PORTLAND, Ore.—Porous three-dimensional (3-D) electrodes aim to simultaneously boost the energy density and the current delivery capacity (power density) of lithium ion batteries, according to their inventors at the University of Illinois-Urbana.
Batteries today trade-off lower current delivery capacity for higher energy density, but by crafting arrays of nanoscale interdigitated anode and cathodes—electro-deposited on a porous nickel scaffold--these researchers claim that their batteries have the best of both worlds. Super-capacitor trade-off lower energy density for higher current carrying capacity, delivering up to 2000-times the current of lithium ion batteries, but with as much as 10-times less energy density, making them unsuitable as a substitute for batteries in most electronic devices.
However, by going to porous interdigitated 3-D electrodes, William King, a professor and lead researcher at the University of Illinois-Urbana, claims that his nanoscale lithium ion batteries can have the best of both worlds—high current delivery capacity and high energy density. King worked on the project with fellow professor Paul Braun—who designed the cathode material--and doctoral candidate James Pikul who worked with King on designing the anode material.
By combining the two materials in the same micro-battery prototype, the researchers were also able to demonstrate that their nanoscale lithium-ion batteries could be recharged 1000 time faster than other thin-film battery technologies. The tiny batteries can be fabricated about 30-time smaller than conventional batteries, making them ideal for powering medical implants, wireless sensor nodes and the like.
Porous 3-D interdigitated anode (left) and cathode (right) repeated hundreds of times inside a lithium ion battery simultaneously boosts both its energy density and current capacity.
Source: University of Illinois-Urbana
Next the researchers plan to demonstrate their materials technology powering a real electronic device, as well as optimize the fabrication process for manufacturing. Funding for the project was provided by The National Science Foundation and the Air Force Office of Scientific Research.