A new nanobattery has been built by a group from Cornell University which could charge your electronics in just seconds. A standard battery was redesigned by the group. Rather than having an anode and cathode on either side of a non-conducting separator, they intertwined the components in a self-assembling 3D gyroidal structure. This resulted in thousands of nanoscale pores filled with the elements necessary for energy storage and delivery.
“This is truly a revolutionary battery architecture,” said Ulrich Wiesner, professor of engineering at the school. “This three-dimensional architecture basically eliminates all losses from dead volume in your device. More importantly, shrinking the dimensions of these interpenetrated domains down to the nanoscale, as we did, gives you orders of magnitude higher power density. ‘In other words, you can access the energy in much shorter times than what’s usually done with conventional battery architectures.”
The battery has been shrunk down to the nanoscale, so that “by the time you put your cable into the socket, in seconds, perhaps even faster, the battery would be charged.” There are thousands of pores that are just 40 nm wide on the thing films of carbon making up the anode.
These carbon films are coated with a 10 nm thick separator that is an insulator but is also ion-conducting. This results in the production of a pinhole-free layer. This is of paramount importance as defects such as holes in the separator can result in fires in cell phones and laptops.
The cathode is made of sulfur which does not completely fill the remaining pores. Sulfur can accept electrons but does not conduct electricity. The final step involves backfilling the pores with an electronically conducting polymer. This has a lot of challenges and is not easy to accomplish.
There are volume changes during discharging and charging of the battery and the polymer charge collector is gradually degraded as it does not face the same volume expansion that sulfur does. “When the sulfur expands,” Wiesner said, “you have these little bits of polymer that get ripped apart, and then it doesn’t reconnect when it shrinks again. This means there are pieces of the 3-D battery that you then cannot access.”
The team is currently working on perfecting the design.