The 3D battery is a proof of concept but has the potential to change how batteries work. A mockup of the 3D battery architecture with interpenetrating anode, separator, and cathode each about 20 nanometers in size. (Photo via Cornell University)


Companies are rushing to make smart devices sleeker, more powerful, and faster than last year’s model. But one thing that they still have trouble nailing down is reliable battery life. Battery life is the top concern for consumers and often receives the most complaints when it comes to devices. Most companies tackle this problem by focusing on how to reduce your power usage. Others try to make it easier to charge the device no matter where you are. Scientists from Cornell University are approaching the problem differently. They’re looking at redesigning batteries so they can hold more power and charge much faster.


The team, led by Professor Ulrich Wiesner, wanted to try out a new battery that intertwined its components in a self-assembling, 3D structure containing thousands of nanoscale pores filled with the needed components for energy storage and delivery. According to Wiesner, the 3D shape “eliminates all losses from dead volume in your device.” He continues saying “shrinking the dimensions of these interpenetrated domains down to the nanoscale, as we did, gives you orders of magnitude higher power density.” This means it takes less time to access energy than it does in conventional batteries.


So how fast exactly? Because the battery’s elements are shrunk down to nanoscale, Wiesner said the battery would be charged “by the time you put your cable into the socket.” That’s insanely fast. Imagine plugging in your phone and having it at 100 percent instantly.


The 3D structure takes inspiration from block copolymer self-assembly, which the team has used in other devices, like a gyroidal solar cell and a gyroidal superconductor. Since these devices were a success, they wanted to try this concept on carbon materials. The battery’s anode, created by block copolymer self-assembly, has gyroidal thin films of carbon filled with pores that are 40 nanometers wide. These are then covered with a 10 nm-thick electronically insulating, yet ion conducting separator. This results in a separation layer free of pinholes, which is often the cause of fires in mobile devices. Their next step is to add a cathode material, in this case, sulfur, in a way that didn’t overfill the remaining holes. Finally, holes were backfilled with an electronically conducting polymer, PEDOT.


It sounds promising and could change conventional batteries, but Wiesner reminds us it’s only a proof of concept so far. The team still has many challenges to face before they think about releasing it to the masses. Using 3D nano-networked architectures for electrical energy storage (EES) systems has great advantages over conventional designs, yet there are only a few systems with nanoscale dimensions that exist.


Another hold up is how the volume changes during discharging and charging the battery. During this process, the PEDOT charge collector will gradually degrade. Bits of polymer are ripped apart when the sulfur expands meaning pieces of the 3D battery are inaccessible. The project is a work in progress, but the team did apply for patent protection for the battery.


With constant complaints regarding battery life in smart devices, it’s clear the conventional battery needs to be changed. While Cornell’s 3D battery is still a proof of concept, it’s great to see teams working on how to improve the battery and hopefully it’ll make it to fruition. For now, have your chargers nearby.


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