which of the following is a rechargeable battery with the highest energy density currently in use?\n\na…

Brief Explanations:

Lead - acid batteries have relatively low energy density. Nickel - cadmium batteries have some toxicity and moderate energy density. Nickel - metal hydride has higher energy density than nickel - cadmium but still lower than lithium - ion. Lithium - ion batteries are known for their high energy density, which makes them suitable for applications like smartphones, laptops, and electric vehicles.

Answer:

d. Lithium - ion