The nickel-rich cathode material Li[Ni0.8Mn0.1Co0.1]O2 is a much sought after material in Li-ion batteries for the future of electric vehicles due to its high specific capacity. However, it exhibits fast degradation during its use due to the interaction between the electrolyte and the cathode surface leading to capacity loss. In this thesis, the surface interaction of pristine and alumina coated NMC811, and NiO powder with electrolyte was investigated to observe difference in surface reactivity and if hydroxide groups on the surface could be a potential culprit in degradation. Thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) analysis were used to measure thermal properties, surface area and adsorptive properties respectively between pristine and coated powders but no distinct difference was found. A soaking experiment was performed to induce electrolyte degradation on the powders by soaking them in the electrolyte LP40 for a duration of two weeks at 50°C. The electrolyte and the soaked powders were thereafter investigated through various spectroscopy methods like Attenuated Total Reflection – Fourier Transform Infrared (ATR-FTIR) and Raman spectroscopy to find potential degradation products but were found insignificant or inconclusive difference. The electrochemical testing was performed on NMC811 half-cells at 3-4.2V and 3-4.4V with a 0.5C – rate. The coated heat-treated NMC811 was found to have the best cyclability at both potential ranges. In conclusion, the difference in surface reactivity of the pristine, coated, and coated heat-treated powders were found to be insignificant. However, the coated heat-treated NMC811 was found to have improved electrochemical performance at both potential ranges but it remains uncertain if hydroxide groups could be a culprit in the degradation.

Ce travail ouvre plusieurs perspectives, tout d'abord le processus de séchage des gradients horizontaux et verticaux doit sans doute avoir un rôle important sur la morphologie finale. La deuxième perspective concerne l'étude des contraintes internes et leurs relaxations, au cours du séchage, par la formation de fractures.

Chemical sciences research in India has been mapped with data collected from the CD-ROM version of Chemistry Citation Index [publication year : 2002]. Roughly, 4.5% of the global R&D output in chemical sciences was contributed by Indian in 2002. Indian researchers published 6186 papers from 569 journals and 12 non-journal sources. More than 45% of these papers appeared in journals with an impact factor less than 1.000. Around 2% of the papers were either published in journals with no impact factor or not indexed in JCR 2003. The average impact factor for journal articles during this period is 1.359. While 26% of papers published by Indians were in US journals, the percentages for Indian and UK journals were 21 and 20%, respectively. Among Indian journals, the Asian Journal of Chemistry (IF 0.211) took the major chunk of 269 papers, while the Journal of Indian Chemical Society (IF 0.275) and the Indian Journal of Chemistry B (IF 0.492) carried 224 and 209 papers, respectively. In all, 563 institutions contributed 6199 papers in 2002. Of these papers, 68% were contributed by 10% of Indian institutions. The Indian Institute of Science, Bangalore ranks first with 345 papers. This is followed by the Indian Institute of Chemical Technology, Hyderabad with 263 papers. Bhabha Atomic Research Centre, Mumbai with 259 papers and the National Chemical Laboratory, Pune with 246 papers come in the third and fourth places, respectively. The largest contributions came from Mumbai, Bangalore, Hyderabad and Kolkata. In terms of states, Maharashtra, Tamil Nadu, Karnataka, Andhra Pradesh and West Bengal are major contributors. About 16% of the papers had international collaboration (with as many as 53 county ies). Major collaborating countries in chemical sciences were the US, Germany, Japan and Great Britain.

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