Science & Tech · Battery Technologies (Li-ion, Sodium-ion, Solid-State)
The concept being tested: Electric vehicle battery cathode composition (lithium, cobalt, nickel, graphite).
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?
A typical electric vehicle battery is lithium-ion, and its cathode is built from lithium combined with a mix of transition metals. In the dominant chemistries used in EVs today, NMC (nickel manganese cobalt oxide) and NCA (nickel cobalt aluminium oxide), the cathode is a lithium metal oxide in which nickel and cobalt are the key metals alongside lithium itself. Graphite does not belong here at all: it is the standard material used to build the anode, the electrode on the opposite side of the cell, not the cathode. So out of Cobalt, Graphite, Lithium and Nickel, three of them, Cobalt, Lithium and Nickel, usually make up the cathode, while Graphite is excluded because its role is on the anode side. That is why the answer is only three.
What UPSC was testing
The question is really testing whether aspirants know that graphite belongs to the anode, not the cathode, of a lithium-ion EV battery; conflating the two electrodes is the trap the framing is built around.
How often this comes up
This concept has appeared 7 times in UPSC Prelims General Studies Paper I between 2015 and 2025 — in 2015, 2019, 2024 and 2025.
The option-by-option autopsy for this question — why each of the other three is wrong, and which neighbouring concept each one was built from — is in the app.
Other past-year questions touching Battery Technologies (Li-ion, Sodium-ion, Solid-State).