📘 IAS Prelims 2025 — GS-I Q.43 | Classroom Explanation

(Science & Technology | Electric Vehicles)

📌 Question

Q.43) 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) Only one
(b) Only two
(c) Only three
(d) All the four

✅ Correct Answer: (c) Only three

🧑‍🏫 Classroom Explanation

This question tests basic lithium-ion battery chemistry, a favourite UPSC area linking EVs, minerals, and energy transition.

🔍 Core Concept: Lithium-Ion Battery Structure

A typical Li-ion battery has three main components:

1. Cathode (positive electrode) → Metal oxides
2. Anode (negative electrode) → Usually carbon-based
3. Electrolyte → Lithium-ion conducting medium

🔍 Statement-wise Analysis

✅ I. Cobalt — Correct

• Widely used in cathode materials such as:

• Lithium Cobalt Oxide (LCO)
• NMC (Nickel-Manganese-Cobalt)
• NCA (Nickel-Cobalt-Aluminium)

• Improves:

• Energy density
• Thermal stability
• Battery life

✔️ Part of cathode.

❌ II. Graphite — Incorrect

• Graphite is NOT a cathode material.
• It is the most common anode material in lithium-ion batteries.
• Function: Stores lithium ions during charging.

❌ Not part of cathode.

✅ III. Lithium — Correct

• Lithium is an essential component of the cathode compound.
• Present in cathode materials such as:

• LiCoO₂
• LiFePO₄
• LiNiMnCoO₂

✔️ Central to cathode chemistry.

✅ IV. Nickel — Correct

• Used in modern high-energy cathodes like:

• NMC
• NCA

• Enhances:

• Energy density
• Driving range of EVs

✔️ Part of cathode.

🧮 UPSC-Style Count

➡️ Total correct = 3

🎯 Final Answer

✅ Correct Answer: (c) Only three

📦 High-Value Prelims Add-Ons (Info Box Ready)

🧠 1-Line Memory Hook

Cathode = Lithium + Metals | Anode = Graphite

⚠️ UPSC Trap Alert

• Graphite almost always appears as a trap → remember ANODE ONLY.
• Questions often mix battery minerals + EV policy + geopolitics.

🌍 Current Affairs Link

• India’s concern over Lithium, Cobalt, Nickel supply chains
• Push for LFP batteries (Lithium-Iron-Phosphate) to reduce cobalt dependence