User:SideAndLength/sandbox/Silicon-Air Battery

The Silicon-Air Battery is a source of energy that uses silicon and oxygen. Upon use, the liquid oxygen solution in the battery will dissolve wafers of silicon into grains of silicon. The battery is able to sustain itself for 6,000 hours without usage, giving it a very long shelf life. The design of the battery was published online by Professor Yair-Ein-Eli in 2011 after experimenting different ways the silicon can be turned into usable energy. Since then, further research into the battery has greatly increased with funding from organizations such as the Pentagon.

History
The only research report available to the public was done by its creator Professor Yair-Ein-Eli. Eli began research in Technion - Israel Institute of Technology with Dr. David Starosvetsky, graduate student Gil Cohen of Technion, Professor Digby Macdonald of Pennsylvania State University, and Professor Rika Hagiwara of Kyoto University. Eli's reasoning for using silicon as a fuel cell is because of its high specific energy, availability as a resource(eighth most plentiful in the universe, second most plentiful in Earth's crust), tolerance of places with high humidity, and non-toxic properties. In their experiments, they tested for different potential energies and voltages using different liquid oxygen solutions. The experimental results and theories on the battery were published online in 2009 in the journal Electrochemistry Communications. This got the attention of organizations such as DARPA and the Pentagon where they are currently working on military usage of this battery. The battery is still under research by these organizations and not available for commercial use.

Design
The battery's energy source is made using an ionic liquid known as EMI·2.3HF·F (classified in the article as an Room Temperature Ionic Liquid [RTIL]) and wafers containing high amounts of silicon. The wafers act as an anode(fuel source) and the RTIL acts as an electrolyte which turns the wafers into usable energy. In its idle state, the RTIL dissolves the wafers at a slow rate because there is no semi-conductor to speed up the reaction. When put into use, the RTIL will then react faster to dissolve the silicon wafers, which will produce energy for use in any electronics. The battery lacks a built-in cathode that most batteries use to balance the anode's charge. Instead, the membrane of the battery allows oxygen from the atmosphere to flow through it and acts as the cathode.

SPECTRE
A variation of the silicon-air battery, known as the Stressed Pillar-Engineered CMOS Technology Readied for Evanescence(SPECTRE), is currently being researched by DARPA and partially by SRI It works exactly like the silicon-air battery, but with an added feature. The battery will be used in any piece of military equipment and then the a "kill" signal is sent out to the battery which will then prompt the battery to self destruct along with the device it is powering.

Storage
The storage of the battery is very comparable to the Aluminum-air battery. The specific energy of the silicon-air battery is estimated to be 8470 W h/kg and the energy density is about 21,090 W H/l. The voltage of the battery is 1-1.2 V.

Usage
Prof. Yair-Ein-Eli proposed that the battery should be used for medical devices such as hearing aids or diabetic pumps which can be tedious for people to charge. The nature of the battery also allows it to be used in places like Singapore or Central America where the humidity is very high. SRI is currently researching ways to use the battery for daily life use. Different possibilities can include electronics used daily like a laptop or a phone. On higher scales, it is possible the battery can be used to power cars or even space stations. With SPECTRE, lost military equipment, such as drones, can be destroyed with just a simple signal to prevent the devices from getting into the enemy's hands.