The Embedded Micro-Battery Laboratory at CEA focuses its research on the development of new micro-storage energy solutions, specifically high performance lithium microbatteries, with the help of ST Microelectronics. During this internship, my role was mainly to characterize a solid-state electrolyte, Lithium Phosphorous Oxynitride (LiPON), using electrochemical impedance spectroscopy (EIS).

Some of the major disadvantages to a conventional liquid electrolyte are dendrite formation that trigger explosions and leakage of hazardous materials. To overcome this problem, solid state electrolytes have been introduced; advantages include no leakage, no vaporization, and no phase transitions at low temperatures. One of the most commonly used solid-state electrolytes is LiPON.

The following are parameters to be explored to increase the efficiency of a microbattery:

• Lithium composition
• Deposition chamber
• Architecture
• Process of deposition – the electrolyte was deposited through a mask or deposited full-sheet and etched

• Determined the properties of the micro batteries’ electrolytes for the fabrication of efficient batteries
• Collaborated with team of five members and communicated in French
• Presented findings to lab of 40 people