Short Circuit

By short circuit we mean an electrical short circuit, a very low resistance path between the positive and negative sides of the cell or cells. A short circuit can be inside a battery cell or external to a battery cell.

Internal Short Circuit

cell temperature versus type of internal short circuit and then diagram of the internal short

There are a number of things that can cause an internal short circuit within a battery cell. The primary focus has to be on manufacturing and the processes deployed to mitigate or reduce these risks.

  • Metallic foreign body in the raw materials
  • Introduction of a metallic particle during cell production
  • Damage to electrodes
  • Particles or damage during tab welding
  • Particles from cell case welding
  • Dendrite growth during cell use

External Short Circuit

A number of methods are normally deployed to reduce the effect of external short circuits, including:

  • fuse in main electrical circuit
  • Current Interrupt Device inside the cell
  • current measurement by BMS and control of contactors to connect/disconnect external circuit