Question 43→ 2025 IAS Prelims GS I : Genius Classroom Explanation
📘 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:
- Cathode (positive electrode) → Metal oxides
- Anode (negative electrode) → Usually carbon-based
- 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
| Element | Cathode Component? |
|---|---|
| Cobalt | ✅ |
| Graphite | ❌ |
| Lithium | ✅ |
| Nickel | ✅ |
➡️ 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