Three-Dimensional Nickel-Zinc Microbatteries

A silicon-micromachined rechargeable nickel-zinc alkaline microbattery featuring out-of-plane interdigitated electrodes is reported. The three-dimensional (3-D) battery architecture offers a new approach in developing miniaturized power sources to provide enough power and energy density for autonomous MEMS devices and microelectronic circuits on their small foot print. The battery consists of nickel hydroxide cathode and zinc anode post electrodes which are densely packed in an interdigitated manner. The posts are 50 µ m in diameter and 400 µ m tall, with foot print area of 5x5 mm². Initial prototypes demonstrated a functional battery for the first few cycles of operation.