Companies are racing to find better ways to store electricity – and so provide us with cheaper energy when and where we want it
WE ONLY notice them when they are about to run out. Icons glow red, warnings flash. The curse of modern mobility: our battery’s about to give up.
It’s a trivial, everyday annoyance. But the ramifications go far beyond just laptops and smartphones. Humans rely on two things to control their environment: information and. Shrinking transistors and the rise of microprocessors have given us immense control over the first: the capacity to store and manipulate data that we hold in the palms of our hands would have been inconceivable a generation ago.
But with energy, we’re stuck in a rut. The development of electric cars stutters forwards thanks to the lack of ways to power them cheaply, efficiently and over long distances. And while we’ve made great strides in harnessing wind, wave and sun to generate cleaner electricity, again, the technology to store that juice lags badly behind.
Corporations and governments are pouring billions of dollars into improving existing battery technologies – with some success. But if we are to continue to compute and communicate with more freedom, while liberating ourselves from our dependence on fossil fuels, conventional thinking needs an overhaul. We’re going to need a better battery.
The cutting edge of current energy storage technology is probably in your pocket right now – and 2 billion others around the world. The lithium-ion batteries that power most smartphones were born in the early 1990s as a quirk of the dying cassette tape industry. The rise of compact discs had Japanese company Sony casting around for something to do with old equipment for making tapes, saysof Argonne National Laboratory in Chicago. Instead of coating the tape with magnetic film that could record data, they started coating it with goopy layers of an electrode that could store electric charge.
The first lithium-ion batteries contained rolls of these film electrodes, wound up in a cylinder like the spool of a cassette. They were instantly twice as good as anything else out there for compact energy storage. Existing nickel-cadmium and nickel-metal hydride batteries used chemical changes on the surface of two electrodes within them to shunt charge-bearing hydroxide ions and protons this way and that, and so charge and discharge. The new technology achieved the same by exchanging lithium ions, but slotting them into and out of nanoscale gaps within the material of the battery’s electrodes in a chemical process called intercalation.
Because it is a light metal, lithium has a lot of charge-carrying ions for its weight, making for batteries that are smaller but more powerful. Lithium-ion batteries boomed from their serendipitous beginnings, driven first by the rise of personal electronic devices such as camcorders, and then mobile phones and laptops. Although they are still dwarfed in most respects by the bulky lead-acid batteries found in almost every car on the road today, in 2015, lithium-ion batteries will account for around a third of the money spent on rechargeable batteries globally (see “Turn it on”), and just under a sixth of the total energy stored,.
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