Flexible battery prototype (via KAIST)
Breaking or cracking displays can thoroughly ruin a device. Bendable displays like those in e-readers have been successfully manufactured but, until now, batteries have always remained a rigid component of circuitry holding back the pliability of our gadgets. Professor Keon Jae Lee, of the Korean Advanced Institute of Science and Technology, has figured out a way to produce ultra thin, rechargeable and flexible lithium ion batteries (LIBs) that maintain a constant voltage even while they are being bent.
There were a few problems creating flexible LIBs that Professor Lee and his team had to overcome. The first was to find compatible electrodes from a small list of LIB electrodes. Lithium transition metal oxides are used as cathodes on LIBs, but these cannot be properly annealed at the necessary high temperatures on flexible polymer substrates.
To solve this, Lee and his team developed a universal transfer approach. The thin LIB is first fabricated on a mica substrate that can endure the high temperatures during annealing. The LIB is then transferred to a polymer substrate and the mica is discarded.
This was how Lee produced the first flexible LIB, but now him and his team must tackle the second problem of increasing power delivery. His plans to do this involve researching 3D stacking structures that aim to increase charge density.
The team is researching a laser lift-off method that could help in mass-producing these LIBs. Significant headway has been made, but this is still in the pioneering stages. Nonetheless, fully flexible electronics are finally possible.