ABSTRACT
The fast-charging capability is critical for the wide adoption of electric vehicles (EVs), which, however, can result in lithium (Li) plating on the graphite anode and thus aggravate cell degradation and increase the safety risk. Li plating is also prone to occur during charging at low temperatures. In this work, we fabricate Li-ion full cells in transparent glass capillaries to probe the real-time dynamic evolution of the lithiated phases throughout the graphite anode toward the onset of lithium plating during fast charging and under low temperatures. We observed that Li plating can occur well before 70% state of charge (SOC), even at a low C-rate and at room temperature. Our operando experiments provide the direct proof that subtle features in the electrochemical responses are caused by the Li plating, which can be utilized to improve battery management strategy. Mathematical simulations confirm that the local overpotential due to the strong concentration polarization is the root cause of the axial reaction heterogeneity in the graphite anode and the Li plating on the fully lithiated particles.
ABSTRACT
To elucidate the deleterious effects of excess lead on radish (Raphanus sativus) cv. Jaunpuri plants were grown in refined sand in complete nutrient solution for 30 days. On the 31st day lead nitrate was superimposed at 0.1 and 0.5mM to radish for 65 days. A set of plants in complete nutrient solution was maintained as control for the same period without lead. Excess Pb at 0.5mM showed growth depression with interveinal chlorosis on young leaves at apex. Excess Pb reduced the fresh and dry weight pronouncedly at d 65. Lead accumulation reduced the concentration of chlorophyll, iron, sulphur (in tops), Hill reaction activity and catalase activity whereas increased the concentration of phosphorus, sulphur (in roots) and activity of peroxidase, acid phosphatase and ribonuclease in leaves of radish.
