Now, it comes to a practical step. How really we can get some old cells out. It comes to the package available to us.

Today, we have lithium cells in few forms:

old laptops with either out-of-date hardware, or recently replaced battery bank

power bank: some models packed with 6-10 cells of 18650 size

battery from old cell phones, camera,

online selling such as battery from e-bike, lifting & pulling mover

Also, while I attempted to write up theoretical idea behind lithium ion, someone else already did it much better. Here is video how how electricity is produced inside the battery.

Laptop battery

This is the form you can access easily since we have at least one laptop around. Laptop battery is wrapped by clampshell plastic. Two plastic pieces are locked together by inside dovetails. You need a flat-head screwdriver and go between the locking. Notice that don't prick or punt a sharp metal directly into the cell. Go around and unlock dovetails.

After-market laptop with half clampshell in place, showing the circuit board and blue cell on the background

Inside a 3S laptop battery with two cells in paralel from a Lenovo laptop

Polymer lithium battery (Lipo) is found in newer models. Those battery comes in a flat shape rather a long and removable pack.

Inside a 3S laptop battery with one lipo cell from a Dell laptop. Cells made by Samsung SDI part #666480

E-bike or mover battery

This type can be excellent since the pack is replaced when the battery went LOW, not just die as other electronics.

Cells from ebike with 7S configuration, two cells each level. Cells made by SANYO. The actual capacity from used packs is ~1500mAh (rated as 2200mAh)

You may notice that I leave extra tin taps attached to the cells. There is a good reason for it. If you have a spot welder (most of us don't), you will be fine to solder them, but if you have a tin solder, making a good joint to a terminal is not easy. In fact, trying the solder tin can heat up termials and decease your battery capacity. You can eventually destroy the cells if pushing the hot iron to the cell for a good joint. That extra tin taps make easier to re-wire them later, such as building back a 3S (3 cells in parallel) for solar charger.