I hope the question was meant mostly in jest, but just in case:
No... Just because it can be done, doesn't mean it should be. :shakehead
If you have a bucket of sand or two and several dry chem fire extinguishers nearby, in a metal benched flame retardant office lab, WELL SEPARATED from your home and loved ones... and an iron with sufficient thermal mass, low temp solder, some active flux, great soldering skills, safety glasses, don't carry the results in your pocket or otherwise on your person, or even hand it to the uninformed, and you carry more insurance than Mutual of Omaha... But come on, what for? Really?
RANT ON
In the early days of Laser Products (the original name for SureFire) I worked at a defense contractor just a few miles from Laser Products Fountain Grove headquarters. My employer was developing a product intended to be powered by F cell size Lithium (sub chemistry deleted) Chloride ~24V (no load) battery packs. Our "thingies" were very high current, and needed to have minimal losses, plus look good when our DoD customer came to visit. The Project Engineer wanted contacts soldered directly to cells in the battery packs, so they could be bolted to our prototype, like they would be in production.
I was too junior and uninformed to say aloud that this idea wasn't safe, but my experience soldering more ordinary cells suggested it could not be done without risking damage to the VERY expensive and reportedly volatile batteries. We had a "Super Tech" who was a NASA Certified solderer saying he could "solder anything" and anxious to impress the Project Engineer. As usual he completed his task swiftly, and his work was visually perfect.
I was not present when our "thingy" was fired up for the customer. The first cell soon vented, then lit up. Other cells followed. Bolted to our prototype product, the battery could no longer be pushed into our sand-filled safety box. Even if it could, the air tight lid could not close, due to the overall product's size.
Our entire building (full of classified stuff on most every bench and desk) was evacuated and the fire department responded in force. Two people were kept overnight in the hospital. The prototype was destroyed along with the battery and the workbench. Direct financial losses would have bought several new Mercedes, but no one suffered any permanent injuries. The Project and Lab Managers were demoted or fired; I can't remember. The Tech was reprimanded and ended up reporting to me some time later. He had 15 years experience on me.
We finished our project development, powering our "thingy" with 2 big automotive starter batteries and an HP charger - power supply, in a 4 foot coffin-like enclosure. Ironic, yes? The company never allowed another lithium battery, of any type, in the lab again.
Flash forward to the present: My little college town Fire Department dealt with at least 2 (probably 3) causal lithium fires in 2006, including one in their own vehicle, which seriously endangered a surprised firefighter as well as a $150K vehicle. They view the risks as serious enough the Fire Marshal declined to assist me in any destructive lithium battery fault testing. It was suggested I talk to the bomb squad of our police department before I "... deliberately create any incendiary devices anywhere within (the) city limits."
Whenever I handle an unusual lithium battery, or even a common lithium cell that may have been treated unusually, I think about the safety of my loved ones. Every time I see a small coffin or similarly shaped box, I can't help thinking about that difficult learning experience, and all the lithium based batteries today powering my hotwired lights, laptops, radios, and other projects.
If you don't mind the occasional fire, explosion, corrosive chemicals and/or toxic fumes release, you should be fine soldering away on your lithium primaries. Once you get those wires soldered on, you could give 'em a quick reverse charge too, if you have yet to see the predicted results.
...
