[MIT Video] How are 18650 batteries made? March 14 2016, 0 Comments


In this short 2-minute video, MIT explores how lithium-ion 18650 batteries are produced.

These particular batteries are different because their electrolyte is stable up to 300 degrees Celcius. Whereas traditionally, the 18650 batteries we sell on Battery Bro for example only keep a stable electrolyte up to 70 - 80 degrees Celcius.

The steps to create the batteries are as follows:

  1. Mixing materials into a slurry (to make the cathode and anode)
  2. The slurry gets coated by stuff including a current collector for transporting electrons
  3. Drying to remove solvents
  4. Calendering (pressing materials to evenly distribute them. Note this is calender with an 'E' - it's a machine that presses things to make them thin and smooth.)
  5. Material is made into sheets and cut
  6. Sheets are rolled and put into a steel case and hermetically* sealed

Finally, the cells undergo charge and discharge testing at various temperatures.

*Did you know? The word hermetic comes from the Greek God... you guessed it, Hermes! That is because Hermes inspired alchemy. A hermetic seal just means it is air-tight.


Want to watch more? Take a look at this slightly longer 7-minute video for a broader overview, from mining to use.