An aluminum battery is a rechargeable energy storage device that is powered by the interaction between an aluminum anode and a cathode that uses another substance such as air or graphite. For the most part, aluminum battery technologies have produced working models but they have not yet made it to the consumer market. Researchers at Stanford University have come up with a lightweight aluminum graphite battery that charges more quickly, runs longer on a charge and is safer in use than lithium ion (Li-Ion) batteries. The device has many potential applications, including smartphones and laptops, electric grid power and flexible displays. The aluminum-graphite battery consists of a polymerized pouch containing an aluminum anode and a graphite cathode in an ionic liquid salt. Aluminum-graphite batteries are flexible and stable: They won't catch fire even if pierced. The batteries can charge in as little as a minute and offer charge cycles in the range of 7500 before degrading much greater than the 1000 cycles of lithium ion batteries. These batteries aren't yet without caveat, however: Currently they have a much lower power density than Li-Ion, which means that for higher-power applications the batteries become very heavy. In 2014 an Israeli startup called Phinergy announced an aluminum-air battery aimed at extending trips in electric vehicles. Phinergys' battery offers eight times the travel distance of a Li-Ion car battery and is lighter as well. The car's battery is filled with pure water. The vehicle can then can go for as far as 100 miles with water top ups. The anode plates of aluminum are quite expensive, however, which has mainly resulted in the devices being limited to military use. Another problem with the anode plates is that they eventually degrade to aluminum oxide, which is difficult to recycle back to aluminum, making the design less sustainable