Lithium - ion batteries are a cornerstone of our engineering due to their energy storage capabilities . But Li itself is not that great when one considers the environmental and monetary costs of its production . A better alternative would be sodium , which is abundant on Earth but cause sodium battery is notwithout its difficulty . However , one of those might have been sort .
Researchers from Chalmers University of Technology have been able to build gamey - carrying into action electrode materials for sodium batteries with a special type of graphene . The battery shows energy capacity very close to what can be find in received atomic number 3 battery . The breakthrough is published inScience Advances .
In atomic number 3 assault and battery , the anode is made of plumbago , the material in a pencil lead , which is layer upon bed of graphene . Lithium ions are small enough to move in and out of graphene layers , but atomic number 11 is much chunkier so it ca n’t use the same trick . And that ’s where the Janus graphene comes in . This interpretation of graphene can be organized in layers that allow Na ions to flow .
“ We have added a mote spacer on one side of the graphene layer . When the layer are stacked together , the molecule create larger space between graphene sheets and provides an interaction point , which lead to a significantly higher electrical capacity , ” lead writer Dr. Jinhua Sun said in astatement .
The capacity of a atomic number 11 assault and battery using standard black lead is 35 milliampere hours per gram , which is less than one - tenth part of what you get from a stock lithium battery . The new approach with the Jannus graphene gets to 322 milliampere 60 minutes per gram . Still less than lithium , but much closer . And they are fully reversible and have gamy cycling stability .
“ It was really exciting when we honor the sodium - ion embolism with such eminent capacity . The inquiry is still at an early stagecoach , but the answer are very promising . This shows that it ’s possible to contrive graphene layers in an coherent structure that beseem sodium ions , crap it comparable to graphite , ” impart Professor Aleksandar Matic at the Department of Physics at Chalmers .
The name of this graphene comes from theRoman god , Janus . Graphene is made of carbon organized in a individual one - atom - thick layer . Janus is known for have two faces so here it symbolizes the fact that this layer looks unlike on one side due to the molecule spacer . Janus is also the god of doors , and the team liked the thought that the stuff willopen the doorto raw technology .
“ Our Janus material is still far from industrial applications , but the young answer show that we can direct the ultrathin graphene sheets – and the diminutive space in between them – for high - electrical capacity vim memory . We are very well-chosen to give a construct with cost - effective , abundant and sustainable metal , ” conclude Vincenzo Palermo , Affiliated Professor at the Department of Industrial and Materials Science at Chalmers .
