ABSTRACT
Using a new class of (BH4)- substituted argyrodite Li6PS5Z0.83(BH4)0.17, (Z = Cl, I) solid electrolyte, Li-metal solid-state batteries operating at room temperature have been developed. The cells were made by combining the modified argyrodite with an In-Li anode and two types of cathode: an oxide, LixMO2 (M = â Ni, â Mn, â Co; so called NMC) and a titanium disulfide, TiS2. The performance of the cells was evaluated through galvanostatic cycling and Alternating Current AC electrochemical impedance measurements. Reversible capacities were observed for both cathodes for at least tens of cycles. However, the high-voltage oxide cathode cell shows lower reversible capacity and larger fading upon cycling than the sulfide one. The AC impedance measurements revealed an increasing interfacial resistance at the cathode side for the oxide cathode inducing the capacity fading. This resistance was attributed to the intrinsic poor conductivity of NMC and interfacial reactions between the oxide material and the argyrodite electrolyte. On the contrary, the low interfacial resistance of the TiS2 cell during cycling evidences a better chemical compatibility between this active material and substituted argyrodites, allowing full cycling of the cathode material, 240 mAhg-1, for at least 35 cycles with a coulombic efficiency above 97%.
ABSTRACT
A total of 214 consumers and street vendors at Hai Ba Trung district, Ha Noi city, were trained in safe food handling knowledge as well as practices. It is an effective measure to improve the practices of street food preparation. The results were found that 89% of street vendors avoided contact of the bare hand with cooked foods, 73% used separate utensils for raw materials and cooked food, and 88% of them kept food hot for sell. Strengthening food safety, quality control systems, educating community about knowledge and safe food handling practices are essential in the community
