This may look like a scrap of kitchen foil, but it’s actually a new kind of aluminum battery that could out-perform the lithium-ion cells in your smartphone.
Developed by chemists from Stanford, the new battery swaps out lithium from the cell in favor of aluminum. In the past, aluminum batteries have failed fast, managing just 100 recharge cycles before they start to degrade.
The new cell uses aluminum for it anode—the negatively charged electrode in the battery—and graphite for the positive cathode. The whole lot sits inside a salt, liquid at room temperature, which acts as the electrolyte. The resulting cells can undergo 7,500 recharge cycles without losing capacity—far better than old aluminum cells, and in fact better than li-on batteries that usually begin to suffer after 1,000 cycles.
The battery can also charge incredibly quickly, reaching full capacity within a minute. Compared to li-on batteries they’re also rather more robust, too: the “new battery won’t catch fire, even if you drill through it,” said Stanford chemistry professor Dai Hongjie, who created the cell, in a press release.
There are, however, some downsides. First, the cells can only muster 2 volts across their electrodes—just over 50 percent of the voltage that li-on batteries can provide. Nor do they pack energy into themselves as efficiently, managing to store just 40 watts of electricity per kilogram, compared to 200 or so for li-on batteries.
Neither of those are deal breakers. Tweaks to the electrode design could boost voltage, and speedy charging may in fact be more desirable than absolute energy capacity for a given size. But for now, it’s at least interesting to know that a lackluster battery technology may yet prove incredibly useful. [Stanford via Engadget]