Introduction to battery-management systems- COURSERA WEEK 02 FINAL QUIZ -2 ANSWERS

   Introduction to battery-management systems- COURSERA WEEK 02   FINAL QUIZ -2 ANSWERS

1.

Question 1

Which of the following is true?

1 point

For a given volume, higher energy density stores more energy.

For a given weight, lower specific energy stores more energy.

For a given storage capacity, higher energy density cells are larger.

For a given storage capacity, lower specific energy cells are lighter.

2.

Question 2

Which of the following statements are true concerning intercalation compounds? Select all that apply.

1 point

The compound must have an open crystal structure, allowing insertion or extraction of lithium ions in the vacant spaces

Lithium forms a strong chemical bond with the compound when it intercalates into its crystal structure

When Li$^+$ enters the compound, the compound also must have an ability to accept compensating electrons from the external circuit

Lithium moves automatically from high-concentration regions of the compound to low-concentration regions of the compound via diffusion

3.

Question 3

When charging a lithium-ion cell, which of the following are true? Select all that apply.

1 point

Lithium diffuses from the center of a negative-electrode particle toward its surface

Lithium at the surface of negative-electrode particles give up electrons and enter the electrolyte as Li$^+$ cations

Lithium at the surface of positive-electrode particles give up electrons and enter the electrolyte as Li$^+$ cations

Li$^+$ cations diffuse through the electrolyte from high-concentration regions to low-concentration regions

Lithium diffuses from the center of a positive-electrode particle toward its surface

4.

Question 4

Which of the following is not a good candidate material to use in a lithium-ion negative electrode?

1 point

Lithium cobalt oxide (LiCoO$_2$, or "LCO")

Hard carbon

Silicon

Lithium titanate oxide (Li$_4$Ti$_5$O$_{12}$, or "LTO")

Graphite

5.

Question 5

Which of the following statements is true regarding cells having lithium titanate oxide (Li$_4$Ti$_5$O$_{12}$, or "LTO") negative electrodes?

1 point

LTO cells tend to have short lifetimes when compared with lithium-ion cells having different negative-electrode materials.

LTO cells have higher energy density than lithium-ion cells having different negative-electrode materials.

LTO cells have lower per-cell open-circuit voltage than lithium-ion cells having different negative-electrode materials.

LTO cells are inexpensive to manufacture compared with lithium-ion cells having different negative-electrode materials.

6.

Question 6

Which of the following are "cubic-spinel" positive-electrode materials? Select all that apply.

1 point

Lithium nickel manganese cobalt oxide ("NMC")

Lithium manganese oxide (Li$_x$Mn$_2$O$_4$, or "LMO")

Lithium iron phosphate (Li$_x$FePO$_4$, or "LFP")

Lithium cobalt oxide (Li$_x$CoO$_2$, or "LCO")

Lithium nickel cobalt aluminum oxide ("NCA")

7.

Question 7

Which of the following statements are true regarding a comparison between NMC and LCO? Select all that apply.

1 point

Replacing some cobalt with nickel increases cell safety

Replacing some cobalt with manganese decreases cost

Replacing some cobalt with manganese increases toxicity

Replacing some cobalt with nickel increases cell voltage

8.

Question 8

What are some key properties that must be satisfied by an electrolyte for a lithium-ion cell? (Select all that apply.)

1 point

It must be able to withstand voltages in excess of 3V without breaking down.

It must be aqueous.

It must conduct ions with little resistance but be an electronic insulator.

It must comprise a solvent plus a lithium-based salt.

9.

Question 9

The negative-electrode current collector is usually made from a metal foil of which element?

1 point

10.

Question 10

Which of the elements in the following list is more abundant than the others, according to the U.S. Geological Survey?

1 point

Nickel

Lead

Lithium

Cadmium