CEA-Leti is a French-based company that specializes in designing nanotechnology and microelectronics. It is the world’s largest institute for electronics and information technologies.
Researchers have just designed all-solid, inorganic thin-film batteries (TFBs) that are only 1mm thick. In their initial testing, they offer better performance than previous models. The team of researchers is hopeful these can be used in medical implantable devices, as well as injectables.
The team presented a research paper at the International Electron Devices Meeting (IEDM) titled “Millimeter Scale Thin-Film Batteries for Integrated High-Energy-Density Storage.” The new design has the highest reported areal energy density of 890 μAh.cm-2. This newly designed TFB also shows a high power density, registering as high as 450 μAh.cm-2 under 3mA.cm-2. The paper was published in Nature Electronics.
The authors explain:
“Thin-film batteries provide some of the highest energy densities of electrochemical energy storage devices, but the inability to increase the electrodes’ thicknesses and control the geometry on the micrometer scale has thus far hindered their effective areal energy density and integration in miniaturized devices.”
To help increase the thickness and electrodes, the team added silicon wafers and used UV photolithography and etching. This helped with the patterns and successive deposition on each layer. This creates a high-energy-density, thin millimeter-scale film battery that integrates a 20μm-thick LiCoO 2 cathode in a Li-free anode configuration. The team says this new design will cut down on assembly costs and make them ideal for use in electronic devices such as implantables.
“Implantable sensors or biological-function monitoring systems such as intra-ocular pressure sensors and blood-glucose measurement would be particularly suited for our TFBs,” observed Sami Oukassi, lead author of the paper. “External systems, such as cochlear implants and smart contact lenses, would also benefit from the advantages of this breakthrough.”
“Battery manufacturers have been struggling to produce a power source that not only functions at the micro-scale but has high power density and energy,” Oukassi said. “CEA-Leti TFBs offer this opportunity with the highest performance reported so far, compared with current TFBs and micro-supercapacitor solutions.”
