micro energy cell (MEC)

Micro Energy Cells(MEC) are micro batteries or thin film batteries. They are small, rechargeable energy storage devices with a long service life that are used in combination with small microprocessors in microsystems technology, smart cards, wireless sensors and energy harvesting.

MEC cells can be manufactured using thin-film technology and as printed batteries, and have dimensions ranging from a few millimeters to a few centimeters and a thickness that can be well below 1 mm, depending on the nominal capacity.

Thin-film battery, Micro Energy Cell (MEC), for 0.7 mAh, photo: gizmag.com.

Thin-film batteries are solid-state batteries built up in layers. They consist of a silicon substrate on which a platinum collector and a cathode made of lithium cobalt oxide are deposited. The solid electrolyte is lithium phosphorus oxynitride (LiPON) and the overlying anode is lithium aluminum. The individual layers can be produced using chemical vapor deposition( CVD).

Depending on the application, microbatteries have nominal capacities ranging from a few micro ampere hours (µ Ah) to a few milli ampere hours (mAh). They are characterized by a long service life and can tolerate several thousand charging cycles. Self-discharge is also extremely low at 1% to 2% per year. The energy and power density of microbatteries lies between that of batteries and supercapacitors.