Fabrication of 3D patterned electrodes for micro lithium-ion batteries

New electrode architecture, in which a polymer wall exists in the gap between interdigitated current collectors on SiO2/Si substrate, was developed for increasing the capacity of micro lithium-ion batteries with keeping good rate performance. The polymer wall with 30 μm thickness successfully provided the corresponding 3D Sn-Ni anode and LiFePO4 composite cathode with an aspect ratio of 1.5. This 3D configuration of electrodes resulted in a great improvement of cell capacity up to 114.9 μA h cm-2 from 4.8 μA h cm-2 of the cell previously prepared by applying sols of LiMn2O4 and Li4Ti5O12 to a conventional non-wall electrode substrate.