Scientists at the University of Science and Technology of China in Hefei have designed a structured anode that allows a standard lithium-ion battery to charge to 60 per cent in 5.6 minutes and to 80 per cent in 11.4 minutes.
Slow charge times are often cited as a deterrent to wider uptake of electric vehicles. Battery swapping networks are a way of partially bypassing the issue, but quicker charge times could of course represent a more straightforward solution.
New Scientist reports that Yao Hongbin and his colleagues have designed a lithium-ion battery anode where the graphite particles through which charge flows are ordered by particle size and porosity.
To do this, they coated the particles with copper and mixed in copper nanowires. The particles were then heated, cooled and compressed.
“In our design, we control the whole density in the electrode,” said Yao. “We use a higher porosity in the top [of the anode] but lower porosity in the bottom, so that the average porosity has a normal value.”
The results were impressive, but Billy Wu at Imperial College London points out that the additional processing steps would significantly add to the cost of an anode, which is otherwise one of the cheaper battery components.
In October, we reported on a lithium-carbon battery concept developed by Mahle Powertrain that would allow the charging of e-bikes and other small electric vehicles in under 90 seconds.
The battery features a high-rate battery-type anode and a high-capacity electric double layer capacitor (EDLC)-style cathode separated by an organic electrolyte.
The benefit of this, according to Mahle, is that the battery retains stability at far higher temperatures and can therefore charge at significantly higher wattages.