Fe3O4-modified FeCl3/graphite intercalation compound confinement architecture for unleashing the high-performance anode potential of lithium-ion batteries.

The ferric trichloride (FeCl3)-intercalated graphite intercalation compound (GIC) has high reversible capacity and bulk density, making it a promising anode material for lithium ion batteries. However, its practical application has been limited by the poor cycle performance due to chloride dissolution and shuttling issues. Herein, FeCl3-GIC is used as the precursor material to synthesize a nano-Fe3O4-modified intercalation material by a solvothermal method. The Fe3O4 moiety at the edge of FeCl3-GIC provides a robust chemical anchoring effect on the chlorides. Together with the two-dimensional graphite layer, it forms a confinement space, which effectively immobilizes soluble chlorides. Attributed to the distinctive structural design, the Fe3O4-FeCl3/GIC 25% C electrode offers a high reversible capacity of 691.4 mA h g-1 at 1000 mA g-1 after 400 cycles. At 2000 and 5000 mA g-1, the reversible specific capacity of the Fe3O4-FeCl3/GIC 25% C electrode is 345.6 and 218.3 mA h g-1, respectively. This work presents an innovative method to improve the lifespan of GIC.

Sulfur dioxide emissions from combustion in china: from 1990 to 2007.

China has become the world's largest emitter of SO(2) since 2005, and aggressive deployment of flue gas desulfurization (FGD) at coal-fired power plants appeared in China when facing the formidable pressure of environment pollution. In this work, we estimate the annual emission from combustion sources at provincial levels in China from 1990 to 2007, with updated data investigations. We have implemented the method of transportation matrix to gain a better understanding of sulfur content of coal in consuming provinces, which in turn improved the inventory. The total emissions from combustion in 2007 were 28.3 Tg, half of which was contributed by coal-fired power plants. Meanwhile, the industrial boiler coal combustion and residential coal consumed in centralized heating were responsible for another 32% of the total emissions. From 1990 to 2007, annual SO(2) emission was fluctuated with two peaks (1996 and 2006), and total emission doubled from 15.4 Tg to 30.8 Tg, at an annual growth rate of 4.4% (6.3% since 2000). Due to the extensive application of FGD technology and the phase-out of small, high emitting units, the SO(2) emission began to decrease after 2006. Furthermore, the differences among estimates reported in literatures highlight a great need for further research to reduce the uncertainties with more detailed information on key sources and actual operation of devices.

[First flush analysis of PAHs in roof runoff in Beijing].

Roof runoff samples of six storm events were collected at three different sites in the urban area of Beijing during the rainy season of 2008. The samples were analyzed for PAHs in both particle and dissolved phases. On the basis of the field measured data, the first flush phenomenon of PAHs was quantitatively analyzed using a newly defined FF(n-Max), and the influences of the storm event characteristics were discussed. In roof runoff, the first flush phenomena of total PAHs and PAHs in particle phase were noted, and PAHs in dissolved phase was not observed with first flush. The ranges of the first flush values for FF25 and FF30 were 0.6-2.4 and 0.6-2.1, respectively. For different types of roof materials, the strength of the first flush followed the order of: tile roof, cement roof > asphaltic felt roof. There is no significant difference between the tile roof and cement roof. No significant correlation was observed between the occurrence of first flush and the rainfall characteristics.