When is a novel battery not a battery? When its only an experimental cell and developed at a University. That’s the fact under the hype of last week’s news that researchers had developed an ultrafast charging battery that could replace conventional lithium cells used in today’s consumer electronics.
Published in the high flying journal Nature the team, from Stamford University, constructed Al/graphite cells in a pouch format using an aluminium foil (thickness ~15–250 μm) anode, a graphitic cathode, and an ionic liquid electrolyte made from vacuum dried AlCl /1-ethyl-3-methylimidazolium chloride.
What was encouraging from the results was the cell’s discharge voltage— at around 2.25 Volts— was higher than any experimenter has obtained to date.
But there was limited rate capability when the cell was charged and discharged with a simple cathode construction.
But when the team switched a flexible graphitic foam which could cope with the intercalation and subsequent huge swelling without disintegrating, the cell could be charged and discharged at a current density up to 5,000 mA g-1, about 75 times higher (that is, at a 75 C rate, <1 min charge/discharge time) than the earlier Al/PG version while maintaining a similar voltage profile.
Also, a similar voltage profile and discharge capacity retention was observed over 7,500 cycles with a Coulombic efficiency of 97%.
This is the first time an ultrafast Al-ion battery has been constructed with stability over thousands of cycles— two considerable electrochemical achievements.
So is this electrochemical couple going to change the world? The newshound thinks just a little too much detail was published in Nature to make anyone rich.