Li2CO3}, and ce{ROCO2Li}. These are in accordance with what would be expected from results in the literature. SEM was used to find surface orientation of the basal and edge planes, and XRD was used to find the crystallinity.parThese results showed that more graphitized powders were better with emphasis on irreversible capacity. The treated carbon nanocone powders had higher capacity than the graphitized ones, but also higher irreversible capacity

Structural and magnetic aspects of La4(Co1-xNix)3O10+δ (0 ≤ x ≤ 1)

The Ruddlesden–Popper (RP3) type oxides, La4Co3O10+δ and La4Ni3O10+δ, form a complete solid solution. Powder X-ray and neutron diffraction data show that La4(Co1−xNix)3O10+δ is isostructural to the monoclinic La4Co3O10+δ structure (P21/a) described for all compositions without any further structural distortions as suggested in the literature. A slight elongation of the Co/Ni–O bonds facing the rock salt interlayer occurs for Ni-rich compositions. The magnetic properties of the solid solution series are mapped in the temperature range from 4 to 300 K, and the results are presented in a magnetic phase diagram. Three regimes with antiferromagnetic order (AF) exist at low temperatures, TN 0.80. The possibility to tune the oxidation state of the transition metal atoms is demonstrated for La4Co3O10+δ, and exemplified by weakening of a temperature-induced spin transition at around 480 K. This is an Accepted Manuscript of an article published by Taylor & Francis Group in Phase Transitions: A Multinational Journal, available online: http://www.tandfonline.co

Crystallinity of silicon nanoparticles: Direct influence on the electrochemical performance of lithium ion battery anodes

The use of silicon (Si) in the form of nanoparticles is one of the most promising routes for boosting the capacity of modern Li‐ion batteries. Many parameters influence the performance of Si making the comparison of materials complicated. The present work demonstrates a direct comparison of Si nanoparticles with amorphous and crystalline structures prepared through the same chemistry with the same particle size and morphology. The amorphous Si nanoparticles with an average diameter of 100 nm were synthesized through silane pyrolysis, and their crystalline analogues were obtained through subsequent annealing not altering size or morphology of the nanoparticles. Such direct comparison allows evaluation of the specific impact of crystallinity on the material's performance. From electrochemical analysis of these materials, the electrodes prepared from amorphous nanoparticles were found to exhibit improved cycle life compared to electrodes prepared from crystalline nanoparticles when the delithiation capacity of the anode was limited to 1000 mAh/gSi.publishedVersio

Morphology engineering of silicon nanoparticles for better performance in Li-ion battery anodes

publishedVersio

Crystallinity of silicon nanoparticles: Direct influence on the electrochemical performance of lithium ion battery anodes

The use of silicon (Si) in the form of nanoparticles is one of the most promising routes for boosting the capacity of modern Li‐ion batteries. Many parameters influence the performance of Si making the comparison of materials complicated. The present work demonstrates a direct comparison of Si nanoparticles with amorphous and crystalline structures prepared through the same chemistry with the same particle size and morphology. The amorphous Si nanoparticles with an average diameter of 100 nm were synthesized through silane pyrolysis, and their crystalline analogues were obtained through subsequent annealing not altering size or morphology of the nanoparticles. Such direct comparison allows evaluation of the specific impact of crystallinity on the material's performance. From electrochemical analysis of these materials, the electrodes prepared from amorphous nanoparticles were found to exhibit improved cycle life compared to electrodes prepared from crystalline nanoparticles when the delithiation capacity of the anode was limited to 1000 mAh/gSi

Crystallinity of silicon nanoparticles: Direct influence on the electrochemical performance of lithium ion battery anodes

The use of silicon (Si) in the form of nanoparticles is one of the most promising routes for boosting the capacity of modern Li‐ion batteries. Many parameters influence the performance of Si making the comparison of materials complicated. The present work demonstrates a direct comparison of Si nanoparticles with amorphous and crystalline structures prepared through the same chemistry with the same particle size and morphology. The amorphous Si nanoparticles with an average diameter of 100 nm were synthesized through silane pyrolysis, and their crystalline analogues were obtained through subsequent annealing not altering size or morphology of the nanoparticles. Such direct comparison allows evaluation of the specific impact of crystallinity on the material's performance. From electrochemical analysis of these materials, the electrodes prepared from amorphous nanoparticles were found to exhibit improved cycle life compared to electrodes prepared from crystalline nanoparticles when the delithiation capacity of the anode was limited to 1000 mAh/gSi