Variations like lithium-air and lithium metal batteries are in the works to possibly replace them, and now researchers at Rice University have improved the latter with the help of an unlikely ingredient. The team found that adding asphalt to the anode made for lithium metal batteries that charge faster and are less likely to short circuit and fail.

To make their new battery, the Rice researchers used untreated gilsonite, a derivative of asphalt, and mixed it with conductive graphene nanoribbons. Then, that composite was coated in lithium metal through the process of electrochemical deposition, to create an anode. The final battery is made by combining this anode with a cathode of sulfurized carbon.

The team tested these new asphalt-lithium metal batteries over more than 500 charge-discharge cycles, and found the porous carbon material from the asphalt made the battery more stable. The batteries were found to have a power density of 1,322 watts per kg, and an energy density of 943 watt-hours per kg. Meanwhile, a high current density of 20 mA per square cm means that these batteries could be recharged from empty much faster than standard lithium-ion batteries.