Cigarette Flavouring Regulation by Using Aroma-producing Microorganism Isolated from Maotai Daqu

The selected Moutai aromatic microorganisms and their metabolites were applied into the fermentation of tobacco leaves in order to improve the tobacco quality. The results showed that a variety of aromatic substances in Moutai, as well as the typical flavor substances commonly used in cigarettes, were detected in the fermented tobacco leaf extract. In view of the GC-MS results as well as the sensory smoking evaluation of tobacco leaf extracts under designed experimental conditions, the optimal parameters of stable single-strain fermentation process was at 40 ℃ for 10-15 days. The results of specific effects of different fermentation conditions on the content of aroma substances in different parts of tobacco leaves after fermentation, as well as the subsequent sensory evaluation, provided basic data for the improvement of tobacco fermentation and aroma flavoring technology, which was conducive to the development of new cigarettes

Formulation and ageing mechanisms of Silicon/Graphite based negative electrodes for high energy density Li-ion batteries

Pour accroître l’autonomie des véhicules électriques, il est nécessaire d’augmenter la densité d’énergie des batteries Li-ion. Le silicium (Si) est un matériau actif d’électrode négative très prometteur par sa grande capacité spécifique théorique, supérieure à celle du graphite (Gr), qui est le matériau actuellement utilisé. Néanmoins, le silicium souffre d’une variation volumique importante lors de son fonctionnement, provoquant les dégradations mécaniques de l’électrode et chimique de l’électrolyte. La gestion des variations de volume et des réactions à l’interface électrode/électrolyte sont les verrous technologiques à lever. De ce fait, l’optimisation de la formulation de l’électrode est critique pour résoudre ou atténuer ces problématiques. L’approche choisie ici consiste à utiliser : (i) un mélange Si/Gr permettant de réduire la variation de volume moyenne de l’électrode tout en gardant une densité d’énergie attractive, (ii) le liant acide polyacrylique (PAAH1-xLix) en modulant son degré de neutralisation, et (iii) un électrolyte spécifique riche en fluorocarbonate de propylène. Les propriétés rhéologiques des encres d’électrode ont été soigneusement ajustées en fonction du pH imposé par le liant et des électrodes homogènes de grammages pertinents pour l’application industrielle ont été obtenues. Les analyses physico-chimiques des électrodes avant et pendant le cyclage ainsi que les mécanismes de vieillissement caractérisés aux différentes échelles par MEB, EIS, MET-EELS et RMN, montrent que le taux de neutralisation du liant est un paramètre crucial vis-à-vis des propriétés et des performances de l’électrodeTo increase the range of electric vehicles, it is necessary to increase the energy density of Li-ion batteries. Silicon (Si) is a very promising negative electrode active material due to its high theoretical specific capacity, greater than that of graphite (Gr), which is the material currently used. However, silicon suffers from a significant volume variation during its operation, causing mechanical degradation of the electrode and chemical degradation of the electrolyte. The management of volume variations and reactions at the electrode / electrolyte interface are the technological obstacles to be removed. Hence, optimizing the electrode formulation is critical to solving or alleviating these issues. The approach chosen here consists in using: (i) a Si/Gr mixture making it possible to reduce the average volume variation of the electrode while keeping an attractive energy density, (ii) the polyacrylic acid binder (PAAH1-xLix) by modulating its degree of neutralization, and (iii) a specific electrolyte rich in propylene fluorocarbonate. The rheological properties of the electrode slurries were carefully adjusted according to the pH imposed by the binder and homogeneous electrodes of loadings relevant for industrial application were obtained. The physico-chemical analyzes of the electrodes before and during cycling as well as the ageing mechanisms characterized at different scales by SEM, EIS, TEM-EELS and NMR, show that the degree of neutralization of the binder is a crucial parameter with regard to the properties and performance of the electrode

Sequential focused ion beam scanning electron microscopy analyses for monitoring cycled-induced morphological evolution in battery composite electrodes. Silicon-graphite electrode as exemplary case

International audienceIn the present work, an alternative to the standard ex-situ and destructive focused ion beam scanning electron microscopy (FIB/SEM) analysis procedure is demonstrated for monitoring the morphological degradation of a single Si/graphite (1/1 mass ratio) blended electrode for Li-ion batteries. For this purpose, a FIB milled microcavity is created in the pristine electrode, which is observed in FIB- polished cross section by SEM at different cycling periods (pristine, 1st, 9th and 50th cycles). This allows studying the same cycled electrode as for an in-situ method. Its cycling-induced morphological change is characterized at the electrode and particle scales by monitoring the evolution of the electrode thickness, mass and porosity, the Si particle morphology, Si interparticle distance, surface fraction and twisting of the graphite flakes. This is correlated to the evolution of the electrode discharge capacity and impedance. As a result, a more comprehensive view of the degradation phenomena of the Si/graphite blended electrode is established

Cigarette Flavouring Regulation by Using Aroma-producing Microorganism Isolated from Maotai Daqu

The selected Moutai aromatic microorganisms and their metabolites were applied into the fermentation of tobacco leaves in order to improve the tobacco quality. The results showed that a variety of aromatic substances in Moutai, as well as the typical flavor substances commonly used in cigarettes, were detected in the fermented tobacco leaf extract. In view of the GC-MS results as well as the sensory smoking evaluation of tobacco leaf extracts under designed experimental conditions, the optimal parameters of stable single-strain fermentation process was at 40 ℃ for 10-15 days. The results of specific effects of different fermentation conditions on the content of aroma substances in different parts of tobacco leaves after fermentation, as well as the subsequent sensory evaluation, provided basic data for the improvement of tobacco fermentation and aroma flavoring technology, which was conducive to the development of new cigarettes