Search

LiFePO (LFP) nanobars, microplates and nanorods have been selectively synthesized via a solvothermal method in a water-ethylene glycol (EG) binary solvent with HPO, LiOH·HO, and FeSO·7HO as starting materials. The morphology and size of the as-obtained LFP products can be deliberately controlled by varying the volume ratio of EG to water. The formation mechanism and electrochemical properties of different LFP morphologies have been investigated. With carbon coating, the Li-ion diffusion coefficients of LFP nanorods, nanobars and micro-plates are 2.58×10, 2.91×10, and 7.22×10 cm s, respectively. For the carbon-coated nanorods, excellent rate capability and cyclability were attained. At 5 C, the capacity was 141 mAh g for the first cycle and maintained 120 mAh g after 100 cycles; at 10 C, the capacity was still as high as 132 mAh g. [ABSTRACT FROM AUTHOR]

series of LiNiMnCoO $$ \left( {0 < {2}x \leqslant 0.{33}} \right) $$ compounds were prepared by solid-state reaction from nickel manganese cobalt oxides, and their characteristics were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and charge-discharge test. LiNiMnCoO samples have single phase of layered structure with a space group of $$ {\hbox{R}}\overline 3 {\hbox{m}} $$ for 2 x = 0.02, 0.05, 0.10, 0.20, and 0.33. Both the lattice constants of a- and c-axis and Li/Ni mixing degree decreased with the increase in Co contents in samples. The valence states of Ni, Mn, and Co in the samples are predominantly +2, +4, and 3, respectively, with a small amount of Ni, Mn, and Co. LiNiMnCoO gives excellent cycling performance in the voltage range of 2.5-4.4 V at the current rate of 20 and 100 mA g over 50 cycles. High-rate capacity test of LiNiMnCoO shows that even at a current rate of 1,000 mA g, stable capacity about 63 mAh g is retained. [ABSTRACT FROM AUTHOR]

The article evaluates the primary electrochemical performance of surface modified spherical graphite in relation to the distribution of conductive additive particles on the coated electrode material. It has been observed that the cycling behavior was influenced by the dispersion of conductive additive. The initial reversible capacity was greater than that of commercial synthetic graphite. Also, poor dispersion produced numerous white deposits.