With the advent of thin and flexible displays, the development of flexible batteries had to be the next object in the eyes of electronics researchers .Although rechargeable lithium-ion batteries (LIB) have been regarded as a strong candidate for a high-performance flexible energy source, compliant electrodes for bendable LIBs are restricted to only a few materials, So an efficient battery with a high power density and thermal stability was yet to be discovered. The performance of LIBs, also was not sufficient enough, and thus difficult to use with possible electronics products including flexible displays.
This was not the only drawback, lithium transition metal oxides used as a cathode electrode have to be treated in high temperature (e.g., ~ 700 degrees for lithium cobalt oxide). But, it is not possible to anneal the metal oxides, an active material, at this high temperature on a flexible polymer substrates.
Recently, a research team headed by Professor Keon Jae Lee from the Department of Materials Science and Engineering, KAIST has come up with a high performance flexible solid state battery constructed of of LIB structured with high density inorganic thin films by using a universal transfer technique. The thin film LIB is fabricated on a mica substrate with high annealing temperature ,and is then transferred onto a polymer substrates through a simple physical delamination of the substrate.
In the words of Professor Lee, “The advent of a high performance flexible thin film battery will accelerate the development of next-generation fully flexible electronic systems in combination with existing flexible components such as display, memory, and LED.”
The research team is currently weighing the option of using a laser lift-off technology to help in the mass production of flexible LIBs and 3D stacking structures to enhance charge density of batteries.
Video demonstrates Flexible battery turning on blue LED and maintains voltage during bending/unbending conditions.
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