Rice University scientists have created a rechargeable lithium metal battery with three times the capacity of commercial lithium-ion batteries by resolving something that has long stumped researchers: the dendrite problem. The Rice battery stores lithium in a unique anode, a seamless hybrid of graphene and carbon nanotubes. The material first created at Rice in 2012 is essentially a three-dimensional carbon surface that provides abundant area for lithium to inhabit. The anode itself approaches the theoretical maximum for storage of lithium metal while resisting the formation of damaging dendrites or "mossy" deposits. Dendrites have bedeviled attempts to replace lithium-ion with advanced lithium metal batteries that last longer and charge faster. Dendrites are lithium deposits that grow into the battery's electrolyte. If they bridge the anode and cathode and create a short circuit, the battery may fail, catch fire or even explode. Rice researchers led by chemist...