From Scientific Protocols for Fire Investigation, CRC Press 2018, 3rd ed, page 239:

Any time a lithium ion–powered device is the suspected cause of a fire, a fire investigator must work diligently to harvest all of the components. This includes finding all of the constituent pieces of the battery cells—cans, end caps, straps, copper jelly roll, and so on, or pouches, chargers, and the battery management circuit boards. To avoid spoliation, special attention must be given to the harvesting and storage of the steel cans of 18650 cells as the cans quickly rust, corrode and ultimately disintegrate in evidence containers not properly prepared. As such, the optimum method of harvesting and storing these cans for long-term storage prior to a laboratory evidence exam is in a sealed
container with a desiccant package (See attached Figure).

John J. Lentini, CFI
Scientific Fire Analysis
Islamorada, FL
www.firescientist.com
scientific.fire@yahoo.com