Zinc-Air Batteries
QSI leverages advanced materials and proprietary components to deliver low cost, high-performance, light weight, green/eco-friendly, small and large form factor, metal air battery systems for on-demand portable power applications.

Zinc-Air Technology
Zinc–air batteries (non-rechargeable), and zinc–air fuel cells, (mechanically/chemically-rechargeable) are electro-chemical batteries powered by oxidizing zinc with oxygen from the air. These batteries have very high energy densities and are relatively inexpensive to produce. Sizes range from very small button cells for hearing aids, mid-size for remote portable applications, to very large systems used for electric vehicle propulsion.

In operation, a mass of zinc particles forms a porous anode, which is saturated with an electrolyte. Oxygen from the air reacts at the cathode and forms hydroxyl ions which migrate into the zinc paste and form zincate (Zn(OH)2−4), releasing electrons to travel to the cathode. The zincate decays into zinc oxide and water returns to the electrolyte. The water and hydroxyls from the anode are recycled at the cathode, so the water is not consumed. The reactions produce a theoretical 1.65 volts, but this is reduced to 1.4–1.35 open circuit voltage in available cells. Under load, the voltage is reduced to a stable 1.14 volts.

Zinc–air batteries have higher energy capacity-to-volume (and weight) ratio than any other commercially available batteries because air from the atmosphere is one of the battery reactants. Because the air is not packaged with the battery, a cell can use more zinc in the anode to increase capacity, or energy storage in the battery. For every gram of zinc in the anode, the battery will provide roughly .82 amp hours (or about 1 watt hour) of power.

QSI’s zinc-air batteries outperform lead-acid and nickel-metal hydride (NiMH) batteries in a smaller and lighter form-factor, and avoid the high cost and safety issues associated with lithium-ion (Li-ion) batteries — providing a highly recyclable and renewable, lead-free alternative to existing technologies in the multi-billion dollar battery market.

QSI-Nano Inside
QSI’s proprietary air electrode allows oxygen to enter the cell while providing a stable boundary for the oxygen reduction to produce a current. The resulting performance delivers up to 50% more power and efficiency through the use of QSI’s high rate air electrode design leveraging advanced high surface area nano scale catalysts blended into to the carbon layer in the gas diffusion electrode, or air cathode. During discharge, oxygen is reduced to form hydroxyl ions, which migrate through the electrolyte to a proprietary zinc anode made of a low cost, abundant, and domestic supply of recycled zinc metal powder.

Once the zinc in the anode oxidizes and releases electrons, the resulting "spent fuel" is a bio-degradable zinc oxide, which is used as an active ingredient in many sunscreens and cosmetics today. Since the only by-product of the depleted battery cell is zinc oxide, the battery is considered safe (non-toxic, non-combustible), green (non-polluting, uses recycled zinc metal, contains zero mercury, cadmium, lead or lithium), approved for air travel, and generally disposable in the normal waste stream. While the smaller form factor zinc air batteries are primary disposable systems, larger systems can be mechanically or chemically re-charged by simply replacing a cartridge of dry or wet zinc fuel or pumping new zinc and electrolyte into the battery (as noted here: The Zinc Air Battery and the Zinc Economy: A Virtuous Circle).

Zinc-Air Electric Vehicle Advantages:

  • One advantage of utilizing zinc-air batteries for electric vehicles is the availability of zinc metal is 100 times greater than that of lithium, per unit of battery energy.

  • Current yearly global zinc production is enough to produce zinc-air batteries to power one billion electric vehicles, current lithium production can only produce ten million lithium-ion powered vehicles.

  • Approximately 35% of the world’s supply, or 1.8 gigatons of zinc reserves are found in the United States, whereas the U.S. holds only 0.38% of known lithium reserves.

Zinc-Air Chemistry Advantages:

  • High Energy Density – The zinc-air cell has a gravimetric energy density that is up to five times the energy of alkaline systems and up to ten times of lithium rechargeable systems. The highest energy is delivered under conditions of frequent or continuous use and operating temperatures between 0ºC and 50ºC (32ºF and 122ºF).

  • Low Operating Cost – Zinc-air cells and batteries deliver the highest energy density (capacity) of any commercially available system, and at the lowest operating cost on a per-kilowatt-hour basis.

  • Excellent Sealed Shelf Life – The sealed (inactivated) zinc-air cell has been demonstrated to retain greater than 98% of its rated capacity after one year of storage at 21ºC (70ºF). The inactivated storage life is rated up to 5 years. Activated batteries should be used within 2 months.

  • Flat Discharge Profile – Typically zinc-air cells maintain a constant output voltage between 1.1 and 1.25 volts throughout the discharge life of the cell at low-to medium drain rates.

  • Intrinsically Safe – Zinc-air cells offer a means of self-venting any internally generated gases through air-access holes located on the cathode can, eliminating the possibility of cell rupture or explosion. In addition, zinc-air cells are generally considered non-toxic and environmentally safe (contains zero mercury, cadmium, lead or lithium), and under most conditions do not require special handling or disposal procedures.

About QSI
QSI is an industry leader in the design, development, and manufacture of high performance, low cost metal-air battery systems. Founded in 2002 and based in Santa Ana, California, QSI’s patented and ISO 9001:2008 Certified production processes deliver advanced catalyst materials and high rate gas diffusion electrodes enabling its line of MetAir™ batteries to deliver the highest energy density of any commercially available battery, at the lowest cost per kilowatt hour (by weight and volume). QSI zinc-air batteries offer up to a five year shelf life, employ a modular and flexible cell construction for customized and wearable form factors, utilize electric arc furnace (EAF) dust – a hazardous waste material which is recycled and purified to deliver a non-toxic zinc fuel source for clean, portable battery power. QSI MetAir™ battery systems are lightweight, safe, and environmentally friendly (containing zero lead, mercury, cadmium or lithium) and designed for off-the-grid power needs including outdoor sports & recreation, emergency preparedness & response, and portable back-up power systems for consumer electronics, military, electric vehicles, and large scale industrial applications. QSI offers its metal air battery components, replaceable MetAir power stack modules, and complete battery systems directly to end-user customers, as well as through reseller and distributor channels. More info: www.qsinano.com.

Sources: Wikipedia, Duracell, Energizer