Si-based anode materials are considered as potential materials for high-energy lithium-ion batteries (LIBs) with the advantages of high specific capacities and low operating voltages. However, significant initial capacity loss and large volume variations during cycles are the primary restrictions for the practical application of Si-based anodes. Herein, we propose an affordable and scalable synthesis of double-layered SiO x /Mg2SiO4/SiO x composites through the magnesiothermic reduction of micro-sized SiO with Mg metal powder at 750 °C for 2 h. The distinctive morphology and microstructure of the double-layered SiO x /Mg2SiO4/SiO x composite are beneficial as they remarkably improve the reversibility in the first cycle and completely suppress the volume variations during cycling. In our material design, the outermost layer with a highly porous SiO x structure provides abundant active sites by securing a pathway for efficient access to electrons and electrolytes. The inner layer of Mg2SiO4 can constrain the large volume expansion to increase the initial Coulombic efficiency (ICE). Owing to these promising structural features, the composite prepared with a 2:1 molar ratio of SiO to Mg exhibited initial charge and discharge capacities of 1826 and 1381 mA h g–1, respectively, with an ICE of 75.6%. Moreover, it showed a stable cycle performance, maintaining high capacity retention of up to >86.0% even after 300 cycles. The proposed approach provides practical insight into the mass production of advanced anode materials for high-energy LIBs.

Karachi is the largest city of Pakistan. The temperature change in Karachi is studied in this research by analyzing the time series data of mean maximum temperature (MMxT), mean minimum temperature (MMiT) and mean annual temperature (MAT) from 1947 to 2005 (59 years). Data is analyzed in three parts by running linear regression and by taking anomalies of all time periods: (a) whole period from 1947-2005; (b) phase one 1947-1975 and (c) phase two 1976-2005. During 1947 to 2005 MMxT has increased about 4.6 • C, MMiT has no change and MAT has increased 2.25 • C. During 1947-1975, MMxT increased 1.9 • C, in this period there is −1.3 • C decrease in MMiT and MAT has raised upto 0.3 • C. During 1976-2005, the MMxT, MMiT and MAT increased 2.7 • C, 1.2 • C and 1.95 • C, respectively. The analysis shows significantly the role of extreme vulnerability of MMxT in rising the temperature of Karachi than the MMiT.

Purpose-The purpose of this paper is to explore the trends of changing temperature of Lahore in Pakistan due to invigorating urbanization process since 1950-2007. Design/methodology/approach-This research is designed by using the numerical time series data of mean minimum temperature (MMiT), mean maximum temperature (MMxT) and mean annual temperature (MAT). The growth in urban population, area and transportation are also evaluated by using the available data. Linear regression method is applied to investigate the results of change in temperature. Three different approaches to examine the MAT are testified; first as an entire period (1950-2007), and then by dividing the entire period into two equal phases as Phase I (1950-1974) and Phase II (1975-2207). MMiT and MMxT are analysed for the entire period without making any division. Findings-The results of the paper are significantly indicating an increase in MAT and MMiT which have risen up to 0.89 and 2.518C, respectively, while MMxT remained resolute throughout the study period. Change in MMiT is observed regular and brisk than other parameters of temperature. Increase in temperature in Phase I is observed only 0.0628C and in Phase II it is observed 0.948C. Research limitations/implications-This research can be further worked out by using different meteorological models to study the effects of urbanization on lower surface atmosphere and urban heat island effects in Lahore. Originality/value-By taking into consideration these results, the town planners and government can make different strategies to mitigate the urban effects on rising temperature in Pakistan.

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