Here’s some info I found on-line from a couple of years back.

They can be shipped under IATA without having to lodge a dgd, If you have the battery manufacturers declaration.

exert from -IATA Guidance Document
Transport of Lithium Metal and Lithium Ion Batteries
Dated 16-12-2008

Exceptions
Small lithium metal and lithium ion batteries are excepted from most of the requirements
of the ICAO Technical Instructions and IATA DGR provided that they comply with all of
the requirements set out in Part 1 of Packing Instructions 965, 966 and 967 for lithium
ion batteries and Part 1 of Packing Instructions 968, 969 and 970 for lithium metal
batteries in the 50th edition of the IATA DGR.
Packages containing lithium batteries, or lithium batteries contained in, or packed with,
equipment that meet the provisions of Part 1 of these packing instructions are not
required to have a Class 9 hazard label and there is no requirement for a Shipper’s
Guidance Document – Transport of Lithium Batteries
16 December 2008

Declaration for Dangerous Goods for consignments of these batteries. However, in the
event of an incident involving these batteries, the incident reporting requirements apply.
Note:
Only batteries that have successfully passed the test procedures of Part III, Sub-Section
38.3 of the UN Manual of Tests and Criteria qualify under this exception. This is also true
for so-called “OEM” or “aftermarket” batteries. Any battery manufacturer or distributor
should be able to provide documentation confirming that the batteries have been so
tested.