In the context of electric vehicle batteries, consider the following elements: I. Cobalt II. Graphite III. Lithium IV. Nickel How many of the above usually make up battery cathodes?

1. A. Only one
2. B. Only two
3. C. Only three
4. D. All the four

Answer: C

Explanation

A typical lithium-ion battery consists of a cathode (positive electrode), an anode (negative electrode), and an electrolyte. Cobalt (I) is a common component in cathodes, particularly in Lithium Cobalt Oxide (LCO) and Nickel Manganese Cobalt (NMC) batteries, enhancing energy density and battery life. Lithium (III) is fundamental to lithium-ion batteries, present in cathode compounds (e.g., LiCoO2) and the electrolyte. Nickel (IV) is also widely used in cathodes, especially in NMC and Nickel Cobalt Aluminum (NCA) formulations, to increase energy density and storage capacity. Graphite (II), however, is predominantly used as the anode material in most lithium-ion batteries due to its excellent intercalation properties for lithium ions. Therefore, Cobalt, Lithium, and Nickel are typically found in battery cathodes, while Graphite is used in anodes. The increasing adoption of electric vehicles and the strategic importance of critical minerals for battery production make this a significant topic for UPSC.