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
Explanation
The correct answer is C, Only three. Cobalt, lithium and nickel are cathode materials, while graphite is used for the anode.
A lithium-ion battery has a positive electrode (cathode), a negative electrode (anode) and an electrolyte through which lithium ions move. The cathode is usually a lithium metal oxide: common types for electric vehicles are NMC (lithium nickel manganese cobalt oxide), NCA (lithium nickel cobalt aluminium oxide) and LFP (lithium iron phosphate). Nickel raises energy density and cobalt keeps the structure stable. The anode is mostly graphite, a form of carbon whose layers hold lithium ions when the battery is charged, sometimes mixed with a little silicon.
A is wrong: three of the four elements, not one, are cathode materials.
B is wrong: lithium, nickel and cobalt all go into cathodes, so the count is more than two.
D is wrong: graphite forms the anode, not the cathode.
Exam tip: EV cathode = lithium + nickel + cobalt (NMC, NCA) or iron phosphate (LFP); anode = graphite.
Practice Questions
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- A.Marut
- B.Garud
- C.Tejas
- D.Pushpak
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- D.Shankhnaad
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- C.The college teachers of the country.
- D.The school children studying in classes 6 - 10 in the age group of 10 - 15 years.
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- B.The name BrahMos came from two rivers, Brahmaputra of India and Moskva of Russia.
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