Why the Samsung Galaxy Note 7 explodes
Samsung's Galaxy Note 7 is a casualty of the race for stronger but smaller batteries, says nanotechnology expert Michelle Dickinson.
The Korean company's flagship phone was praised by critics, but after dozens of them caught fire it's been forced to recall 2.5 million of them worldwide.
The phone's lithium battery is to blame.
"Lithium loves to react with everything. It is so explosive. If you put lithium in water for example, it makes for a great experiment because it just blows up in front of you," Ms Dickinson told Paul Henry on Monday.
"The problem is you're making these cells much, much smaller because you want your phone to be smaller, and so the membrane separator that stops the reaction happening is getting so small and so thin, there's now a chance these cathodes and electrodes can come into contact with each other, creating an explosion."
A burned-out Note 7 (Ariel Gonzalez / YouTube)
What makes for a good science experiment hasn't been so great for Samsung's bottom line - its stock price plummeting 15 percent since the Galaxy Note 7's release.
But don't expect the company to try a different kind of battery - lithium gives the best bang for your buck of any commercially available battery (no pun intended). It can also be charged at any time, without having to run it down to empty first, like old kinds of batteries.
"The lithium part is explosive, but when it works really well, it's amazing," says Ms Dickinson.
"The Samsung phone is actually an amazing phone, and they've been tarred by this horrible battery situation."
What the Galaxy Note 7 is supposed to look like (Samsung / supplied)
Samsung's not the first company to have a lithium battery nightmare.
PC manufacturer Dell recalled 4 million laptops a decade ago after their Sony-made lithium batteries kept catching fire.
And in 2013, a number of Boeing's 787 Dreamliner aircraft had similar problems.
Air NZ has understandably banned passengers from using the Galaxy Note 7, forcing passengers to carry them at all times and keep an eye on them.
"If you drop a battery it can explode," says Ms Dickinson. "There's less likely to be an impact if you have it as a carry-on."