An Effective Strategy on Synthesizing a Stable SiOx-Based Anode for High Density Lithium-Ion Batteries.

Silicon oxides (SiOx) have received extensive attention as an promising anode candidate for next-generation lithium-ion batteries (LIBs). However, their commerical applications have been seriously hindered by low conductivity, large volume expansion and unstable soild-electrolyte interface (SEI) layer, which result in low intial coulombic efficiency, poor rate performance and short cycling lifepan. In this work, we demonstrate a simple way to prepare a series of SiOx materials with lithium fluoride (LiF) modified by hydrothermal method and carbothermal modification. When the mass ratio of SiOx and LiF equals 1:0.15, the long-term cycling capacity retention can be greatly improve form 30.2% to 76.7% after 200 cycles. The result is primarily because the enhancement of electrons and Li+-ions transport and the stability of SEI layer due to LiF addition. However, excess LiF addition can hinder the diffusion of Li+-ions. This study presents the great potential of LiF modified on SiOx anode materials for LIBs.

[Health Benefit Assessment of Coal-to-electricity Policy on PM2.5 Pollution in Beijing-Tianjin-Hebei Region].

To accurately assess the health benefits of the coal-to-electricity policy during the heating period in the Beijing-Tianjin-Hebei(BTH) Region, the premature deaths caused by PM2.5 before and after the implementation of the coal-to-electricity policy during the heating period in each district and county of the BTH Region were estimated, and the corresponding health loss values were calculated using the willingness to pay method. The results showed that the implementation of the coal-to-electricity policy in the BTH Region brought 1745 cases(95% CI:1443-1907) of health benefits and 2.38 billion yuan(95% CI:1.45-3.06) in economic benefits. In Beijing, Tianjin, and Hebei there were 495 cases(95% CI:436-554), 296 cases(95% CI:238-354), and 954 cases(95% CI:693-1076) of health benefits, respectively. The economic benefits were 0.35 billion yuan(95% CI:0.30-0.39), 0.33 billion yuan(95% CI:0.27-0.40), and 1.70 billion yuan(95% CI:0.88-2.28), respectively, accounting for 0.01%, 0.02%, and 0.04% of GDP in each region. The number of premature deaths due to COPD, LC, ALRI, IHD, and STROKE decreased by 187 cases(95% CI:165-224), 318 cases(95% CI:178-458), 193 cases(95% CI:115-204), 506 cases(95% CI:232-780), and 542 cases(95% CI:463-621), respectively. Areas with relatively high environmental PM2.5 concentrations and concentrated population-intensive pollution emissions can achieve significant health and economic benefits.