Battery Internal Resistance A-level Challenge

Battery pressure and internal resistance A-level challenge

Can you get 100%? Use research into clamped lithium-ion cells to test stress, internal resistance and terminal potential difference in one original A-level Physics question.

Exam Studio is just one part of PhysicsUK membership.

More Physics toolsPhysicsUK Solve, QWC, MCQ and Worksheet Studio give you different ways to practise.

Saved progressKeep your answers, feedback and markbook evidence together across your course.

Personalised next stepsSee the topic or skill PhysicsUK recommends from your recent work.

Question

8 marks

Show your working and give units where appropriate.

1(a)

AQA defines tensile stress as force divided by cross-sectional area. Engineers use the same force-per-area relationship to quote the mean compressive stack pressure on a pouch cell. A flat lithium-ion cell has face area

1.20 \times 1 0^{- 2} m^{2}

. A test rig applies a uniform compressive force of

480 N

perpendicular to the face. Calculate the mean stack pressure.

[2 marks]

1(b)

The cell has emf

4.00 V

and supplies a current of

8.0 A

. Its internal resistance is initially

0.040 ohm

. Calculate the terminal potential difference of the cell.

[3 marks]

1(c)

Excessive stack pressure can reduce open pathways for lithium ions and increase the cell's internal resistance. The current remains

8.0 A

while the internal resistance rises to

0.100 ohm

. Calculate the new terminal potential difference and explain why a larger internal resistance can increase unwanted heating inside the cell.

[3 marks]

Start the question to write your answer, receive marks and ask Sherlock Ohms for text help.