BTW: It is more than silly of the airlines to command the transportation of lithium cells in the freight department and not cabin. It is and was proven to be impossible to extinguish a lithium fire through their Halon systems.
There is nothing on board to stop a 800°C Lithium fire.
Even if it were true that they're not going to be able to put the fire out with halon (it's not true), it's still not a bad idea to put the cells in the hold. I can think of at least 2 reasons:
1) these types of catastrophic cell failures produce very noxious gases, and on an airplane you can't just open a window to get away from them. At least if it's in the hold, these fumes won't be poisoning the passengers (as much).
2) The cells are much more likely to fail if they're being used (especially if they're being charged, and especially if they're warm). Keeping them in the hold ensures that they're unused and kept cool, making them less likely to fail.
Anyway, halon will not extinguish a lithium primary cell fire, but will put out a lithium-ion rechargable cell fire (as will a conventional fire extinguisher) according to Motorola's Jason Howard's testimony to the NTSB inquiry into UPS flight 1307.
As to your quoted disasters, most of them relate to cargo shipments of lithium primary (non-rechargable) batteries, a practise which has been banned on passenger-carrying flights since December 2004. A single lithium ion battery in a passenger's bag is quite different to a palette full of primary cells.
The Lauda Air disaster had a shipment of wristwatches, with their batteries, which was initially suspected, but later cleared (it was actually caused by a problem with the thrust-reverser isolation valve).
South African Airlines flight 295 had a bulk shipment of lithium batteries that was kept in the passenger deck, rather than in the cargo hold (this practise was disallowed shortly after, and as I said, now bulk lithium primary battery shipments are not allowed on passenger planes at all). And it seems likely that a big factor in this accident was that the fumes overcame the crew, although the official verdict is inconclusive.
There's a good summary of lithium battery incidents by the NTSB here:
There's also a good document by the CAA into extinguishing lithium battery fires on passnger planes (in which they intentionally set fire to Thinkpad 380Z's). They conclude that:
*) Lithium fires are uncommon, but possible.
*) There will likely be severe harm to any passengers in the immediate vicinity, from fire, fumes, explosion.
*) Any explosion doesn't pose a threat to the integrity of the plane.
*) There will be panic on the aircraft
*) All the types of fire extinguishers they tested were effective.
The document is here: