Solid State Batteries
Gary Marshall goes panning in the river of rumour for nuggets of knowledge
The new MacBook’s impressively tiny motherboard and genuinely clever battery design are trying to compensate for a fundamental problem: you can only squeeze so much juice out of a lithium battery. Apple has made its batteries bigger, has found ingenious ways of fitting them inside devices and has optimised those devices incredibly well. But it keeps running up against some fundamental laws of physics and chemistry. So Apple’s working on something else. In 2013, the US Patent and Trademark Office published an Apple patent application that described charging techniques for a kind of battery called a solid state battery. Where normal batteries use liquid electrolytes, solid state ones – as the name suggests – use solid ones. That means they can be packaged much more densely than traditional batteries, and at present they last three to four times longer than current batteries.
There are other advantages. Solid state batteries don’t leak, don’t go on fire and need less cooling. You can also make them into interesting and/or flexible shapes, which makes them particularly useful for portable and wearable devices.
An Apple Watch whose entire strap is a battery, or an iPhone so thin you can use it to chop vegetables, are enticing prospects. You can see why firms such as Toyota and Dyson are also investing in the technology: the potential for the former’s electric vehicles and the latter’s high-tech vacuum cleaners are enormous.
The downsides? Solid state batteries aren’t as conductive as liquid ones and that can limit power output. And like any nascent technology, currently, prices are high and manufacturing yields are low. But those issues can be fixed by smart people waving big piles of money. And Apple isn’t short of either.