The Stanford scientists have overcome the above problems using a carbon nanosphere wall to coat the lithium anode. This 20nm thick "flexible, uniform and non-reactive film… protects the unstable lithium from the drawbacks that have made it such a challenge," reports Phys.org. The layer is both "chemically stable to protect against the chemical reactions with the electrolyte and mechanically strong to withstand the expansion of the lithium during charge," said Prof Cui.
There is still refinements to be done but batteries made using the above outlined method are "within reach". The coulombic efficiency of these new design battery cells is currently at 99 per cent over 150 recharge/discharge cycles. To be commercially viable this efficiency should be 99.9 per cent or more explains Cui. However this is a big step up from previous lithium anode attempts where the efficiency dropped to less than 50 per cent in just 100 cycles.
Researchers make battery with pure lithium anode
Posted on Tuesday, Jul 29 2014 @ 16:15 CEST by Thomas De Maesschalck
Hexus reports researchers at Stanford University devised a way to create a battery with a stable lithium anode. Current lithium battery designs use this metal within the electrolyte solution contained inside the cells but not as the anode material due to issues with its stability and reactivity. By using a 20nm thick carbon coating on the lithium, the researchers managed to achieve a working battery with a pure lithium anode that promises to deliver three to four times times the capacity of current li-ion batteries.