Performance evaluation of aluminum/phosphate cell for powering small electronic devices

a r t i c l e i n f o Keywords: ZnO nanoparticulates Phosphate Al activation Capacitor Electrochemical power sources We report on an innovative membrane-free aluminum/phosphate cell based on the activation of aluminum (Al) as anodic material using ZnO nanocrystal in phosphate rich electrolyte that is capable of generating sufficient power to power a light-emitting diode (LED), selected as a model of a small electronic device. The energy from the cell is periodically supplied in high power bursts due to the charge and discharge cycle of the capacitor. The entire process is controlled by a switched capacitor regulator. The Al/phosphate cell was studied in neutral 100 mM phosphate buffer solution (7.4) at a temperature of 25 °C. We demonstrate that two Al/phosphate cells connected in series can generate an open circuit voltage (Voc) up to 1.66 V to continuously power a LED via a switched capacitor regulator circuit. The switched capacitor regulator circuit enabled the 1 μF capacitor to store the incoming power from the cell and discharge it in a large power burst to supply the necessary drive strength required by the LED. This new Al/phosphate cell configuration is a 'green' alternative to the use of glucose abiotic and biofuel cells for powering ultra-low power implantable electronic devices. Abiotic fuel cells represent a promising technology for the conversion of organic fuel, such as glucose into electricity for powering bio-implantable devices that require ultra-low power sources [1–3]. Abiotically catalyzed glucose fuel cells employ abiotic catalysts such as noble metals, activated carbon, and zinc oxide to electrochemically cat-alyze the oxidation of glucose fuel and reduction of oxygen, thereby converting the chemical energy stored in the glucose fuel into electricity [3–9]. Although abiotic fuel cells use catalysts that do not denature and/ or desorb from the electrode surface as observed with enzymes used in enzymatic based glucose biofuel cells, they usually operate at extremely low power (μW) compared to enzymatic based fuel cells. This key disadvantage has resulted in the development of an alternative energy generator for powering bio-implantable devices. Al/phosphate hybrid cell systems have been proven as an attractive strategy to generate energy from the activation of Al via ZnO nanocrys-tal in neutral phosphate buffer solution and physiological saline buffer [10]. However, the generated power from a single Al/phosphate cell is not sufficient for operating any device. Several research groups have used power management systems to enhance the voltages …