3-5 years under ideal conditions. Stick a battery in a phone/laptop that regularly gets used in the heat and it will give up the ghost within a year. It's not even so much the ultimate lifetime that matters so much as the longer 95% capacity life, which is much shorter now. I wouldn't be surprised if this also has some major catch, like manufacturing cost, heat degradation, or instability under mechanical stress. So while it could be an really important discovery, I'll remain skeptic until I have a laptop battery that lasts for longer than 12 hours after a year of heavy use in a hot, humid climate.