Video Transcript
Which of the following is not true
about the composition of a lithium-ion battery? (A) The cathode electrode will
mostly be lithium cobalt oxide, LiCoO2. (B) The two electrodes and the
separator are dipped in the electrolyte of the anhydrous solution of LiCO3. (C) A very thin layer of plastic
separates two electrodes, the anode and the cathode, and allows the passage of
ions. (D) The anode electrode will mostly
be lithium graphite, LiC6. Or (E) the two electrodes and the
separator are dipped in the electrolyte of the anhydrous solution of LiPF6.
The lithium-ion battery is a
secondary cell that is often used in portable electronics like cell phones and
laptops due to its relatively lightweight and capacity to store large amounts of
energy.
Let’s clear a little space and look
at the structure of a lithium-ion battery. The cathodes in lithium-ion
batteries are typically made from lithium cobalt oxide, LiCoO2. The anodes are made from lithium
graphite, LiC6. A thin plastic separator sits
between the two electrodes. But it does not restrict the
movement of the lithium ions. This ensures that the ions and
electrons can flow and a current can power an electronic device. The electrolyte liquid is anhydrous
lithium hexafluorophosphate, LiPF6. After dipping in the electrolyte,
this liquid coats the two electrodes as well as the separator.
We now know the structure of the
lithium-ion battery. It is the same regardless of the
phase it is operating in. But the polarity of the electrodes
will reverse depending on which phase the cell is operating in. Let’s now look at the answer
choices in turn.
Answer choice (A) states that the
cathode electrode will mostly be lithium cobalt oxide, LiCoO2. We can see from the diagram that
this is the case. But the question asks, which of the
following is not true about the battery composition? Thus, answer choice (A) is
incorrect.
Answer choice (B) states that the
two electrodes and the separator are dipped in the electrolyte of the anhydrous
solution of LiCO3. Although the two electrodes and
separator are dipped in electrolyte, it is the anhydrous solution of LiPF6, not
LiCO3. Therefore, it seems as though
answer choice (B) is correct. But to confirm, let’s check the
other options.
Answer choice (C) states that a
very thin layer of plastic separates two electrodes, the anode and the cathode, and
allows the passage of ions. We can see from the diagram that
this is true. Thus, answer choice (C) is
incorrect.
Answer choice (D) states that the
anode electrode will be mostly lithium graphite, LiC6. We can see that this is true. Thus, option (D) is not the answer
to this question.
Answer choice (E) states that the
two electrodes and the separator are dipped in the electrolyte of the anhydrous
solution of LiPF6. We can see that this is true. Therefore, answer choice (E) is
incorrect.
If we bring back all of the answer
choices, we can confirm that the false statement regarding the composition of a
lithium-ion battery is (B). The two electrodes and the
separator are dipped in the electrolyte of the anhydrous solution of LiCO3.
