What are the requirements for the carriage of lithium batteries by air?

Electronic devices (e.g. laptop computers, cellular phones, cameras, camcorders and so on) or portable medical electronic devices containing lithium metal batteries not exceeding 2 grams or lithium ion batteries not exceeding 100 Wh can be carried both in carry-on baggage or checked-in baggage. All spare batteries must be put in carry-on baggage.

For electronic devices or portable medical electronic devices containing lithium metal batteries exceeding 2 grams but not exceeding 8 grams or lithium ion batteries exceeding 100Wh but not exceeding 160 Wh, OR if for health reasons or other special reasons mobility aids (e.g. wheelchairs) that are powered by lithium batteries must be carried during the travel, passengers must make the request to the airline. With the approval of the airline, passengers can then follow the instructions given by the airline to put the devices in carry-on baggage or checked-in baggage.  However, all spare batteries must still be put in carry-on baggage.